ANNUAL REPORT

OF THE

DIRECTOR

OF THE

BUREAU OF STANDARDS

TO THE

SECRETARY OF COMMERCE

FOR THE

FISCAL YEAR ENDED JUNE 30, 1922

(Miscellaneous PubHcatkiu—No. 50)

WASHINGTON

GOVERNMENT PRINTING OFFICE

1922

ANNUAL REPORT

OF THE

DIRECTOR

OF THE

BUREAU OF STANDARDS

TO THE

SECRETARY OF COMMERCE

FOR THE

FISCAL YEAR ENDED JUNE 30, 1922

I

(Miscellaneous Publications—No. 50)

WASHINGTON

GOVERNMENT PRINTING OFFICE

1922
Persons on a regular mailing list of the Department of Commerce should give

prompt notice to the " Division of Publications, Department of Commerce,

Washington, D. C," of any change of address, stating specifically the form of

address in which the publication has previously been received, as well as the

new address. The department should also be advised promptly when a publication is no longer desired.

II
CONTENTS.

Page.

Chart showing functions of bureau facing 1

I. FUNCTIONS, ORGANIZATION, AND LOCATION.

Definition of standards 1

Standards of measurement 1 Physical constants (standard values) 2 Standards of quality 2

Standards of performance 3

Standards of practice 3

Relation of the bureau's work to the public 3

Comparison of standards of scientific and educational institutions or

of the public with those of the bureau 3

Work of the bureau in an advisory capacity 4

Relation of the bureau's work to the industries ; 4

Assistance in establishing exact standards of measurement needed in industries 4

The collection of fundamental data for the industries 5

Standardization 6

Simplification 7

Elimination of industrial wastes 7

Training of experts in various industrial fields 9

Relation of the bureau's work to the Government 9

Comparison of standards of otlier Government departments with

those of the bureau 9

Performance of tests and investigations and the collection of scientific data of a fundamental nature 9

Advisory and consulting capacity 10

The bureau as a testing laboratory and its work in the preparation

of specifications on which to base the purchase of materials 10

Organization 11

Location . 12

II. SCIENTIFIC AND TECHNICAL DIVISIONS.

Weights and measures 13

General 13

Scope of weights and measures work 13

Length 13

Investigation in precision length measurements 13

Apparatus 14

Research in screw cutting and precision dividing engines 14

Information on length measurements and standards 1.5 Routine testing 15

Visitors 16

Statement of present condition of the section and recommendations for the following year 16

Revision of publications 17

Mass 17

Mass standards of the bureau 17

Tests 17

State standards 18

Manufacturers' standards 18

ni
IV CONTENTS.

Weights and measures—Continued.

Mass—Continued. Page.

Accuracj' of American weiglits 18

Imported \^eis;lits 18

Improvement in types of weiglits 18

Repair of analytical weights 19

Equivalents 19

Personnel 19

Time 19

Research in diurnal variation of clock rates 19

Horological Institute of America 20

Improvements in equipment 20

Testing 20

Future work 20

Additional equipment 20

Travel 21

Capacity and density 21

Research 21

Hydrometer scale for petroleum oils 21

Calibration of horizontal tanks 22

Testing 22

Apparatus on hand July 1, 1922 24

Visitors 24

Gas measurement 24

Research in connection with orifice meters 24

Standard methods for determining and rating the capacities of

dry meters 25

Measurement of compressed gases 2.5 Gas-measuring instruments, routine tests 26

Thermal expansion 26

Research in dental inlays 26

The ultra micrometer 26

Tests 26

Investigations and tests on commercial scales and related work 27

Investigation of railroad track scales 27

Calibration of privately OM'ned test cars 29

Calibration of master scales .30 Bureau of Standards master track scale 31

Mine scale investigation . 31

Miscellaneous tests of weighing and measuring devices 32

Investigations concerning weights and measures tests and practices 33

Automatic dial scales 34

Grain scales ^ 34

Railroad depot scales 34

Strength specifications for scales ; 35

Specifications for testing machines 35

Precision test of large capacity scales 35

Weighing by substitution 36

Mathematical character of scale errors 36

Correspondence 36

Cooperation with State and local officials in weights and measures

administi'ation 36

General cooperation with States 36

Fifteenth Annual Conference on Weights and Measures 37

Weights and measures laws 37

Weights per bushel .38 Foreign weights and measures 3S

Gauges 38

Investigation , ,SS Tests and studies for the National Screw Thread Commission .30 Constant-temperature room 39

(')rdiianee gauge shop 39

Design and construction 40

Routine tests of gauges 40

(xovernnient tests 40

Tests for commercial concerns 41
CONTENTS. V

Page.

Weights and measures—Continued.

General standardization work

National Screw Thread Commission

Special committee work

Standardization of rig irons ,.~ Adding machines ,t Publications ri

Electricity

General

Scope of electrical work

Public utility investigations

General condition of the division

Resistance measurements '^^ Routine testing 'f^ Change in resistance of a conductor with change in its potentialGalvanometers „ Fundamental measurements of resistance '^^ Standard for the conductivity of aluminum '^J, Inductance and capacitance 4^

Inductance and capacitance laboratory

Inductance research IS

Capacitance research '18 Methods of measuring dielectric loss 48

Properties of insulators for submarine cables

Absolute determination of the ohm 49

Electrical nieasur ng instruments 49

Testing of electrical instruments- ». 49

Cooperation with associations 49

Federal standard specifications 5'^ Cooperation with manufacturers 5'^ Development of apparatus 50

Ignition apparatus 50

Magnetic measurements 51

General magnetic measurements 51

Correlation of properties 51

Thermoniagnetic analysis 51

Magnetic compasses 51

Miscellaneous activities 51

Photometry and illuminating engineering 52

Calibration of standard lamps 52

Miniature standard lamps 52

Photometric methods 5.3 Corrections for flame standards 53

Specifications for incandescent electric lamps 53

Inspection and life tests of electric lamps purchased by the Government 54

Automobile headlights 55

Miscellaneous illumination problems .55 Radio connnunication 56

Radio research and information 56

Electron tubes as generators 57

Electron tubes as amplifiers 57

Radio control 57

Radiotelephony 57

Arc converters : 57

Direction finding 58

Interference measurement 58

Radio fog s'gnaling 58

Radio receiving sets : 58

Standardization of radio equipment 59

Interdepartnient Advisory Committee on Governmental Radio

Broadcasting ,59 Radiotelephony conference 59

International conferences 59

International Union of Scientific Radiotelegraphy GO
VI CONTENTS.

Electricity—Continued. Paee- Electric batteries 60

Tests of batteries 60

Standardization of dry cells 60

Circular on dry cells 61

Specifications for airplane batteries 61

Cooperation with technical committees 62

Electromotive force of cells at low temperatures 62

Resistance and potential measurements of dry cells 62

Rate of sulphation of storage-battery plates 63

Study of storage-battery separators 63

Exhibit of foreign dry cells 63

Measurements of current and voltage in starting an airplane

engine 63

Radioactivity and X-ray measurements 64

Gamma-ray measurements of radioactive preparations 64

Self-luminous materials 64

X rays 64

Electrolysis prevention , 65

Scope of current electrolysis work 65

Report of American committee on electrolysis 65

Earth current meter 65

Work carried on jointly with the American committee on elec- trolysis 65

Soil corrosion 66

Safety engineering and safety standards 67

National electrical safety code 67

Electrical safety conference 68

Lightning protection 68

Combined electrical code - G8

Industrial safety standards 69

Code for head and eye protection 89

Logging and sawmill code 70

Aeronautical safety code 70

Elevator code 70

Gas engineering 70

Utilization of gas 70

Standards for gas service 72

Gas safety code 72

Electrical and related service standards 72

Standards for electric service 72

Standards for heating service 72

Street-lighting service 73

Electrical standardization 73

Telephony 73

Quantity and quality of telephone service 73

General survey of the Government's telephone systems 74

Revision of the Government's supply schedule for telephone

service : 74

New billing forms for telephone service 75

Tests of coast defense fire-control equipment 75

Tests of i-adio receivers at audible frequencies 75

Circular on telephone transmission 75

Submarine cable problem 75

Ballistics and other spec al problems 76

Cooperation with Navy Department 76

A study of the variation in gun pressure with time 76

Primer explosion times 76

Ejection velocities 76

Piessure in recoil cylinders 76

Velocity of the projectile Inside the bore of a gun 77

Photographs of projectiles in flight 77

Movements and stresses in turrets and turret structures 77

Torsional vibrations of crank shafts 77

Seismomelry 77

Electric telemeter 78

Publications 79
CONTENTS, VII

Page.

Temperature and heat 82

General 82

Functions of the division 82

Thermometry 82

Clinical thermometers 82

Laboratory thermometers 83

New testing regulations and fee schedules 83

Tests of pure platinum 83

Temperature measurement and control 83

Equipment 83

High temperatures 84

Industrial pyrometry 84

Standard samples for thermoelectric fixed points 85

Research in pyrometry 85

Investigations in atomic properties 85

Heat measurements 86

Specific heat of superheated ammonia vapor 87

Specific volume of superheated ammonia vapor 87

Ammonia tables and Mollier chart 88

Properties of steam 88

Tliermal conductivity and heat transmission 89

Equipment 90

Cryogenic laboratory 90

Operation of plant , 90

Liquid hydrogen 90

Vacuum-insulated containers 91

Fire-resistive properties of structural materials 91

Fire tests of brick vs^alls 91

Hollow tile investigation 92

Fire tests of concrete columns 93

Strength of materials at high temperatures 93

Building codes 93

Safety to life 93

Standardization and interpretation of flre tests 94

Miscellaneous fire-Tresistance activities 94

Automotive power plants, fuels, and lubricants 94

Altitude laboratory 95

Ignition_l 95

Carburetion 96

Fuels 97

Internal combustion engine lubrication 97

Cooling problems 98

Automobile brake linings 98

Truck rear axles 99

Phenomena of combustion 99

Miscellaneous , 100

Testing, information, and publications 100

Thermometer, pyrometer, and heat tests 100

Information, cooperation with societies, etc 101

Publications 101

Optics 103

General 103

Outstanding accomplishments 103

General condition of the division 103

Spectroscopy 104

Standard wave lengths 104

Investigation of arc spectra 104

Spectrographic analysis 105

Spectrum tubes , 105

Polarimetry 106

Cooperation with United States customs laboratories 306

Supplies for the customs service 106

Testing of cover glasses 107

Testing of molasses 107

The rare sugars 107

Raffinose in beet-sugar products 108
VIII CONTENTS.

Optics—Continued.

Polarimetry—Continued. Pag».

Preparation of levulose 10&

Tlie utilization of molasses 100

Molasses formation 110

Saving of waste siisar 110

Commercial productic^n of pure dextrose 110

Tiie laboratories of sugar technology 111

Special sugar apparatus 111

Table sirups of high density 111

Viscosities of sugar sirups 111

Decomposition of invert sugar in the presence of hydrochloric

acid 112

Crystallization 112

Diffusion process in sugar manufacture 112

Standardization of commercial sugars 113

Storage and shipment of sugar 113

Color measui-ement in the sugar industry 113

Gradation of sugars by sieve analysis 114

Enzymic estimation of suci'ose 114

Decolorizing agents 114

Adjustment and standardization of saccharimeters 115

Basis of saccharimeter standardization ^ 115

Quartz-control plates 116

Properties of quartz at high temperatures 116

" Reaction " of sugar products 117

Polariscopic determination of double refraction in glass 117

Polarimetry of oils 117

Refractometer in sugar analysis 117

Rotation dispersion of sugars 118

Monochromatic light sources 118

Saccharimeter light filters HQ'

Standard samples 119

Society of sugar chemists and technologists '. 119

Colorimetry , 119

White light 119

Color grading of artificial illuminants and daylight in terms

of color temperature 120

Spectral center of gravity scale for color grading of illuminants- 121

Spectral distribution of energy from a complete radiator 121

The visibility of radiant energy 121

Physiologic optics 122

The spectral transmissive properties of dyes 122

The spectral transmissive properties of vegetable coloring

matters 123

The spectral transmission of spectrometers 123

The spectral reflection of enamels 123

Refractometry and optical instruments 123

The testing of photographic lenses 123

Silvering apparatus 123

Luminous cross wires 124

Design of a magnifying stereoscope 124

Design and construction of a field telemeter 124

• Study of spherometer 124

Redesign of apparatus for measuring transmission of optical

glass 125

Optical system for horizontal angle measuring instrument 125

Modification of special cameras for the Navy 125

Standard prism drawings . . 125

Standard laboratory telescopes 125

Radionietry 125

Roof covering for balloon hangars 125

Radiation characteristics of quartz mercury vapor lamps used

for therapeutic purposes 126

Stellar radiation 126

Planetary radiation 126

I'hotoelectrical investigations 127
CONTENTS. IX

Optics—Continued.

Radiometry—Continued. '^^^'^ Experiments on tlie direct transformation of light into electric

current

Dispersoids

Assistance to the District of Columbia fire department in smokemask training 128

Turbidimetry 128

Ultramicroscopy 128

Statistical standards 129

Interferometry 129

Thermal expansion 129

Index of retraction 129

Calibration of end standards 129

Ruling of line standards ISO

Dimensional changes of materials 130

Photographic technology 130

" Inertia " of photograpliic plates and films 130

Color sensitizing of photographic plates by bathing 130

The action of charred paper on the photographic plate 131

Veterans' Bureau school of photography 131

Testing, infoi'mation and publications 181

Tests completed during the year 131

Information, cooperation with societies, etc 131

Publications 132

Chemistry 134

General 134

Reorganization of sections 134

Cooperation with technical societies 134

Electrochemistry 134

Nickel deposition ^ _ 134

Gas chemistry 135

Investigation of methods of producing hydrogen for aeronautical purposes 135

Balloon fabrics 137

Portable permeability apparatus . 137

Balloon gas-purity indicator . 138

Problems not connected with aviation 138

Reagents and apparatus 140

Chemical reagents and apparatus ^_ 140

Platinum metals investigation 140

Metal and ore analysis and standard samples , 142

Standard analyzed samples 142

Cooperation in the analysis of British chemical standards 143

Cooperation in the development of standard analytical methods, 143

Umpire analyses and standardization of various metallurgical

materials 143

Routine analysis of ferrous and nonferrous materials 143

Cooperation with the American Society for Testing Materials 143

Lubricating oils, rubber, paper, textiles, ink, and glue 143

Airplane dopes 144

Balloon fabrics 144

Rubber chemistry 144

Textile chemistry 144

Sealskins ^ 144

Dyes 145

Writing and copying inks 145

Stamping, tnarking, and related inks 145

Typewriter and similar ribbons , 145

Carbon paper 145

Glue, mucilage, and paste 145

Fingerprinting device 146

Lubricants 146

Specifications 146

Detergents, cements, corrosion, etc 147

Detergents 147

Cements, etc 148
X CONTENTS.

Chemistry—Continued.

Detergents, cements, corrosion, etc.—Continued. Pag*-. Corrosion, waters, etc 148

Miscellaneous worlv 149

Paint, varnish, and bituminous materials 149

Federal Specifications Board 149

American Society for Testing Materials 149

Researches 150

Chemical testing 150

Publications 150

Engineering physics 151

General 151

Engineering instruments and appliances 152

Current meter rating station 152

Calibration of instruments 1.52 Fire extinguishers 152

Radiator return-line valves 1.52 Miscellaneous engineering tests 1.53 Safety release devices for hydrogen cylinders 153

Investigation of elevator safety devices 153

Sound measurements 153

Sound sources 153

Sound-intensity measurements ; 154

Sound chamber 1.54 Auditorium acoustics 154

Voice-tube experiments 154

Fog-landing experiments 155

Sound ranging 155

High-speed oscillograph camera - 155

' Precision time scale for oscillograph measurements 155

Radio time recorder , 156

Solenoid chronograph 156

Pressures in guns 156

Small-arms projectiles 156

Yaw instrument 156

Measurement of linear and angular speeds and of torsional oscil- lations 157

Aeronautic instruments 157

Altitude effect on air-speed indicators 157

Diaphragm investigation 158

Tension experiments on metallic strips 158

Bourdon tubes 158

Compass investigation 158

Ground speed and drift indicator 159

Air-speed indicator 159

Water-speed indicator 159

Turn indicators 159

Turn meters 159

Angle of incidence recorder 160

Precision barometer 160

Temperature-compensated altimeter 160

Temperature-compensated thermobarograph 160

Temperature-compensated barograph 160

Precision barograph 160

Statoscope 161

Combined statoscope and rate-of-climb indicator 161

Rate-of-climb recorder 161

Astronomical-position finder , 161

Aircraft sextants , 161

Airplane compasses 162

Distant reading compass 162

Earth inductor compass 162

Latitude indicator for airplanes 162

Altitude and azimuth indicator 163

:\Iaiw, map hoards, and methods of reducing observations 163

Horizontal-angle indicator 163

Bomb sights 163
CONTENTS. XI

Engineering physics—Continued.

Aeronautic instruments—Continued. Page.

Aircraft electric-resistance tliermometer 163

Ballonet volume indicator for dirigibles 163

Balloon and airship manometers 164

Kymograph or airplane oscillation recorder 164

Standard testing sets 164

Aircraft chronograph 164

Sphygmomanometers 164

Routine testing 164

7 Flight te.sts on aeronautic instruments 165

; Aeronautic instrument collection 165

Aerodynamical physics 165

Aerodynamical characteristics of aircraft bombs 166

Forces on an airship shielded by wind screens 166

Resistance of ice-coated electric wires to wind 167

Studies of wind tunnel air streams 167

Cooperative tests with Weather Bureau 167

Resistance measurements in a high-speed air stream 167

Jet propulsion for airplanes 168

Orifice meter investigations 168

General investigations 168

Plumbing investigations 168

Hardware standardization 169

Plasticity of soft materials 169

Publications 169

Structural, engineering, and miscellaneous materials 170

General 170

Structural and engineering materials 171

Theory of columns 171

Fatigue resistance of metals 172

Verification of testing machines 173

Investigation of the physical properties of dental alloys 174

Crinkling stresses in steel tubing 174

Shrapnel diaphragms 174

Marine glue specifications 174

Tungsten carbide balls for Brinell hardness tests 175

Investigation of motor-truck wheels 175

Tests of oil-well material 175

Strength of large columns of H-shaped cross section ^ 175

Investigation of the strength of brick walls 176

Tests of girder hooks 176

Welded structural members 176

Cooperation 177

Cement, concrete, stone, gravel, and sand 177

Specifications for concrete and reinforced concrete 177

Floor-slab tests 177

Effect of direction of reinforcement on strength of slabs sup- ported on two edges 177

ReroUed steel investigation 178

Durability of concrete in alkali and sea water 179

General investigation of building stones 179

Exposure tests on colorless waterproofing materials 180

Elastic pointing and calking materials 180

Discoloration of Indiana limestone 180

Concrete tanks for oil storage 181

Stucco ^_ 181

Study of concrete-house construction 181

Investigation of sewer pipe in the city of Los Angeles 182

Air analyzer 182

United States standard sieve series 182

Standard samples 182

Caustic magnes a cement 183

Constitution of Portland cement 183

General concrete investigations 184

Testing and shipment of cement for Government purposes 184
XII CONTENTS,

Structural, engineering, and miscellaneous materials—Continued. Page.

Lime, gypsum, and sand-lime brick 185

Hydrated lime in concrete 185

Panel test of lime plaster 185

Measurement of plasticity 186

Measurement of sand-carrying capacity 186

Making hydrate plastic 186

The constitution of hydrated lime 186

Properties of commercial limes . 186

..i. Action of lime on clay . 186

Propert es of lime-cement-sand mortars 187

Quick setting of lime plaster 187

Adhesion of gypsum plaster to concrete 187

Effect of temperature of calc:nation on the properties of cal- c ned gypsum 187

Pottery plaster 187

Determination of anhydrite 187

Effect of clay in gypsum 188

Measurement of consistency 188

Weatherproof gypsum 188

Tests of gypsum plaster boards and wall boards 188

Properties of plastering sands 188

Cooperation 188

Rubber 189

New equipment 189

Power losses in automobile tires 190

Asbestos packing 190

Insulating tape 190

Insulated wire 190

Rubber heels and soles 190

Rubber tubing 190

Jar rings for canning 190

Compounding ingredients 190

Rubber analysis 191

Miscellaneous materials 191

Cooperation ^ 192

Specifications 192

Leather 192

Sole leather 192

Synthetic tanning materials 193

Siiark leather 193

Rubber heels : 194

Experimental tannery 194" Specifications 194

Cooperation : 194

Textiles 195

Standardization of textiles 195

Numbered duck 195

Hosiery 195

Cordage 196

Sheeting 196

Press cloth 196

Conveyor belting , 197

Heat-retaining properties of fabrics 197

Physics of balloon fabrics 198

Low-grade cotton 198

Tent and awning duck 199

Pima cotton 199

Abrasion of fabrics 200

Cloth for Federal Trade Commission 200

Cartridge bag cloth 200

Fishlines 201

Fasteners for cartridge belts 201

'Xead lines 201

Effect of washing on sheeting 201

Suiting . 201

Printers' blankets 202
CONTENTS. XIII

Structural, engineering, and miscellaneous materials—Continued.

Textiles—Continued.

Bandages 202 ^ Conferences 202

Paper 203

General conditions 203

Tearing strength of paper 203

Thickness of paper 203

Blotting quality of paper 204

Effect of relative humidity on paper 204

Paper for cement bags 205

Blue-print paper . 203

Carbon paper 208

Sizing quality of paper 206

Herzberg stain 206

Photomicrography 207

Color of paper 207

Flax straw and tow 207

Clay in paper as filler 208

Clay for coating wall paper 209

Standardization of paper 209

Government specifications 209

Lime for sulphite pulp 210

f rubricating oils 210

Reclaiming used petroleum lubricating oils 210

Standardization of viscos.meters 210

Oil friction testing machine 211

Cooperative work 211

Testing, information, and publications 211

Tests completed during the year 211

Cooperation 214

Publications 215

Metallurgy 216

General i 216

Researches in cooperation with technical committees 218

Investigation of the effect of sulphur and phosphorus in steel 218

Molding sand research 218

Welded rail joints 218

Bearing metals 218

Car-wheel investigations 219

Corrosion of metals 219

Gauge steels 219

Mine-drill steel 219

Deoxidation of steel * 220

Metals Conunittee Federal Specifications Board 220

Conferences -. 220

Committee membei'ships 220

Circulars of information 221

Optical metallurgy 221

Crystalliuity in wrought iron 221

Corrosion of special steels 221

Microstructural changes accompanying the tempering of martensitic steels 222

Metallographic etching reagents for nonferrous alloys 222

Metallographic etching for the identification of carbides, tungstides, and other compounds in alloy steels 222

Bmbrittlement of steel by hydrogen 223

Graphitization of white and gray cast iron 223

Relation of grain size to the mechanical properties of steel 224

Microphotographic work 224

Investigations continued and proposed 224

Thermal metallurgy 224

Thermal analysis 224

Mechanical properties of steels at h'gh temperatures 225

Effect of heat treatment on properties of structural steels 225

Surrounding atmosphere in heat treatment and gases in steels . 226
XIV CONTENTS.

Metallurgy—Continued. I'age. Thermal metallurgy—Continued.

High-speed tool steels 226

Dimensional changes in hardening steels 226

Proposed new investigations 226

Mechanical metallurgy 226

Titiinium treated and untreated rails . 226

Corrosion of iron-silicon alloys 227

Effect of rolling conditions on the properties of a medium

carbon steel 227

Equilibria of tin-rich ternary alloys 227

Wear testing 227

Invar tape and shapes 227

Properties of large crystals 227

Foreign travel and exchange of research personnel 228

Miscellaneous 228

Metal specifications , 228

Chemical metallurgy 228

Gases in metals 228

Method for total gases in metals 228

Two forms of nitrogen in steel 229

Direct method for nitrogen 229

The decarburization of ferrochromium by hydrogen 229

The effect of carbon and manganese on the mechanical properties of iron 230

Invar (36 per cent nickel-iron alloys) 230

Platinum and plantinum-metal alloys 231

Special alloys and castings 231

Proposed new work 231

Experimental foundry 232

Production of castings 232

Molding-sand tests and investigations 232

Problems of military interest 232

Erosion of special machine-gun barrel'steels 232

Development of light armor plate 232

Corrosion of metals by ammonia and its constituent gases 233

Miscellaneous investigations 233

Research associates 233

Iron in brass 233

Sherardizing 234

Embrittlement of malleable iron by galvanizing . 234

Deoxidation of iron and steel 234

Hot shortness of ingot iroji 235

The Trent process 235

Effect of cold rolling on some mechanical properties of monel

metal sheet 236

Equilibria of nickel-nickel oxide 237

Stress corrosion test on monel metal 237

The effect of impurities on the malleability of nickel 237

Tests 237

Fusible boiler plugs 237

Tests involving the microscopy of metals 238

Steel from Knickerbocker Theatre 238

Failed parts, subject to stress 238

Duralumin forms 238

Welded sheet aluminum 239

Corroded copper tubing 239

Brass condenser tubing 239

Special rolled steel 239

Cooperative tests 239

Effect of hot gases upon steel 240

Chart of tests 240

Publications 240

Publications i.ssued during the year 240

Publications in press 242

Ceramics ' 243

General 243
CONTENTS. XV

Ceramics—Continued. Page.

Clay pi-oducts 244

Development of methods of test and specifications for vitrified

ii china and semiporcehiin tableware 244

' Physical properties of hotel china bodies 245

Effect of thickness of plates on resistance to impact 245

Properties of foreign and domestic ball clay 245

Comparison of foreign and domestic clays as fillers for paper— 246

Clays for coating paper 246

Plasticity of clays 247

Cooperative investigation of water smoking and dehydration

of clays 247

Glass 248

Specifications for glass products 248

Standardization of milk bottles 249

Specifications for lime for glass making 249

Strength of window glass 249

Study of disintegration of glass in water 249

Ampoule glass 250

Glass Containers Association fellowship . 250

Optical glass : 250

Thermal properties of glass „ 251

Hardened glass 251

Cooperation with the Navy Department 251

Burning glass pots and stirring rods 252

Inspection 252

Chemical 252

Refractories 252

Specifications for refractories 252

Glass pots for use in experimental optical glass making 253

Resistance of glass pots to corrosion 254

Terra Cotta 254

Cooperative investigation of problems relating to architectural

terra cotta 254

Enameled metals 255

Wet-process enamels for cast iron 255

Fish scaling of enamels on sheet iron and steel 255

Specifications for enameled kitchen ware 256

Relation of composition and properties of sheet-steel enamels 256

Cooperative investigations 257

Testing and information 257

Cooperation with technical societies 258

Publications 259

Building and housing 259

General 2.59 Scope of the work on building and housing 259

General condition in the division 260

Technical service for municipalities 261

Building codes 261

Plumbing codes 262

Zoning for towns and cities 262

Current statistics 263

Economic and statistical studies 263

Elimination of waste and service to home builders 263

Elimination of waste 263

Service to individual home builders 264

Cooperation, information, and publications 264

Cooperation with public bodies and societies 264

Publications , 265

Simplified practice 265

General 265

Elimination of useless sizes 266

Paving brick 266

Metal and wood beds 266

Preparatory surveys of the field 267

Simplification of dimensional size and varieties 267

Work now under way 267

Requests for assistance 267
XVI CONTENTS.

III. THE OFFICE.

Page.

General condition in tlie office 268

Finance , 268

Funds 268

Appropriation statements 268

Personnel 271

Bureau staff 271

Changes in staff 271

Sources of personnel 271

Leave of absence 271

Deaths 271

Special activities 272

Purchase 272

Procurement of equipment and materials 272

Scientific catalogue library 273

Property, stores, and transportation 273

Stores 273

Property 273

Shipping 273

Transportation 273

Mails and files 273

Communications 273

Schedules 274

Availability and use of files 274

Standard correspondence practice 274

General services 274

Library 274

Accessions of technical literature 274

Relations with other libraries 275

Subject analysis of periodicals 275

Library expenditures 275

General services 275

Information 275

Scope of the information work 275

Special reports 276

Directing Inquiries 276

Announcements of new publications 276

Publications issued during the year 276

Tests : 277

IV. ENGINEERING AND CONSTRUCTION.

General 278

Aims and recommendations 278

Operation and maintenance of mechanical plant 278

Construction and repair 279

Electrical 279

Plumbing : 279

Miscellaneous 279

Buildings and grounds 279

Janitors and laborers 279

Watchmen 280

Grounds 280

V. GENERAL RECOMMENDATIONS.

Salaries 281

Power plant -l: : 281

Care of buildings 282

Buildings and grounds 282
)
BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

Washington, D. C.

1922

FUNCTIONS

Development, construction, custody, and maintenance

of reference and working

STANDARDS

and their intercomparison, improvement, and application

in science, engineering, industry, and commerce.

9644—22. (Pace p. 1.)
REPORT

OF THE

DIRECTOR, BUREAU OF STANDARDS.

Department of Commerce,

Bureau of Standards,

Washington, July 1, 1922.

Sir: There is submitted herewith a report of the work of the

Bureau of Standards for the fiscal year ended June 30, 1922.

1. FUNCTIONS, ORGANIZATION, AND LOCATION.

Before describing in detail the various scientific and technical

problems in which the Bureau of Standards is engaged the following brief statement as to its functions and organization may be

helpful to those unfamiliar with the subject of standardization in

its broad and modern sense. The standards with which the bureau is authorized to deal may

be conveniently classed as follows: Standards of measurement,

standard values of constants, standards of quality, standards of

mechanical performance, and standards of practice.

DEFINITION OF STANDARDS.

Standards of Measurement.

A standard of length may be taken as an example of a standard

of measurement. It must be a length which is unchanging, reproducible, and capable of being compared with the working standards

used in the most precise scientific work or with those used in commerce and industry. In order to carry out such comparisons, Avorking standards must be prepared which are subdivisions and multiples

of the fundamental standard, and this process of subdividing and

multiplying the standard involves difficulties as great as those met

with in the preparation of the fundamental standard itself.

The construction of a set of standard weights from a single unit

is also an illustration ; a Avhole set of standard weights must be prepared before the standard weight of the Government can become

available to the public. Before these working standards, made up of

subdivisions and multiples of the fundamental standard, can be prepared questions as to the methods of comparison arise, which again

involve the solution of difficult scientific problems in connection with

the balance or the methods used. These balances range from that

capable of measuring the thousandth part of a milligram to the

large testing machine with a capacity of thousands of tons. The

9644—22 2 1
BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

Washington, D. C. 1922

FUNCTIONS

Development, construction, custody, and maintenance

of reference and working

STANDARDS

and their intercomparison, improvement, and application

in science, engineering, industry, and commerce.

9844—22, (Pace p. 1.)

STANDARDS PURPOSE

1 STANDARDS OF MEASUREMENTReference and working standards for measurements of all kinds, including fundamental and derived STANDARDS OF MEASUREMENT for expressing

the quantitative aspects of space, time, matter, energy, motion and of their interrelations. By definition, specification, or material standard, covering, for example, length, area, and volume; mass, weight, density, and pressure; heat, light, electricity, and radioactivity! including quantity, flux, intensity, density, etc.

STANDARD CONSTANTS Natural standards or the measured numerical data as to materials and energy

" known as physical or STANDARD CONSTANTS, i. e.. the fixed points of quantities which underlie scientific research and industrial processes when scientifically organized. Mechanical equivalent of heal, light, and electricity and of gravitation: .pecific densities- viscos.t.es; melling and boiling point.: heat capacity: heats of combustion: velocity of propagation of light: conductivities of material, to heat and light: eleetrochemic.l and atomic weights and many similar magnitudes determined experimentally with maximum precision and referred to fundamental standards of measure.

To aid ACCURACY IN INDUSTRY through uniform and correct m To ASSIST COMMERCE IN SIZE STANDARDIZATION „, products; »'1UN of container, a„j To PROMOTE JUSTICE IN DAILY TRADE through systematic and regulation; 'Vstematic mapection To facilitate PRECISION IN SCIENCE and TECHNOLOGIC RE«.,> through calibration of units, measures, and instrument, involved.

To SERVE as an EXACT BASIS for scientific study, experiment c. and design; "Periment, compulation, To FURNISH an EFFICIENT CONTROL for industrial processes in reproducible and uniformly high quality in output- To SECURE UNIFORMITY OF PRACTICE in graduating measurin, ments, uniformity

compiling tables, in standards of quality and performanT anTwher" is desirable; "unce, and wherever To AID LABORATORY RESEARCH BY REDUCING ERRORS and lainty caused by use of data of doubtful accuracy.

STANDARDS OF QUALITY Specifications for material (by description, sample, "or bo'th) " knVwn ' al" STANDARDS OF QUALITY, fixing in measurable terms a prope^y or group

of properties which determine the quality. The numerical magnitude of each conntituent properly pertinent to the quality involved ;o"fi,:s:io'rrfriu-::r.,h'err""" " -"""-.rr:

To secure HIGH UTILITY in the PRODUCTS of industry by setting an attain able standard of quality; To furnish a SCIENTIFIC BASIS for FAIR DEALING to avoid disputes or settle differences; To PROMOTE TRUTHFUL BRANDING and ADVERTISING by suitable standards and methods of test; To PROMOTE PRECISION and AVOID WASTE in science and industry by affording quality standards by which materials may be made, sold, and tested.

STANDARDS OF PERFORMANCE

<5TAMnAtn= T"'"" '<" -acMne"s"";n"d""de"v"i;."s:"

STANDARDS OF PRACTICE Codes and regulations impartially analyzed and foTM"ura"t;d'" "aFt^rs't'udri;;" "rl:::; f

'^^"^'^^ °' •'"'^"'CE for technlca, regria ion con' plrLrance <" -asurement. quality,

de^:;rt^;:x^e::-m;:::;;:^ir^"r^=ir^" °'

To CLARIFY THE UNDERSTANDING between maker, seller, buyer, and user as to operative efficiency of appliances and machines- To make EXACT KNOWLEDGE THE BASIS OP the buyers choice; To STIMULATE AND MEASURE MECHANICAL PROGRESS

To FURNISH for each utility a single IMPERSONAL STANDARD of pracUce as a BASIS FOR AGREEMENT of all interests clearly defined in measurable terms; To INSURE EFFECTIVE DESIGN and INSTALLATION of utilities of all kinds; To PROMOTE SAFETY, EFFICIENCY, and CONVENIENCE in the mainle- nance and OPERATION of such utilities; To SECURE UNIFORMITY OF PRACTICE where such is practicable, and EFFECTIVE ALTERNATES in other cases.

2 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

complete range must be covered. Avhich involves not only a large

number of working standards, all of which must agree with the

fundamental standard, but apparatus suitable for the comparison of

these standards with all of the lengths or weights found in practice.

These steps and equipment are absolutely essential in order to secure uniform measurements of length or weight throughout the country,

and they have their counterpart in every quantity that has to be

measured, whether it be length, weight, temperature, heat, light, or the various electrical measurements or other standards of measurement. These standards in one form or another are involved in

practically every scientific investigation, industrial process, engineering structure, or commercial transaction.

Physical Constants (Standard Values).

There are many fixed relations between phj^sical quantities, the

values of which it is extremely important to knoAv. These values are usually termed " physical constants " and are used in eA^ery branch

of scientific Avork or industry. The amount of heat required to

change a poimd of Avater into steam under normal conditions and the

relation betAveen heat and mechanical energy are two important

phvsical constants. Their values are used in practically every compiitation in connection Avith the designing of steam engines and boilers, the tests of their efficiencies, or the measurement of their output.

The amount of heat required to turn liquid ammonia into vapor or

the amount of heat required to melt a pound of ice are constants

equally important in the refrigerating industries. The A'alue of the

relation betAveen electrical and mechanical energy is involved in many

commercial transactions concerned in electricity.

Accurate and authoritatiA^e A^alues of these constants are just as

essential as in the case of standards of measurement. Many of those

now in use are old and obsolete and need redetermination by means

of the best modern facilities for physical measurement. Their determination involves the most difficult and precise Avork in all branches

of physics and chemistry—a fact not generally Imown by those not

engaged in the scientific or technical work where these constants are

used.

Standards of Quality.

A standard of quality for a given material may sometimes take

the form of a sample of that material Avith which other materials of

the same kind can be compared, but this is generally a makeshift of

the poorest sort. It is only resorted to in the absence of definite and

reliable specifications in terms of measurable properties; that is to

say, a standard of quality of a material usually takes the form of a

specification or definition of its properties, involving, of course, the

measurement of those proj^erties by means of the usual standards of

measurement. A certain kind of steel, a cement, a paint, an oil, a paper, or a cloth is found by use to be good or poor for a definite

purpose. The questions then arise: Why is it good or poor? What

are the physical or chemical properties or the particular combination of elements Avhich make it of good or poor quality? How are its properties to be measured or its constituents determined? These are questions for the laboratory to ansAA^er and invoh'e physical and

chemical investigations of tlie most difficult sort.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 3

A standard of quality for a given material necessarily takes into

account the purpose for which the material is to be used. To set the

standard too low results in losses, poor efficiency, and even loss of

life ; to make it too high may result precisely in the same thing

;

that is to say. the material must be suitable for the purpose intended, and the bureau's investigations in connection with the

IDroperties of materials are to enable the user of these materials, first,

to select intelligently the material best suited for the purpose;

second, to specify it in terms which the producer can not mistake;,

and, third, to make the necessary tests to ascertain whether or not

the material supplied is in accordance with the specifications.

Standards of Performance.

The value of an instrument, device, or machine almost always depends upon the efficiency of its performance. In such cases it is necessary to state the performance desired or guaranteed in terms

which are correct and susceptible of measui'ement. As in the case of standards of quality, the standard involved is more often in the

form of a specification, but specifications are useless unless based

upon correct scientific and mechanical principles and supplemented

with a statement of the method to be used in ascertaining whether

or not the specification or guaranties have been complied with.

The performance of an engine or boiler, a pump, an electrical

generator or motor, a weighing device, or a telescope can usually be

measured, but the quantities to be measured and the methods used

must be specified correctly and understood by all the parties con- cerned in the construction, purchase, or use of such apparatus. To

secure information upon which to base proper standards of performance involves investigations quite as scientific in character and

as difficult as in the case of other standards, as well as a knowledge

of technical and manufacturing processes. In this field, as well as

in the field dealing 'with the properties of materials, the bureau

has had the hearty cooperation of the various Government experts,

manufacturers, engineers, and technical societies. It has conducted

many investigations which have led to improvements in machinery,

appliances, and manufacturing processes.

Standards of Practice.

Standards of practice are generally involved in the enactment of

laws when technical and scientific matters are concerned, in the

ordinances relating to the regulation of public utilities, and in the

establishment of building and safety codes. Like standards of

performance, they are dependent upon standards of measurement

and standards of quality and are of the most vital importance in

questions pertaining to the welfare and safety of the public. In a

field so broad the bureau can only touch upon the more important

aspects of the work, where national uniformity is desired—fields

which are not covered in private laboratories.

RELATION OF THE BUREAU'S WORK TO THE PUBLIC.

Comparison of Standards of Scientific and Educational Institutions or of the Public with Those of the Bureau.

It is perfectly obvious, even to one unfamiliar with the subject,

that the maintenance on the part of the Government of correct stand-
4 EEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

ards of measurement or quality or performance calls for continuous

scientific and technical investigations of the highest grade, involving

the most competent expert services and the best scientific equipment.

When this is accomplished, there still remains the serious problem of

making the results available and useful to the public.

The bureau compares with its own standards of measurement the

standards and measuring instruments of States, cities, scientific laboratories, educational institutions, and the public. In this way the

standards of the National Government are made available to every- one in the country. For these comparisons a nominal fee is charged,

except in the case of National and State Government institutions.

The bureau is at all times glad to assist these institutions in matters

concerning these standards or their use, whether it be in connection

with the enactment of laws, regulations, or ordinances concerning

the weights and measures of everyday trade or in connection with

precision standards used in scientific work.

Work of the Bureau in an Advisory Capacity.

The bureau serves in an advisory capacity for those officials of the

States and municipalities charged with the administration of the

laAvs governing weights and measures. Likewise its advice is gladly

given concerning the use of exact standards in all lines of work.

This information is of the first importance to many individuals and

industries. As an example it may be stated that the success or

failure of an industrial enterprise may depend upon the securing of

correct information concerning the conti'ol of temperature, advice

which can be secured only from such an institution as the bureau.

A great many inquiries are also received concerning the use of

the various materials of construction. The bureau has frequently

been able to assist in the intelligent selection of materials for given

purposes and in advising concerning the best forms of construction

to use under difficult or peculiar conditions. * Many questions of disagreement between the public and utility

companies as to matters involving the use of standards are referred

to the bureau for advice or adjustment, often avoiding unfair and

inconsistent regulations, as well as long-drawn-out and expensive liti- gation. There is a great need on the part of the public for unbiased

and reliable information pertaining to the standards entering into

the regulation and sale of the services of public utilities. As far as possible such information is given in the form of publications upon

definite subjects.

In the formulation of safety codes, designed to govern electrical

and other constriiction, the bureau has taken an active part, particularly in the collecting and study of data, upon the correct interpretation of which the success of such regulations must always depend.

RELATION OF THE BUREAU'S WORK TO THE

INDUSTRIES.

Assistance in Establishing Exact Standards of Measurement Needed

in Industries.

As before mentioned, it must not be inferred from the above that

the bureau's activities are devoted principally to the interests of the

user or consumer. The fundamental facts regarding standards of
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 5

measurement, quality, oi' performance are the very things which

most deepl_y concern manufacturers; they are fundamentally concerned, either directly or indirectly, with the improvement of

methods of production or the quality of the output. It may be said

that the bureau occupies somewhat the same position with respect to

the manufacturing interests of this country that the bureaus of the

Department of Agriculture do to the agricultural interests. Many

industries realize the importance of scientific investigation which, in

l^ractically every case, involve some kind of precision measurement.

It is upon qualit}' as well as upon price that competition must

finally depend, whether in domestic or foreign commerce. The use of exact methods and scientific results is the greatest factor in the

improvement of quality, efficiency, or the development of new industries. The educational value of the bureau's work in this respect

is almost entirely unknoAvn to the general public, and yet the bureau

receives hundreds of letters, as well as many personal visits, from

manufacturers seeking information as to standards of measurement,

how to use them, how to measure the properties of materials, or

as to the fundamental, physical, and chemical principles involved;

also, what is of even greater importance, how to initiate and carry

out scientific investigations and tests on their own account in their

particular fields of work.

The importance of maintaining scientific institutions having to

do with standardization and the application of precise measurements

to the industries has been recognized by all the leading countries of

the world. Great Britain maintains the Standards Department of

the Board of Trade, which is in charge of the standards and inspeci tion service of the trade weights and measures; also the National

; Phj^sical Laboratory, whose functions include matters pertaining to

scientific and technical standards, physical constants, and to some

j extent the properties of materials. The Laboratoire d'Essais of

France, while not as extensive as the English institution, is charged

I with similar duties. Germany maintains three such institutions

! the Normal-Eichungs Kommission, equipped with the buildings, perI sonnel, and apparatus necessary in standardizing and controlling

j the weights and measures of trade; the Physikalisch-Technische

j Eeichsanstalt, covering testing and investigations in connection with

I scientific and technical standards other than weights and measures;

and the Materialpriifungsam.t of the Prussian Government, a large

institution devoted to the investigating and testing of structural,

engineering, and other materials. It is generally recognized that

I these institutions have been exceedingly important factors in the

" industrial progress of these countries.

The Collection of Fundamental Data for the Industries.

During the past year the bureau has continued its close cooperation with American industries. It has continued to act as a clearing

house for fundamental, scientific, and technical information, and

manufacturers are coming to realize more and more that they can

often secure from the bureau general and sometimes even specific

advice concerning impi'ovements in their particular industrial

processes. The solution of many difficult problems in the industries

I can not be reached in commercial plants, but requires the work of

' a specially equipped research laboratory, working always in close
6 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

cooperation with manufacturers who are the best judges of the practical aspects of the problem.

Standardization.

Definition.—Standardization is the unification of methods and

practices involved in manufacturing and construction and all lines of

endeavor which present the necessity of performing repetition work.

P/imes of standardization.—Standardization of nomenclature enables buyer and seller to use the same language and makes it possible to compel competitive sellers to do likewise. Standardization

of variety, or simplification, involves the elimination of unnecessary

types, shapes, sizes, and grades of manufactured articles. Dimensional standardization insures ready interchangeability of supplies

and the proper interworking of parts which may be manufactured

or assembled by different manufacturers. Standard specifications

and tests put tenders on an easily comparable basis and promote

fairness in trade competition.

Benefits.—In industrial standardization it is the buyer in the

first instance to whom standardizatioii is of the greatest importance

and value, for it enables him to know exactly what he can purchase and to be sure that he gets what he asks for in return for

his money. But it is also of great value to the manufacturer, for it simplifies his work and enables him to produce what is required by

the i^urcliaser cheaply and expeditiously.

IJow accG?npIished.—For many years the Bureau of Standards has

been serving in an advisory capacity and as a testing laboratory for

the various branches of the Government and to industry with ref- erence to the best methods of testing materials. It has also made

tests and inspections and aided in the preparation of specifications.

This has been very useful to the bui'eau as well as to the Government and industry, for it has brought the bureau into direct contact with tlie actual user. An important function of the bureau is to

build up specifications on a proper scientific basis.

In the building up of these specifications or in the investigation

of materials the bureau can not proceed far nor would it be fair or proper to do so without cooperation with the manufacturer, for it

is, of course, very important to know the conditions and limitations

with which the manufacturer is confronted in producing tlie material before prescribing the conditions, requirements, and tests which

his product should meet.

Bureau experts handling the particular work meet with representatives of the manufacturers and users of the materials and dis- cuss the subject from every angle. From the combined experience

of all concerned standards and specifications are developed. Subsequent meetings bring out the improvements in the art of production

and conditions of use and it becomes necessary to revise the specifications and methods of testing. This requires constant contact between user and manufacturer.

Results.—During the past year the Federal Specifications Board

has been organized as a part of the economy program of the Government under the Bureau of the Budget. This board is bringing

about the use of standard specifications by all departments and
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 7

independent establishments of the Government for use in connection with the purchase of the more important materials. This is

done by the cooperation and advice of the experts in the use of a given article or material in the Government service, and especially

through the research and testing bureaus of the Government.

The Bureau of Standards has taken an active part in this work,

and a complete revision 6i the Government specifications for the

more important commercial materials is well under way. Several

standard specifications have been adopted and promulgated as official Government standards. Those promulgated to date are : Portland cement; petroleum products; pneumatic and solid tires and

inner tubes ; various paints, varnishes, and oils ; incandescent electric

lamps ; lumber ; feeds and forage ; soap ; leather belting ; and fire

extinguisher liquid. Technical committees are at work on specifications for the following groups of materials : Rubber products

;

refractories ; electrical supplies ; metals ; builders' hardware ; plumbing fixtures ; textiles ; wire rope and cables ; bituminous roofing and

waterproofing compounds ; pipe, tubing, and valves ; linoleum and

mastic flooring ; heat insulating material ; gaskets and packing

;

coal ; brushes and brooms ; hand fire extinguishers ; and miscellaneous oils.

Simplification.

Another very important class of work in which the Department

of Commerce is greatly interested is the simplification of industrial

products through the elimination of useless sizes, unnecessary variations in the composition of materials intended for the same purpose, and the concentration of the attention of manufacturers upon

articles of the greatest interchangeability.

To illustrate the need of this work, it is only necessary to consider

that in the majority of our industries many sizes and styles of products have come into use, not through any real demand for such a

variety of articles but through the natural expansion of the business.

The keeping of so many sizes and styles in stock is a source of unnecessary expense, and several investigations recently conducted

have shown that large sums can be saved to many of our industries

by simplifications of this sort.

Elimination of Industrial Wastes.

In cooperation with the industries of the country the bureau is

assisting in the great problem of the elimination of industrial wastes,

which, like all major problems, depends for its solution upon correct

fundamental scientific and technical data. For many years the

bureau has kept in touch with industrial processes and has acted

as a clearing house for certain kinds of information concerning iml^rovements in methods of production. It has assisted in the preparation of specifications, codes, and ordinances, all having for their

primary object the increasing of industrial efficiency. Through its

researches ways and means have been found for the better utilization

of our raw materials, for cheapening and improving the quality

of manufactured articles, and for turning to useful purposes the

by-products of industrial plants. The following are some of the
8 REPOET OF DIRECTOR OF BUREAU OF STANDARDS.

investigations directly bearing on this subject, which are now in

progress in the bureau's laboratories

A complete study of automobile engine performance, both in the

laboratory and in cars on the road, is being carried out with the

object of increasing the efficiency of internal-combustion engines.

If the bureau, through this Avork, can assist in lowering the gasoline

consumption of automobiles only 10 per cent for a given mileage,

it will represent a saving to the country of something like $100,000,-

000 per year.

Large sums are lost each year through the corrosion of underground pipes, conduits, and metal structures. Part of this is the

result of electrolytic action, while part is caused by conditions of

the soil. The bureau has mapped out an extensive program to

study this subject, and, if possible, to suggest means for preventing this waste. Pieces of pipe have been buried in different

sections of the country, and the effect of the soil in these localities

on the metal will be studied.

Most appliances used for heating by gas are operated at very

low efficiency, with a consequent waste of gas and also with a very bad effect on persons working in the same room, because)

imperfect combustion means generation of carbon monoxide, which

is extremely poisonous. The bureau has studied very thoroughly

the subject of improving both natiirai and artificial gas burners

and has already issued recommendations which will greatly reduce

gas consumption and improve the health of the users. In the field of building construction more material than is neces- sary is often used for a wall, column, or floor slab, because information concerning the stresses which such structures or members

can safely bear, their ability to resist fire, etc., is inaccurate or incomplete. In order to more definitely formulate safe and

economical standards in this field the bureau is investigating the

suitability of rerolled steel as a reinforcement for concrete, the

strength of walls and floors, the resistance of buildings to fire, and

the constitution of cement and concrete.

Electroplating plays an important part in many industries, but

until recently very littte attention has been paid to the scientific

side of the problem. The bureau has found that by properly controlling the baths, regulating the current, etc., great economies can

be effected and a more satisfactory product turned out. For this reason a great deal of work is being done in this field with the

hearty cooperation of the electroplating industries.

Work of equal importance in connection with the elimination of

waste now in progress in the laboratories includes: Research on

electric batteries ; determination of dielectric losses ; study of heat

flow in structures and materials ; thermal conductivity of materials

at high temperatures; study of sound transmission of structural

materials ; spectroscopic analysis of metals ; elimination of gases in

metals; power losses in automobile tires; reclamation of used lubricating oil ; use of low-grade cotton for bagging, etc. ; study of the

heat-retaining properties of blankets and clothing; utilization of

American clays in the paper industry ; utilization of flax straw and

tow for making paper; utilization of refuse molasses; recovery of

waste sugar, as well as many other investigations.
^ REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 9

Training of Experts in Various Industrial Fields.

One of the greatest services which the bureau performs for the industries is the training of men for scientific and technical research

work. Many young men receive what is, in some respects, better

than a postgraduate course by working in some of the minor scientific positions at the bureau during the years immediately following

the completion of their college course. These men then go into the

industries with a better conception of the problems of research work.

In this connection it should be mentioned that, while the entrance

salaries in these lower-grade positions are perhaps sufficient, those

paid the more experienced members of the scientific staff are wholly

inadequate. This has resulted in the present difficulty of retaining

the most valuable men in the Government service. It is assumed that

as soon as possible this unsatisfactory condition will be remedied and

the salaries of these experts placed more on a plane with the compensation for similar work in industrial and even educational institutions. Unless steps are taken to meet this situation it will be impossible to maintain the bureau's staff on the high plane of efficiency

which it has always occupied.

RELATION OF THE BUREAU'S WORK TO THE

GOVERNMENT.

Comparison of Standards of Other Government Departments with

Those of the Bureau.

The use of standards enters into almost every activity of the Government, as it does into every industry and into the everyday life

of all persons. The work done for the Government is in no wise different from that carried on for individuals and involves the same

problems.

Many bureaus of the Government service are charged with the

administration of laws and the establishment of regulations, the intelligent application of which depends very largely on the use of

exact standards. This is true to a greater extent than is generally

supposed. The Bureau of Standards has cooperated freely with these

branches of the Government, and the service rendered has involved

every department of physics and chemistry covered by the bureau's

activities. The neglect of such matters in the past has been a frequent source of misunderstanding and litigation between the Government service and the public. Conspicuous examples of bureaus to

which assistance has been given are the Customs and Internal Eevenue Services, Steamboat Inspection and Coast Guard Services, and

the Bureau of Navigation of the Department of Commerce, as well

as all bureaus of the War and Navy Departments engaged in construction or development work.

Performance of Tests and Investigations and the Collection of

Scientific Data of a Fundamental Nature.

The engineering and building construction in progress at all times

by the Government is exceedingly great, both in variety and magnitude. In all of it a knowledge of the materials employed is of fundamental importance from the standpoints of economy, efficiency, and

safety. The work of investigating the properties of structural mate-
10 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

rials was taken up and is carried on primarily for the purpose of

securing the information needed by the Government service in its

structural work. This information is necessary to the public in

construction work, and every effort is made by the bureau to render

its findings available to the public generally. The demands for information of this sort have come from practically all Government

bureaus and establishments, but especially in connection with the

structural work carried on by the office of the Supervising Architect, the engineering branches of the Army, the Bureau of Construction and Repair of the Navy, the Panama Canal, and the Reclamation Service. ^

Advisory and Consulting Capacity.

One of the most important services which the bureau has been

able to render to other departments of the Government, both civil

and militai'v. has been of an advisory and consulting nature in matters pertaining to the scientific work in which these departments

are interested. Too great emphasis can not be placed on the importance of this phase of the bureau's work. Its maintenance woiild

be warranted for this reason alone, even though its usefulness in this

field is but a small portion of the total service which it has rendered

other branches of the Government.

The bureau's laboratories have been open and its experts aA^ailable

at all times to every department of the Government, and in manycases substantial help has been rendered to the military and civil

departments through the familiarity of the bureau with certain kinds

of work and its ability to quickly decide whether the particular

methods, materials, or devices were suitable for the service in question.

The Bureau as a Testing Laboratory and Its Work in the Preparation of Specifications on Which to Base the Purchase of

Materials.

The Bureau of Standards serves as a testing bureau for the various

departments of the Government when called upon ; and, as such, is assisting to place Government purchases upon an economical and

businesslike basis. The example of the Government in such matters

has a far greater influence upon the public than is generally supposed. The Government can do no greater service to the country

than to place its own purchases upon a basis which may be taken as

a standard by the public at large. This work involves the specification of a wide range of structural and miscellaneous materials and

their testing, Avhen delivered, to ascertain whether or not they comply witli the siDecifications. This is especially important, since such

materials are purchased by means of competitiA^e bids, a method

resulting in much fraud and injustice unless suitable standards are established and successful bidders held absolutely to this standard in

making deliveries. Furthermore, most purchasing officers are realizing the great importance of having such testing done by a disinterested institution equipped Avith the scientific and other facilities for

performing the service in a manner that is fair to both parties con- cerned in the purchases.

Among the Government bureaus and establishments which haA-e

utilized the Bureau of Standards as a testing institution in connec-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 11

tion with the purchase of supplies may be mentioned the Government

Printing Office, in connection with the purchase of paper, inks, and

printing supplies, and the Post Office Department, in connection with

the purchase of paper, twine, textiles, etc. A wide range of materials

has been tested for the Quartermaster Corps of the Army, the Bureau

of Supplies and Accounts of the Navy, and the Panama Canal. The

General Supply Committee has called upon the bureau for assistance

in the specification of all sorts of supplies and equipment, as well as the testing of samples submitted by bidders of the supplies bid upon.

Practically every branch of the Government service, including the

District of Columbia, utilizes the Bureau of Standards as a testing

bureau. Here, again, as in other fields of the bureau's activities, it gains much useful knowledge, which is given to the public in the

form of suitable publications.

ORGANIZATION.

The organization of the bureau's scientific and technical staff is

based upon the nature of the expert service involved rather than

upon the classes of standards. For example, the division of weights

and measures has to do with all matters pertaining to standards of

length, mass (weight, as it is commonly termed), time, density, and

similar questions, whether they arise in connection with the precision

standards used in scientific investigation, the master standards of

manufacturers, or the ordinary weights and measures of trade. A

standard of quality or performance where any of the above meas- urements form the fundamental and most important factor would

be referred to this division.

The division of temperature and heat has to do with heat standards, the testing oi heat-measuring apparatus, the determination of

heat constants, of which there are many, and all investigations pertaining to quality or performance where heat measurement is the

essential and predominating factor.

Similarly, the electrical division is concerned with all the electrical problems that may be taken up at the bureau, whether in connection with the various electrical standards of measurement, electrical constants, the electrical properties of materials, or the performance of electrical equipment.

Questions in optics enter into standards of all kinds to a greater

extent than has been supposed. Hence, there is an optical division

provided with experts in spectroscopy, polarimetry (used in sugar

analysis), color measurement, the principles of optical instruments,

and the measurement of the optical properties of materials.

Practically all investigations concerning the various classes of

standards involve chemistry in one form or another. There are also

many chemical standards and questions which arise in connection

with chemical work generally, especially in the industries. Hence,

there is a chemical division cooperating with every other division

of the bureau, as well as taking care of the questions of a purely

chemical nature that come to the bureau and which fall within its

functions.

In the case of the more important technical fields, divisions have

been formed dealing more specifically with large and important

classes of materials, but many of the purely scientific questions in-
12 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS,

volved would be handled b_v one of the above-mentioned scientificdivisions or jointly with it. The work of the technical divisions is just as scientific in character, but deals more specifically with manufactured products.

The work of the structural engineering and miscellaneous materials division includes the investigation, testing, and preparation of

specifications for these materials, such as the metals and their alloys,

stone, cement, concrete, lime, paints, oils, paper, textiles, rubber, and

other miscellaneous materials.

The division of engineering physics makes investigations and

tests regarding the performance and efficiency of instruments, devices, and machinery. Tliis work includes the testing of water and

other meters, aeronautic instruments, etc., as well as investigations

in aerod3mamic }ohysics and the study of sound.

Questions pertaining to the manufacture, specifications, testing,

and use of the metals and their alloys is so important that a separate

division, known as the metallurgical division, is provided to deal

with these problems.

The ceramic division is concerned with all problems in connection

with the use of clays and clay products, with investigations in the

field of glass manufacture, and with questions involving the use of

refractory materials and enameled metals.

The division of building and housing is engaged in the problems

of standardizing building materials throughout the country with

the object of cheapening and improving the construction of houses.

The work of the division of simplified commercial practice includes a systematic study of the needs of standards in the industries,

with special reference to the elimination of unnecessary sizes, and

other means for reducing waste.

The employees engaged in clerical work, purchasing, files, records,

and accounting, as well as those of the library and information sec- tion, form the office division, while those employed in the operation

of the mechanical plant, the various shops, and the care of the buildings and grounds make up the engineering and construction division.

LOCATION.

The laboratories and offices of the Bureau of Standards are located

on a tract of about 35 acres in the northwest section of Washington,

on Pierce Mill Road, near Connecticut Avenue, and are reached by

the Chevy Chase car line. They were placed outside of the business

center of Washington in order to insure freedom from mechanical,

electrical, and other disturbances common to the business and more

thickly i^opulated sections of a city. Furthermore, the area of

ground necessary precluded a site nearer the city. It has been found

by experience that the efficiency of the employees, especially those

engaged in testing and scientific investigations, has been greatly

increased by the location of the laboratories in a section free from

the ordinary disturbances of metropolitan life.
I. SCIENTIFIC AND TECHNICAL DIVISIONS.

WEIGHTS AND MEASURES.

The division of weights and measures is concerned with measurements involving the fundamental units of length, mass, and time, and such derived or secondary units as area, volume, density, and pressure. The activities of the division also include preparation of

specifications and tolerances for use in connection v/ith standardization of weighing and

measuring apparatus, gauges, and screw threads; cooperation with States in the preparation and enforcement of weights and measures legislation; the design, improvement, and

inspection of weights and measures apparatus; the carrying out of researches designed

to result in more accurate knowledge of physical constants; and improvements in en- gineering practice.

GENERAL.

Scope of Weights and Measures Work.

Three factors enter into every commercial transaction—namely,

quantity, quality, and price—and no transaction can be on a satisfactory basis until these three factors are expressed in definite and

measurable terms. Witli this in mind the vital importance of ac- curacy in weights and measures is readily apparent, since the determination of quantity is directly dependent upon some form of

Avei_2:hing or measuring, and furthermore since in many cases the

qualit}'^ of a mechanism, as measured by performance, is also dependent upon the accuracy of measurement and nicety of fit of the

parts.

LENGTH.

Investigation in Precision Length Measurements.

The precision 1-meter comparator has received considerable attention dui'ing the year. The temperature control of the comparator

box has been developed and put into complete operation so that now

the bath can be kept at a constant temperature to about 0°.01 C. for

any desired length of time. Any temperature required for this work

can be obtained very quickly by regulating the thermostat and

auxiliary apparatus.

An investigation was made of several micrometer microscope screws used in precision work in this laboratory. Although more investigation is needed along this line, it is found that the micrometer screws

in the laboratory are sufficiently accurate for all except the highest

class of work One micrometer screw was found to have periodic and

progressive errors of such small magnitude as never to require a cor- rection to be made in any work done with it. Another instrument has

errors several times as large but still of a negligible magnitude. This

instrument is defective, however, in the mechanical construction of

the micrometer and in the matter of rigidity of the microscope and

freedom from lost motion which makes the instrument very much less

reliable in actual use than the one first mentioned.

As a result of the improved apparatus now in use in the geodetic

comparator for the test of precise base-line tapes, a greater accuracy

13
14 EEPORT or DIRECTOR OF BUREAU OF STANDARDS.

and reliability in the test of these tapes is now obtained than heretofore. This is largely due to the elimination of friction and the ability

to apply exactly the tension desired. Kecent tests have shown that,

with tapes in good condition and properly graduated, the length can

be obtained with a probable error not exceeding one part in 3,000,000.

These lengths are also correct in absolute value to nearly the same

degree. It shoidd be pointed out that careful examination of test records shows that previous work done on the geodetic comparator

has been of such i-eliability as never to have been the source of serious

error. The present apparatus can be regarded simply as a logical

development of the work in precise tape testing along the lines so well laid out by L. A. Fischer, for many years chief of the weights

and measures division.

The feasibilit}'' of standardizing tapes of a moderate degree of

accuracy by direct comparison with standard tapes has been demonstrated and additional tapes have been ordered to make this method

more effective and reliable.

Apparatus.

Besides the developments and improvements in apparatus already

noted, the most important development is that of the sieve-projection

apparatus. This is a very convenient method of testing sieves by

measurements of the image of the sieve wires, magnified about 260

times on a ground-glass screen. The measurements can be made much,

more rapidly by this apparatus than in any other way, no dark room

is needed, and eye strain is greatly reduced. A complete account of

this has been prepared for publication.

For several years the need of the following three instruments has

been felt : (a) Comparator for calibrating the intervals of a graduated standard; (6) a small comparator for calibrating sieves and

small scales, etc; (c) projection apparatus for testing sieves. Of

these, (c) has been built and has proved to be very much of a success. The need for (a) becomes increasingly great and should be filled

by the purchase of a suitable instrument, a preliminary blue print of

Avhich is now in the files of the bureau. The small comparator (h)

for the small scales and for testing the micrometer of mici'ometer microscopes can probably be supplied by an apparatus to be built at the

bureau. The need for this apparatus in the testing of sieves has

been successfully met by the projection apparatus.

Research in Screw Cutting and Precision Dividing Engines.

The principle of the interferometer has been applied to the determination of errors of screws and is giving excellent results. Periodic

errors are accurately and rapidly detected. The progressive errors and other defects can also be detected with this testing apparatus.

This has enabled the bureau to make substantial progress in the ai't of precision-screw cutting.

The success thus far justifies the enlargment of the work and plans

are being made accordingly. The effects of lubrication, type of bearings, temperature, etc., are to be tried out on apparatus designed for . these tests.

} All the above problems are progressing rather slowly, but the acj curacy of the work can not be sacrificed to satisfy the desire for i greater speed.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 15

Information on Length Measurements and Standards.

A rather complete bibliography on precision length measurements

primarily and also on the miscellaneous work of the length section

has been made. In gathering together this bibliography an effort

has been made to find the primary sources of information relating

to metrology and its historical development from the introduction

of the micrometer microscope to the present methods of measurement

in terms of light waves. It has been interesting to note that many

metrologists seeking to establish the relation between the yard and

the meter have neglected the fact of temperature—that the prototype

meter has a length of 1 meter only at 0° C, and that the British

imperial yard has a length of 1 yard only at 62° F. That is, they

fail to distinguish clearly between the yard and meter as units

of length, and specific yard and meter bars as standards of length.

This bibliography, which is now in card index form, has already been

of great assistance in answering correspondence and in supplying information needed in the laboratory. Cross indexing is now in progress to make this still more effective. It is also probable that this will serve as a basis on which a paper can be prepared on the subject of

length standards and their measurement.

In order that information regarding the standard weights and

measures which have been supplied to the States by the Federal Government might be more readily accessible for reference, this material

has been collected from various sources and compiled in one volume.

A copy of the information has been placed in the vault for preservation.

Further information is being gathered and measurements made on

various standards in the possession of the bureau which are of historical interest.

Routine Testing.

The following articles were tested as to length during the year

:

9 length standards and precision scales, 19 invar base line tapes, 157

steel tapes, 104 " metallic " tapes, 34 level rods, 40 level rod strips,

276 haemacytometers (blood-counting chambers), 540 extra cover

glasses for haemacytometers, 111 sieves, 14 pieces of sieve cloth, and

73 miscellaneous articles tested for length or angle.

Among the length standards tested during the year, one of peculiar

interest was a yard and ell standard from Alexandria, Va. This

standard, which bore the inscription " County of Fairfax " and the

date " 1744," is the oldest length standard which has been submitted

I to this bureau for test. It was found to be correct within the usual

tolerance f»r commercial measures. As a result of the bureau's experiences in determining the coefficient of expansion of invar level-rod strips, a means for doing this

accurately and quickly has been developed. There is the objectionable feature that it is necessary to change the temperature of the entire tape tunnel. On this accovmt, the method as at present used can

not be regarded as final. It is apparent from the requests for the testing of sieves that the

specifications for the United States standard series of sieves have now

I been well distributed, since in a majority of cases the test for comI pliance with these specifications is specificall}' requested.
16 BEPOET OF DIEECTOR OF BUBEATJ OF STANDARDS.

In the haemacytometer testing, the most notahle feature has been

the testing of one-piece chambers on a quantity basis.

A standard temperature of 68° F. (20° C.) for all steel tapes has

been agreed upon, effective July 1, 1922. This temperature is now

very generally accepted in the United States as the standard temperature for all standards of length. Previously this has been the

standard temperature for tapes graduated in metric units only,

English tapes being ordinarily standard at 62° F. in accordance

with English practice. The standard tension for tapes is under

consideration with the manufacturers and it is expected that definite

specifications will be agreed upon at an early date.

Visitors.

During the year there have been many visitors in the laboratory

from various instrument firms and other companies making or using

apparatus involving length measurements.

Statement of Present Condition of the Section and Recommendations for the Following Year.

1. At the present time all routine testing is practically up to date.

2. Suggested changes in routine testing:

(a) Development of a projection method, using the sieve-projection apparatus, for testing the rulings of haemacytometer chambers.

(b) Use of micrometer eyepiece microscope instead of micrometer

microscope for the rough measurement of many capillary tubes.

(c) More scales on glass should be ruled for obtaining the mesh

of finer sieves by the " picket-fence interference." The need for

these is sufficient to warrant its having early attention.

3. Improvement in tape testing:

(a) Permanent, adjustable microscope holders especially designed

for the work will avoid scratching the bench, will improve the

appearance of the apparatus, and may still further increase the

reliability of the results.

(&) It would be desirable to substitute weights for spring balances

in the steel tape testing. No satisfactory arrangement has been

devised as yet, however.

(<?) Six additional ta]De supports for the geodetic comparator are recommended. This will enable comparisons of tapes to be made so near the condition of support throughout that the difference between

the two cases as calculated by the formula would be so small as not

to require any considerable refinement in the measurement of the

weight per imit length of the tape. These supports would also

be useful when a considerable number of supports ai'e definitely

specified.

(d) The most serious need in the tape testing is one which can not

be remedied at once. The tape tunnel is not long enough. For geodetic tapes an increase in length of slightly over 5 meters is needed,

but there is no way of providing this room in the present tunnel. A

tape bench of 200 feet or longer is also an ideal to work for. It is hoped that these may in time be provided in a new metrology

building.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 17

Revision of Publications.

Two publications relating to work of this section have been out

of print for a considerable length of time. These are—Circular 2

on Measurements of Length and Circular 39 on Measurement of

Sieves. The first of these has been revised for republication. The

second was revised nearly two years ago but has not yet been republished on account of certain questions as to specifications covering

" sieving value." It is now proposed to lewrite the circular so as to

deal with the standardization of sieves from the standpoint of standard dimensions only.

MASS.

Mass Standards of the Bureau.

Important calibrations of some of the standards of mass of the

bureau have been made during the year; a set of platinum-iriclium

standards from .500 g to 1 mg have been made available for use, and a valuable old set of gold-plated brass standards was replated

and readjusted. Some of these standards were compared directly

with National Prototype Kilograms No. 20 and No. 4, whose values

have been certified by the International Bureau of Weights and

Measures. In the fundamental comparison of standards or sums of

standards equaling 1 k, about 80 weighings Avere made, while many

hundreds of weighings were made in the intercomparison of the

weights of the various sets. In the fundamental comparisons each

" weighing " included 4 interchangings of the standards and 2 determinations of the sensitiveness of the balance. These were so arranged

as to give practically' independent determinations of the dilference

between the standarcls being compared. The fundamental comparisons were made with a " calculated probable error " of 0.003 mg

while in 19 pairs of weighings among the platinum and platinumiridium standards the maximum discrepancy between the weighings

was only 0.02 mg, or 1 part in 50,000,000.

One of the very gratifjdng features of the work was the close

agreement of results based on the two national standards, the differ- ence in the values derived from the one and from the other being

less than the probable error of the results.

A secondary kilogram of pure platinum has shown a total loss relative to the national standards of about 0.1 mg, or of 1 part in 10,000,-

000 during the last 22 years.

Preliminary comparisons of some of the ordinary working standards with these newly calibrated standards show that the values of

these working standards will be practically unchanged by the recalibration. The great benefit of the work is therefore the greater

certainty with which values are known and in the assurance that the

values of these working standards have been maintained on the

proper basis during the past years.

Tests.

During the year more than .5,000 precision weights of various classes

were tested by the bureau, the Avork being done for State governments, private laboratories, manufacturers, other departments of the

Government, and other sections of the bureau. The number sub9644—22 3
18 EEPOKT or DTKECTOR OF BUREAU OP STANDARDS.

mitted for test was about equal to that submitted in 1920, which

represented cin increase of 60 per cent over any preceding year,

although a decrease of 14 per cent from the number submitted last

year was noted. This small decrease in the number of routine tests,

taken together with the increased efficiency of the staff, has made it possible to devote time to a thorough recalibration of the standards

of the bureau, work which was of urgent importance and which has

been briefly described above.

State Standards.

Primary standards were tested for the States of Massachusetts,

Michigan, North Dakota, and Wyoming.

Manufacturers' Standards.

Primary standards were tested for two large manufacturers of

high-precision weights. In one case the standard tested was a highgrade one-piece weight of gold-plated brass and the result showed

that this had not changed by more than a few parts in 10,000,000

since it was tested at this bureau 13 years ago. In the other case the

standards were lacquered screw-knob weights, and these were found

to have undergone serious changes within a few years.

Accuracy of American Weights.

The American-made weights submitted for test have shown marked

improvement, the accuracy being the highest yet attained. Everyone of over 200 precision weights submitted hj one maker during a period of several months were found accurate within the tolerances.

Another maker submitted a somewhat smaller number during the

latter part of the year, also without any rejections, and a third maker

recently submitted 12 sets or nearly 250 weights, all of which were

not in error by more than the tolerance allowed. Such records are striking examples of what can be accomplished by careful work and

sufficiently thorough factory inspection.

Imported Weights.

Very few imported weights have been tested, but those tested

showed 5 to 15 per cent in error by more than the tolerances for

high-grade analytical weights. Some of the imported weights in the

denominations just below 1 gram, instead of being made of platinum,

were found to be of some magnetic material. Such weights are not

suitable for many uses on account of the danger of errors arising

from magnetic attraction when used on ordinary analytical balances

and in connection with other weights or other objects.

Improvement in Types of Weights.

One maker has spent a large amount of time and effort in developing an improved sealing device for class C test weights such as are much used in factory work and ir official tests of scales in commercial

use. The device has now been developed to such a point that formal

approval of this new form can soon be given by the bureau.

Two additional makers of standard weights are considering the

manufacture of standards intermediate between ordinary test weights

and the highest grade of gold-jilated one-piece standards. These
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 19

intermediate standards (called class B standard weights) are veryuseful since they make available better standards to some who would

in the absence of these buy poorer standards than are required for

the service to which they will be put, and money is saved to others

who otherwise would be required to procure a better grade of weight

than is necessary.

Repair of Analytical Weights.

k5uch great difficulty and expense were involved in the repair of

worn sets of analytical weights when the Avork was done elsewhere

that experiments have been concluded on relacquering and readjusting the brass weights of sets belonging to the chemistry division

where a large number of such sets were in need of repairs. The sav- ing was found to be so material that about 30 such sets have already

been repaired in the bureau's laboratories, and arrangements ai'e being made for handling such work regularly for all weights used

in the bureau, and it is hoped to extend its scope so that other

branches of the Government that may find it to their advantage may

also be accommodated.

Equivalents.

A large number of equivalents between rare foreign weights and

the metric or United States customary units have been checked up

with a special view to ascertaining whether published values were

reall}^ authoritative. This work has strongly emphasized the lack

of reliability in many published tables and the need of getting such

data directlj'^ from official sources in the country concerned.

At present a number of tables are being checked for an engineers'

handbook. These involve not only checking and computations, but

there will also be required careful consideration of the definitions of

i gravitational units of force, on which there is at present a great deal

! of disagreement and ambiguity.

Personnel.

This section has been very fortunate in having retained for nearly

j two years four of the five assistants now in the section, although

! the salaries paid can not be said to be large enough to be attractive

ones. The amount of work found possible recently, when contrasted

|j with the preceding few years, serves to emphasize very strongly the

I benefits of such continuous service, and proves that increasing sal-

'I aries to a point where such assistance can generally be held will not,

j in the long run, result in an increase in total expense of operation.

One of the leading astronomical observatories of the country re-

^; cently announced that the rate of a clock has a diurnal variation;

I that is, that the rate is faster at one titne of the day than at another.

I The maximum difference in rate between the extremes is said to be

sufficient to make it of appreciable importance. It is not known

I whether the effect, if real, is due to the principle on which pendulum

I clocl?s operate, to faulty construction of clocks, or to some diuiTin]

TIME.

i Research in Diurnal Variation of Clock Rates.
20 EEPORT OF DIKECTOR OF BUREAU OF STANDARDS.

effect upon the supports of the clocks. This ):)roblem is being studied

by the bureau with the cooperation of the Naval Observatory in so far as the available equipment and time will permit. This investigation may not conclusively prove or disprove the original state- ment, but may be expected to have some ^ alue relative to the problem.

Horological Institute of America.

The work of last year in aiding the National Research Council to

form an association for improving conditions in the horological industry has continued actively during the present year. The association formed is known as the " Horological Institute of America."

The major work which it has undertaken to date is the examination

and certification of watch repairmen according to their proficiency.

This work will be of benefit to all who are interested in the proper

maintenance of timepieces. Part of the examination consists in

testing a watch that has been repaired by the candidate for a proficiency certificate. The bureau is aiding this program considerably

by testing the repaired watches and in other ways whenever possible,

including aid in drawing up certification specifications. A member

of the bureau serves on the executive committee of the institute and

also as secretary of its certification committee.

Improvements in Equipment.

Arrangements have been completed for the installation of a radio

chronogi'aphic-recording receiver for receiving the Arlington time

signal. This apparatus will displace the permanently-connected pair

of telephone Avires leading to the Naval Observatory by means of

which the time signal is now received. The receiver is being constructed by the bureau and will probably be ready for use shortly.

The initial cost will be less than the annual rental of the telephone

wires.

Testing.

The following tests have been completed during the year

Railroad precision watclies 181

Ship watches 145

Stop watches 51

Wrist watclies (for Government service) 1, 674

Miscellaneous 2

Total 2, 053

Future Work.

A problem which needs solution is the development of a method

for an accurate determination of the daily rate of a watch in a period

of a few minutes. If a relatively inexpensive piece of equipment for

accomplishing this can be developed, it will be of material advantage

in other work which is contemplated. The principles upon which

this instrument would be based are already developed. There re- mains merely the mechanical construction and development.

Additional Equipment.

A piece of needed equipment, to which attention was called last

year, is an instrument for supplying a reliable time sigiuil with a signal-interval of one-tenth or one-twentieth of a second.
REPOET OF DIRECTOR OF BUREAU OF STANDARDS. 21

An oscillograph is also needed for measuring with precision shorter

time intervals than can be measured with an ordinary drum crono- graph.

Travel.

The work of the bureau in the testing of watches has been described

before several local and State jewelers' organizations. This has

served to quicken the interest of the public and of the Horological

Institute of America in this phase of the bureau's work. Two addresses of interest to the jewelry trade were made during the year by

a member of the bureau and published in the Jewelers' Circular, February 1 and March 8, 1922.

CAPACITY AND DENSITY.

Research.

Considerable work has been done during the year on the density

and thermal expansion of sodium chloride solutions. Additional observations are still to be made on the density of saturated solutions at

4° C, as considerable time appears to be necessary to reach a condition

of equilibrium at that temperature. When satisfactory data can be

obtained at that temperature the work can be prepared for publication, as all of the other necessary observations have been completed.

Hydrometer Scale for Petroleum Oils.

Confusion has existed for several j^ears in regard to the hydrometer

scales used in the measurement of petroleum oils. The so-called gravity of oils is ordinarily expressed in terms of an arbitrary scale which

bears a certain relation to specific gravity. This arbitrary^ scale,

commonly known as the Baume scale for light liquids was originally

based on the following relation to specific gravitv

:

140

Baume degrees= ^ r—- —130. ^ specific gravity

It was discovered a few years ago that, unfortunately, many of the

hydrometers in use in the petroleum-oil industry were not graduated

in accordance with the above relation, but were more nearly in agreement with the relation expressed when the constants 140 and IHO were

replaced by 141.5 and 131.5, respectively.

It Avas held by the bureau that this deviation from the original

relation to specific gravity was the result of an error and that the error should be corrected by correcting the instruments. It was

held by the manufacturer of these instruments, however, that they

were in agreement Avith certain other instruments which had been

adopted by the industry as standards and that they were, therefore,

correct in spite of the fact that they did not agree with the formula

on which they were originally based.

The result of this difference of opinion as to the correct basis of

graduation was that both scales were widelj^ used in the oil trade

;

one being known as the United States standard scale, and the other

as the Tagliabue scale, and both as the Baume scale. The confusion

resulting from this situation was very great.

During the past two years it has become increasingly apparent that

the question must be settled by the exclusive use in the oil trade of

either the one scale or the other. The (juestion was taken up by a
22 REPORT OF DTRECTOR OF BUREAU OF STANDARDS.

joint committee composed of members from the American Petroleum

Institute, the Bureau of Mines, and the Bureau of Standards in an

attempt to arrive at a satisfactory settlement. It ^Yas the opinion of

the bureau that the original scale, based on the modulus 140 should be

adopted and used in the measurement of oils as well as other light

liquids. The sentiment in the oil industry, however, appeared to be

A'^ery strongly in favor of making an exception in the case of petroleum oils, and adopting the modified scale, based on the modulus

141.5.

After careful consideration of the relative extent to which the two

scales were used, and the cost and inconvenience involved in changing

to either scale, the committee agreed to recommend to the petroleum

oil industry the adoption and exclusive use of the scale based on the

modulus 141.5; this scale to be known as the American Petroleum

Institute scale, and to be used exclusively in the petroleurn-oil industry. This recommendation has been approved by the industry, and a long and profitless controversy has at last been settled. While it may

be considered unfortunate that it could not have been settled by the

adoption and exclusive use of the other scale, still it is better settled as at present than not at all. The bureau will now certify h^^drometers graduated in accordance with this scale, and will lend its influence to secure the universal use of this scale in the petroleum

industry.

Calibration of Horizontal Tanks.

The bureau is frequently called upon to supply a formula for computing the contents of a partially filled horizontal tank with bulged

ends, such as a railroad tank car. The necessar}' formulas for this

work have been developed and extended tables prepared for use in

applying the formulas. A mimeographed circular will be available

for distribution shortly.

Testing.

The following is a report of the testing done by the volumetric sec- tion for the year ended June 30, 1922

Kind of apparatus.

G)ass volumetric: Burettes

Cylindrical graduates. Dilution pipettes

Flasl<s Pipettes, transtco. Pipettes, measuring. .

Pipettes, Bahcork

Specific gravity Masks.

Hydrometers

.Mptul capacity measures.

-Calibrating bulbs

Miscellaneous

Total pieces of apparatus tested

other tests—Density delerminations.

Total number of tests

Number

.sub- mitted.

2, 246

fi20 568

fi, 021 4,226

64742

27

Number

tested.

14,397

.563 105

668

1,939

.56,'; 557 5,000

3, 858

G31

1626

12, 592

5.59 105

064

1172

13, 339

114

13,453

Number

passed.

1,622

242

542 3,sn

3, 393

596

6

6

10, 218

358

85

443

Per- centage

passed.

.^9 95

63

8092

1422

71

64

81

66
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 23

An examination of the above data shows that of the volumetric

glassware submitted for test 87 per cent was eligible for test. The

remaining 13 per cent was rejected vipon preliminary examination.

The rejections in the case of flasks were due to unsatisfactory blanks

having striae and bubbles, and some rejections were on account of

the apparatus being unstable. The burette rejections were due to

strife and leaky stopcocks. The general quality of the glassware

was very much improved over that submitted the previous year.

Seventy-one per cent of the glassware submitted passed the test,

and of that actually tested 81 per cent passed test. This is a better

showing than the previous year, due, no doubt, to better methods and

closer attention to details on the part of American manufacturers of

volumetric apparatus.

Sixty-four per cent of the hydrometers submitted passed the test. For the greater number of those not passing the test reports were

issued giving corrections so that the instruments could still be used, even though not complying with all of the bureau specifications as to

accuracy and inscriptions.

For the purpose of comparison, a summary of the work done by

the section for the fiscal year ended June 30, 1921, with the present

3'ear is given

:

Number

submitted. Number

tested. Numberpassed.

Percentage

passed.

1921 1922 1921 1922 1921 1922 1921

6168

77

1922

Volumetric apparatus

Hvdrometers

MPtal capacity measures

Calibrating bulbs

10, 353 628

210

14,937

105

7,932

619

21060

15655

12, 592

559

105

1172

114

6,339

427

161

10, 218 358

85

7164

81

Density determinations

Total number oX tests 9,032 13,453

I Examination of the above data shows that there was an increase

of 39 per cent in the amount of glass volumetric apparatus submitted for the test over the previous year, while the number that

passed test was 61 per cen^ more than for the previous year.

A decrease of 10 per cent in the number of hydrometers submitted is explained by the fact that the Internal Revenue Service no longer sends alcoholometers for test, as that department has

little use for the instruments since prohibition has been in force.

The hydrometers submitted were mainly on small orders and of

varying ranges. This would indicate that the instruments now

certified by the bureau are used principally in the industries and

as working standards for manufacturers of hydrometers. The

number of capacity measures submitted showed a decrease over the

previous year. They were, however, found to be more accurately

adjusted.

The density of a number of samples of steel prepared under

different conditions was determined for the metallurgical division

of the bureau in connection with their investigations, and of several samples of storage-battery plate material for the electrical

division for their .storage-battery investigation ; also several de-
24 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

terminations of the density of pure platinum were made to determine the presence of voids in the samples.

Apparatus on Hand July i, 1922.

The following apparatus was on hand July 1, 1922: 168 flasks,

217 burettes, 594 pipettes. 110 cylinders, 2 specific-gravity flasks,

and 3 pieces of special apparatus, a total of 1,094 pieces as compared with 3,155 pieces one year ago. The hydrometers are tested

to date, and one capacity measure only is on hand. This condition is very gratifying to the bureau and is sure to be appreciated by those submitting apparatus for test, as the delay on apparatus submitted will be materially decreased.

Visitors.

A large number of representatives from the makers of glass volumetric apparatus visited the bureau during the year. These visits,

which make possible an interchange of ideas, r are very helpful

in bringing about a better understanding and more cooperation

between the bureau and the manufacturers than could be accomplished in any other way.

A meeting of the makers, dealers, and users of chemical glassware,

especially beakers and flasks, was held at the bureau on January

28, 1922, for the purpose of standardizing sizes and shapes and

eliminating unnecessary sizes. Good progress was made in the

program of standardization.

GAS MEASUREMENT.

Research in Connection with Orifice Meters.

In response to an urgent demand from another department of

the Federal Government, State governments, and several other

sources the bureau is inaugurating an investigation to develop

some fundamental data on orifice meters for the measurement of

gas.

The commercial development of this type of meter has been due

to a demand for a large-volume meter of relatively low initial cost

and low upkeep cost, but which will have for commercial purposes

a fairly high degree of accuracy, even under widely varying conditions of pressure and temperature. It has come to be extensively

used, particularly in the natural-gas fields, for measuring enormous

quantities of gas, and very large payments depend upon its reliability. For example, royalties received by the United States

Government on natural gas, determined from orifice meter readings, amount to some $600,000 a year from one reservation alone.

Doubt and controversies often arise concerning the accuracy of

orifice meters or the proper interpretations of their readings, and

these can not be settled by reference to unimpeachable authority, nor

is it possible, in general, to guarantee an accuracy of better than 5

per cent because no authoritative and sufficiently accurate experimental work has been done anywhere.

In the practical use of an orifice meter the quantities directly

observed are the static pressure, the temperature in the line, and the

differential or drop in pressure through the orifice. These quantities are usually obtained by automatic or recording devices.
REPORT OF DIRECTOR OE BUREAU OE STANDARDS. 25

From the static pressure and temperature, the density of the. gas

may be found, and from the density and differential pressure, to- gether with the diameters of the pipe and orifice, the so-called

theoretical rate of flow may be computed by a simple equation. The

actual flow differs from the theoretical by an empirical factor or

" discharge coefficient " which must be determined experimentally.

The final accuracy of the meter indications is, therefore, very largely

dependent upon the accuracy with which the discharge coefficients are determined.

The problem is, therefore, to determine the discharge coefficients

under all the variable circumstances that may effect it, so that its

value may be known a priori, Avith satisfactory accuracy, under

any set of conditions that may reasonably occur within the range

of commercial or engineering practice. To study this problem sat- isfactorily requires the use of a large volume of gas, preferabl}' air,

under conditions which may be altered as desired. Equipment capable of providing a large flow of air under a wide range of pressures

is available at Edgewood Arsenal and arrangements have been made

for carr_ying out an extensive series of experiments there. Work on

setting up the experimental pipe line and preparing the comi^ressors

for the work is well under way and actual tests will be started within

a few weeks.

Standard Methods for Determining and Rating the Capacities of

Dry Meters.

Due to the many improvements in dry meter designs and the great

expansion in the utilization of gas during the past two or three decades, the old method of rating gas meters according to their light

capacity has become almost meaningless. This has caused considerable confusion and inefficiency in the use of gas meters. Therefore the consumers' meter committee of the American Gas Association and the bureau are cooperating in taking definite steps to improve this situation. This work has already resulted in the adoption

by the committee of a uniform method for designating meter sizes

and capacities. There is now being prepared by the bureau an outline of a method for testing gas meters for capacit3^ suitable for

adoption as a standard method. This should not only meet all essential technical requirements, but should be so simply worded

that it will be easy to understand and to carry out.

Measurement of Compressed Gases.

Steps are now being taken to assist in the establishment of nationally uniform methods for measuring compressed gases. This section

is cooperating with a committee appointed by the Compressed Gas

Manufacturers Association, and questions relating to the present

practices followed in the measurement of compressed gases are being

considered. It appears that there are some points on which closer

agreement is desirable, and it is hoped that such agreements may

be arrived at as a result of this work.
26 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Gas-Measuring Instruments, Routine Tests.

The following: is a summary of the tests made on which reports

were issued by this section during the past fiscal year

Dry meters 3S

Wet meters 5 Portable cubic-foot standards, Stillman type 8

Orifice meters 22

Pitot tubes 6

Flow meters 3 Spirometers 9

Total 80

THERMAL EXPANSION.

Research in Dental Inlays.

Arrangements have been made whereby the bureau has been able

to take up an investigation of dental inlay materials. While the

work is far from completion, sufficient progress has been made to

warrant the statement that it will be possible to supply accurate information on many disputed points connected with the inlay

technique.

The questions of plaster behavior, wax manipulation, and gold

casting are being studied, both from the standpoint of laboratory

technique usually employed and fundamental relations.

Already the commercial laboratories have expressed their approval

of the methods employed and are planning to install apparatus

similar to that designed and used at the bureau. This work will

result in enormous savings to the general public which has often

been a victim of the mistakes of a comparatively new profession,

hampered by inadequate information and experience.

The Ultra Micrometer.

With the cooperation of the electrical division an oscillating valve

circuit for detecting small length changes has been constructed and

calibrated. This micrometer Avas calibrated by measuring the change

in frequency of the circuit, as determined by the use of tuning forks,

and comparing this change with the fractional shift in wave lengths

of light of one of two silvered glass capacity plates. These plates

were so arranged that they formed the essential surfaces of an interferometer having a separation of about 1/100 mm, and accurately

parallel.

The shift of the fringe seii'ed as an accurate measure of the

actual change in separation of the capacity plates. While the apparatus is capable of detecting the most minute changes in length

(one billionth of an inch, as claimed by the inventor) there are many

sources of difficulty in its practical application. Unless a laboratory

is prepared to provide constant) temperature, extremely uniform

electrical circuits and conditions, freedom from vibrations and

other disturbances, it will not be possible to use the instrument to

the limit stated above.

Tests.

The following tests were completed during the year: Thirty-two

representative aluminum alloys, 10 nickel steels, 24 dental investments and waxes, 8 valve steels, and 17 enamels and glasses.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 27

These are parts of series of researches on the corresponding materials or alloys. At the completion of the series the data will be

assembled for publication.

The bureau has been unable to keep up with the demand for this

class of work. The importance of this work is indicated by the

fact that three commercial laboratories have sent representatives

here during the year, each planning to duplicate the bureau's apparatus and carry out their own testing.

It is unfortunate that on account of inadequate funds the bureau

is obliged to limit its activities along this line. In spite of the

necessary limitations, however, good progress has been made in this

work. The upper temperature limit for tests has been extended

above 1,000° C. The use of neutral gas in the test chamber has

made possible the testing of specimens at temperatures above their

usual oxidizing points.

INVESTIGATIONS AND TESTS ON COMMERCIAL SCALES AND

RELATED WORK.

Investigation of Railroad Track Scales.

Exceptional progress has been made during the year in the investigation of the condition of railroad track scales throughout the country. It was pointed out in the last annual report that during the

year 1921 extensive repairs and replacements were made to railroad

track scale-testing equipments Nos. 1 and 2, and that it was hoped

thereby to keep them in efficient service. That the bureau's expectations in this regard have been fully realized is indicated by the fact

that during the first 10 months of this year these equipments have

been maintained in almost continuous service without the necessity

of frequent repairs. It was necessary, however, to lay up these equipments during the greater part of May and Jvme on accoimt of lack of

sufficient funds to keep them in the field.

Notwithstanding this lack of funds there were tested during the

year 894 track scales as well as 17 master scales by these equipments

and by equipment No. 3. The greatest number of track scales which

have heretofore been tested in one year with these equipments was

081. Therefore there was an increase of 220 tests, or about 32 per

cent, over the previous high record of a year's work. This has largely

been made possible by the fact that the personnel has remained almost

constant during the year, all of the men now in this work having

l>een previously trained in this service. The efficient testing of track

scales and the moving of the equipments are tasks requiring considerable experience, and when frequent changes in personnel occur the

}iumber of tests possible to obtain is very greatly reduced.

The work done was well distributed throughout the country, scales

having been tested in the following 33 States and in the District of

Columbia

:

Alabama. Louisiana. Oklahoma.

Ai-kansas. Maine. Pennsylvania.

California. Minnesota. South Carolina.

Colorado. Missouri. Tennessee.

Florida. Nebraska. Texas.

Gef)rgia. Nevada. Utah.

Illinois. New Hampshire. Vermont.

Indiana. New Mexico. Virginia.

Iowa. New York. West Virginia.

Kansas. North Carolina. Wisconsin.

Ohio. Wyoming.
28 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The accompanying map shows in a general way the routes followed

by the three testing equipments, and also the location of master scales

throughout the country.

The distribution of tests among numerous owners also serves to

make the figures representative, scales owned by 99 different railroads and by a very large number of industrial concerns being

included.

A resume of the results of the tests of railroad track scales is presented in the following table. This does not include the results of

master-scale tests which are shown elsewhere. For the purpose of

bringing out certain facts of interest the data have been arranged

geographically, the country being divided into three sections which

have been designated East, West, and South, the subdivision following closely that adopted by the Interstate Commerce Commission in

its report on the statistics of railways. The table is also classified

to show the ownership of the track scales whether by railroads, industries, or the Federal, State, and local governments. The mean numerical error on scales listed as incorrect is shown and a short analysis of the errors of such scales is included.

Results of Tests o.\ Track Scaler.-.

Location and Number.

Correct. { Incorrect. Analysis of errors on incorrect scales.

Per \ Per Mean

nu1 Plus. 1 Minus.

1 ownership. Number.

cent

of

total

scales

Number.

cent

of

total

scales.

merical error in per

cent.

Number.

Per

cent of incorrect

scales.

44.6

48.4, 100.0

Mean

plus

error in per

cent.

0.41 .39

. 22

Number.

1 Per

cent of incorrect

scales.

1 Mean

minus

error in per

cent.

East:Railroad

Industries Government

Total

West:

Railroad

Industries Government

Total

South:

Railroad

Industries Government

Total

All sections: Railroad

Industries Government

Total

172

74

3

80

43

1

46.5

58.1 33.3

92

312

.53.5 41.9 66.70.60

.64 .22

41

15

2

5116

. : ^ i

55.4

51.6

0.75

.88

249 124 49.8 125 50.2 .61 58 46.4 .40 67 53.6 .79

251 182

2

1,52 98

1

60.6

53. S

50.

99

84

1

39.4 46.2

.50.0

1.55

1.53 .70

62

44

62.6

52.4 00.0

1.43 1.42 3740

1

37.4

47.6

100.0

.70

.64 .70

435 251 57.7 184 42.3 1.54 106 57.6 1.42 78 42.4 .70

182

27

1

50

9

27.5

33.3 00.0

132

18

1

72.5

66.7

100.0

.78

1. 55

1. IS

60

5

45.5 27.8

00.0

.62

.39 7213

1

54.5

72.2

100.0

.92

1.62

1. 18

210 59 28.1 151 71.9 1.76 65 43.0 1.60 86 57.0 .88

605

283

6

202

1502

46.6

.53.0 33.3

323

133

4

53.4

47.0 66.7

1.66

1.56 .58

16364

2

50. 5 48.1 50.0

1.49

1.41 .22

16069

2

49. 5 51.9

50.0

.k:5 1.70 .94

894 434 48.5 460 51.5 '.63 229 49.8 1.47 231 50.2 .79

1 The errors of several scales have been omitted from the computation of these mean errors. See para- graph immediately following table for detailed information as to these. The above table shows that 48.5 per cent of the scales tested were

within the tolerances allowed, namely. 200 pounds per 100,000 pounds

of applied load. By geographical subdivisions it is found that 57.7


REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 29

per cent were correct in the West, 49.8 per cent in the East, and 28.1

per cent in the South. The mean numerical errors of the incorrect

scales in these sections were in the same order of merit, the West

having the lowest pei'centage error, 0.54 per cent, the East being

next with 0.61 per cent, and the South having the largest, 0.76 per

cent, the general mean error for all sections being 0.63 per cent.

(These figures exclude several scales having extremely abnormal

errors, since the inclusion of these would have unduly influenced the

averages. These scales are as follows: One railroad scale and one

industrial scale in the western section having errors of +34.55 per

cent and +11.55 per cent, respectively; and one industrial scale in

the South having an error of —17.39 per cent.) The table also indicates that there was no preponderance of errors in either the plus

(fast) or minus (slow) direction since 49.8 per cent of the scales were

fast and 50.2 per cent were slow.

In general these figures seem to indicate that the advances of ac- curacy made heretofore in the railroad track-scale field were well

maintained during the year. The general percentage figure for cor- rect scales, 48.5 per cent, is higher than in any previous year with

the exception of last year, former figures being 32 per cent in 1914

and 1915, when the work was inaugurated, 38.2 per cent in 1916, 44

per cent in 1917, 39.1 per cent in 1918, 46 per cent in 1919, and 41.8

per cent in 1920, the general average of these yearly figures being

39 per cent. The general figure on average correctness this year is noted as being somewhat lower than last year, when it was 53.2 per

cent. Nevertheless consideration should be given to the fact that the

figure this year includes the large number of 210 scales in the South

having an average correctness of only 28.1 per cent, while but little

work was done in this section last year, only 34 scales for an ave-rage

correctness of 44.1 per cent being included.

Comparing the percentage of correct scales throughout the country, exclusive of the South, in 1921 and 1922 we find the figures to

be practically identical, or 54.4 per cent and 54.8 per cent, respectively. The mean numerical error of incorrect scales is found to be

identical, namely, 0.57 per cent. This maintaining of last year's percentages seems to be an excellent record in view of the widespi-ead

industrial depression which has existed, which in general has meant

that considerably fewer men were employed by railroads and industries in the maintenance of scales than has formerly been the case. It was found possible for the bureau's field force to adjust more

scales found incorrect than in any preceding year, the errors on 99

scales having been thus reduced. This service is extended to the

i owners whenever the condition of the scale justifies it and it can be

i done without loss of time which could be utilized in making additional tests.

Calibration of Privately Owned Test Cars.

Thirty-eight test cars belonging to railroads and industries were

I calibrated. This service is extremely important, since it assures that

1 a correct rather than an incorrect standard will be used in private

adjustments of scales for the testing of which such test cars are

utilized. A striking example encountered during the year of the

Use of an incorrect standard may be cited: A test car of a certain

railroad was tested by one of the bureau's equipments and found to
30 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

be in error by 160 pounds, the car being light. This car had been in

service in tliis condition for some time and had been used in testing

and adjusting a number of scales, 8 of which shortly thereafter were

tested by the bureau. In the bureau's tests every one of these 8

scales showed a plus error, and 7 out of the 8 were outside the tolerance, the average error being 0.41 per cent. The character of these

errors was such as would be expected if the scales had been sealed

by a light test car. Further, when the error introduced by the test car as found on calibration, viz, -\-0.2& per cent, is deducted from

the scale errors determined, it is found that 4 out of the 7 deficient

scales will be within the tolerance and 1 will exceed it only by a scant margin. The dates on which the scales were tested by the incorrect test car and on which they were tested by the bureau happened to be so close together as to clearly prove that the incorrect

performance of the scales reflected the defective condition of the

test car.

Calibration of Master Scales.

The general arrangement for the testing of master scales throughout the United States has remained the same as it was last year and

for several years before the control of the Railroad Administration,

the agreement between this bureau and the American Railway Association still being in force. This agreement contemplates that the

bureau will maintain the standard of weight for track scales by

testing once in each year each master scale which is suitable for use and is being used by States, railroads, or industries in the calibration of test cars, and by adjusting those which require adjustment

to bring them within the tolerance. In return for this service the

American Railway Association furnishes free transportation for

the track scale testing equipments when operating upon masterscale schedules, which are laid out in advance by mutual agreement.

The necessity of this work is obvious. It has been pointed out above

that serious errors in many scales may be caused by the inaccuracy

of one test car. If then a master scale, which may be and often is

used in the calibration of a number of test cars, were to be inaccurate

all of these cai-s and the scales tested by them would be adjusted to an

incorrect standard. Therefore, the bureau in its efforts to improve

general weighing conditions throughout the country pays particular

attention to this phase of the work and considers it of paramount

importance. The bureau's equipments Nos. 1 and 2 are the only

ones in the country which are suitable for work of this character.

The master scales are located in all sections of the United States

and the bureau's equipments are especially designed to transport

80,000 pounds of accurately sealed weights from place to place.

As an example of the precision with which master scales throughout the country are being adjusted and their accuracy maintained

by the bureau's testing equipments, a recent instance of which the

bureau was advised by the parties involved may be cited. A railroad-owned test car of a nominal weight of 80,000 pounds was adjusted by the builder on a master scale in Pennsylvania and shipped

to Colorado for use by a western railroad. Upon arrival it was

check weighed on a master scale there and a discrepancy in the

weight of the car of only 5 pounds was found.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 31

The yearly master-scale schedules are now coextensive with the

fiscal years starting July 1. The bureau is pleased to report that

all the suitable master scales in the country, 17 in number, were

tested during the past 12 months and were left in proper weighing

condition. It is encouraging to note that several new master scales

have recently been installed either to furnish facilities in new locations or to replace former unsatisfactory scales, and that additional

installations are already arranged for or are in contemplation.

Bureau of Standards Master Track Scale.

The master scale purchased by the bureau some years ago is now

in storage, but the bureau has no proper site and is still without

funds to install it and thus put it to the use for which it is intended.

Until this scale can be installed for use the bureau can not realize

upon its investment, its scale work can not be made of maximum

efficiency, and the service which the bureau should render must

necessarily be greatly curtailed.

As pointed out last year, this scale was contracted for in 1916 and

it was intended to house it in a centrally located test depot. This

has not yet been done, although since that time the track-scale work

has broadened in scope and the need has consequently become more

urgent. Track-scale testing equipment No. 3, contemplated at the

time of the purchase of the scale and put into service at a more recent

date, comprises test cars Nos. 3 and 4, these being 40,000 and 80,000

pound self-contained test units traveling on their own wheels.

Therefore, they must be reweighed at intervals not exceeding two

months in order to maintain and assure their accuracy, and this

reweighing should be done on a scale operated and guaranteed by

the bureau. Moreover, the 160,000 pounds of test weights (inclucling the special trucks) carried on equipments Nos. 1 and 2, which are used in certifying to the accuracy of every master scale in the United

States, must be repainted and adjusted from time to time and the

equipments ovei-hauled. The bureau has no present facilities for

doing work of this character.

In addition to the needs of the bureau the proposed testing station

would also be used for standardization of the test cars of all railroads in the vicinity of the scale, the calibration of weights carried

thereon, as well as all heavy weights submitted for test by industries or railroads in that locality. The maintenance of a Governmentowned master scale and testing depot at some central point would do

more, perhaps, than any other thing to furnish a correct standard of

weight to be transferred to railroad-owned and industi-ial scales, to

quicken the appreciation of accurate weights and weighing, and to

reduce claims, allay suspicions, and provide a more stable basis for all

business carried on by weight.

In the opinion of the bureau, the city of Chicago is the most favorably situated in the country for the station. This location, being a

central one, would most efficiently be reached by the several equipments, and it also would enable the bureavi to serve a maximum number of railroads and industries.

Mine Scale Investigation.

The investigation of the condition and accuracy of the so-called

tipple scales used at coal mines in determining the amoimt of coal

9644—22 4
32 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

mined by the individual miners, from which results the wages due the

various workers are determined, was carried on during the year in so far as this was found possible. The equipments worked in the

Illinois fields during the summer months until all urgent work there

Avas completed. The work with the equipments was then discontinued as on account of the lateness of the season and road conditions movement into new territory would have been impracticable.

It was intended at that time again to start active operations in the

early s^jring, but the general strike in the organized fields rendered

it impracticable to carry out this plan since in the unorganized fields,

which were the only ones in which work could have been done,

scales are not ordinarily employed in the determination of wages, the

miners here being paid by measure rather than by weight. Work

done this spring in connection with this investigation has therefore

largely been confined to investigations necessary for the preparation

of proper specifications for tipple scales and other similar scales.

Such specifications have been practically completed and are nearly

ready for publication.

One hundred and twenty-nine scales were tested in Illinois. Of

this number only 21 scales, or 16.3 per cent of the total, were found to

be correct, the remaining 108 scales, or 83.7 per cent, having errors in excess of the tolerance allowed scales of this type, namely, 0.4 per

cent, or twice the tolerance allowed on track scales. This extremely

unsatisfactory percentage of accuracy emphasizes the necessity of

actively i:>rosecuting this work and the bureau intends to resume it as soon as conditions warrant.

Miscellaneous Tests of Weighing and Measuring Devices.

These tests and examinations of weighing and measuring devices

may be roughly divided into two classes, namely, those made at the

request of a State or of some department or bureau of the Federal

Government, and those made at the request of a manufacturer of

such devices. The first class includes tests on the accuracy of individual devices to determine the acceptance or rejection of equipment

purchased, or the corrections to be applied where unusual precision

is demanded, and also retests of equipment in use to determine its

fitness for continued service; in this class are also included tests of

devices in which the object is not so much to determine the accuracy

of the particular machine submitted as it is to determine the suitability of machines of that type for a particular service. Among the

inspections and tests made during the past year falling into this

gi'oup may be mentioned tlie following: Ten scales tested at Camp

Humphreys and belonging to the Quartermaster Department of the

Army; 11 dynamometers and 9 personal weighing scales tested for

the Public Health Service ; 7 dynamometers tested for the Bureau of

Markets ; motor-truck scale tested for the Navy Yard at Washington,

D. C. ; scales tested for the Post Office Department and for the Childi-en's Bureau of the Department of Labor; 4 portable weighing

devices, having a capacity of 15,000 pounds each, tested for the State

of New York (designed for weighing trucks on the highways in the

enforcement of the State road laws) ; several testing machines and

paper scales and dynamometers for other sections of the bureau, etc. The second class of tests—that is, those made at the request of a

manufactui'er—are performed for the information of the bureau and
KEPORT OF DIBECTOR OF BUREAU OF STAI^DARDS. 33

of State weights and measures officials and for the purpose of advising tlie manufacturer as to the performance of liis product and its

compliance or noncompliance with such weights and measures regulations as are applicable to it. This work is of especial importance in

that it results in raising the general character of the weighing and

measuring devices placed upon the market. Manufacturers in general have shown themselves willing and anxious to comply with the

suggestions made by the bureau and this cooperation has resulted

in benefit to all concerned. It is greatly to be regretted that the funds

available for work of this character are so limited that only a relatively small amount of it may be undertaken. During the past year,

however, it has been found possible to make very thorough inspections and tests of several types of gasoline-dispensing devices and

attachments for such devices, a meter designed to vend liquids of

various kinds, weighing scales, etc. A considerable nimiber of tests were made during the year in con- nection with tlie enforcement of the standard barrel law. on new

types of barrels to be used for cranberries and apples. The manufacturers desired to develop new types of packages to contain onehalf standard cranberry barrel and one-half standard barrel, re- spectively, and the bureau not only tested sample packages submitted

but also assisted the manufacturers in computing the dimensions

necessary to produce a package of the desired capacity.

Investigations Concerning Weights and Measures Tests and Practices.

At the request of the Fourteenth Annual Conference on Weights

and Measures the bureau conducted t\^o investigations to assist in

standardizing testing procedure. The evaporation loss from the delivery ho.se used on gasoline-dispensing devices was determined in

connection with elapsed-time tests on such devices, and also there was

developed a simple and effective field-test method to be used in test- ing fabric-measuring devices used in retail dry goods stores in

measuring cloth. Reports were rendered on both these matters to

the fifteenth annual conference.

An investigation was also started to determine the hysteresis effect

in connection with coiled steel springs such as are used in many types

of weighing scales. The preliminary work done indicated that re- sults of importance were to be anticipated from a complete investigation along these lines and it is hoped that this investigation may

be completed during the coming year.

Upon complaint from a purchaser of smokeless powder the bureau

m.ade an investigation of the methods of sale used by different manufacturers of this product. The use of the so-called bulk pound,"

which in reality was a more or less flexible unit of measure instead

of weight, was found to be practically universal among powder

manufacturers. Owing to the fact that the value of this unit was inconsistent with its nomenclature and that its use was misleading to

the purchaser, the bureau recommended that its use be discontinued.

Through concerted action by the manufacturers this was done.

A manufacturer submitted to the bureau 48 glazed kid skins, the

area of which he desired to have measured. Half of the skins were

imported and half of them were of domestic origin. It was fountl
34 EEPORT OF DIRECTOR OF BUREAU OF STAISTDARDS.

that the areas reported for the domestic skins agreed fairly closely

with those found, whereas the areas given for the skins of foreign

origin were very much greater than the areas actually found, the

difference being almost 10 per cent.

Automatic-Dial Scales.

Automatic-dial scales were made the subject of a special investigation during the past year. This type of scale is being used to an increasing extent and is daily becoming a more common and important

industrial device. In order to accumulate and add to the firsthand information and data respecting the existing condition of these

scales in service a special investigation was conducted by the

Bureau of Standards and participated in by representati^ es of

the committee on sj)ecifications and tolerances of the Annual Conference on Weights and Measures and by a railroad which was a user of a nmnber of these devices. A large number of scales Avere

examined in several different cities and the results obtained i)ermitted a good idea to be gained as to the actual conditions of scales

of this character when used for various purposes. The percentage

of scales which would pass inspection when different tolerances which

have been suggested for use in testing these scales were appl.ed

was also studied.

Grain Scales.

The past year has disclosed the fact that much remains to be done

in reference to scales used for weighing grain. However, a gradual

adjustment of ideas is being effected and it is felt that before long a general agreement based upon carefully considered data respecting

the design, use, and test of these scales will be arrived at. The bureau

is studying this problem closely and has assisted in the solution of

some of the phases of it by having a representative present at meetings of committees concerned with the subject. It is planned that a representative of the bureau make a special trip through the grain

region in the continuation of the study of the general subject. Inform.ation so gained will be incorporated in a publication outlining

the equipment required for testing grain scales which will assist in

overcoming many of the typical difficulties experienced in the field.

Railroad Depot Scales.

The bureau is cooperating in the preparation of specifications of

scales used by the railroads, such as motor-truck scales, depot scales,

warehouse scales, and the like. This work is being done by a committee which in a joint capacity represents the American Railway

Engineering Association and the American Railroad Association.

The Bureau of Standards has a representative on this committee, and

tbe committee is succeeding in di-awing up s]iecifications satisfactory

to all interests.

An important economy can be achieved without any practical

sacrifice in the choice of scales available for different weighing purposes by reducing the number of standard sizes manufactured, and

thiis ]-educing the number of patterns and the amount of stock Avhich are now required to be maintained by the manufacturers.
KEPOKT OF DIKECTOR OP BUREAU OF STANDARDS. 35

Strength Specifications for Scales.

In the design of scales strength and stiffness are important factors.

In past years the nominal capacity usually associated with a given

design of scale often bore little or no relation to its actual weighing

capacity. Through the insistence of the bureau that there be a reasonable and proper relation between the strength of a scale and its

nominal capacity, and that the capacities of scales should be based

upon sound engineering principles, much improvement has been

made in the last 10 years. Many scales now have a nominal capacity

corresponding to the actual weighing capacity where this was not the

case before. This is particularly true in reference to raili'oad track

scales.

The drafting of specifications which will serve to define the capacities of scales and the working stresses which should form the basis

of scale design are matters of fundamental importance. In scale

levers cast iron is employed in transverse bending, and this material

appears to have certain practical advantages for such use, although

it has proved to be a rather variable material in respect to strength.,

and consequently it has long been abandoned by most industi'ies in

favor of steel or other material.

The bureau is now cooperating in the study of this question of

working stresses for cast iron. Specimen levers and specially prepared test bars have been broken, and other tests have been made

under the supervision of a representative of the bureau. This work

has just been completed. The bureau is making a study of the results, and the findings will be prepared in the form of ai report

which, it is believed, will have an important bearing on problems

of scale design.

Specifications for Testing Machines.

Most testing machines, a large number of which are used in commercial and industrial laboratories, are essentially a special form of

weighing scale in which the force applied to bend or break a specimen

is weighed b}^ means of a compound-lever scale sj^stem. The subject

of the proper verification of such machines is now receiving the at- tention of many interested parties, including engineering societies, industrial and engineering concerns, railroads, schools, and other technical laboratories, and the Bureau of Standards.

The weights and measures division has already been able to make

suggestions respecting the verification of these testing machines and

to point out the undesirability of certain proposed provisions which

were about to be accepted. Since a difference of opinion prevails

among the users of testing machines as to what tolerances should be

applied, during the coming year tests will be made and information

gathered which it is expected will make possible the establishment of

tolerances for standardizing testing machines.

Precision Test of Large Capacity Scales.

Grain-hopper scales and railroad master scales of large capacity

are often necessarily tested and adjusted according to very exacting

requirements. It is generally desired to reduce the errors to but

a few poimds per 100,000 pounds. Different ideas prevail both in re- gard to methods of test and interpretation of the results obtained.
36 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

During the year a publication was issued, Technologic Paper 199.

Method for Precision Test of Large Capacity Scales," which ex- plains the procedure to be followed in testing scales with great exactness. The plan used is one which was developed by the Bureau of

Standards in the test of railroad master scales and gi'ain-hopper

scales, and represents the practical adaptation of laboratory methods

to field work.

Weighing by Substitution.

In standardizing very heavy weights at the bureau, a method of

weighing was developed whereb}^ it became possible to obtain a high

degree of accuracy m the adjustments by using a compound-lever

scale according to laboratory methods. The plan developed is applicable in a large number of cases where it is necessary to make weighings, especially of large objects, with sj^ecial accuracy, as in technical or industrial laboratories. This method of substitution weighing is

described in a publication issued during the year as Technologic

Paper 208, " Weighing by Substitution," which describes the plan

in detail.

Mathematical Character of Scale Errors.

A continued study of the nature of scale errors shows that in many

cases the errors found for large-capacity scales, such as grain-hopper scales, follow a fairly definite law which can be formulated in

mathematical terms. As soon as an agreement, expressed in definite

terms, can be reached among those interested as to just what should

be accomplished in the test and adjustment of scales, the results of

this study can be used in the fornmlation of specifications respecting

the procedure of test and the tolerances and methods of adjustments

to be observed. It has been demonstrated that up to this time certain

practices in the adjustment of grain-hopper scales have been based

upon wrong ideas, so that the supposed results were not being

realized.

Correspondence.

The bureau answers many inquiries covering a wide range of subjects related to the general field of commercial weights and measures. These inquiries come from individuals, manufacturers, newspapers,

trade associations, etc., as well as from weights.,and measures officials.

In many cases the bureau has on file information of the nature desired, but quite as often the answers to these inquiries necessitate investigations or computations of a more or less involved character.

COOPERATION WITH STATE AND LOCAL OFFICIALS IN WEIGHTS

AND MEASURES ADMINISTRATION.

General Cooperation with States.

The bureau has maintained close touch with the activities of the

various State departments of weights and measures throughout the

year and has frequently been called upon for information and advice

by officials from all parts of the country. The assistance which the

l)"ureau has been able to give has been along lines of testing methods,

iww laws or ordinances, interpretations of existing laws, regulations,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 37

specifications, and tolerances, etc. Particularly valuable have been

those opportunities when a representative of the bureau has attended

meetings of weio:hts and measui'es officials and discussed various matters relating to their work. Such State conferences at which the

bureau was represented during- the past year were held in Maine.

Massachusetts. Michigan, New Jersey, New York, Pennsylvania, and

Wisconsin.

Fifteenth Annual Conference on Weights and Measures.

The bureau has always considered one of its functions to be the

promotion of uniformity and efficiency in the administration of

weights and measures laws and regulations throughout the country.

To this end there was organized, in 1905, a

" Conference on the

Weights and Measures of the United States," and except during the

period of the war, meetings of this conference have been held annually. The • conference is an unofficial body whose membership is

made up of weights and measures officials, but its meetings and discussions are open to manufacturers and to all others who are interested in weights and measures matters. It is believed that the conference has been one of the most potent factors in the development,

in the United States, of State and municipal activity in regulating

commercial weighing and measuring and the securing of uniformity

in this regard. This has been brought about through the exchange of

ideas on the part of the officials themselves, through technical papers

presented at the conferences by various authorities on subjects affecting the work of the officials, and through the adoption by the confer- ence of model laws, specifications, tolerances, methods of test, etc.,

which are recommended for adoption by State and local jurisdictions. In other words, the conference is a clearing house for weights

and measures information of all kinds.

The fifteenth annual conference was held at the bureau May 23-26,

1922, and there was a registered attendance of over 200 delegates and

guests. Twenty-six States were represented by 111 weights and

measures officials. Included in the program were papers on leathermeasuring machines, testing of heavy capacity scales, methods of

wholesaling gasoline, serialization of type of weighing and measuring

devices, and the manufacture of precision standards of weight.

Probably the most important matters before the conference, however,

were the reports of the committee on specifications and tolerances

oh the subjects of automatic indicating scales and tolerances for

loaves of bread. Owing to their importance and the desire on the

part of the committee and the conference for further investigation,

action on both of these matters was put over to the succeeding meeting, and additional data will be secured and studied during the year.

A record of the proceedings of the conference is published each

year and this serves to place in the hands of those interested a permanent record of the papers and reports delivered and of the conclusions reached in the discussions.

Weights and Measures Laws.

A revised compilation of the weights and measures laws of the

States and of the Federal (jovernment was prepared for tlie jjrinter

in the fall of 1920, but it has not as yet been found possible to pub-
38 BEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

lish it. It is hoped that it will be possible to issue a new edition of

this work during the present fiscal year, as the last edition (issued in

1912) is no loTiger of much value on account of the large number of

changes in and additions to weights and measvires legislation, both

Federal and State.

A compilation of the weights and measures laws of the various

States is indispensable to the bureau in carrying on its work of

cooperation with and assistance to the weights and measures offi- cials in the States. The two previous editions have been a great

help to State and local officials, to manufacturers and merchants,

and to other departments of the Federal Govermnent. In the ab- sence of this publication it becomes necessary to compile special data,

which are needed from time to time by the bureau in answering cor- respondence and assisting weights and measures officials. Among

these subjects may be mentioned net-weight laws, adoption of tolerances, and specifications ; laws relating to berry baskets, hampers,

barrels, and other containers for fruits, vegetables, etc. ; laws re- lating to weights per gallon, pounds per cubic yard, definitions of the

perch, cord, etc., and similar data.

Weights Per Bushel.

A revision of Circular 10, Legal Weights (in pounds) Per Bushel,

has been commenced, the last edition having been printed in May,

1918. There is a constant demand for this publication, and it is

important that it be kept available for distribution, and fairly well

up to date. It is expected that the revision of this circular will be

completed shortly.

Foreign Weights and Measures.

Considerable information on the subject of foreign weights and

measueres has been accumulated by the bureau during a number of

years, and it has been found very useful in answering correspondence. Requests for information along this line have been more

frequent in recent years than formerly, due no doubt to the increasing interest since the war in the sale of American products

abroad. It is a field of work in which a great deal of help can be

given to American manufacturers, importers, exporters, etc. There is comparatively little literature dealing with the subject

in general, but a great deal of work has been done during the fiscal

year in bringing together (in a separate folder for each country)

letters, reports, pamphlets, etc., on the weights and measures of

each country, and in listing separately for each country various

references found in other publications, so that the general survey

of the weights and measures of a particular country may be made

with as little loss of time in searching as possible. About one thousand references on cards have been added to the index of units of

foreign weights and measures. A bibliography of the literature on

the subject is also under way.

GAUGES.

Investigation.

In cooperation with the paper section an investigation was made

of dial micrometers used in measuring thickness of paper. In addition to determining the errors in the readings of the instruments.
KEPOBT OF DIRECTOR OF BUREAU OF STANDARDS. 39

the static friction, area of contact, and contact pressure of each instrument were determined. Also a study was made of the mechanism

of each instrument to determine how many commercial instruments

could be altered as to have a standard contact pressure with a standard shape contact. The results of this investigation have been submitted for publication in a paper, "A Study of Commercial Dial

Micrometers for Measuring Paper. " An investigation of the effect of errors in pipe threads on the

strength and tightness of pipe joints has been carried on during the

past six months, .jj^pecimens representing various thread errors in

two sizes of pipe have been made and tested. Specimens for a third

size are now being made. The results, showing the relative importance of errors in pitch, angle, taper and thread form, will soon be

ready for publication.

An investigation of the suitability of stellite as a material for

plug gauges has been carried on during the year. Because of the

great resistence of this material to abrasion it was felt that a gauge

made of stellite would show long life in use. A number of plain

plug gauges of stellite were made to drawings submitted by various

manufacturers, the plugs were sent to the manufacturers, and the

rate of wear in use determined in comparision with steel gauges.

The results received up to the present time show a longer life for

stellite than for steel but the increase in life is not as great as was

anticipated.

Tests and Studies for the National Screw Thread Commission.

The torque required to make up stud jfits with dimensional interferences representing the practice of two automobile manufacturers

was determined. The data obtained in this investigation were furnished to the National Screw Thread Commission for use in establishing specifications for wrench fits. Also information was collected for this commission as to whether bolts and nuts purchased

in the usual hardware stores were within the free fit or the loose

fit class as set down by the commission. A number of studies have

also been prepared for this commission. Among these are tap drill

sizes, lead errors and tolerance on commercial taps, compilation of

table of dimensions of bolt heads and nuts, and standai'dization of

widths across flats of bolt heads and nuts. Also the section compiled

and issued a summary of answers to a question on tolerances and

allowances for machine fits issued by the American Societj^ of Mechanical Engineers committee on plain limit gauges.

Constant-Temperature Room.

During the past year the satisfactory temperature reg-ulation of

the constant temperature room for use in the test of precise end

standards has been accomplished. While the regulating device is

normally set to operate on a total temperature range of 0.05° C, between 22 and 22.5° C., nevertheless, when desired the room can be

regulated much closer than 0.5° C, also a temperature of 20° C. can

be attained.

Ordnance Gauge Shop.

Through cooperation with the War Department a small but thoroughly equipped shop is maintained at the bureau for such experi-
40 EJEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

mental work in gauge making as the War Department may have

occasion to carry on. This shop has proven very useful in the working out of new designs in gauges and gauging equipment.

Design and Construction.

In addition to design and construction necessary to carry on the

tests and investigations, a comparator was designed and built to

measure small differences in gauge blocks and for other precision

contact measurements to an accuracy of one-millionth of an inch.

The indicating principle of this comparator coi^sts of two mirrors

Avhich are rotated when the spindle of the instrument is moved. These

mirrors are inserted between the objective and eyepiece of a microscope which is used as the projection-lens system to project the image

of a cross hair on a scale in front of the observer. The rotation of the

mirrors produces an angular displacement of the beam of light so that the movement of the spindle of the instrument of one-millionth

of an inch gives a movement of the image of the cross hair of about

0.04 inch on the scale.

The Avork of the gauge shop during the past year also included the

manufacture of a series of plain gauges, representing two types of

construction made to standard proportions for both large and small

plain gauges. Also a series of adjustable thread-ring gauges were

made to illustrate the proposed standard design for this type of

gauge. In addition, a series of thread plugs and rings were made

to ilhistrate closest and loosest fit for the classes of fit adopted by

the National Screw Thread Commission. Work on 25 sets of precision gauge blocks in metric sizes has been continued as opportunity would permit.

Routine Tests of Gauges.

The following routine tests have been made

Thread gauges 238

Profile gauges 5 Precision gauge bloclcs 979

Plain gauges (plugs, rings, etc.) 1,048

Miscellaneous measuring instruments 48

Total 2,318

The total number of gauges tested during the year is considerably

less than during the preceding year when 4,200 gauges were tested.

The decrease was mainly in the number of polariscope tubes, of which

there were nearly 1,000 tested last year, and in the number of gauge

blocks submitted by one manufacturer. There has been a slight

increase in the number of gauge blocks submitted by others. Usually

these are either new sets of blocks submitted for standardization or used blocks the accuracy of Avhich is questioned. In many instances

serious errors, due to wear, have been found in such blocks.

Government Tests.

The laboratory has been called upon to make contact measure- ments of various kinds for other divisions of the bureau, in connection with their investigations, to a greater extent than in previous

A^ears. For example, the d3aiamometer laboratory in its investigation

of i^ower losses in truck transmissions for the Motor Transport Corps
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 41

was in need of information relative to errors in form and dimensions

of gears. The development of special attachments for the Sanrer

gear-testing machine made it possible to detect, locate, and measure

these errors. Also variations in diameter of a series of die drawncopper Avires were determined for the electrical division in connection with its work on standards of inductance, and a device was designed for determining the length of lever arms in a dynamometer

used in the investigation of power losses already mentioned.

A determination of the wear of gears and bearings of three truck

transmissions, which were run under similar conditions with three

kinds of lubrication, was completed during the year. .

Tests for Commercial Concerns.

The laboratory has again been called upon frequently to settle

disputes between the gauge maker and buyer as to the accuracy of

gauges. The section has also been callecl U2)on to make tests or

investigations involving contact measurements that are not strictly

gauge work. For instance, a determination was made of the relative

wear of two types of phonograph needles when run under similar

conditions.

GENERAL STANDARDIZATION WORK.

National Screw Thread Commission.

The commission, which was authorized by Congress (40 Stats., ch.

156, p. 912,. approved July 18. 1918) for the purpose of standardizing screw threads, and of which the Director of the Bureau of Standards

is chairman, has continued its work, and is now considering special

problems not covered in its original progress report. The questions

that have been given attention during the past year are: Taps, tap

drills, and wire gauges, standard dimensions for nuts, boltheads, and

wrenches; instrument threads and threads cut on brass tubing;

special threads, such as electrical fixture and fittings threads, conduit

threads, and oil-well casing threads. Good progress has been made

along these lines.

Special Committee Work.

The bureau is represented on several sectional committees under the

American Engineering Standards Committee which are engaged in

standardization work, each along a definite line. Among these may

be mentioned (a) the sectional committee on plain gauges for general

engineering work, (b) the sectional committee for the standardization and unification of screw threads, and (c) the sectional committee on bolt, nut, and rivet proportions. Of these committees the

most substantial progress has been made by (a) . Fundamental principles have been laid down, a classification of fits has been established

for machine parts, and a complete system of allowances and toler- ances has been approved by the committee and is now under detailed

consideration by designers, manufacturers, and users of gauges and

machine parts. The adoption and use of a consistent series of allow- ances and tolerances would add tremendously to the efficiency and

economy of interchangeable manufacture, and the work of this committee should prove of great practical value. The manufacturing
42 EEPORT OF DIEECTOR OF BUREAU OF STAKDAEDS.

world is not yet fully awake to the advantages of this type of

standardization, though great strides have been made within the past

few years.

Standardization of Rig Irons.

A member of the bureau visited Tulsa, Okla., to confer with the

standardization committee of the Purchasing Agents' Association

of Tulsa. Okla. The conference had been called for the purpose of

standardizing rig irons used in drilling oil wells. Manufacturers,

purchasing agents, and users of rig irons were well represented at

the conference, and very good progress was made toward rendering

the product of various manfacturers interchangeable. If this is brought about, in the case of breakage of a part, it will be possible

to replace it by a similar part from the same or an}' other manufacturer.

The bureau has agreed to outline a complete series of gauges to be

used in connection with the standardized equipment.

The standardization of rig iron should serve as a beginning of

much needed standardization of all equipment used in the oil fields,

not only in well drilling but in the storage and transportation of

oil. For example, there is now a wide variation in the threads used

on oil Avell casing. This question is being taken up by the bureau in

cooperation with the National Screw Thread Commission.

Adding Machines.

Upon the invitation of the Postmaster General, a member of the

bureau served on the committee for the standardization of adding

machines used in the Postal Service. The committee made a thorough

investigation of the construction, durability, and reliability of a number of types of adding machines, and also their adaptability

for use in the Postal Service. The conclusion of the committee was

immediately put into effect with an appreciable saving to the service.

Publications.

The following publications, relating to the work of the division

of weights and measures, have been issued during the year and may

be obtained from the Superintendent of Documents:

Eeport of tlie annual conference on weights and measures, Mis. Pub. No. 48. Graphic comparison of screw tliread pitches (H. W. Bearce), Mis. Pub. No. 49. Thermal expansion of nickel, monel-metal, stellite, stainless steel and aluminum,

(W. H. Souder and P. Hidnert), Sci. Paper No. 433. Thermal expansion of a few steels. Method for precision test of large capacity scales (C. A. Briggs and E. D. Gordon), Tech. Paper No. 199. Weighing by substitution (C. A. Briggs and E. D. Gordon), Tech. Paper No. 208. The following papers have been submitted for printing or are practically ready for submission

A study of commercial dial micrometers for measuring paper (prepared jointly

with paper section, P. L. Huston and D. R. Miller).

Tlie testing of hydrometers, Cir. No. 16 (revision).

Standard density and volumetric tables, Cir. 19 (revision).

Gas measuring instruments (H. S. Beau).

A paper prepared jointly with the ceramic division on the Cause and control

of fisli scaling of enamel (R. R. Danielson and W. H. Souder) was published

in the Journal of American Ceramic Society, August, 1921. A paper dealing witli the foriimla for computing the volume of a partially

filled lioi-izontal cylindrical i;'nk (by A. F. Beal) has been nearly completed

and will be issued in minioiv.raph form.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 43

ELECTRICITY.

The work of this division covers electrical units, standards, measuring instruments, and

methods of measurement, including electromotive force, resistance, current, inductance,

capacitance, conductivity, insulation, magnetic measurements and properties, radioactivity, radio communication, and properties and performance of electrical equipment, such as lamps and batteries. As a result of cooperation with technical societies, testing laboratories, electrical industries, public service companies, public utility commissions, municipalities, and engineers in problems of standardization, including standards of adequacy

and safety of service, some of the work has been extended to cover more than strictly electrical service. GENERAL.

Scope of Electrical Work.

One of the most important functions of the bureau is the establishment and maintenance of the fundamental standards upon which all

electrical measurements in this country are based. This includes the

intercomparison of standards, extensive research in methods of

measurement, and the development and improvement of subsidiary

and derived standards. These standards are utilized and the results

of the researches are applied in the testing of reference standards

and instruments for manufacturers, testing laboratories, universities, research institutions, electric utilities, utility commissions, engineering and other interests, and various agencies of the Government. Close contact is also maintained with similar institutions in

other countries so as to secure international uniformity.

The testing- of electrical instruments and apparatus is of two main

classes. First, the standardization of reference standards and precision instruments for manufacturing and other institutions which

themselves make or standardize instruments for commercial use or which conduct research work. It is through the work of such institutions that the measurements made in practice are referred back

to the standards of the bureau. Second, a limited amount of testing

of commercial electrical measuring instruments, radio and photometric apparatus, magnetic materials, etc., is done chiefly for the

purpose of keeping the bureau in touch with the needs of the industries, of developing methods, and of improving apparatus and

materials. The greater portion of this testing is conducted for the

Government services and serves the double purpose of providing

information to be used in formulating specifications and of determining the quality of materials furnished upon specifications.

The research work has mainly to do with methods of measurement, the determination of the electric and magnetic properties of

materials, and the development of those phases of engineering science

in which measurement plays an important role. In general, this investigational work deals with fundamental properties and principles, so that the results may be applicable to a class of problems

rather than being limited to the one specific problem under investigation. The work on correlation of magnetic and mechanical properties of iron and steel and in the study of insulating materials are examples.

The research work in radio communication, magnetism, radioactivity, and photometry is along lines quite similar to that in the more

purely electrical measurements. Standards have been and are being

developed, methods of measurements are being improved, and important special problems of significance to the industries and in a number

of cases of particular importance to the Government are being investi-
44 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

gated. Specific examples of the projects in hand diu'ing the past

year are given in the sections below.

Public Utility Investigations.

Another important activity of this division, including more of

engineering and field work than most of the electrical work referred

to above, is the investigation of problems arising in connection with

various public utilities, particularly electric light and power, gas.

street railwa3^ and telephone services. The work includes (1) scientific and engineering research. (2) the study of the conditions which

determine the quality of the public utility service of various kinds,

(3) methods of testing and inspection employed by municipalities

and commissions, (4) safety rules for use by the utility companies to

safeguard their employees and the public, and (5) the collection and

distribution of information by pul)lished papers and through corre- spondence.

This work is a natural outgrowtli of the research and testing done

by the Bui'eau of Standards for the public utility companies and

commissions. The testing of electrical instruments and meters, of

gas lamps and the standards employed in testing gas, the life testing

of electric lamps, the testing of instruments used in telephone work,

research on electrolysis mitigation, and similar investigations and

tests connected with public utilities, have all involved questions of

standards of service. The bureau has gradually accumulated a con- siderable amount of information on these questions and has been able

to contribute materially to the establishment of standards of quality

in several of these services. Furthermore, it has promoted with

marked success the practice of settling disputed questions in this field

on the basis of sound engineering and economic principles and of

cooperation between interests rather than by legal controversy, and

in so doing the bureau has attained a recognized position as an

advisor and mediator in such questions.

The establishment and enforcement of regulations for utility services of the kinds covered by the bureau's work are recognized as proper functions of State or local governments, and the bureau

neither has nor seeks any legal authority to control these services.

However, the mere determination of the facts regarding the quality

of service rendered often involves difficult technical or engineering

questions. To say what constitutes reasonably good service and

whether improvements are practicable is usually not easy. For most

cities and many State commissions it is a difficult matter to judge the

quality of serAace rendered b^^ the utilities. Obviously, it Avill never

be economical or desirable for each commission or city to handle these

questions alone. Though they possess large and able engineering

staffs or employ specialists for each separate problem, the question

of what is good service or whether the service in any given case is adequate, safe, and satisfactory can usually be settled only by refer- ence to what is done under similar circumstances elsewhere in the

country. In other words, standards of good practice and good

service are largely determined by general experience, and should

be studied comparatively using the experience of the entire country.

The bureau has been doing this for several years, and has done

enough to demonstrate the practicability and acceptability of the

method.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 45

In many States the commissions have set standards of service for

the different utilities, and most of those that have done so have been

glad to make use of the bureau's assistance. It will conduce to fair- ness and a good understanding to have the subject studied further

and to have specifications as definite and complete as possible made

available for all branches of public-utility service. The present

status of the utility vpork is summarized in the sections following

those on electrical measurements.

General Condition of the Division.

During this year, as for the past thre^i years, there has been a gradual reduction in the staff of the division, the total personnel

of all classes assigned regularl}^ to its work being 121 on June 30,

1922, as compared with 163, 148, and 128, respectively, at the close

of the three preceding years. On the other hand, the number of

changes in personnel has been relatively small in comparison with

recent years, and the slight decrease in numbers has probably l)een

more than counterbalanced by the added experience of the staff in

general. It has, however, been necessary to extend the work into

some new fields, and the amount of testing required has been very

large. Consequently there is little progress to report on much of

the fundamental work of the division. The character of the work

done in years past has given the bureau an unquestioned supremacy

, in the field of electrical measurements and has put it in position

to render service of great value to the country. Under present conditions, however, the demands for such service are so insistent that

they threaten to undermine the foundations of the work.

The bureau's earlier electrical work was largely on fundamental

problems of measurement ; the results of these researches, in order

to be of practical value, must be applied in commercial measurements and in industrial processes. To make such application possible, the bureau must calibrate laboratoiy and factory standards

and instruments, and must make tests of electrical and magnetic

materials; but all this work takes time and facilities, which have

had to be diverted from the research previously carried on. If governmental and industrial needs are to be met, the work in testing

and calibration must be given precedence, and it has now reached

a magnitude which absorbs practically all the resources of the division and precludes research.

The bureau is consequently in a dilemma. If research is neglected

the bureau can not hope to keep abreast of the needs for greater

refinement in measurements, or to maintain either its physical

standards or the caliber of its personnel. Men of large capacity

will remain on relatively low salaries if the work is stimulating

and affords opportunity for growth ; they will not remain to do

merely routine, work. On the other hand, the finest researches are not profitable unless means are provided for their application.

The only solutions for the difficult}^ appear to be either to obtain

additional support for tlie work or else definitely to abandon some

parts of it, and all parts are of such fundamental importance that

this latter course can be considered only as a last resort.
46 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

RESISTANCE MEASUREMENTS.

Routine Testing.

The demand for the testing of precision resistance standards and

resistance apparatus has been greater than for any previous year

in the history of the bureau. There has, however, been a marked

decrease in the number of tests of insulated wires and cables so that the total amount of routine testing in this section was about

the same as for the year ended June 30, 1921.

Change in Resistanec of a Conductor with Change in Its Potential.

According to a paper by Prof. H. A. Perkins, read before the

American Physical Society in April, 1921, when a conductor is at

a negative potential with respect to its surroundings there is an

abnormal number of electrons within it, and consequently its resist- ance is below normal. Likewise when a conductor is at a positive

potential with respect to surroundings there is a deficiency of electrons within it, and consequently its resistance is above normal. It

was claimed that in a particular case that the change in resistance

on changing the potential by about 10,000 volts amounted to about

1 part in 5,000.

Inasmuch as this effect if real would require modification of the

generally accepted ideas concerning metallic conductors, it seemed

advisable to in^^estigate this matter further. On repeating the

experiment under conditions such that the effect, if real, should have

been more pronounced, no change in resistance was observed, though

the apparatus used was sufficiently sensitive and sufficiently reliable to have detected a change in the resistance of about 1 part

in 5,000,000.

A short paper describing the experiment is ready for publication.

Galvanometers.

A method has been developed for producing at a distance a magnified record of mechanical motions. This method involves the use of (1) a magnet on one and a coil of insulated wire on the other

of the two parts whose relative motion is to be recorded, (2) a galvanometer which, when short-circuited, is excessively damped by

the cuiTent induced in its winding, (3) a fairly large inductance

of low resistance in parallel with the galvanometer, (4) a line con- necting the coil on the part whose motion is to be recorded to the

galvanometer, and (5) a source of light, and photographic means

for recording deflections of the galvanometer.

The inductance counteracts to a very considerable degree the lag

of the deflection of the galvanometer, due to the inertia of its moving system. In fact the inductance gives to the galvanometer an

extra period which may be very short in comparison with the

period determined by its inertia and suspension constants. Further,

the motion in this extra period may be either under damped, over damped, or critically damped.

The method is applicable in the case of motions taking place in

from 0.02 second to 20 seconds or having effective periods in this

range. It was developed particularly for use in the seismological

work referred to in a later section of this report.
1

REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 47

Fundamental Measurements of Resistance,

Work on the determination of the resistance of the bureau's re- sistance standards in ohms as distinguished from international ohms

;

that is, in terms of a unit of length and a unit of time, has been

under way during most of the year. For this work it is neces- sary to have (1) a motor which can be operated at a very constant

speed, and means for determining this speed accurately, (2) one or more self or mutual inductances so designed that their dimensions can be measured and inductances calculated accurately from the dimensions, (3) apparatus of such design and construction that the

electromotiA'e force induced in the inductances can be accurately balanced against the potential drop in a conductor whose resistance is

to be measured.

The different methods used in making such measurements have

been carefully studied and some new ones devised. One of these seems to be superior to any of the methods previously used, and has

been selected as the first of possibly two or three methods which may

be used.

Apparatus for the control and measurement of the speed of the

driving motor has been designed and the construction is nearing

completion. This apparatus will synchronize a motor with either a

!' clock or chronometer having an electrical contacting device operating once per second. Some novel features in symchronism will be

i embodied in this apparatus. The mutual inductances needed, two in

! number, are to be designed by and constructed under the supervision

of the inductance and capacitance section.

The design of the apparatus for balancing the induced electro1 motive force against the potential drop in the conductor whose re- sistance is to be determined is nearing completion.

Standard for the Conductivity of Aluminum.

Some work in cooperation with the Laboratoire Central d'Electricite, the National Physical Laboratory, and the Aluminum Co.

of America has been done toward a determination of the electrical

i properties of the aluminum used for conductor purposes. The purpose of this investigation is the establishment of an international

standard for the electrical conductivity and other properties of

aluminum as was done some years ago for copper. Samples of

aluminum conductor of American manufacture have been procured

and tested in this bureau, the Laboratoire Central d'Electricite, and

the National Physical Laboratory. Samples of French manufacture

have been procured and samples of British manufacture are expected

for use in this investigation.

The Aluminum Co. of America will cooperate at least to the extent of furnishing samples of exceptionally pure aluminum as well

( as samples of what is known as conductor aluminum.

I INDUCTANCE AND CAPACITANCE.

I Inductance and Capacitance Laboratory.

I Work in this laboratory has been so systematized that all ordinary

I tests can be handled promptly, but there is an increasing demand for

measurements of higher precision. Such measurements entail much

9644—22 5

;1
48 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

added work, since the accuracy requested is sometimes greater than

the constancy of the apparatus, and it is therefore necessary to keep

the apparatus under observation for some time.

Inductance Research.

A theoretical and experimental investigation of the effect of frequency on the inductance and resistance of single-layer coils has been

completed. It has been found that most of the existing formulas

are considerably in error. Progress has been made on the derivation of a formula for the alternating current inductance and resistance of a three-phase cable.

While this is not yet completed, it has reached a point where it is possible to indicate the limitations on the size of power cables which can

be economically used on 60-cycle current.

Capacitance Research.

A research on the determination of the capacitance and power factor of some lO-microfared paper condensers shows that there is con- siderable change in the power factor of these paper condensers with

time.

An investigation was carried on under the direction of this laboratory to determine the change of the capacitance and power factor of

some telephone condensers at low temperatures. The condensers investigated were paper and tinfoil impregnated with paraffin. Measurements were made at temperatures ranging from —40° C. to -\-25°

C. The maximum value of the capacitance occurred at about

C. At —40° C. the capacitance was about 3 per cent less. The power

factor showed a linear increase with decrease in temperature, the in- crease between -|-20 and —40° C. being about 100 per cent. The ac- tual measurements in this investigation were made by members of the

auronautic instruments section, the purpose being to determine how

much variation might be expected in apparatus used on airplanes due

to the change in temperature as the airplane ascends.

Methods of Measuring Dielectric Loss.

There have been a number of requests during the year for informa-

"

tion concerning the best methods to be used in measuring the power

loss in dielectrics subjected to alternating electromotive forces. The : problem is a varied one, since in some cases the capacitance is large i and the applied voltage relatively low, whereas in other cases the j capacitance is small and the applied voltage may be very high. Also, |i measurements are sometimes wanted over ^ wide range of frequencies. In particular, some of the large manufacturing companies

desire methods which they can use in their laboratories to make routine tests. Up to the present time the methods of different laboratories have not given consistent results. The bureau has, therefore,

begun a systematic investigation of the different methods of measuring dielectric loss. It is expected to carry this over a considerable

range of voltages and frequencies. A bridge method has been satisfactorily used in the bureau's laboratories but considerable difficulty , has been found in adapting it for use in commercial establishments.

Other methods will be tried in the near future.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 49

Properties of Insulators for Submarine Cables.

At the request of the Signal Corps of the War Department an

investigation of cable insulating materials has been undertaken,

and for several months measurements have been made at frequent

intervals of the insulation resistance, dielectric constant, and dielectric loss of samples of rubber and gutta-percha. While some conclusions have been reached, it is necessary to continue the investigation. It is hoped to try a wider range of materials.

Absolute Determination of the Ohm.

Since a resistance can be experimentally measured in terms of

inductance and time, an absolute determination of resistance can

be made if an inductance is constructed whose value can be computed from its dimensions. The inductance laboratory can make

the necessary measurements with high accuracy, the main difficulty

being the construction of the inductance coil. A number of coils

have been constructed, but as yet coils have not been made which

have the required stability. There are still a few theoretical considerations to be examined regarding the computation of the inductance, but the principal problem to be solved is the construction

of an inductance which will be permanent and which will be of such

form that its physical dimensions can be accurately measured.

ELECTRICAL MEASURING INSTRUMENTS.

Testing of Electrical Instruments.

The volume of testing of instruments for the Government was

substantially the same as during the preceding year, while that for

outside parties (public utility commissions, utility companies, and

individuals) was only 40 per cent of that for the preceding year.

Cooperation with Associations.

The section has been represented on the following committees

:

Instruments and Measurements, American Institute of Electrical

Engineers; Insulation, Engineering Division, National Research

Council ; Terminal Markings of Electrical Apparatus, Electric Power

Club Sectional Committee, under American Engineering Standards

Committee ; Unbalance Factor, Standards Committee of the American Institute of Electrical Engineers; Standard Symbols for Electrical Equipment; Sectional Committee, American Engineering

Standards Committee ; Technical Committees on " Stranding " and

on "Paper Insulation" of the Sectional Committee on Insulated

Wires and Cables.

A number of committee meetings in New York were attended. The

attention of the Instruments and Measurements Committee was called

to the progress in instrument standardization abroad. The bureau's

representative on this committee was thereupon designated as a sub-

; committee of one to make a canvass of the sentiment of American

i makers of electrical instruments. The French and German speciI fications were translated, and copies of these and of the British

I specifications were sent out to all the makers and to the members

i of the two national meter committees. This was supplemented by

I
50 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

personal conferences with the makers at their works. It is hoped

that as a result of this work a conference of makers, users, and independent authorities will be called to consider whether it is desirable to formulate American standard specifications.

A circular letter, summarizing the present confused state of definitions of " Power factor," and Unbalance " in polyphase systems,

Avas prepared and circulated by the Unbalance Factor Committee.

Discussion stimulated by this is still in progress.

Assistance was given the N. E. L. A. meter committee in the revision

of Chapter II of the Meterman's Handbook.

Federal Standard Specifications.

The chief of this section has served as chairman of the electrical

supplies conmiittee of the Federal Specifications Board. Six meetings

have been held, conferences have been held with the undenvriters'

laboratories at Chicago and New York, 10 specifications have been

recommended for adoption, and others are under consideration.

Cooperation with Manufacturers.

Assistance has been fvirnished to a number of firms in developing

improvements in their product. Such work includes : {a) Suggesting

a modification in the design of portable watt-hour meters in order

to reduce the error resulting from internal heating; (Z>) measure- ments on the effect of variations in room temperature and of voltage

on the accuracy of direct-current watt-hour meters constructed with

monel and with german silver resistors, which showed that the use

of monel reduced the errors ver}^ decidedly; (c) planning a new style

of deflection potentiometer and studying the heating errors of the

coils in the volt boxes used to extend the range of the potentiometer

(d) assisting in the development of a convenient portable apparatus

for current transformer testing based on the method described in

Scientific Paper No. 309; and (e) testing a radically new type of

current transformer to determine its possibilities, and preparing a paper for the A. I. E. E. on the subject.

Development of Apparatus.

The work on instrument standardization, mentioned above, has re- quired so much time that no progress has been made on the design

and construction of the 250-kilovolt absolute electrometer referred to

last year. It is hoped that work may soon be resumed on this project.

Some further progress has been made in standardizing the bureau's

voltage transformers, and data have been obtained to indicate their

constancy. Much work still remains to be done on this problem.

A variable resistance standard for current transformer testing,

which will materially reduce the time required for such work, has

been constructed and installed.

Ignition Apparatus.

The investigation of ignition apparatus has been continued in co- operation with the automotive section of the division of temperature

and heat, and a full report on that work is given under that sec- tion. The experiments on the sparking voltage of spark gaps in

which one electrode is decidedly hotter than the other have been con- tinued and a reoort of the results has been made to the Air Service.
REPOET OF DIRECTOR OF BUREAU OF STANDARDS. 51

MAGNETIC MEASUREMENTS.

General Magnetic Measurements.

As time and resources permit, the magnetic laboratory is gradually

extending the range of measurements Avhich it is prepared to make.

During the past year a method for testing small specimens has been

developed which is capable of giving an accuracy sufficient for most

research work on the properties of materials. This method will be

especially valuable in the study of materials of exceptional purity

which are generally available only in small quantities.

Attention has also been given to a general revision of routine test- ing methods to meet more exactly the needs of those submitting

materials for magnetic tests.

Correlation of Properties.

Many practical problems involving the relationship between the

magnetic properties of steel and other physical properties require for

their solution a knowledge of the effect of various factors on the magnetic properties. These governing factors include chemical composition, previous heat treatment, cold work, stresses, etc. During the past year a study has been made of the influence of

composition and heat treatment on the magnetic properties of a series

of iron-carbon alloys of exceptional purity. A paper presenting

the results of this investigation is nearly completed.

An investigation is now under way to determine the effect of

manganese on the magnetic properties of straight carbon steel. For

this purpose a series of \erj pure alloys of iron, carbon, and manganese has been available.

Thermomagnetic Analysis.

One of the lines of investigation hitherto almost entirely untouched

in this country is thermomagnetic analysis in which continuous observations are made of the intensity of magnetization of a specimen

during heating or cooling. By this means much can be learned of the

j structural changes which take place in steel upon heating or cooling.

Apparatus for such observations has been completed during the year

and should prove extremely valuable in the study of magnetic materials.

Magnetic Compasses.

Cooperation with the Ordnance Department, United States Army,

on the use of magnetic compasses in tanks was continued during the

year and a final report has been rendered. It has been found possible under certain conditions to use magnetic compasses with satisfactory results.

Miscellaneous Activities.

The section has cooperated with various organizations on magnetic

Ij subjects, and particularly with the committee on magnetic properties of the American Society for Testing Materials, which is completely revising its specifications for magnetic testing.
52 REPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

PHOTOMETRY AND ILLUMINATING ENGINEERING.

Calibration of Standard Lamps.

The primary functions of this section are the maintenance of the

standard lamps on which all candlepower and illumination measure- ments in the United States are based, and the provision for other

laboratories of lamps calibrated by comparison with the bureau's

refei'ence standards. The latter function has involved an unusually

large amount of work during the year. About 440 electric standard

lamps have been calibrated for research, university, and testing laboratories, and lamp factories, and, in addition, measurements have

been made on four large groups of lamps circulated among the more

important factories in order to secure greater uniformity in the results

of photometric measurements made by them. At the close of the year

there still remain on hand about 125 standards to be calibrated, and

two groups of lamps to be measured for the factory intercomparisons.

Miniature Standard Lamps.

In connection with attempts to obtain agreement on specifications

for miniature lamps (including automobile lamps) comparisons

were made last year between the candlepower and efficiency ratings

assigTied to such lamps by various factories. For this purpose a considerable number of lamps of various kinds were circulated and

measured in different laboratoi-ies. As a result it was found that

differences in the ratings assigned were as large as 10 per cent between different factories. Since that time standards have been interchanged between the different factories and between the bureau and

the factories, and a considerable improvement in uniformity has been

obtained. During the year it has developed, however, that there was

an important outstanding discrepancy in values even of lamps issued

by the bureau. This made it necessary to devote a considerable

amount of time to checking up the measurements which had been

made on miniature standards. The difficulty in establishing satisfactory values for miniature standards arises from three causes: (1)

It is uncertain how well miniature lamps may be depended upon to

maintain their values, and consequently the bureau has not felt justified in depending on miniature standards for the calibration of those

which were sent out. (2) The miniatures, especially of the automobile type, operate at very high efficiency, being comparable in this

respect to gas-filled lamps. This means that they differ very greatly

in value from the standards which are of the same order of intensity as themselves. It is therefore advisable to calibrate these miniatures

in terms of the large gas-filled standards. (3) This stepping down

in intensity from the large lamps to the small ones involves meas- urements over a wide range of candlepowei"s, calling for a precise

knowledge of the transmission of sectored disks and other devices

used in cutting down the intensity over such ranges. In the checks

which have been carried out the values for miniature standards have

been obtained in several different ways, most of which have shown

very satisfactory agreement. More recent checks between the various

factories have also agreed fairly well.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 53

Photometric Methods.

The most urgent practical problems in photometry at present are

those arising from the development of coiled-filament lamps of high

efficiency and correspondingly high temperature, which give more

nearly white light than the older lamps. Because of the irregular

arrangement of filaments these lamps can be satisfactorily measured

only in an integrating sphere, and the tendency is now to measure all

lamps in spheres, because such measurements give directly an indication of the total light output. The bureau has therefore continued to

give special attention to problems connected with sphere measurements. A paper on the general theory, construction, and use of the

sphere is now in press, and another is in preparation dealing particularly with errors arising from lack of perfect whiteness in sphere

coatings.

No general agreement has been reached regarding the methods to

be used in assigning candlepower values to lights differing in color

from the fundamental reference standards. A committee on which

the bureau is represented was appointed last year by the International

Commission on Illumination to deal with this problem, and through

this committee, as well as by direct dealings with the national laboratories of other countries, it is hoped that substantial progress can

soon be made toward a settlement of this difficulty. Pending such

a settlement the bureau is maintaining sets of reference standards

representing the three most important types; that is, carbon lamps

(the original basis of the unit) , vacuum tungsten, and gas-filled tungsten. A paper dealing with these general problems of photometry was

published in the Journal of the Optical Society for July, 1921.

Corrections for Flame Standards,

In work done at the bureau on flame standards of candlepower the

factors found to represent the effect of atmospheric humidity have

differed consistently from those found in England, particularly for

the 10-candle Harcourt pentane lamp, which is the nominal basis

of the British unit. Experimental work carried out several years ago

indicated that the cause of the discrepancy was a small temperature

effect. Recent comparisons of data obtained in England and in

Japan with that obtained at the bureau have confirmed the earlier

laboratory results, and consequently new correction factors have

been proposed. Detailed data are given in the Journal of the Optical

Society, September, 1921.

Specifications for Incandescent Electric Lamps.

A new edition of Circular 13, Standard Specifications for Lfarge

Incandescent Electric Lamps, issued during the year, marked a new

departure in the test procedure for tungsten lamps. For about 15

years electric lamps have been purchased hy the Federal Government

under specifications published in Circular 13. Progress in the art

of lamp manufacture has been so rapid that this circular has had to

be revised nine times in order to keep the specification abreast of

current developments. The original specifications covered only car- bon filament lamps. In later editions metalized carbon and tantalum

lamps were introduced and then discarded, as tvmgsten-filament

lamps gradually displaced them in use. In connection with these
54 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

radical changes in types of lamps, very great improvements were

made in the efficiency and the life required, but no fundamental

change was made in the form of the specifications or in the methods

of testing until this latest edition was prepared. The most notable

of the changes made is the abandonment of the long established provision that the life of test lamps shall be considered as ended when the

candiepower has fallen to 80 per cent of the initial value. The specification of such an end point is convenient and reasonable in the test- ing of carbon lamps, because those lamps will often burn for a long

period after they have become so blackened that they should not be

continued in use. In tungsten lamps, however, means have been

found to prevent excessive blackening of the bulbs, so that the lamps

normally burn out before their efficiency has fallen enough to justify

replacing them. The new tests are therefore based on the total life

to the time of burn out, thus conforming more nearlj^ to actual practice in the use of lamps.

The performance of the lamp throughout its life is also taken into

account through two new provisions. One of these is the evaluation

of life-test results on the basis of average efficiency throughout life,

instead of the initial efficiency; the other is a requirement that

the average light flux during the life of the lamp must not fall below

a specified percentage of the initial flux.

Tests under these new specifications are intended to give a more

complete indication of the performance of lamps than the former

specifications did, and thus to discriminate more exactly between

types of lamps. In the first application of the new specifications it was deemed wise to make the requirements moderate, and it was

recognized that for the first year the application of the new requirements should be more or less experimental. In the application of

the new specifications some difficulties have arisen with regard to

details of procedure, but on the whole the use) of the new tests

has been inaugurated with verj^ little confusion or misunderstanding. A new (tenth) edition of Circular 13 is in course of preparation, but in general its provisions for tungsten lamps will not

differ essentially from those of the ninth edition. In the new edition,

however, carbon lamps will be omitted, thus completing the transition from the early editions which included only this type.

Inspection and Life Tests of Electric Lamps Purchased by the

Government.

Government lamp orders during the preceding year were abnormally large, and it is evident that many of these were for stock,

since purchases during the current j^ear have been abnormally small,

aggregating only 1,380,000 lamps, having a total value of $420,000.

Large tungsten lamps constituted 79 per cent of the total number, being a slightly larger proportion than last year. Large carbon lamps

fell from 14.5 to 9 per cent of the total, while miniature tungstens

and carbons comprised, respectively, 10 and 2 per cent. Of the large

tungsten lamps 17 per cent were gas-filled, costing, however, 40 per

cent of the amount spent for this group. It is understood that practically no large carbon lamps will be ordered during the coming

year. They have heretofore been used on vessels of the Navy because

of their mechanical strength, but the "mill type" tungsten lamps

have now been found sufficiently strong for this purpose.
1

REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 55

Because many lamps ordered during the preceding year were delivered later, the nimiber inspected at the factories has been considerably greater than the number ordered. About 1,640,000 lamps were

so inspected, and 2,350 samples representing them were run on the

life test at the bureau. Of these 1,895 were vacuum tungsten, 180

gas-filled, and 275 carbon-filament lamps.

Automobile Headlights.

During this year the bureau has again taken up actively the problem of automobile headlight regulations particularly with a view to

the promotion of uniformity among the States so far as this is

feasible. Information regarding present laws and their enforcement

has been obtained from nearly all the States. There is still considerable diversity in the laws, and there are also important differences

of procedure in method of enforcement. In order to secure a satisfactory condition, it will be necessary to have (1) uniform laws, (2)

uniform procedure, and (3) an extensive campaign of education both

for enforcement officers and for garage men and drivers of automobiles.

So far as uniformity of legislation has been obtained, it has been

based on the specifications formulated by the committee on motor

vehicle lighting of the Illuminating Engineering Society, on which

the bureau has been represented. These specifications have been

adopted in practically the same form by nearly a dozen States. They

were based on an extensive series of road and laboratory tests and

were intended to provide for two things—(1) a reasonably good driving light and (2) the prevention of glare in the eyes of other

drivers. These specifications have been revised by the committee

during this year in order to bring them up to the requirements of the

most advanced States. The bureau has installed special equipment

for making tests in accordance with these specifications, and has been

1 regularly making tests for New York State,

il Miscellaneous Illumination Problems.

The bureau is called on by Government officers and others for advice and assistance in a great variety of problems involving illumination or its measurement. Some of these requests require considerable time. For example, instruments for measurement of light in

connection with various tests or investigations have been calibrated

for five different branches of the Government service during the year,

[|i brief surveys of illumination in two Government buildings have been

I made, samples have been tested as a basis for the choice of new luminaries for the House of Representatives Office Building, measurements

of light reflected by several metal surfaces have been made for another

! division of the bureau, and equipment for similar measurements has

been provided for the research laboratory of a manufacturer of

metal paints.

An extensive test of kerosene oils was made at the request of the

department offices in connection with the contract for oil for the

Lighthouse Service. This test led to some studies of the behavior

of the lens lanterns in which the oil was to be used, and measureii ments were also made on lenses in combination with electric lamps

I proposed as a substitute for the oil lamps.
56 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

RADIO COMMUNICATION.

Radio Research and Information.

During the past year there has been a remarkable increase in poplar interest in radio communication. This has been greatly stimulated by the fact that there has become available radio-telephone

apparatus of satisfactory performance, by means of which market

and crop reports and other news, music, and entertaiimients have been

transmitted broadcast and received by many persons. This general

interest has resulted in a large increase in the bureau's correspondence

on radio subjects. Dozens of letters asking for radio information

are received each day, and many of these are of considerable importance. In order to answer such inquiries, as well as to keep the

bureau's staff informed on current developments, it has been neces- sary to devote much time to the maintenance of a radio information

service. An unusually large number of visitors have called at the

radio laboratory, and in order to avoid continual interruption of the

regular work in progress special arrangements have been made for

demonstrating the exhibits of most general interest. Members of

the bureau have delivered a number of lectures on radio subjects.

While this necessity for maintaining an enlarged information service has had a direct deterrent effect on the research work in some re- spects, it has, on the other hand, stimulated the work on a number of

research problems and made the need for results more urgent. In addition to the bureau's general program of radio research, attention

has been given during the past year to special problems for the Air

Service, the Signal Corps, and the Department of Agriculture. The

work on the several lines of research is presented in later paragraphs.

Seven scientific papers and circulars prepared by this section have

been issued by the bureau during the year, and two other publications

were issued by other Government agencies. Twelve papers and nine

abstracts were published in outside periodicals. Five Scientific Papers and Circulars are now in press besides four papers in outside

periodicals- Eleven letter circulars were issued- Several of these

were in response to the popular demand for information on the construction and use of simple radio receiving equipment. A second

edition of " The Principles Underlying Radio Communication " was

published. Both the first and second editions of this book were prepared by the Bureau of Standards for the Signal Corps, and isnied

as Signal Corps publications. The first edition was prepared during

1918 for use in training Signal Corps personnel for radio work. The

second edition contains a considerable amount of new material, and

is nearly double the size of the first edition. It is a comprehensive

elementary textbook, and contains over 600 pages.

The Bureau of Standards has also contributed various news items

concerning radio work and publications to the " Radio Service Bulletin," a monthly periodical published hj the Bureau of Navigation

of the Department of Commerce.

Many preliminary reports on radio work of the bureau are prepared in typewritten form as laboratory reports available for distribution to technical workers who have special need for them. During

the year about 100 such reports were prepared.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 57

Electron Tubes as Generators.

Theoretical and experimental investigations were conducted on the

power output of electron-tube generators. A paper was prepared

for publication on methods of testing and rating electron-tube generators.

A special form of electron-tube generator was developed for producing sparks of high frequency for use with recording apparatus

for recording the pressure cycle in a gas engine cylinder.

Electron Tubes as Amplifiers.

Special amplifiers, using both radiofrequency and audiofrequency

amplification, were developed for particular purposes, including

direction finding, radiotelephone communication with surfboats of

the Coast Guard service and reception of material sent broadcast

by radiotelephony.

A 5-stage amplifier was developed which uses 60-cycle alternating

current to supply power for the filaments and plates, instead of the

usual storage and dry batteries. Both radiofrequency and audiofrequency amplification are used in connection with a crystal detector. This amplifier has aroused considerable interest, and is described in a paper which has been published. A special amplifier

was developed for amplifying variations in direct current, or lowfrequency alternating currents.

Radio Control.

A radio-operated relay has been developed which employs audiofrequency tuning and has been found effective for operating an

ordinary telegraph tape recorder, and for operating other mechanisms. Such a relay can be used for the remote control of mechanisms by radio. Ttie relay is rugged and highly selective, and is

very useful when moderate strays or considerable interference exists.

By proper audiofrequency tuning it has made clear tape records of

messages when interference was so severe that an experienced operator could not copy the message at all by the use of telephones.

It can be used for reception at fairly high speeds. Relays of this

type have been constructed for various applications in the Signal

Corps and other branches of the Government service.

Radiotelephony.

At the request of the Coast Guard, radiotelephone transmitting

and receiving equipment was installed on a 36-foot motor-driven

surfboat, and successful communication in both directions was

maintained during a demonstration over a distance of about 5 miles

from shore. The antenna used on the boat was a single-turn coil

antenna, of which the hull of the boat formed a part. A special

multistage amplifier was constructed for use in this work,

A scientific paper was issued describing the operation of the modulator tube in radiotelephone transmitting sets. Arc Converters.

An investigation was conducted to determine the most satisfactory'^

denaturing formula for alcohol used to supply hydrogen in the arc chamber of small arcs, and several kinds of denatured alcohol were
58 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

found which gave more satisfactory operation than ethyl alcohol,

which was used as a comparison standard.

Preliminary developments were made on a short-wave arc using

electrodes submerged in alcohol.

Direction Finding.

Improvements were made in a method of locating an airplane in

flight transmitting radio signals. Two trucks equipped with crossedcoil direction finders were used, and results of satisfactory accuracy

were obtained. Other work has been done on direction finding and

related problems for the Air Service which can not be covered in

this report.

Interference Measurement.

The rapid growth of radiocommunication has made it more important than ever that the wave sent out by a radio transmitting

station shall have such characteristics as will not interfere with waves

sent out from other stations. Interference-producing qualities of

radiotelegrajjh signals sent out by damped waves from spark transmitting stations have been studied for a number of years.

In the past few years the use of continuous waves has greatly increased. The problems of the interference-producing qualities of

such waves, modulated either by keying in telegraph transmission

or by the voice in radiotelephony, are quite different from those of

the damped waves from a spark transmitter, and require careful

study. The Paris conference of the Interallied Technical Committee

gave consideration to this problem. The bureau is making theoretical studies of the problem, Avith a view to establishing a criterion for

the interference-producing qualities of a modulated continuous wave.

Assistance was given to the radio inspection service of the Bureau

of Navigation in connection with an investigation of a spark transmitting station which was using a special type of transmitting apparatus and was causing serious interference.

Radio Fog Signaling.

A scientific paper, describing the applications of the radio direction

finder to navigation, was published during the year. A considerable

number of manufacturers, prepared to make direction finders for

installation on board ship, attended a conference with the Assistant

Secretary of Commerce, the Commissioner of Lighthouses, and the

Director of the Bureau of Standards, and expressed much active interest in the development of radio direction finding. The Bureau of

Lighthouses is installing radio beacon equipment at five additional

light stations, and direction finders are being installed on a con- siderable number of ships. The interest of shipowners in radio

direction finding is increasing. A recalibration was made during the

year of the direction finder on board the lighthouse tender fuMp,

and it was found that the calibration was substantially the same as the one taken about a year previous. A direction finder installed

on the U. S. Army transport Gamhrai was calibrated.

Radio Receiving Sets.

A comprehensive investigation has been made on the construction,

design, and performance of representative types of radio receiving
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 59

sets. The rapid. gro-ni;h of popular interest in radio h^is caused a

verj' large increase in the demand for receiving sets, and many new

manufacturers have commenced to make receiving equipment. This

investigation is, therefore, of immediate commercial importance.

Methods of testing and standards of performance have been developed for receiving sets, and publications covering various classes of

sets are in preparation. Some of this work has been conducted in

cooperation with commercial testing laboratories and retail trade

organizations.

Standardization of Radio Equipment.

The bureau has cooperated with the Institute of Radio Engineers

and the American Society for Testing Materials in the standardization of radio terminology and definitions and in the preparation of

specifications for insulating materials used in radio apparatus. Contact has been maintained with manufacturers of radio apparatus, in

order that the bureau may, so far as possible, adapt its radio work

to the needs of the industry. Information regarding available radio

apparatus has been compiled, but the vei-y rapid growth of the industry has made it impossible to keep this information up to date.

This rapid growth has made the need of standardization even more

imperative than heretofore.

The bureau has cooperated with the National Fire Protection Association in the preparation of a revised rule for radio installations

for the National Electrical code.

Interdepartment Advisory Committee on Governmental Radio

Broadcasting.

Members of the bureau represented the Department of Commerce

on the Interdepartment Advisory Committee on Governmental

Kadio Broadcasting, which considers the problems involved in the

broadcasting by radio of material emanating from various Government departments and other interdepartment phases of the radio

work of the Government.

Radiotelephony Conference.

The number of radio telephone broadcasting stations in the

United States increased very rapidly during the year. Interference

between these stations threatened to become serious, and it was found

impossible for every station to transmit according to its own convenience. The need of new laws and regulations to cover the development of radiotelephony, and broadcasting in particular, became

imperative. The Secretary of Commerce in February called a conference of radio specialists to consider the legal and technical problems of broadcasting. The experts of the bureau gave assistance to

the committees of the conference which considered technical problems.

International Conferences.

During the summer of 1921 there met at Paris representatives of

the British Empire, France, Italy, Japan, and the United States

to consider the technical problems involved in new international

agreements on radio communication which have arisen because of

many important advances since the International Radio Convention
60 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

of 1912. The chief of the radio section of the Bureau of Standards

attended the meeting of tlae committee as a delegate of the Department of Commerce.

The Conference on the Limitation of Armaments held in Washington during the past winter had the problems of communication

on its agenda. In connection with this subject two members of the

bureau served on the technical staff of the American delegation.

International Union of Scientific Radiotelegraphy.

Meetings of the International Union were held at Paris in con- nection with the meetings of the Interallied Technical Committee,

and were attended by a member of the bureau. This organization

organizes radio research on problems that are international in scope.

A number of meetings of the American section of the International

Union, of which a member of the bureau is the technical secretary,

have been held during the year.

ELECTRIC BATTERIES.

Test of Batteries.

During the fiscal year 38 tests of routine nature have been made,

comprising 554 batteries as follows : dry cells and batteries, 487 ; other

forms of primary batteries, 10; battery materials, 4; storage batteries, 53. These included tests for the Panama Canal, Department

of Commerce, Signal Corps, Quartermaster Corps, Post Office Department, General Supply Committee, Treasury Department, and

Bureau of Ordnance of the Navj^ Department. One of the most important of the tests was on starting and lighting batteries for automobile service. Seventeen different makes of batteries were submitted for a competitive test to determine their compliance with the

specifications which were prepared by this bureau, with the cooperation of manufacturers and the Society of Automotive Engineers, for

the use of the Motor Transport Division of the Army. About one- half of these different makes were found to be satisfactory. Defects

revealed by the tests were brought to the attention of the manufacturers, and in some cases they have been able to submit for retest new

batteries that comply with the specifications.

In addition to these routine tests, a number of special ones have

been made to obtain information required in writing specifications

and for miscellaneous purposes. Xhe conference for the standardization of dry cells mentioned below requested the bureau to make

certain tests to determine the performance to be required of the

standard sizes of dry batteries. The bureau accordingly obtained

676 representative samples on which a carefully planned series of

measurements has been made. One hundred and seventy-six other

batteries have been tested in connection with miscellaneous investigations. The total number of batteries tested during the fiscal year

was, therefore, 1,406.

Standardization of Dry Cells.

During the past year the standardization of dry cells and flashlight

batteries has been accomplished through the cordial cooperation

of manufacturers and large users of dry cells. A conference to consider the standardization and specifications for dry cells was held
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 61

at the Bureau of Standards December 5 and 6, 1921. This conference

was attended by representatives of the largest manufacturers, the

various Government departments, and the largest individual users of these batteries. The conference considered 17 different sizes of

dry cells, and standardized 7. It considered 30 different sizes and

kinds of flashlight batteries, and adopted 8 of these as standard. It

considered assembled batteries containing larger sizes of cells, of

which about 30 were being manufactured, and standardized 6. Two

sizes of batteries for radio apparatus were standardized also. In

addition to the standardization of sizes, the conference agreed on

general requirements of performance for the sizes which were

accepted as standard, and the bureau was requested to make tests to determine the minimum performance to be required in cases where

sufficient information was not already available. These tests are now

being made.

The bureau was also requested to revise its specifications for dry

cells to conform with the standardization adopted by the conference.

This revision has been made, and photostat copies of the specifications, showing the additions, omissions, and changes proposed, have

been sent to all members of the conference for criticism.

Circular on Dry Cells.

In 1919 the bureau issued a circular on " The Electrical Characteristics and Testing of Dry Cells," containing also specifications for

dry cells and batteries. The first edition of this circular was quickly

exhausted. The bureau has obtained much additional information

about the performance of dry cells, and a revised edition of the

circular has now been prepared. This circular summarizes the

available information on dry cells. A brief description of the materials and methods of construction and the elementary theory of the

operation of the cells is given. Various sizes and kinds of dry cells

on the market are described. The electrical characteristics of the

cells and methods of testing them are discussed. In the appendix

are given specifications for dry cells, which have been prepared by

this bureau with the cooperation of the manufacturers and principal

users of dry cells. At the close of the fiscal year the text of this

revised circular was ready to be sent to the Printing Office.

Specifications for Airplane Batteries.

At the suggestion of the Navy Department, the Bureau of Standards called a conference of storage-battery manufacturers and others

to discuss the standardization and specifications for airplane batteries.

Very large currents are required from the battery in cranking air-

. plane engines, particularly when the engines are cold, but the general

conditions of airplane service require batteries of light weight having

the maximum output. Because of the special requirements for batteries in this service, the conference designated a conunittee consisting of representatives of the Bureau of Aeronautics, Navy Department, the Air Service of the Army, and the Bureau of Standards to

consider problems relating to the rating of these batteries, the tests to be required of them, and the physical characteristics of which a knowledge is necessary in preparing adequate specifications. This

i committee is preparing a report dealing with these subjects. A com-
62 REPORT OF DIRECTOR OP BUREAU OF STANDARDS.

prehensive series of experiments has been planned to obtain information about physical performance of storage batteries under the conditions peculiar to airplane service.

Cooperation with Technical Committees.

The bureau has cooperated with the standards committee of the

American Institute of Electrical Engineers through the membership

of a bureau representative on the subcommittee for storage batteries.

The work of this committee consisted of a revision of the standard

definitions and nomenclature dealing with storage batteries. A member of the bureau's stalf was appointed conferee of the storage-battery

division of the standards committee of the Society of Automotive

Engineers. This work has been confined chiefly to standardization

of starting and lighting batteries for automobile service. The bureau

has acted as technical adviser of the battery committee of the signal

division of the American Railway Association. This committee prepared specifications for dry cells and has submitted them for adoption

by the signal division. These specifications are in conformity, both

as to requirements and tests- with the specifications prepared by the

bureau in accordance with the recommendations of the conference

on dry cells mentioned above. The bureau has given assistance to the

General Supply Committee in the matter of making awards for dry

cells and storage batteries. In some cases extensive tests have been

made especially for the Supply Committee, and the results of the

various tests made by the bureau on different kinds of batteries have

also been made available for the committee's use.

Electromotive Force of Cells at Low Temperatures.

The experiments mentioned in the report for last year have been

extended to lower temperatures because of the theoretical interest

of the problems presented. The practical importance of a knowledge of the electromotive behavior of dry cells and storage batteries

at low temperatures has arisen from their use in the Arctic and at

high altitudes. Two series of experiments have been made. In the

first of these, dry cells and storage batteries were cooled to —72° C,

and in the second to —170° C. The Gibbs-Hehnholtz equation which

deals with the thermodynamics of such cells was applied to the

observations and excellent agreement between theory and observation was found. At the lowest temperatures unusually high values

of the voltage were sometimes observed and the polarity was often

rcA'ersed. An explanation of this unusual phenomenon was found

on the basis of the Nernst equation. The experiments within the

range of -\-25° C. to —72° C. answer completely the practical questions which prompted the investigation. A publication describing

the results of these experiments has been issued.

Resistance and Potential Measurements of Dry Cells.

A study has been made of methods of measuring the internal resist- ance of dry cells and the potential relations that exist between the

positive and negative electrodes. Both the direct and alternating cur- rent methods have been employed. Measurements by direct current

do not agree with those made by alternating current even if the effects

of polarization are reduced to a minimum. The most promising
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 63

method employed has been a resonance bridge using alternating

current. By means of this bridge it has been possible to follow

the changes in resistance which take place within the cells during

the course of their discharge on various standard tests. The internal

resistance of these cells is a matter of importance since it determines

in large measure the usefulness of the cell under ordinary conditions of service. A series of potential measurements which was

made on cells during the course of their discharge was analyzed

and the results computed. It was found that valuable information can be derived from measurements of the fall in j)otential at each

electrode during the discharge. The results of these measurements,

which have an important bearing on the design and testing of dry

cells, are being prepared for publication.

Rate of Sulphation of Storage-Battery Plates.

Although numerous attempts have been made in the past to

measure the rate of sulphation of storage-battery plates no con- venient and accurate method has hitherto been devised. It is believed that this problem has now been solved hj the method of

weighing the plates when submerged in the electrolyte. It has

been possible to make accurate measurements of the local action

occurring at the positive and negative plates immersed in electrolyte

of varying concentration, provided a balance of sufficient sensitivity

is used and the temperature is maintained constant, as ma}^ be done

by using a suitable thermostat bath. This work is expected to serve as the groundwork for a more extended investigation of the

effect of impurities in storage-battery electrolytes. The experimental

work on normal plates in pure solutions has been completed and the

results are being prepared for publication.

Study of Storage-Battery Separators.

Experiments to determine the electrical resistance of storagebattery separators made of different kinds of wood and also the

resistance of these separators and the action of acid of varying

concentration have been made as the opportunity was afforded during the past year. This is part of a more general investigation to

determine the relative merits of different kinds of storage battery

separators. The experiments were incomplete at the close of the

year.

Exhibit of Foreign Dry Cells.

The bureau has obtained dry cells manufactured in Denmark,

Sweden, England, France, and Germany and has subjected these to

the standard tests such as are made on American cells. These tests

have continued throughout the year. An exhibit of foreign cells was

prepared especially for those attending the conference on dry-cell

standardization, but the exhibit has been continued as a permanent

one. A summary is being prepared showing the comparative performance of the American and the foreign cells on the various standard tests. Measurements of Current and Voltage in Starting an Airplane

Engine.

At the request of the Air Service of the Army a series of experiments was undertaken to cletermine, hj means of an oscillograph, the

964.4—22 6
64 REPORT OF DIRECTOR OF BUREAU OF STAISTDAKDR.

instantaneous values of current and voltage in the battery circuit during the cranking of a 12-cylinder Liberty airplane engine. Measurements of the current and voltage were made when the engine was at

room temperatures and at various lower temperatures down to

—29° C. Experiments were also made with different throttle

openings and with the compression released in the cylinders from 1

to 12 successively. A report summarizing the measurements and

showing the photographic reproductions of the oscillograms has been

sent to the Air Service.

RADIOACTIVITY AND X-RAY MEASUREMENTS.

Gamma-Ray Measurements of Radioactive Preparations.

The amount of gamma-ray testing has been so great that there has

been practically no opportunity for investigations in this field. Although the amount of radium tested has decreased during the last

few months, the total for the year is approximately the sarne as that

for the preceding year. Indications point to another increase in a short time. During the year gamma-ray measurements have been

made of 2,070 radium preparations containing a total of 30,397 mg,

and 17 mesothorium preparations containing a total of 1,010 mg.

This material has a market value of about $3,500,000.

The proportions attained by this work during the eight and one- half years since routine gamma-ray testing was begun are shown in

the following table:

Year. Number

of tests.

•

Equiva- | lent milli

grams of radium.

Year. Number

of tests.

Equivalent milli- grams of radium.

1914 (half year) 28

98

177 292

1,248

486

2,097

4,531 6,638

5,376

1918-1919 1,068

1,413

2, 129 2,087

13,367 25,278

35, 565 31,407

1914-1915 1919-1920 1915-1916 1920-1921 1916-1917 1921-1922

1917-1918

Because of inadequate facilities and lack of time it has been nec- essary to refuse a number of requests for tests of low-grade ores, of solutions, and of spring waters. i Work has been started, however, on the determination of radium

content by the emanation method, and it is hoped that the bureau

will soon be able to conduct such tests. Self-Luminous Materials.

The quantity of luminous material measured for brightness far

exceeded that of any previous year. Nearly all of the 2,389 tests made were on luminous tubes for various branches of the Government. On account of the large amount of this testing and also of the

gamma-ray work, there has been no opportunity to continue investigations begun several years ago.

X Rays.

X-Ray investigations have been entirely discontinued. During

the year only a few tests of protective materials have been made.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 65

ELECTROLYSIS PREVENTION.

Scope of Current Electrolysis Work.

During the year the work of the electrolysis section has comprised

four distinct phases of the subject of electrolysis and corrosion.

These include the completion of the Report of the American Committee on Electrolysis, the further development and field application of the earth current meter, the carrying out of field researches

jointly with the research subcommittee of the American Committee

on Electrolysis with the special object of studying electrolysis mitigative measures, and the investigation of soil corrosion.

Report of American Committee on Electrolysis.

This report, which is a joint report issued by the committee representing all the national associations of utility companies and the

Bureau of Standards, has been in preparation for nearly two years.

The bureau took a very active part in preparing the text of the re- port, its engineers being chairmen of two of the four committees

which prepared the report. After the text was completed the editorial work was undertaken by the bureau at the I'equest of the committee, and arrangements for printing the report were also handled

by the electrolysis section. This report was finally completed and

issued to the public in October. 1921.

Earth Current Meter.

There has been under development by the bureau for more than

two years past new methods and apparatus for making electrolysis

surveys. This has resulted in the development of the earth-current

meter, an apparatus for measuring the intensity of electric current

discharged from a pipe at any particular point, and gives a more ac- curate measure of the rate of corrosion of the pipe surface than has

heretofore been possible. During the past year some further development work was done on this apparatus, and this was supplemented by numerous field trials in Washington and near-by places.

After these had yielded satisfactory results considerable work was

done in a number of cities with the object of developing and standardizing the mode of procedure to be followed in the practical application of the method and instrument. These latter tests wei'e

carried on jointly with the research subcommittee of the American

Committee on Electrolysis. The instrument has now been developed

and standardized to a point where it meets all I'equirements in electrolysis testing, and has been adopted as the standard instrument

for both routine testing and research work by the Bureau of Standards and the American Committee on Electrolysis. The instrument

is now being introduced among utility companies for roiitine maintenance testing on pipe systems.

Work Carried on Jointly with the American Committee on Electrolysis.

For some years this bureau has been engaged jointly with the

American Committee on Electrolysis in conducting research work,

particularly with respect to uiitigative measures that may be applied
66 REPORT OF DIRECTOR OF BUREAU OF STANDARDS, M

for the prevention of electrolj^sis troubles. During the past year

the bureau carried on two extensive researches jointly with the committee, one in Atlanta and the other in New Orleans. These investigations were recently completed and reports have been prepared and

submitted to the American Committee on Electrolysis, which, in turn,

will submit them jointly with the bureau to the local utilities in the

two cities mentioned above. Further investigations of this character are contemplated during the coming year.

^ Soil Corrosion.

The problem of protecting pipes from stray currents from electric

railways has always been rendered much more difficult by the lack

of adequate information regarding the extent of corrosion of buried

pipe systems by ordinary soil influences, and the conditions under

which such corrosion may occur. Because of this difficulty it became

necessarj^ for the bureau to undertake a comprehensive research in

this field. In this investigation the Bureau of Standards has the

cooperation of the Bureau of Soils of the Department of Agriculture,

the pipe manufacturers, and the public utilities through the research

subcommittee of the American Committee on Electrolysis. Fortyfive locations have been selected as representative of the principal

types of soils to be found throughout the United States and in them

will be buried a number of samples of every kind of iron and steel

pipe in commercial use. A few pieces of pipe coated with representative pipe coatings designed to prevent soil corrosion and a few 1

pieces of lead sheath cable both plain and armored will also be buried 1

in each locality. Some of the samples will be uncovered and examined [ from time to time to determine the rate of corrosion.

| Complete data on the ph^^sical and chemical propei'ties of the soils

will be determined, and the chemical analyses of the pipes, their

microstructure, and complete metallurgical history will be determined. Extensive laboratory experiments will be conducted to determine the effects of variations in individual characteristics of both

soils and pipe materials.

Pipe owning companies and others who have metallic structures

buried in the ground experience corrosion trouble in many localities

throughout the United States, and the expense, on account of the

replacement of pipes and the leakage of water, gas, and oil, due to

corrosion of pij^es probably reaches several millions of dollars annually. On account of the pipes being buried, the extent of damage

can not readily be determined and is visually discovered only when

serious leaks develop and the gas or water appears at the surface

of the groimd or in basements of buildings.

The results of the tests should be of great value in determining the causes and importance of soil corrosion and in selecting the kind of

pipe best suited for use in any particular soil. It is expected that

data as to the relative rates of corrosion of different kinds of pipes

in the soils under observation will be obtained within 2 or 3 years,

but the experiment will probably continue over a period of 8 or 10

years. Complete sets of sj^ecimens have now been buried in about 30

of the .45 locations, and the remaining sets will be buried during the

])resent summer.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 67

SAFETY ENGINEERING AND SAFETY STANDARDS.

National Electrical Safety Code.

The bureau has been engaged for nine years in a study of the life

hazard in electrical practice and in the preparation and application

of the National Electrical Safety Code. In this work it has had

the cooperation and assistance of a large number of engineers, many

of whom are connected with the electrical operating and manufacturing companies, others being engineers and inspectors of State

commissions, municipalities, and insurance underwriters. The

various national associations connected with the electrical industry

have also cooperated effectively in this work. The importance of

having a national code uniform in all the States is generally recognized, and also the advantage of having such a code prepared and

presented by a national agency that can study the subject thoroughly

j and consult all the interests affected. The Electrical Safety Code

I consists of four principal parts, as follows

:

j 1. Rules for the installation and maintenance of machinery, switch-

' boards, and wiring in central stations and substations.

2. Eules for the construction and maintenance of overhead and

] underground lines for the transmission and distribution of electrical

j 3. Kules for the installation and maintenance of electrical ap-

! paratus and wiring in factories, residences, and wherever electricity

i is utilized for light, heat, or power.

4. Rules to be observed by operators in working on or near electrical machines or lines.

I A supplementary section includes rules for the grounding of circuits and equipment.

The bureau's thorough study of the diverse conditions under

j which electricity is generated, distributed, and utilized and of the

effect of the rules on operating and construction costs has secured

I a code which involves no unreasonable expense, but in general as- sures an. adequate measure of safety and a useful standardization of

practice. The large number of conferences held in all parts of the

j country for discussion of preliminary drafts of the code aided largely

in its development. The varying conditions in different geographical

sections and in thickly and thinly populated districts have been

given careful attention.

The code was published originally in two installments for ex1 amination and criticism—^the operating rules were published in

j August, 1914, and revised in May, 1915 ; the construction rules were

I published in April, 1915. Both operating and construction rules,

i again revised after a general conference of all interests in Chicago

' in the spring of 1916, were combined in a single volume, Circular

No. 54, which was published in November, 1916, with a recommendation for actual field trial,

i The third edition of the Electrical Safety Code was published

j under date of October 31, 1920, but was not actually issued until the

I early part of 1921. This edition is known as Handbook No. 3.

I The discussion was separated from the rules and issued as a separate

volume known as Handbook No. 4. Both the rules and the discussion have ben extensively revised and amplified, and this edition

l;
68 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

of the rules is in suitable form for adoption by State commissions,

municipalities, and other agencies having appropriate jurisdiction.

Such mandatory application of the rules is already being made,

the States of Iowa, Nevada, North Dakota, Oklahoma, Tennessee, and

Wisconsin having adopted rules based on the third edition and a number of others having them in course of preparation. Other administrative bodies had previously adopted rules comprising this code

in whole or in part, and it is generally recognized as the most complete and satisfactory standard in its field. This code has now been

approved by the American Engineering Standards Committee as an American standard.

A pictorial edition of the rules showing their application by illustrations is in course of preparation. The bureau also plans to publish a volume of engineering data on matters connected with the

rules or with overhead-line construction. These data will include

more extensive tables for the sags of conductors and will include

tables regarding the supporting structures, such as wood and concrete poles and steel towers.

Electrical Safety Conference.

The Electrical Safety Conference has been organized to promote by

cooperative action the orderly, consistent, and proper development of

practice in electrical manufacturing and installation with regard to

accident hazards. Its membership includes representatives of the

Assoc' ated Manufacturers of Electrical Supplies, the Electric Power

Club, the National Bureau of Casualty and Surety Underwriters,

Underwriters' Laboratories, and the Bureau of Standards. Detailed

standards for construction and installation of apparatus will be

worked out in harmony with the Electrical Safety Code. The con- ference has already adopted standards for industrial control equipment, rotating machinery, switchboards, and oil switches and circuit breakers. Others are in course of preparation.

Lightning Protection.

A committee has been formed to assist in the preparation of standards for lightning protection. This work will consist of three parts

(1) the protection of buildings, live stock, ships, etc.; (2) the protection of structures containing inflammable liquids and gases; and

(3) the protection of electrical lines and apparatus.

A tentative draft of rules for the protection of buildings, etc., has

been prepared and is now under consideration by the sectional committee.

Combined Electrical Code.

In 1918 a tentative draft of an electrical code relating to both fire

prevention and accident prevention in the interior wiring of buildings and the employment of electrical utilization apparatus was prepared. This consisted of the rearrangement and combination of the

rules in part 3 of the Electrical Safety Code and the rules enforced

by the fire insurance underwriters and known as the National Electrical Code. This was circulated for criticism and was the subject of

considerable comment and discussion. In the State of Oregon it was adopted by statute and has been legally enforced. During the

current year this code has been revised to conform with the 1920

editions of the two component codes.
X

REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 69

Industrial Safety Standards.

As a result of the work on the National Electrical Safety Code and

the numerous points of contact thus established with State authorities and others interested in safety work, the bureau has been called

upon to enlarge the scope of this work and to consider safety re- quirements in other than the electrical industry. In order to arrange

for more complete cooperation in this work and to insure the coordination of the efforts of all parties concerned, a conference was held at

the bureau on January 15, 1919, which was attended by more than

100 representatives of different organizations concerned with safety

standards.

On December 8, 1919, another conference on industrial safety

codes was held at the bureau and was attended by representatives of

all interests from many parts of the country. The conference voted

in favor of having safety codes prepared under the auspices of the

American Engineering Standards Committee. It also provided for

the formation of a joint safety code committee to prepare a list of

codes already in existence or urgently needed and to recommend

sponsors for preparing and revising these codes. Such a committee

was organized at the time and has since been succeeded by thfe Safety

Code Correlating Committee, upon which the bureau is represented.

Kecommendations have been made to the American Engineering

Standards Committee for a large number of safety codes and most

of the recommendations have been approved by that body.

The Bureau of Standards haSj upon invitation from the American

Engineering Standards Committee, accepted sponsorship for the

following Codes:

Electrical safety code.

Gas safety code (jo.nt sponsorship with the American Gas Association).

Code for the protect on of the heads and eyes of industrial worliers.

Combined electrical fire and safety code.

Code for protection against lightning (joint sponsorship with American Institute

of Electrical Engineers).

Safety code for logging and sawmill operations.

Safety code for aeronautics (joint sponsorship with the Society of Automotive

Engineers).

Code for the colors of traffic signals (joint sponsorship with the National Safety

Council)

.

Safety code for elevators (joint sponsorship with American Society of Mechanical Engineers and the American Institute of Architects).

A number of safety codes are being developed by sectional committees organized by other Federal bureaus and engineering societies as sponsors. The bureau is represented upon a number of these

committees and is doing active work in cooperating with such committees in the development of these codes.

Code for Head and Eye Protection.

The National Safety Code for the Protection of the Heads and

Eyes of Industrial Workers was first issued in 1921. During the

current year it has been revised and a new edition is now ready for

publication. This code states the type of protection needed in various

groups of industries and includes specifications for the goggles,

helmets, and other devices which provide such protection. It has

been generally recognized as the most authoritative work upon this

subject and has been approved by the American Engineering Standards Committee.
70 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Logging and Sawmill Code.

A rough draft of this safety code was prepared from a study of

existing requirements and the bureau's general knowledge of such

operations. Field inspections were made by members of the staff

in the Virginia woods, and later in the South as far as Louisiana, and

in New York State, Michigan, Wisconsin, and New England. As a

result of these field inspections a revised draft of this code was prepared and circulated among those interested in the subject as a tentative suggestion to be used as a basis for the complete code. Comments and criticisms upon this draft have been gathered and submitted to the sectional committee, which is cooperating in the completion of this code. Additional material has also been prepared and

it is expected to issue a complete code during the forthcoming year.

The sectional committee referred to has been organized according to

the scheme of procedure of the American Engineering Standards

Committee and contains representatives of all interests concerned

with this code.

Aeronautical Safety Code.

A sectional committee has been organized to cooperate with the

bureau and the Society of Automotive Engineers in the development

of an aeronautical safety code, which will include the requirements

for airplanes, balloons, landing fields, etc., and will specify the

qualifications for aviators, and the traffic rules to be observed in the

navigation of the air. A preliminary draft of such a code has already been prepared and has formed the basis of the committee work

upon this subject. A revised draft is in preparation and parts of it are ready for circulation for the criticism of those concerned with

this subject.

Elevator Code.

An elevator safety code has already been published by the American Society of Mechanical Engineers, members of the bureau's staff

having taken an active part in its preparation. As joint sponsor

the bureau will take an active part in the revision of this code. During the year an extensive survey of elevator conditions in the city

of Baltimore was made and assistance was given to the officials of

that city in the preparation of elevator rules which were later

adopted. Interlocking devices will be approved for use in Baltimore only after passing tests which will be conducted at the Bureau

of Standards.

GAS ENGINEERING.

Utilization of Gas.

Investigations covering utilization of gas have been continued

from last year and have formed the principal part of the gas engineering section's work. Based upon experience gained in service

investigations in several cities and on the results of laboratory work

carried on during the past two years a short circular (No. 116) was

issued entitled, " How to Get Better Service with Less Natural Gas

in Domestic Gas Appliances." It was considered so valuable by

the gas companies that a private printer has supplied 85,500 copies

to different companies. It was also reprinted in gas journals and in
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 71

several hundred newspapers in towns where natural gas is used, and

the information in it was given wide publicity by the United States

Chamber of Commerce.

In connection with an investigation conducted by the public service commission of Maryland to determine the most economic heating value standard for manufactured gas in the city of Baltimore,

the bureau conducted an extensive series of laboratory tests to determine primarily: (1) the relative utilization efficiency of gases of

different heating value ; (2) the extent to which present appliances can be adapted to give good and efficient service with gases of different heating value and composition; and (3) what adjustment in

appliances is necessary to give the consumers good and efficient service when different kinds of gases are mixed and there is a variation

in the composition, heating value, and the specific gravity of the gas.

The laboratory tests of gases varying in heating value from 300 to

600 Btu per cubic foot indicated that the usefulness for top-burner

cooking is dependent almost wholly upon the total heating value per

cubic foot. Some change in the size of orifice and air-shutter adjustment of burners is necessary to secure the best service when a material

change is made in heating value. Most existing burners can be readily

adjusted to give good service with heating values as low as 450 Btu

per cubic foot without alteration of the burners. Uniformity in heating value, specific gravity, and pressure are essential for the very

best service, yet it is practicable to adjust burners to give satisfactory

service in cities where different gases are mixed and there is considerable variation in the heating value or specific gravity.

Efficiency tests of burners were made as the distance of the utensil

from the burner was varied and the rate of consumption and adjustment of burners were changed. The products of combustion were

analyzed to determine how close a burner could be placed to a utensil

without producing carbon monoxide.

A complete report of this investigation was I'endered to the public

service commission of Maryland and is being printed as a technologic

paper of this bureau.

The increase in the price of gas, which began during the war, and

the conservation programs sponsored by public and private organizations, have brought about the invention of so-called " gas-saving "

devices to be used on top burners of gas ranges. A complete investigation has been made of the efficiency of four types of these devices and

it was found that there is practically no increase in efficiency obtained

by their use and they in no way justify the claims of economy made

by the makers. By their use the secondary air necessary for complete

combustion of the gas is excluded from the flame, which causes rapid

liberation of carbon monoxide in sufficient quantity to be a positive

menace to health. The leading gas journals are publishing the report

of this work.

As a result of the bureau's publications on design of gas burners,

manufacturers are applying the information given and some have

submitted their improved burners for test and criticism.

The section had an exhibit at the convention of the Natural Gas

Association of America held at Kansas City, Mo., in May. The exhibit showed the right and the wrong use of natural gas in domestic

gas ranges and was very effective in showing the consumer how to use natural gas more efficiently.
72 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Standards for Gas Service.

The section has continued to cooperate actively during the past

year with municipalities and State public utility commissions in the

establishment of proper standards for gas service. The suggested

rules as contained in Circular No. 32, " Standards for Gas Service,"

continue to be a model for commissions adopting standards. The

supply of the fourth edition of Circular No. 32 has been almost ex- hausted. The section dealing with State and municipal standards

now in force is being revised for the new edition.

Gas Safety Code.

The sectional committee on the Gas Safety Code, organized under

the rules of the Amei'ican Engineering Standards Committee, is practically complete. The American Gas Association, the joint sponsor on

the National Gas Safety Code, is making very good progress on the

revision and enlargement of the material in the first draft of the five

parts of the code submitted to them by the bureau.

ELECTRICAL AND RELATED SERVICE STANDARDS.

Standards for Electric Service.

For some years the bureau has been studying questions arising in

connection with specifications for electric light and power service and

the technical and engineering requirements that should be embodied

by municipalities or by State public utility commissions in the or- dinances and rules and regulations promulgated by them. Public

service commissions in 40 States and in the District of Columbia are empowered by law to ascertain and fix adequate and reasonable standards for the measurement of quality and other conditions pertaining

to the service rendered by any public utility and to prescribe reasonable regulations for examination and testing of such product or

service and for its measurement.

In 1916 the bureau's Circular 56, " Standards for Electric Service,"

which covers the field of electric service, was published. This circular

contained suggested rules for adoption by State commissions, three

model ordinances for use of cities in States where no commission

exists, or where cities have regulatory powers in addition to the State

commission, and a complete and exhaustive digest of all regulatory

rules and ordinances then in force. This circular has been out of

print for some time and a new edition is now in press.

Since the first edition was published, the States of Alabama, Arkansas, Louisiana, North Dakota, South Carolina, Tennessee, and Utah

have created new commissions or extended the jurisdiction of

existing commissions and rules and regulations are now in force in

30 of the States and the District of Columbia. The new edition of

the circular completed during the year includes the new laws, the

new and amended rules, and a discussion of the engineering features

of electric service regulation. It is, therefore, an exhaustive summary

of the technical and engineering features of electric service regulation

by commissions and municipalities.

Standards for Heating Service. •

Central-station heating, either by hot water or by steam, is technically very closely related to electric central-station operation, and
REPORT or DIRECTOR OF BUREAU OF STANDARDS, 73

in 1918 a study of the requirements of central station hot-water heating service was undertaken at the request of the public service commission of Indiana, Field investigations were made in Ohio, Indiana,

and Illinois, heating plants visited, and conferences held with operating engineers. The cordial cooperation of the educational committee of the National District Heating Association was obtained and

has been of much value. A proposed set of rules for the regulation of

central hot-water heating plants was formulated and submitted to

the Indiana commission, and after public hearing and criticism was

made the basis for the rules formally adopted by that commission.

The bureau has continued its studies of the engineering factors

entering into the quality of central-station heating, and has the manuscript of a circular on standards for central-station heating partially

prepared. This contains summaries of regulations so far adopted by

States for both steam and hot water systems and proposed rules and

regulations for commission adoption. Methods for calculating " radiation " (that is, customers' heating requirements), engineering phases

of contracts with customers, and brief suggested contracts, are included in the study. It is hoped to complete this circular during the

next fiscal year with the cooperation of the special committee of the

National District Heating Association and other associations and

engineers interested in central-station heating problems.

Street-Lighting Service.

Many requests for information are received from municipal engi- neers and city electricians with reference to street-lighting problems.

For some years the bureau has collected information, contracts, and

engineering data on street lighting and has made suggestions in

numerous street lighting negotiations between municipalities and

electric light and power companies.

Electrical Standardization.

A representative of the bureau has for some years been a member

of the standards committee of the American Institute of Electrical

Engineers. The electrical division of the bureau has several investigations under way in cooperation with the institute and there has

been the fullest cooperation throughout the year.

TELEPHONY.

Quantity and Quality of Telephone Service.

The telephone section since its organization has been engaged in

laying the necessary groundwork for the determination of standard

measures for quantity and quality of telephone service applicable

the country over. This involved the collection on a large scale of

data regarding the design and operation of all types of telephone

systems, manual, automatic and semiautomatic, and an analysis of

telephone service into elementary parts to each of which measures

are applicable.

The results of this work have been embodied in part in Circular

No. 112, entitled "Telephone Service." This circular was released

for publication late in August, 1921, when complimentary copies

were forwarded to the State commissions, to telephone engineers, and
74 REPORT OF DIRECTOR OP BUREAU OF STANDARDS.

to the electrical engineering departments of various universities.

The demand for the circular has been quite large, the third prmting

having been found necessary before the end of the year, and requests

for it are still being received.

The preparation of material for the above circular having been

completed, work was immediately begun on the determination of

the most suitable measures of quantity and quality of telephone service. Although a good start was made on this fundamentally important work, its postponement was found necessary because of a special

assignment by the Bureau of the Budget.

General Survey of the Government's Telephone Systems.

In October the Bureau of Standards was requested by the Chief

Coordinator for General Supply, acting for the Bureau of the

Budget, to make a general survey of existing telephone systems in the

various executive departments and independent establishments in

the District of Columbia, to determine whether efficient service could

not be maintained at lower cost. Since that time the bulk of the work

of the telephone section has been in connection with this survey.

Each department and independent establishment, at the instance

of the chief coordinator, appointed a representative to deal with the

bureau regarding telephone matters. These and officials of the telephone company, who have struggled for years to learn the requirements of the various Government establishments sufficiently far in

advance to meet them economically, have heartily cooperated in the

survey.

The order of procedure, briefly stated, has been to determine,

through analysis of monthly bills, the kind and quantity of facilities

now serving each unit and the cost thereof; to determine through

traffic studies the kind and quantity of equipment that would most

economically meet the actual requirements without adversely affecting the service, and to advise the representative directly concerned as

to what equipment changes, if any, should be made. During the

survey the bureau was requested on numerous occasions to assist in

special determinations requiring prompt consideration. These were,

of course, given preference over the bureau's own plans.

As a result of the survey, thus far limited to local service only,

there has been effected an actual annual economy approximating

$50,000. Nearly one-half of this sum is the direct result of the elimination of excess equipment, the consolidation of switchboards, the

rerouting of certain classes of calls, etc., all without adversely affecting the service. The balance resulted from rate reductions made

as a consequence of this survey of facilities.

Revision of the Government Supply Schedule for Telephone Service.

Inaugurated previous to the present survey but carried on in con- junction therewith, a complete revision of the supply schedule for

telephone service was made at the instance of the subcommittee on

class 20 of the General Supply Committee. The occasion for this

work arose from the fact that many items of the old schedule were

difficult to interpret. The schedule as revised and accepted by the

Supply Committee will be adopted as the Government's contract with

the telephone company for the next fiscal year. It is a systematic

arrangement of the various items, worded so as to minimize all chances of misinterpretation and numbered in a logical manner.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 75

New Billing Forms for Telephone Service.

In the course of the survey of the Government's telephone facilities

it was necessary to carefully analyze and check all bills in order to

determine the layout of the whole network, the mileages involved, the

kind and amount of facilities provided for each establishment, the

volume of service rendered, etc. The telephone company now submits its bills for local service on 40 different Government voucher

forms in addition to its own bill form which is accepted in some cases. The desirability of uniformity in the method and order of billing

the numerous service items and the resulting economy in time and

effort in checking and auditing the bills were immedin.tely apparent.

By tabulating a large number of bills item by item in accordance

with the newly assigned item numbers the frequency of occurrence of

each item was determined. Data thus obtained were used in drafting

a simple bill form, the advantages of which have been discussed with

the telephone officials, with representatives of the departments, and

with the coordinator for telephone service. It seems highly probable that all bills for local service will be rendered on identical forms

during the new fiscal year.

Tests of Coast Defense Fire-Control Equipment.

Acting for the Signal Corps, a series of tests were made on telephone equipment representative of that in use at the Coast Defense

stations to determine how best to modify the apparatus, designed for

short distances only, so as to meet the present requirements for telephone service over somewhat greater distances.

Tests of Radio Receivers at Audible Frequencies.

A large number of radio head sets, representing the product of

various manufacturers, was tested at audiofrequencies to determine

their respective electromechanical efficiencies and other fundamental

characteristics. This work was done in cooperation with the radio

section which conducted similar tests at radiofrequencies.

Circular on Telephone Transmission.

Most of the material for the proposed circular on telephone transmission has been rewritten and expanded to include a section on filter

circuits and circuits of optimum transmission. Some examples were

worked out for typical standard circuits. The use of the complex

variable and vector diagram in alternating current circuits, which

has been a subject of dispute among teachers and engineers, has been

exhaustively discussed.

Submarine Cable Problem.

The work on the problem of submarine cable signaling, set aside

during the previous fiscal year for more urgent work, was resumed

this year on a broadened basis. Siibstantial progress was made in

several of its most difficult theoretical phases. A study was made

of the relation between the mathematical methods of attack on the

cable problem developed at the bureau and those used by Continental and American research engineers.

In particular, two basic subsidiary problems, for which no satisfactory solution seems to have been obtained heretofore, have been
76 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

successfully solved. One is the determination of the natural oscillations of a cable with any receiving and sending apparatus. The

other is the solution of general circuits associated with the cable in

whicli the ordinarily fixed circuit constants are variable. Both solutions are grounded on very general processes of modem mathematical analysis, and admit of wide application to other forms of signaling circuits; as, for example, those containing microphones or audion amplifiers. This makes the solutions especially valuable in

circuit design because of the widespread use of variable elements, in

particular the vacuum tube, in electric circuits.

BALLISTICS AND OTHER SPECIAL PROBLEMS.

Cooperation with Navy Department.

The electrical method for recording short-time intervals, which

was developed in connection with ballistic measurements, has been

applied to a number of new problems. The majority of these problems have been undertaken at the request of the Navy Department,

which has furnished the necessary facilities for carrying on the inA^estigation. In each case the Bureau of Standards has designed the

necessary apparatus, has cooperated in taking the data, and has prepared a report which includes the interpretation of the data obtained.

A Study of the Variation in Gun Pressure with Time.

Improvements have been made in the electrical gauge for measuring pressures in guns, which was mentioned in last year's report.

The improved gauges have been used in several firings during the

year and valuable results have been obtained. It is hoped that this

gauge will soon be in such form that it can be made a standard test- ing apparatus at proving grounds.

Primer Explosion Times.

A report of the results obtained on a very large number of primers

in the laboratory has been submitted to the Navy Department.

These are all electrical primers and the report shows the elfect of

variations in the voltage at the time of firing the primers.

Ejection Velocities.

Measurements made at the proving grovmd show that the method

of measuring ejection velocity will give an accuracy of at least one- half of 1 per cent. This is quite sufficient for battleship work. The

bureau has been asked to consider the possibility of designing apparatus for installation on each battleship, so that velocity measure- ments can be made at any time.

Pressure in Recoil Cylinders.

Pressure gauges have been used in recoil cylinders to obtain the

rise of pressure with time. These are considerably more accurate

than the indicator diagram usually obtained, but have the disadvantage that they give a curve of pressure with time instead of a pressure-displacement curve. However, it is relatively simple to convert

these, provided a satisfactory recoil curve has been taken.
1

REPOBT OF DIRECTOR OF BUREAU OF STANDARDS. 77

Velocity of the Projectile Inside the Bore of the Gun.

An effort has been made to determine the time at which the projectile passes a given plane by observing the expansion of the gun

at that plane. This method gives considerable promise, but has not

yet reached a point where it can be definitely depended upon.

Photographs of Projectiles in Flight.

A camera capable of taking 250 pictures per second has been built

for this purpose. It is believed that this method can be used to

determine the velocity of the projectile at any part of its trajectory.

Movements and Stresses in Turrets and Turret Structures.

At the request of the Bureau of Construction and Repair, Navy

Department, the Bureau of Standards made very extensive investigations of the movements and stresses in turrets on the U. S. S.

California during gunfire. Preparations for this investigation were

under way for over a year. The apparatus was installed and the

data obtained during the month of November, 1921, by a party of

10 from this bureau. Eight oscillographs were used for recording

the motions of the turret, and two special large photographic drums

were used for recording the movements in connection with the turning gear mechanism. A large amount of auxiliary apparatus with

complicated wiring was required, and it was necessary to install a

fairly complete temporary laboratory in one of the ship's compartments. Measurements were made of the tangential, radial, and vertical motions of the turret at a number of points. In addition, measurements were made to determine the distortion of the turret foundation. Check measurements of the maximum motion and distortion

were made by mechanical methods at practically all points. MeasI urements were made to show the distortion of various parts of the

turning gear at each instant during the firing process. Curves have

j|, been plotted showing the relationship between all of these movements.

I While much has been done in the way of preparing a report, considerable time will yet be required to make a complete analysis of

j the data.

Torsional Vibrations of Crank Shafts.

At the request of the Bureau of Engineering, Navy Department,

apparatus has been designed for the measurement of torsional vibrations in crank shafts. This consists of accurately made commutators

j I placed at each end of the crankshaft so that the displacement can

!

' Ije determined at any instant. The apparatus is now being made at

the New York Navy Yard and tests on an engine will be carried out

as soon as this apparatus is completed.

Seismometry,

ji| The bureau is working in cooperation with the Carnegie Institufl tion of Washington, the California Institute of Technology, and

various other institutions in the development of a device for the study

ji of earth movements. The special requirement is that the apparatus

record fairly quick motions such as occur in the vicinity of faults in

'! action with sufficient accuracy so that from the records of near-by

I

i
78 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

stations it will be possible to locate the origin by the triangulation

method. The work of the bureau has been directed mainly along the

line of the development of a seismometer suitable for use in this particular problem. The design of a pendulum type of seismometer for

vertical motions has been completed, and it is now under construction in the California Institute of Technology. Other parts of the

apparatus have also been designed and are under construction. In

this apparatus photographic registration will be employed and the

magnification obtained will be by the electromagnetic method developed by the bureau.

Electric Telemeter. I During the past two years this section has devoted considerable

time and attention to the study of electric telemetric (remote recording) devices, more particularly with respect to their application to

reading and recording of stresses and strains in bridges and other

structural members. There has long been felt among structural

engineers an urgent need for more accurate and reliable strain gauges

than have heretofore been available, and more particularly for a

strain gauge that could be read and made to give a graphic record at

points more or less remote from the member, the strain in which is

being measured. This is true in case of a test on bridges where the

members are usually inaccessible, even for the attachment of recording apparatus. Heretofore only indicating strain gauges have been

available, and these have been adapted only to give average stresses, so that it has not been possible to measure transient stresses due to live

loading. These transient stresses are often of much greater magnitude than the average stresses, and it is therefore more important to

determine these than it is to determine average load conditions. The

telemeter strain gauge, therefore, permits one to obtain important

information that it has not been possible to secure by any means

heretofore available.

Prior to the initiation of the investigation here discussed, numerous

attempts had been made by other investigators to utilize the property

of carbon contacts in making pressure gauges and similar instruments.

Systematic attempts in this direction had been made by the War

Department and by numerous engineers interested in studying

stresses in structural members, but all of these attempts resulted

in failure. In general, three serious difficulties in all instruments

of this kind were encountered, none of which were overcome prior i to the initiation of the bureau's investigation. These difficulties were I the lack of constancy of the apparatus, resulting in frequent changes I in calibration, marked hysteresis effects, and a nonlinear relationship ) between pressures or displacements and the electrical resistance of fl the carbon contact devices. These difficulties have all been overcome

and the instrument is now on a thoroughly practical basis for a number of important lines of engineering materials testing. A number

of instruments with recorders have been built and delivered to the

aircraft section of the Bureau of Construction and Repair of the

Navy Department. A modified type of strain gauge has also been

developed in cooperation with the sound section of the bureau for the

War Department, to be used for the measurement of pressures developed in large-caliber guns when fired.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 79

During the last few months a set of these instruments has been

continuously in use in the bureau in connection with the testing of

rigid girders for dirigibles. These trials have shown that the apparatus is not only thoroughly practical and reliable, but that for

many purposes it is superior to any strain gauge heretofore available.

Members of the bureau's staff connected with this work have stated

without hesitation that it is the best strain gauge now available, and

that so far as accuracy is concerned it approaches a precision instrument.

Careful tests have also been made in the laboratory to determine

the ability of the instrument to record high frequency stresses and

transients of short duration. These tests have established conclusively that high frequency stresses running up to many hundred

cycles per second are recorded in their true proportions without

amplification or reduction, regardless of their frequencies within this

range. Transient stresses are also given their true value even though

they persist for but a few thousandths of a second.

Another form of apparatus has recently been designed and built

for measuring the stresses and stress distribution in bridges and other

large structures. This ajjparatus is now ready for use and it is ex- pected that some field researches will be made with it in the near

future.

PUBLICATIONS.

The following papers relating to the work of the electrical division, have appeared during the year among the publications of the

Bureau of Standards:

Mathematical theory of induced voltage in the high-tension magneto (F. B.

Silsbee), Sci. Paper No. 424. Standai'd specifications for large incandescent electric lamps, Circular No. 13

(ninth edition).

Operation of the modulator tube in radio telephone sets (E. S. Purington),

Sci. Paper No. 423. Some effects of the distribvited capacity between inductance coils and the

ground (G. Breit), Sci. Paper No. 427. The radio direction finder and its application to navigation (F. A. Kolster and

F. W. Dunmore), Sci. Paper No. 428. The high-frequency resistance of inductance coils (G. Breit), Sci. Paper No. 430. The field radiated from two horizontal coils (G. Breit), Sci. Paper No. 431. The construction and operation of a simple homemade radio receiving outfit,

Circular No. 120. Sources of elementary radio information, Circular No. 122. Results of a survey of elevator interlocks and an analysis of elevator accident

statistics (C. E. Oakes and .T. A. Dickinson), Tech. Paper No. 202. Design of atmospheric gas burners (W. M. Berry, I. V. Brumbaugh, G. F. Moulton, and G. B. Shawn), Tech. Paper No. 193. How to get better service with less natural gas in domestic gas appliances,

Circular No. 116. Carbon monoxide in the products of combustion from natural gas burners (I. V. Brumbaugh with G. W. .Tones, of U. S. Bureau of Mines), Tech. Paper No.

212. Electromotive force of cells at low temperatures (G. W. Vinal and F. W.

Altrup), Sci. Paper No. 434. The following mimeographed letter circulars were prepared

:

No. 36. A list of bureau publications on public utility problems.

No. 39. List of sources of elementary radio information.

No. 40. Radio publications of the Bureau of Standards.

No. 41. Extension of the Dewey decimal classification applied to radio.

9644—22 7
80 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

No. 43. Construction and operation of a very simple radio receiving equipment.

(Superseded by Circular No. 120.) No. 44. Construct'on and operation of a two-circuit radio receiving equipment

with crystal detector. (Superseded by Circular No. 121.) No. 45. Construction and operation of a simple radiotelegraphic code practice

set. No. 56. Methods of direction finding as an aid to navigation : The relative

advantages of locating the direction finder on shore and on .shipboard. No. 60. A list of publications on accident prevention and safety. No. 62. Proposed revision of rule 86 of the National Electrical Code on radio

equipment.

No. 65. Electron tube amplifier using 60-cycle alternating current to supply

power for the filaments and plates.

No. 66. List of manufacturers and sole United States distributors of radio

receiving equipment.

No. 68. The common uses of electricity.

The papers listed below have appeared in current scientific and

technical publications:

A galvanometer method for producing at a distance a magnified record of

mechanical motions (F. Wenner), Phys. Rev., 19, p. 410, 1922 (abstract).

The two-stage current transformer (H. B. Broolts, with P. C. Holtz of Sangamo

Electric Co.), Jour. Amer. Inst. Elect. Eng'rs., 41, p. 389, June, 1922. Simplified theory of the magneto (F. B. Silsbee), Nat. Adv. Comm. for Aeronautics, Report No. 123. Magnetic analysis of steel (R. L. Sanfoi'd), Amer. Machinist, 55, p. 836, 1921. Some major problems in photometry (E. C. Crittenden and J. F. SlvOgland), Jour. Opt. Soc. Amer., 5, p. 366, 1921.

Atmospheric corrections for the Harcourt standard pentane lamp (E. B. Rosa,

E. C. Crittenden, and A. H. Taylor), Jour. Opt. Soc. Amer., 5, p. 444, 1921.

A simple type of radio direction finder for use on shipboard—its application,

construction, and operation (F. W. Dunmore), Radio Service Bulletin, October

1, 1921 ; Radio News, 3, p. 588, January, 1922.

The principles underlying radio conununication (Signal Corps Radio Communication Pamphlet No. 40), book of 600 pages. Revised edition, March 23,

1922. Prepared by the Bureau of Standards.

A relay recorder for remote control by radio (F. W. Dunmore), Jour. Amer.

Inst. Elect. Eng'rs., 41, p. 310, April, 1922 ; Radio News, 4, p. 51, July, 1922.

Standard radio wavemeter. Bureau of Standards Type R70-B (R. T. Cox), Jour. Opt. Soc. Amer., 6, pp. 162-168, March, 1922. Radio Topics, 1, p. 6, January,

1922. Aviation and Wireless News, 4, p. 16, February, 1922.

Portable wavemeter for shortwave radio (S. Kruse and R. T. Cox), Q. S. T.,

5, p. 14. September, 1921.

An electron tube amplifier for amplifying direct current (H. A. Snow), Jour. Opt. Soc. Amer., 6, p. 186, March. 1922.

A high-voltage storage battery for use with electron tube generators of radiofrequencv currents (B. L. Hall and J. L. Pre.ston), .Tour. Opt. Soc. Amer., 6, p. 177, March, 1922.

The development of radiotelephone communication between lifeboats and shore

stations (F. W. Dunmore), Radio News, 3. p. 694, February, 1922.

The effective capacitv of multilayer coils with square and circular section

(G. Breit). Phil. Mag., 43, p. 963, May, 1922.

A method of measuring coil capacities and standardizing wavemeters (G. Breit),

Radio Review, 3, p. 71, February, 1922. Notation for electron tube circuits (J. H. Dellinger), Radio Review, 2, p. 454,

September, 1921.

Objects that distort radio waves (L. E. Whittemore), Radio Broadcast, 1, p. 101,

June, 1922.

Radio and timekeeping (L. E. Whittemore), Manufacturing Jeweler, 70, p. 3049,

May 25, 1922.

Calculation of inductance of circular coils of rectangular cross section (brief

abstract) (F. W. Grover), Phys. Rev., 18, pp. 136-139, August, 1921.

The high-frequency resistance of inductance coils (brief abstract) (G. Breit),

Phys. Rev., 18, p. 135, August, 1921.

Method of measuring coil capacities and standardizing wavemeters (brief ab- stract) (G. Breit), Phys. Rev., 18, p. 136, August, 1921.
REPORT OF DIRE(;T0R OF BUREAU OF STANDARDS. 81

The distributed capacity of inductance coils (tjrief abstract) {(i. Kreir), I'liys.

Rev., 18, pp. 133-135, August, 1921.

Radio signal fading plienomena (brief abstract) (J. H. Bellinger and L. B:

Wliittemore), Phys. Rev., 18, pp. 148-149, August, 1921. Tlie radio research field (brief abstract) (J. H. Bellinger and h. E. Whittemore), Phys. Rev., 18, pp. 152-153, August, 1921. Tlie design of a standard wavemeter (brief abstract) (R. T. Cox), Phys. Rev.,

18, p. 149, August, 1921.

Some physical problems of aircraft radio (brief abstract) (L. B. Whittemore),

Phys. Rev., 18, p. 149, August, 1921.

The high-frequency impedance of radio telephone receivers (brief abstract)

(C. T. Zahn), Phys. Rev., 18, p. 150, August, 1921.

The measurement of earth currents (Burton McCuUom), Elect. Ry. Jour., 58, p. 809, November 5, 1921.

The work of the Bureau of Standards in cooperation with other organizations

(M. G. Lloyd), Proc. 26th Annual Convention of International Association of

Municipal Electricians, 1921, pp. 87-9S.

Hazards in overhead construction (M. G. Lloyd), Telephony, 82, pp. 17-18,

March 4, 1922. Avoid overhead line perils (M. G. Lloyd), Telephone Engineer, 26, pp. 33-36,.

January, 1922.

Safety inspectors and inspections (J. A. Dickinson), American Machinist, December 1, 1921.

The dollars and cents value of safety (J. A. Dickinson), American Machinist,

January 5, 1921.

The fundamental principles of safeguarding (J. A. Dickinson), Proceedings

National Safety Council October, 1921.

The national logging code (J. A. Dickinson), Proc. National Safety Council,

October, 1921.

Electromotive force of cells at low temperatures (G. W. Vinal and F. W. Altrup),

Jour. Wash. Acad. Sci. 12, p. 64, February 4, 1922.

The following papers are in press

:

The magnetic susceptibility and iron content of tin red brass (L. H. Marshall

and R. L. Sanford), Tech. Paper No. 221. The testing and use of magnetic compasses for airplanes (R. L. Sanford), Part

II of Nat. Adv. Comm. for Aeronautics. Report No. 128. The theory, construction, and use of the photometric integrating sphere (E. B.

Rosa and A. H. Taylor), Sci. Paper No. 447. Tables for the calculation of inductance of circular coils of rectangular cross

section (F. W. Grover), Sci. Paper.

Note on the development of an electron tube amplifier which uses 60-cycle alter- nating current to supply power for the filaments and plates (P. D. Lowell),

Jour. Amer. Inst. Elect. Eng'rs., 41, pp. 488-490, July, 1922.

Radio-frequency amplifiers (P. D. Lowell), Sci. Paper No. 449. An electron tube amplifier using 60-cycle alternating current to supply power

for the filaments and plates (P. D. Lowell), Sci. Paper No. 450. Properties of electrical insulating materials of the laminated, phenol-methyleue

tj'pe (J. H. Dellinger and J. L. Preston), Tech. Paper No. 21(5. The construction and operation of a two-circuit radio receiving equipment with

crystal detector. Circular No. 121. A method for testing and rating electron tube generators (L. M. Hull), to appear in the procedings of the institute of radio engineers.

Recent developments in radio in the United States (J. H. Dellinger), to appear

in the Pan-American Bulletin.

The effective capacity of a pancake coil (G. Breit), to appear in the Philosophical Magazine.

Some measurements of telephone sensitivity (Helen H. Smith) to appear in the

Wireless Age. ^

Hazards of overhead line construction and methods of meeting them (M. G.

Lloyd), Proceedings of Missouri Association of Public Utilities, May 4-6, 1922.

Overhead line construction for safety (M. G. Lloyd), Proceedings of Oklahoma

Utilities Association, March 14-16, 1922.

National electrical safety code and its relation to distribution (M. G. Lloyd),

Safety Engineering, July, 1922.
82 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Elevator service and its relation to safety (J. A. Dickinson), Proceedings of

National Building Owners and Managers Association, June 19-24, 1922.

Relative usefulness of gases of different heating value and adjustments of burners for changes in heating value and specific gravity (W. M. Berry, I. V. Brumbaugh, G. F. Moulton, J. H. Eiseman, and G. B. Shawn), Tech. Paper

No. 222. TEMPERATURE AND HEAT.

The work of this division includes establishment of the standard scales of temperature

throughout the range of measurable temperatures; testing and standardization of ther- mometers, pyrometers, and other temperature-measuring instruments; determination of

specific and latent heats, heats of reaction, melting and freezing points, and other properties of materials in the determination of which precise heat and temperature measure- ments are the principal requirements; standardization of calorimeters; production and dis- tribution of standard heat and temperature samples; industrial applications of heat and

temperature measurements; determination of fundamental engineering data involving

thermal constants; determination of the fire-resistive properties of structural materials;

investigations relating to automotive power plants, fuels, and lubricants. GENERAL.

Functions of the Division.

A fundamental function of the division is the establishment, maintenance, and distribution of the standard scale of temperature from

the lowest to the highest attainable temperature. The establishment

of a satisfactory working scale covering the range of temperatures

met with in research and testing has been emphasized, although the

necessity of contributing to the fundamental data has been recognized

and some work of this kind has been and is being conducted. In the

determination of physical constants requiring precise temperature

and heat measurements, a great deal of work in precision calorimetry

has been carried out, special attention having been given during the

last few years to the measurement of the thermodynamic properties of

fluids. These investigations, while representing the highest type of

research work, yield results which find immediate application in engineering.

In recent years there has been a marked extension in the direction

of industrial and engineering applications of temperature and heat

measurements as exemplified by the investigations in industrial

pyrometry, of thermal conductivity and heat transmission of materials, investigations of the fire-resistive properties of structural materials, and the investigations of automotive power plants, fuels, and

lubricants.

THERMOMETRY.

This section is concerned with researches on the standard scale of

temperature and thermometric fixed points from the lowest attainable temperature up to about 500° C. ; maintenance of working standards within the above range ; methods of standardizing temperaturemeasuring instruments, such as liquid in glass thermometers, vaporpressure thermometers, resistance thermometers, thermocouples; the

testing and certification of temperature-measuring instruments ; and

methods of measurin^temperatures.

Clinical Thermometers.

There has been a marked change in the character of the clinical

thermometers submitted for test. While last year, over 96 per cent of

some 26,000 thermometers submitted were for veterinary use, during
BEPOKT OP DIRECTOR OF BUREAU OF STANDARDS. 83

the present year only about 10 per cent of the 15.086 submitted were

for such use. While the number tested represents a considerable de- crease as compared with last year, it shows an increase of about

12,000 thermometers intended for general medical and hospital use. The question of compulsory testing of clinical thermometers has

come up from time to time. Testing of clinical thermometers is compulsory in France, Germany, and Japan, and was in force in Great

Britain for several years. A number of the States are beginning to

show an interest in the subject, and the adoption of numerous forms of

State regulation promises to develop a very unsatisfactor}' situation.

The manufacturers and jobbers of clinical thermometers are about the

only ones who have taken an active interest in national regulation,

and their attitude, in general, is determined by business interests.

Laboratory Thermometers.

The section has cooperated with manufacturers and users of thermometers and with the American Society for Testing Materials in the

standardization of specifications for laboratory thermometers.

New Testing Regulations and Fee Schedules.

With the publication of the third edition of Circular No. 8 on the

testing of thermometers, new testing regulations and fee schedules

have been put into effect. Thermometers which are free from defects

and which are foiind correct within the tolerances established by the

bureau receive certificates, while others receive reports of test with a statement as to why certification was refused. 'V'^^iile the tolerances

set by the bureau are, in general, more liberal than those proposed

by some of the manufacturers in the preparation of specifications, the

numerous cases in Avhich thermometers were refused certification

have resulted in some dissatisfaction and a much closer scrutin}^ of

the results of the bureau's tests. In none of the cases in which results

were questioned and retests were made has it been found that reports

issued by the bureau were in error.

Tests of Pure Platinum.

The determination of the temperature coefficient of resistance is one

of the most valuable tests of the purity of platinum. Such tests were

made of a number of samples of pure material prepared in the chemistry division. The method of test was such as to minimize the introduction of strains and contamination into the wire under test. Temperature Measurement and Control.

Some time has been given to the perfection of devices for automatic

control of temperature, the construction of heating coils to meet

special requirements, and to giving adA'ice and assistance to other divisions and sections in problems involving temperature measurement

and control. Considerable improvement in automatic temperature

regulation has been made, although, in general, requirements in this

field have kept ahead of developments.

Equipment.

A number of special resistance thermometers, much smaller than

those ordinarily used, were made and are undei'going test. Additional

resistance thermometers of the types already in use were constructed.
84 BEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

A new oil bath, replacing one which had become obsolete, was installed and has proved satisfactor}'. The ventilating system was improved, and it is now possible to keep the room in which the oil baths

are installed both clean and comfortable.

HIGH TEMPERATURES.

This work includes researches on the standard scale and temperature and thermometric fixed points in the interval from 500° C. up

to the highest attainable temperature; maintenance of working

standards in the above range: standardization and distribution of

standard samples for thermometric fixed points (for example, a

series of pure metals of certified melting points) ; methods of standardization and testing and certification of pyrometers, such as thermocouples, resistance pyrometers, pyrometer galvanometers, optical pyrometers, including absorption glasses and color screens, radiation pyrometers, etc. ; physical ])roperties of materials at high temperatures, such as emissivity, monochromatic and total, specific heats,

melting points of refractories, metals, fire brick, etc. ; ionization and

radiation in gases and vapors, etc. ; industrial pyrometry ; and the

measurement of the temperatures in industrial processes.

Industrial Pyrometry.

The rare metal thermocouple, consisting of one wire of platinum

and one wire of an alloy of 10 per cent rhodium with 90 per cent

platinum, is used to such an extent in this country that a large group

of manufacturers have been interested in the life tests of these

couples, initiated last year. Formerly a large portion of the pure

metal and alloy required by the industries for thermocouple manufacture was imported from Germany. Since the war, however, practically no metal has been obtained from this source for the reason

that as good, if not better, material is now refined in both America

and England.

As a result of the bureau's investigations, one manufacturer of an

inferior grade of metal so rapidly improved his product that it is now

equal to the best obtainable in the market. The report of the tests was published in Chemical and Metallurgical Engineering and has

since been reprinted and widely distributed, one manufacturer purchasing 10,000 copies of the reprint.

Besides rendering aid in this manner to the manufacturers of

thermocouples and pyrometric apparatus, the industrial public has

been greatly benefited since reliable rare metal couples are now obtainable from every American manufacturer of pyrometric equipment. When errors of 50° C. may result, and have been encountered

in general up to the present year, because of insufficient purity of the

metals employed, the elimination of this source of error has been

appreciated by all concerned.

The demand by the industries for greater accuracy in high-temperature measurement has affected the type of research problems undertaken by this laboratory during the past two years.

.11 1
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 85

Standard Samples for Thermoelectric Fixed Points.

The work on the preparation of standard pyrometric samples,

through the agency of which the temperature scale of this bureau

is distributed to the industries, has been continued. In addition to

samples of pure tin, zinc, lead, aluminum, and copper, the bureau is preparing to issue samples of gold, palladium, and platinum with

certified melting points. These latter metals will be distributed

probably in exchange for metal of commercial purity with a service

charge of 50 per cent in weight to cover the cost of preparing pure

materials. The samples will be prepared in the form of wire. The

platinum already available is probably 99.999 per cent pure.

Research in Pyrometry.

It has become necessary to determine more accurately and to define by fixed points the " working " scale of high temperatures.

Desirable fixed points between 1,500 and 1,800° C. are the melting

points of palladium and platinum. Before this work could be at- tempted it was necessary to secure metals of the highest possible

purity, and a great amount of time has been spent, in cooperation with

the chemical and optics divisions, in preparing the materials in a

sufficiently pure state. Supposedly pure metals from various sources have differed in their melting points by as much as 2° C. The

bureau has now produced palladium and platinum of exceedingly

high purity, and preliminary work on the former indicates that the

melting point adopted by the bureau several years ago is in error by at least 5° C. It is hoped that this work will be completed during

the early part of the coming year.

In order to measure accurately the melting points of these metals

and to check their purity many new laboratory methods have been

developed.

The thermoelectric method of measuring an impurity has proven

to possess exceptional sensitivity. Platinum which shows no impurity whatever by the method of spectroscopic analysis may be satisfactorily graded by a measurement of its thermoelectric properties.

An optical pyrometer has been developed which is capable of a

precision of 0.2° C. or better at 1,500° C. This instrument is of the

standard disappearing filament type in which the errors, usually

present on account of diffraction effects, have been eliminated. A

considerable part of the past two years has been spent in the study

and testing of this instrument, which presents problems in physical optics of considerable difficulty.

Investigations in Atomic Properties.

It is becoming more and more apparent that material progress in

the development of efficient illuminants and of many important

devices involving electron emission is conditioned by a thorough

understanding of the nature of collisions between atoms and electrons.

Any contribution to our knowledge of the mechanism of radiation

and of the structure of atoms is certain to result in new applications

of value from the utilitarian standpoint. Notable examples of such

development are the Coolidge X-ray tube and the entire field of

radio-bulb design, which have been an outgrowth in the past decade

of the most academic type of research problem. This is a field of
86 REPORT OP DIRECTOR OF BUREAU OF STANDARDS.

research upon which vast sums are now being expended by the technical industries and one to which this bureau should devote much

more attention than it has been able to give in the past. At the

present time the work on atomic structure has been confined to two

or three members of the staff, whereas the opportunities in this

field well justify a section of at least 20 scientifically trained men,

with a specific appropriation of funds continued over a period of

several years. Five papers have been published during the year

and a book mentioned later is now in press.

Two papers have been published on enhanced spectra. From

theoretical considerations the ordinary arc line spectrum of an element should arise in a neutral atom, while the enhanced spectrum

should arise in an atom from which an electron has been removed.

It may be shown that if this theory is correct the amount of energy

required to excite enhanced spectra is comparatively small, and that

the enhanced lines should appear in a low voltage arc, in general,

below 50 volts. In the past it has beesn thought necessary to employ

10,000 volts or more in a spark discharge. The enhanced spectra of

magnesium, sodium, and potassium have been investigated, and it

was shown that these spectra are readily produced at precisely the

low voltage predicted by theories of atomic structure.

An extensive investigation of X rays excited by low voltage electronic impact has been published. When this work was initiated

the ultra-violet region of the spectrum had been extended to about

300A, while the longest X rays known had a wave length of about

12A. The ultra-violet region has been recently pushed to 130A,

leaving a gap to be bridged between visible light and X rays, ex- tending fronl 130 to 12A. The bureau has investigated the X rays

lying in this heretofore inaccessible region and by a new method of

measurement has observed characteristic X radiation of both gases

and solids in the interval 700 to 26A. Work of a similar character

has been carried on at Princeton University with solids, and characteristic radiation has been measured by the same general method

of as short wave-length as 12A, so that we may now consider the

great gap between visible light and X rays as satisfactorily bridged.

On account of the fact that these rays are absorbed by the air, by

glass, or by any intervening substance whatever, their therapeutic

possibilities are of no interest. However, the work is of great importance from the standpoint of atomic structure, and an extensive

development in this range of X-ray spectroscopy may be expected

in the immediate future, both in America and abroad.

A book by Paul D. Foote and F. L. Mohler, entitled " The Origin

of Spectra," has been submitted to the press. This work, which

will print to possibly 350 pages and which is illustrated by about 50

half tones and zinc etchings, will appear as a volume in the monograph series of the American Chemical Society.

HEAT MEASUREMENTS.

Measurements are made in this section over a wide range of temperatures of thermal properties of materials, such as specific heats,

latent heats, pressure-volume-temperature relations for liquids and

gases ; heats of reaction, particularly heats of_ combustion of solid,

tiquid, and gaseous fuels; and heat transmission and thermal con-
REPOBT OF DIRECTOR OF BUREAU OF STANDARDS. 87

ductivity. Work is also done on the development of calorimetric

apparatus and methods and on methods for temperature control,

pressure measurements, measurement of heat transmission, etc. Practically all of the research work of this section during the year

has been devoted to the determination of those fundamental physical

constants of materials which find application in refrigeration en- gineering.

Specific Heat of Superheated Ammonia Vapor.

An elaborate series of measurements of the specific heat of superheated ammonia vapor was completed.

The experimental equipment was specially designed and con- structed with reference to the particular requirements of this investigation, and its preparation has been in progress for the past two

years. It includes a flow calorimeter and accessory elements for ex- perimental operation and measurement. The novelty of the apparatus lies in the combination of two features, adequacy to cover the

required range of temperature and pressure, and a high degree of

accuracy in the measurments. Detailed descriptions of this apparatus and of its experimental operation form the subjects of scientific papers now in preparation.

While the phenomenon or physical process under observation is a simple one, its isolation from external disturbing influences and

control of constancy to a degree insuring accurate results is not a simple problem, and the apparatus which has led to a satisfactory

solution is extremely complicated.

The final series of measurements consisted of 90 complete experiments establishing the value of the specific heat of ammonia vapor at

85 different states in the range of temperature and pressure. The

range covered was from —16° to -j-160° C. and from one-half to 20

atmospheres pressure. The results are accurate to a small fraction

of a per cent, which is quite sufficient for engineering purposes.

While the preparation for this series of measurements has been

slow and expensive it appears to have been justified in the completeness of the results, the excellence of their quality, the certainty of

precision, and speed of experimentation. These attributes of the work

as a whole constitute an advance in the technique of calorimetry of

gases.

Specific Volume of Superheated Ammonia Vapor.

A series of measurements of the specific volume of superheated

ammonia vapor, using a constant volume gas thermometer with a monel metal bulb having a capacity of about 900 ml. was completed.

On account of absorption phenomena it Avas necessary to carry

through a second series of measurements with another bulb, having

a different ratio of area to volume. A second bulb, made of coiled

tubing, was constructed, tested, and calibrated ready to begin a series

of observations with ammonia. The data s'o far obtained cover a range of specific volumes from 85 to 1,300 milliliters per gram while

the temperature range extends from a little above saturation temperature to 4-250° C.
88 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Ammonia Tables and Mollier Chart.

The past year is a notable one in the history of the bureau's work

in heat measurements in that it marks the completion, with a minor

exception, of a series of investigations of the thermodynamic properties of ammonia, begun eight years ago. These investigations pro\dde

a basis for new, accurate, and authoritative tables of the properties

of this important refrigerant. Each of the investigations has yielded

as a result numerical values of a specific property of ammonia, and the

comjDlete series makes possible the calculation of the thermodynamic

behavior of the fluid in any cycle in which it is likely to be used as a

refrigerant. The last investigations are important as furnishing, in

the chain of mutually related quantities, the link which makes possible a test of the consistency of the whole.

Although the preparation of complete ammonia tables must await

the completion of the last of the experimental work and the careful

correlation of the whole series of measurements, as well as the evaluation of data from other sources, one set of tables has already been

issued in the form of a Mollier chart, thus making the results of the

bureau's investigations available for engineering use. The accuracy

of the chart is sufficient for all practical purposes, although allowing room for some readjustment in the final values.

The chart of thermodynamic properties thus embodies results of

actual measurements made upon ammonia of known purity, in a single laboratory, in a program of individual investigations, each

complete in itself, each planned and executed according to a high

standard of accuracy, and all extending over or beyond the range

of conditions to be encountered in practice. The data resulting from

this series of investigations have been made mutually consistent, not

so much by mutual adjustment of values or by arbitrai-y choice as by

refinement of experimental work to the point where thermodynamic

discrepancies are negligible.

The completion of the work will probably bring to ammonia the

distinction of being better known as to its thermodynamic properties

within its working range than any other substance, and the data

available appear to be sufficiently reliable to meet all possible re- quirements for many years to come.

Properties of Steam.

Interest of mechanical engineers has lately been directed to improvement of tables of the thermodynamic properties of steam, both

as to accuracy and extension of the range to keep pace with modem

steam-turbine practice. The American Society of Mechanical Engineers, by its indorsement of the report of a conference of engineers

and investigators on the subject of " Present State of Knowledge of

the Properties of Steam," has sought the cooperation of the Bureau

of Standards with several other suitably equipped institutions in a program of investigations leading to new data for the formulation

of steam tables adequate to present needs.

The jDroblem suggested as the appropriate initial work for the

Bureau of Standards was the measurement of the spedfio heai of

water. Two phases of this problem are presented. In one particular, data of greatest possible accuracy on the specific heat of water

from to 100° C. in terms of international units of energy are
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 89

Avanted to establish the fundamental heat unit to a better degree of

certainty than it is known at present. In addition, data of a precision suitable to engineerin<r purposes are wanted on the heat ca- pacity of water from 100° C. to as much higher as is practicable, as

a further basis of steam-table construction.

As a part of the preliminary survey of the problem, the theory of

saturated fluid calorimetry has been further studied, Avith the result

of more simply expressing the relations between the directly measurable heat quantities and the fundamental thermal properties of a

fluid when saturated.

The previous work in determining the liquid total heat and heat

of vaporization of ammonia has show^n the practicability and expediency of making both types of measurement in the same apparatus.

The recent further development of the theory of these processes (in

preparation for iDublication ) confirms the fact that from the experimental standpoint these two measurements, together with a third, are mutually complementary and therefore are appropriately undertaken in conjunction. Successful completion of a program of ex- perimental work so planned would lead to the direct determination

not only of fhe total heat function (E+pv) of the saturated liquid,

but also the heat of raporizat'wn^ the ratio between the specific volumes of the saturated liquid and vapor; and thus indeed, except for

the measurement of the vapor pressure and the specific volume of the

liquid, would completely establish the thermodynamic properties of

the fluid when saturated.

The instrumental equipment best suited to the three calorimetric

measurements just referred to furnishes likewise a surrounding so well adapted to the measurement of the pressure and liquid volume

that addition of supplementary means for observing these would be

an obvious possibility to be considered in the general plan of work.

The design of a calorimeter for this investigation is now in progj-ess. Because of the special nature of the problem much of the

construction is tentative until its suitability is confirmed by experiment. Several features of the design involving novelty have already

been the subjects of experiment and others are now in process of

construction.

No useful object would be served in hastily conceived measure- ments carried out in crudely designed and roughly constructed apparatus. Only by strict attention to detail and patience in its

thorough execution can calorimetric data of unquestionable reliability

be obtained. This is one of the object lessons of the previous investigations of ammonia. For this reason no definite time can be set for completion of the work.

Thermal Conductivity and Heat Transmission.

This work had been suspended during the previous year on account

of lack of personnel. The work was resumed early in the present

fiscal year, attention being given chiefly to perfecting equipment

partly completed several years ago for measurement of thermal conductivities of insulating materials at high temperatures. Installation of the apparatus and auxiliary equipment is well under way.

This equipment will be available for measuring conductivities of

insulators and refractories at temperatures up to 700 or 800° C.
90 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

In perfecting the design of this apparatus it became necessary to

obtain data on the resistance to heat flow at surfaces in contact. The

apparatus constructed for these special experiments proved to be suitable for measurements of conductivity of metals and alloys, to a moderate degree of accuracy, and it was used to measure the conductivities of a number of aluminum alloys submitted by the Air

Service of the Army.

Late in the year work was started on measurement of heat transmission in building structures. Equipment was designed or jDurchased, test specimens have been prepared, and the equipment was

practically ready for installation at the end of the year.

Preliminary designs for measurement of thermal conductivities at temperatures higher than can be used with the equipment mentioned

above, for the measurement of conductivities of metals, and for

measurement of heat transfer across air spaces have been worked

out and work on these will be carried on as rapidly as the bureau's

resources permit.

Equipment.

A new Wheatstone bridge for resistance thermometry' was received

during the year and equipped with apparatus for automatic temperature control. Two new piston gauges for precision measurement of

pressure were nearly completed in the instrument shop and improvements made in an older one. The section is now well equipped for

precision measurements of temperature, for pressure measurements

except in the lower ranges, for measurement of electric power, production of high vacuum, and the production and maintenance of con- stant temperature.

CRYOGENIC LABORATORY.

This work is concerned with the production of low temperatures

down to those of liqiiid-hydrogen (ultimately liquid helium), preparation and storage of pure gases, development of methods of producing and maintaining low temperatures, liquefaction and separation of

gases at low temperature, and special tests requiring the facilities of

the low-temperature plant.

Operation of Plant.

The plant has been operated as needed, for supplying liquid air

to meet requirements of the bureau, and, to some extent, to supph' the

needs of scientific workers outside the bureau. Repairs made during

the year have greatly increased the efficiency of the compressor.

Liquid Hydrogen.

One of the greatest difficulties in the production of liquid hydrogen

is the result of traces of impurities in the gaseous hydrogen, which

become solidified in the liquefier and clog it. The most troublesome

impurity is nitrogen, because it is not readily removed. In this labOratory liquid hydrogen was made some time ago with a liquefier, the operation of which was frequently unsuccessful and

always troublesome as the result of clogging. A new liquefier,

which is larger and more elaborate, has given even more trouble

with clogging and up to the present time has not been operated
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 91

successfully. Part of the difficulty has resulted from the fact

that the ordinary methods of gas analysis give entirely unreliable

results in the determination of one-tenth per cent or less of nitrogen

in hydrogen. A new method of analysis has just been developed

which gives quite satisfactory results and permits a careful investigation of the sources of contamination. These sources are air dissolved

in the water of the electrolytic generator, air dissolved in the oil or water used in the gas holder, air sucked in on the intake side of the

hydrogen compressor, and air not completely removed from the

equipment before hydrogen is introduced.

Experiments are also being made to find means of thoroughly re- moving from the hydrogen just before it enters the liquefier any trace

of nitrogen or other impurities that can not otherwise be avoided.

Vacuum-Insulatd Containers.

A new type of vacuum-insulated container has been developed intended to hold liquefied gases, or for other purposes requiring especially good thermal insulation. A vessel has been completed which

insulates five times as well as the best double-walled Dewar vessel

of the same capacity. One is now under construction designed to

have about 10 times the insulation efficiency of the best Dewar vessel.

FIRE-RESISTIVE PROPERTIES OF STRUCTURAL MATERIALS.

The object of the investigations on the fire-resistive properties of

! structural materials is to furnish architects, engineers, builders, State

and city building bureaus, insurance interests, and others with fundamental engineering data relative to the behavior and safety under

J fire conditions of the various types of building materials and constructions. To this end fire tests of structural materials and structural

i members are conducted; investigations are made to develop engineering data relative to the general fire-resistive featur,es of buildI ing construction ; tests are made of fire prevention and fire retarding

devices ; testing conditions and testing methods are investigated with

a view to standardization ; and recommendations are made for proper

provisions in building codes and fire codes.

Fire Tests of Brick Walls.

The program of fire tests of brick walls begun last year has been

continued and is now nearing completion. This is the initial series

of a number that it is proposed to carry out with this equipment, the

intention being to include all the wall and partition materials in common use. It was deemed advisable to introduce the tests with brick

first, because brick is a primary building material that has been in

long and universal use, and the values obtained with each thickness can be used as a standard of comparison in interpreting the results

with other materials. There is at present much demand for infor-

; mation on the fire values and stability under fire conditions of brick

I walls. Opinion as reflected in building ordinances varies greatly

relative to wall thickness requirements, and while this is due in part

j to considerations other than those relating to fire, it is thought that

I a pro]>erly planned series of fire tests will help materially to determine the minimum thickness which is safe for use.
92 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The panels are 11 feet high and 16 feet wide. They are built by a masonry contractor at a fixed price per panel, as determined by competitive bids. The series includes tests with brick made of two types

of surface clay and one shale, and also with sand-lime and Portlandcement brick. Studies have been made on the effect of changing the

cement and lime content of the mortar. The panels are either

built solidly into their containing frames to approximate conditions of restraint sometimes present in practice or they are built

free from the sides and top of the frame, some with stiffening

pilasters at the ends, to simulate conditions of use in the upper

stories of some buildings. Heat is applied to one side of the panel,

using fuel oil atomized by jets of steam or compressed air, and temperatures are measured at a number of points in the furnace as well as on the exposed and unexposed faces of the panel and at intermediate

points within it. The deflections of panel relative to the restraining

frame are measured, as also the expansion of the unrestrained panels.

The fire test is continued for six hours, provided failure does not occur earlier. Water will be applied in some of the tests after a one-hour fire exposure. Auxiliary strength tests are made of brick

and masonry.

The series consists of 30 tests of solid and hollow walls, of which

23 have been completed. The tests were planned particularly to

determine the effectiveness of the 8-inch wall, although tests of the

4-inch and 12-inch thickness are included. During the first half of

the present year some modifications in equipment, found necessarjconsequent to the tests conducted last year, were made. As a result

of the tests it can be stated that within limitations as to height and

construction details the 8-inch wall is adequate for use in exterior

walls, and also in party, division, and fire walls where the fire ex- posure is not too severe. The 12-inch thickness is apparently adequate for all uses and conditions as related to fires that ordinarily occur in budldings, although heavier thicknesses may be necessary

under some conditions from the standpoint of strength and stability.

Hollow Tile Investigation.

The investigation of the fire-resistive and other properties of

hollow building tile, conducted in cooperation with the Hollow

Building Tile Association, has been continued and tests of tile representative of the types and classes now being manufactured have

been completed. A large range in fire-resistive properties developed as between tile of different types and clays, and the present

work is concerned with effecting improvements in this respect

where needed. For this purpose tests have been made with tile made

with various percentages of burnt clay (grog) additions to the

raw clay. Panels have been built to determine the effectiveness

of plaster protections on hollow tile and further tests are proposed to determine the effect of size and shape of unit. In order to obtain more representative conditions in the fire test, the equipment

was rebuilt to accommodate a larger test panel. Provision is made

for making the fire test under working load and also with the test panel fully restrained within the frame. Equipment has been

provided for studying the weathering resistance by means of alternate freezing and thawing, in an effort to determine what relation

it has to fire resisting properties.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 98

>||||i Compressive strength and absorption determinations have been

made of all the tile used in the fire tests. In connection therewith

an investigation was made of Droper materials and nie b'vlc for use in capping tile for compresion tests, and also of the effective- ness of different methods of making absorption determinations.

The results of the latter have been prepared for publication.

Fire Tests of Concrete Columns.

A brief summary of the nature of these tests, which were con- ducted at the Pittsburgh laboratories of the bureau, together with

some of the more general conclusions, have been given in previous

reports.

Detailed descriptions of the results of this investigation have

been published in the Proceedings of the American Concrete Institute for 1918, 1919, and 1920. A complete report of the investigation will be published as a bureau technologic paper during the

coming year.

Strength of Materials at High Temperatures.

Brief descriptions of an apparatus for determining the compressive strength and elastic properties of materials at temperatures

up to 1,000° C. have been given in previous reports with notes on

results obtained in tests on structural steel, concrete, and timber.

Eeassembly and calibration of the equipment, consequent on the

'[ transfer of the bureau's Chicago activities to Washington, have

j now been completed, and it is intended to continue the work during

the coming year.

Building Codes.

A considerable amount of technical work relative to buildingcode requirements has been done in connection with the bureau's

general activity in this field. At the request of the committee

jl framing the code for residence construction, an examination was

I made of over 100 representative building codes relative to the re-

! quirements for thickness of walls of buildings of the residence

class, which were tabulated, compared, and averaged. The use of

these average values as bases for uniform requirements was dis-

. cussed and applications made to the different types of walls. The

i properties of wall materials were outlined and relations indicated

between the properties of the masonry and those of the individual units. Investigation was made of the functions of walls and

I

j critei'ia established for strength and stabilit5^

' The tentative recommendations of the committee were reviewed,

as also proposed or revised codes of a number of cities that had been

submitted for criticism. A number of conferences and committee

meetings dealing with building regulations were attended. The

building code library was brought up to date and now constitutes a

I fairly complete collection of State and city regulations.

A tentative classification of building construction Avas made from

, the standpoint of general fire resistive properties.

Safety to Life.

I! This work is concerned with building exits, inclosure of hazardous

operations, and other items relating to life hazard under fire con-
94 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

ditions in buildings. The bureau was represented on the American

Engineering Standards sectional committee on building exits, a code

for egress from school buildings being drafted.

At the request of Government units concerned with the use of

motion pictures, examination of the hazards involved in the use of the various types of projectors was made, and recommendations

submitted relative to operation and inclosure.

An investigation is being made of the fire resistance and safety

of various types of theater fire curtains.

Standardization and Interpretation of Fire Tests.

In connection with the conduct of fire tests a standard pyrometer

and mounting have been developed. The indications of this instrument are used in interpreting the time-temperature curve for fire

exposure.

An investigation has been begun of the intensity and duration of

fires in buildings, such data being necessary in order to properly

apply the results of fire tests to the various types of buildings and

occupancies. Examination of several buildings after fire has been

made, the severity of the fire being judged by the effects on the materials exposed and the fusion of glass, metals, and alloys. A building is being constructed that will be fitted up to simulate typical

occupancies, and burnt out, measurement of temperature being made

at a number of points, as also observation of effects in building

materials and devices.

Miscellaneous Fire Resistance Activities.

At the request of Treasury officials, an investigation was made of

the cause of a recent fire on the roof of the Treasury Building, runs being made under representative conditions with the equipment

thought to have caused the fire. Tests were conducted of the fire resistance of concrete chimney

blocks, at the request of the engineer department of the District of

Columbia.

Investigation was made of an underground fire that had partly

destroyed the foundations imder a large industrial plant.

Response to frequent requests for information on the fire resistance or fire hazard of materials and constructions were made where

it could be done without undue experimentation or research.

Ground was cleared and leveled for the erection of test structures

and furnaces included in the program of work that should be undertaken within the coming few years.

AUTOMOTIVE POWER PLANTS, FUELS, AND LUBRICANTS.

This work includes the investigation of fundamental problems of

a scientific and technical nature arising in connection with the design, operation, and testing of internal combustion engines and their

accessories as applied to automotive purposes, and the qualities and

characteristics of fuels, lubricants, etc., used in such power plants

and accessories. Much of the work has been conducted in close co- operation with the military branches of the Government and with

the National Advisory Committee for Aeronautics. Many investigations are sponsored directly by the engineering division of the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 95

Air Service, McCook Field, Ohio, the motor transport division of the

Quartermaster Corps of the Army, or by the Bureau of Aeronautics

of the Navy Department, and are supported in whole or in part by

funds transferred from their appropriations under the terms of the

appropriation statutes. In such cases results are reported direct to

sponsor and their publication is under its supervision.

Altitude Laboratory.

In the vacuum chambers, which simulate pressure and temperature conditions of flight, tests have been made of two engines, a 300-

horsepower aircraft engine, the Packard 1237, and a 300-horsepower

dirigible engine, the Packard 1551. The former engine was tested

for the engineering division of the Air Service, and the latter for

the Bureau of Aeronautics of the Navy Department. The test for

the Army was made in accordance with the standard altitude laboratory test of engines outlined by the engineering division and previously followed in tests of the German Maybach and B. M. W., and

the American Liberty and Hispano-Suiza engines. The program of

tests followed in the case of the Navy engine was quite comprehensive and that department has requested similar tests on a number of

engines during the coming year. The results of both series of tests

have been reported to the departments requesting this work.

An aneroid type of automatic air fuel ratio control has been deli veloped and calibrated. This work was done on a 300-horsepower

Wright aircraft engine mounted in the altitude chamber. The re- sults were reported to the engineering division of the Army Air

Service for whom the work was done.

\ A series of indicator cards has been taken on an engine when

j operating under a wide variety of conditions typical of those met

j with in flight up to altitudes of about 25,000 feet. It is believed that

1 this series of cards is the most complete ever obtained on an aviation

I engine. This work was carried out under the auspices of the engineering division of the Army Air Service and a report of the results

1 has been submitted to them.

The investigation of the effect of changes in compression ratio on

aircraft engine performance has been continued and a report will be

prepared during the ensuing year.

Ignition.

Ignition problems have been handled jointly by this and the electrical division of the bureau and a portion of the work is described

I in the report of that division.

Tests have been made on a number of spark plugs and attachments

I to be used with them for various Government departments, municipalities, and, in special cases, for manufacturers.

Work is well under way on a series of measurements of the rate of

combustion of mixtures of permanent gases ignited by sparks of

different electrical quality. The results obtained so far give no eviI dence of any effect on the rate of combustion by even extreme variaj tions in the energy in the igniting spark.

An investigation has been made of the liability of spark plugs to

discharge over the outer surface of the insulator when used under

I conditions paralleling those in a supercharged engine at extremely

9644—22 8
96 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

high altitudes. This investigation was carried out under the auspices

of the engineering division of the Air Service and the results have

been submitted to them.

A compilation has been made of data now available on the voltage

required to produce a spark under the various conditions of pressure,

temperature, etc., met with in the cylinders of internal-combustion

engines. This has been supplemented and the more important conclusions checked by a considerable number of measurements. The re- sults of this work have been reported to the engineering division of

the Air Service, for whom the work was done.

During some engine tests the engineering division of the Air Service

found that the widening of a spark plug gap apparently decreased

the tendency of the plug to preignite. The bureau was asked to investigate the causes for this behavior. The results of a series of tests indicated that an increase in the gap Avidth of some spark plugs would

cause the spark to occur at a different place in the plug and would

thus reduce the effective spark advance. A report on this work

has been submitted to the engineering division.

Carburetion.

Several methods for the inherent control of the fuel-air ratio supplied by aircraft carburetox-s have been tentatively tried out. An

informal report on this work has been submitted to the engineering

division, by whom this investigation was requested. It is hoped that

the possibilities and limitations of these methods can be more completely determined during the coming year.

A short investigation has been made of the effect of changes in the

viscosity and density of fuels on the metering of carburetors. A

report on this work will be prepared during the ensuing year.

An investigation has been started of the differences in the fuel-air

ratios supplied by carburetors when steady and pulsating air streams

pass through them. A report giving the preliminary results obtained

in this investigation is in preparation for submission to the engineermg division of the Air Service, under whose auspices this work is

being done.

An investigation of the disintegration of liquid jets into drops and

the transportation of the drops by a moving air stream is in progress.

In connection with an investigation of the performance of car- buretors and intake manifolds, with a view to increasing the fuel

mileage of motor cars, apparatus has been devised for the measure- ment of the performance of engines in cars while being driven on

the road. This apparatus gives synchronous records of (1) rate of

fuel consumption; (2) car acceleration : (3) car speed; (4) relative

air speed; (5) intake manifold pressure; (6) rate of air consumption

of the engine; (7) inlet water temperature; (8) outlet water temperature; (9) engine oil temperature; (10) transmission oil temperature; (11) differential oil temperature, (12) air temperature, and

(13) fuel temperature. By its use it should be possible to obtain

data of great value to the automotive industry. A description of this

apparatus has been presented before the Society of Automotive En,"-i- neers.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 97

Fuels.

An investigation has been made to determine the most satisfactory

benzol-gasoline blend for use as a fuel in a conventional type of aircraft engine having a compression ratio of 6. This involved an estimation of the supply of benzol available, its corrosive properties, the

freezing point of benzol-gasoline blends, as well as the metering

characteristics of carburetor's and the performance of an engine when

using these blends as a fuel. The Bureau of Mines cooperated in this

investigation by preparing an estimate of the benzol available, and

assisted in the determination of the corrosive properties of a number

of samples. A report covering the results of this investigation and

including recommended specifications for a fuel blend has been

submitted to the Bureau of Aeronautics of the Navy Department,

under the auspices of which the investigation was conducted.

The tendency of a fuel to detonate is of great importance in the

determination of its suitability for use in high-compression engines.

An analysis based on the work of many experiments has been incorporated in a technical note titled " The Background of Detonation,

and published by the National Advisory Committee for Aeronautics.

From a considerable amount of miscellaneous information obtained

incidental to the investigations in the altitude laboratory, it has become apparent that fuel conforming to the present United States

Government specifications for aviation gasoline may be so volatile as to form vapor locks in the gasoline, thus making it impracticable

for use in a gravity-feed fuel system. This question is being further

investigated, and the results will be placed before the Interdepartmental Committee on Petroleum Specifications.

An investigat'on to determine the effect of definite changes in fuel

volatility on the mileage obtained with motor vehicles in service has

been conducted in cooperation with the Post Office Department. The

results of this work have been presented before the Society of Automotive Engineers in a paper now in press. A further investigation

on this subject is under way in cooperation with the Society of Automotive Engineers, the American Petroleum Institute, and the National Automobile Chamber of Commerce.

A short investigation of the effect of slight changes in the method

of gasoline distillation as described in specifications has been made

and reported to the Interdepartmental Committee on Petroleum

Specifications.

Internal Combustion Engine Lubrication.

The greater proportion of the lubrication work of the section has

been carried out under the auspices of the eng'neering division of

the Air Service. These investigations, which are in progress, are outlined in the following paragraphs.

(1) The development of apparatus and the methods of manipulation for the more ready use and standardization of the Waters oxidation test. This test promises to be one of the most important means

of specifying satisfactory oils for internal-combustion engines.

(2) The investigation of the relations between the values obtained

from the present " cold test," and more direct measurements of plasticity at low temperatures for application in predicting the rate at
98 REPORT OF DIRECTOR OF BUREAU OF STAXDAKDS.

which oils will flow into the suction of engine oil pumps under se- vere winter conditions.

(3) The investigation of the friction losses in standard types of en- gine bearings with oils of varjdng characteristics under the severe condition of heavy loads and low speeds.

(4) The investigation of the action of lubricants under very high

unit pressures, such as are encountered in ball bearings and gear

teeth.

(5) The development of a method for the examination of finished

lubricating oils by means of vacuum distillation and the examination

of the properties of the several oil fractions so obtained.

As none of these investigations have been completed, no reports

have been prepared; but a report covering all the engine tests on

lubricants so far conducted at the bureau has been forwarded to the

engineering division of the 'Air kService.

In addition to the above work a large number of special examinations of oils have been made for various departments of the Government.

Cooling Problems.

Under the auspices of the engineering division of the Air Service,

an investigation was initiated to determine the ratio of power dissipated as heat by air-cooled engine cylinders to the power losses

chargeable to their cooling fins. Only preliminary results had been

obtained when the request for the investigation was withdrawn by

the engineering division.

The cooling characteristics of several types of aircraft radiators

have been measured as a continuation of work in previous years. A

summary of the investigations at the bureau relative to aircraft

radiators, which was compiled during the fiscal year 1921, was sent

to press during the current year.

During the current year the radiator-test plant was moved to new

quarters and extended in capacity.

A mathematical analysis of thermal conduction in the fins of aircooled engine cylinders was completed and submitted to the en- gineering division of the Air Service. Although this report is a detailed mathematical treatment of the subject, a series of graphic

charts are included which are so arranged as to avoid all necessity

for reference to laborious mathematics and can serve as a guide for

the designing engineer. This report is being published by the National Advisory Committee for Aeronautics.

An investigation has been started having as its object the determination of methods for the measurement of the distribution of air

flow in the several tubes of a honeycomb radiator and around the

fins of air-cooled engine cylinders. This work, which is being car- ried on under the auspices of the National Advisory Committee for

Aeronautics, has not yet been completed.

Automobile Brake Linings.

The investigation of brake-lining materials begun two years ago

at the request and with the assistance of the motor transport division,

Quartermaster Corps, has been continued.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 99

The extensive preliminary Avork necessary for developing a snitahle method of testing these materials has been continued and considerable data of value obtained.

The tentative recommendations for test equipment and methods

of test made by the bureau in the previous year have been modified

in details.

While much remains to be done, the following has been accomplished : (1) General agreement in the industry on the value of a standard

method for testing brake linings.

(2) Very wide differences in performance have been shown to

exist between the various brake linings on the market, although sold

to the ultimate consumer at the same price for a given size.

(3) Manufacturers whose production totals probably 90 per cent

of the gross output, have been led to give much thought to the improvement of their product and are availing themselves of the methods and equipment so far developed by the bureau. The admittedly

more or less haphazard methods previously employed are giving wav

to systematic investigations.

(4) A very marked increase in durability has been found in the

product of many manufacturers compared with their standard product of a year ago.

(5) Branches of the Government service are basing their purchases

of brake linings on the bureau's tests and it is believed that the re- sulting saving to the Government will be considerable.

Service tests on passenger cars and trucks as a check on laboratorytests have been initiated and will be extended as rapidly as possible.

In view of the very large annual consumption of asbestos brake

linings, the improvement in durability which manufacturers are bringing about as a result of the bureau's undertaking this investigation promises to lead to a very considerable saving to the automotive

industry and the public.

Truck Rear Axles.

An investigation of the relative merits of the various types of rear

axles for trucks which was begun during the preceding year under

the auspices of the motor transport division. Quartermaster Corps,

has been continued and it is believed will be concluded this coming

year. This work has included the determination of (1) the efficiency

of power transmission of a number of axles over the whole range of

speeds and power for which the axles are suited, and (2) the relative

strength of the various parts of the axles as determined hj endurance

runs under heavy loads.

The data obtained are expected (1) to assist in the selection of

the most efficient and reliable axles for Government use; and (2) to

make available information which should be of assistance to the industry in the improvement of its product.

Phenomena of Combustion.

This work, which was initiated several years ago, has been continued with the support of the National Advisory Committee for

Aeronautics.

Apparatus has been developed for the measurement of flame velocities by two independent methods; one using an adaptation of the
100 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Bunsen-Gouy method and the other a transparent constant pressure

bomb. The second method has been developed entirely at the bureau

and promises to yield results of great value.

A large number of measurements of the flame velocity of carbon

monoxide and oxygen mixtures have been made at a number of temperatures and with varying amounts of inert gases present as diluents.

The results of the several thousand observations taken have indicated

that very reliable generalizations on the reaction rates at high temperatures may be possible. It is hoped to continue the work with

fuels of more complex chemical structure and obtain information of

a fundamental nature on the phenomena of combustion of internal

combustion engine fuels.

Miscellaneous.

In some of the engine tests made at the bureau the fracture of

thin metal diaphragms has been found very convenient as a means

of comparing maximum cylinder pressures. The method of mounting the diapliragms and using them to compare maximum pressures

has been described in a technical note published by the National

Advisory Committee for Aeronautics under the title " Comparing

Maximum Pressures in Internal Combustion Engines."

A technical note entitled " The Use of Multiplied Pressures for

Automatic Altitude Adjustments has been submitted to the National Advisory Committee for Aeronautics for publication. This

note suggests a method of obtaining automatic adjustments of aircraft engine carburetor, variable pitch propellor, etc., that, so far as

is known, has never been tried but which appears to have many very

desirable characteristics.

At the request of an engine manufacturer a short investigation

of a case of very rapid wear of exhaust valve seats has been made

in cooperation with the metallurgical division.

TESTING, INFORMATION, AND PUBLICATIONS.

Thermometer, Pyrometer, and Heat Tests.

The tests completed in the division during the year are summarized

as follows:

The number of liquid-in-glass thermometers of all kinds, exclusive of clinical thermometers, submitted for test was 3,008, of

which 1,565 were certified and 472 received reports, the failure to

receive certificates being due either to defects in design or construction or to the fact that the errors exceeded the established tolerances.

In some cases a single report is rendered, giving results of tests of

all thermometers in a given lot. Of the thermometers submitted

706 were reported in this way. Of the remaining thermometers 34

were received broken, 52 were broken in test, of which 9 were or- iginally defective, and 146 were rejected as unsuitable for test. The

percentage of thermometers broken in test, 1.4 per cent, is some- what below the average of previous years. Among the thermometers

submitted were 251 calorimetric thermometers, 115 Beckmann

thermometers, and 66 clinical standards.

Of the 15,085 clinical thermometers submitted, 12,587 were certified, but only 6,689 received the certificate showing that the ther-
KEPOKT OF DIEECTOB OF BUREAU OF STANDARDS. 101

mometer was without appreciable error. Of the remainder 933

were rejected on account of defects which could be detected by inspection while 1,486 were rejected due to defects which were found

as the result of the tests. The 27 thermometers broken in test represent only about 0.2 per cent of those handled.

In addition to the above there were tested 29 resistance thermometers, 29 thermocouples, and a number of samples of platinum wire.

A number of freezing-point determinations were also made.

In the high temperature laboratories tests were made of 106

thermocouples, 15 indicators for thermocouples, and 1 resistance

thermometer. One radiation pyrometer and 9 optical pyrometers

were tested, and, in addition, 5 lamps and 1 absorption glass for

use in such pyrometers. Melting-point tests of 36 materials, such

as fire brick, sand, fire clay, metals, etc., were made.

A number of tests completed in the sections dealing with the

fire-resistive properties of structural materials and with automotive

power plants, fuels, and lubricants were not of a routine character

and have been summarized in the reports of these sections.

Information, Cooperation with Societies, etc. An important part of the division's activities has consisted in

furnishing information on scientific and technical subjects related

to its work by extensive correspondence, reports, or directly to technical men visiting its several laboratories. Many of the requests

for information relate to physical data which are readily accessible

to anyone interested, but a considerable proportion relate to special

equipment or information developed by the bureau, or they may reqviire considerable investigation. Information has been given on

such matters as the installation of a complete dynamometer equipment for engine testing, on equipment for testing brake linings, on

a number of matters relating to fire protection and preA'^ention.

Members of the division have cooperated in the activities of various

scientific and technical societies and organizations including

:

American Federation of Construction Industries, American Petroleum Institute, American Physical Society, American Society of

Mechanical Engineers, American Society of Refrigerating Engineers,

American Society for Testing Materials, Association of American

Clinical Thermometer Manufacturers, Building Officials Conference,

Common Brick Manufactures' Association, Hollow Building Tile

Association, Interdepartmental Committee on Petroleum Specifications, National Advisory Committee for Aeronautics, National Brick

Manufacturers' Association. National Fire Protection Association,

Optical Society of America, and the Society of Automotive Engineers.

The division has been actively represented in the committee work

of several of these societies, notably the American Society for Testing Materials, the National Fire Protection Association, the American Society of Refrigerating Engineers and the Society of Automotive Engineers. Numerous papers dealing with the work of the

division have been presented before scientific and technical societies.

Publications.

The following publications relating to the work of the division

have appeared during the year among the publications of the Bureau
102 BEPOBT OF DIRECTOR OF BUREAU OF STANDARDS.

of Standards, and may be obtained from the office of the Superintendent of Documents, Government Printing Office, Washington, D. C.

Prices are given in Bureau of Standards Circular 24

The production of liquid air on a laboratory scale (J. W. Cook), Sci. Papers, 17

p. 277; 1921 (No. 419).

Specific volume of liquid ammonia (C. S. Cragoe and D. R. Harper, 3d), Sci. Papers, 17, p. 287; 1921 (No. 419).

Mathematical theory of induced voltage in the high-tension magneto (F. B.

Silsbee), Sci. Papers, 17. p. 407; 1921 (No. 424).

Characteristic soft X rays from arcs in gases and vapors (F. L. Mohler and

Paul D. Foote), Sci. Papers 17. p. 471; 1921 (No. 425).

Cutting fluids (E. C. Bingham), Tech. Paper No. 204; 1921. The papers listed below have appeared in current scientific and

technical publications

Life tests of platinum, platinum-rhodium thermocouples (C. O. Fairchild and

H. M. Schmitt), Chem. and Met. Eng., 26, pp. 158-160; 1922. Characteristic soft X rays from arcs in gases and vapors (F. L. Mohler and

Paul D. Foote), Sci. Papers, 17. p. 471; 1921 (No. 425). Abstracts in Jour. Wash. Acad. Sci., 11, p. 273 ; 1921, and in .Tour. Opt. Soc. of Am., 5. p. .328

1921. The excitation of the enhanced spectrum of magnesium in a low voltage arc (Paul D. Foote, W. F. Meggers, and F. L. Mohler), Phil. Mag., 42, p. 1002;

1921.

The significance of the % terms in spectral series formulae (Paul D. Foote

and F. L. Mohler), .Tour. Opt. Soc. of Am. and Rev. Sci. Insts.. 6. p. 54; 1922.

A significant exception to the principle of selection (Paul D. Foote, F. L. Mphler, and W. F. Meggers), Phil. Mag., 43, p. 659; 1922.

The excitation of the enhanced spectra of sodium and potassium in a low

voltage arc (Paul D. Foote. W. F. Meggers, and F. L. Mohler), Astrophys.

Jour., 55. p. 145 ; 1922. Properties of Ammonia (Mollier chart), published by Am. Soc. of Ref. Engs.,

1922. Lessons of Are tests (S. H. Ingberg), address before National Brick Manufacturers Association. Published in Clay-Worker, June, 1922.

Factors affecting fire resistance of building columns (S. H. Ingberg), Engineering News-Record, June 29, 1922.

The ideal wall construction (in conjunction Avith Div. VII-1), Letter-Circular

No. 29. The safety of portable motion picture projectors (jointly with Div. V-7), Letter Circular No. 70. Tentative classification of building construction with reference to fire resist- ance, Letter Circular No. 71. Radiators for Aircraft Engines (D. R. Harper, 3rd.), .Tour. Wash Acad. Sci., Vol. II, No. 17 ; Jour, of Soc. of Automotive Engrs., October 19, 1921.

Developing a method for testing brake linings (S. von Ammon), Jour, of Soc. of Automotive Engrs., March, 1922.

EEPOETS or THE NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS.

Performance of Maybach 300 horsepower airplane engine (S. W. Sparrow),

Tech. Report 134. Performance of B. M. W. 185 horsepower airplane engine (S. W. Sparrow),

Tech. Report 135. Simplified theory of the magneto (F. B. Silsbee), Tech. Report 123.

TECHNICAL NOTES OF THE NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS.

The background of detonation (S. W. Sparrow), Tech. Note 93. Comparing maximum pressures in internal combustion engines ( S.. W. Sparrow

and S. M. Lee), Tech. Note 101.
REPORT OF DIRECTOR OF BUREAU OF STAXDARDS. 103

The following papers are in press or have been submitted for

publication

:

The origin of Spectra (Paul D. Foote and F. L. Moliler). lioolv to appear in

the Monograpli Series of Am. Clieni. Soc. The effectiveness of different methods of making absorption determinations as

. applied to hollow building tile (H. D. Foster). Jour. Am. Cer. Soc.

The work of the optical division includes: Radiation and absorption spectra, along with

certain phases of qualitative and quantitative chemical analysis for which these are es- pecially applicable, and the development of infra-red photography for astronomical observations and aviation purposes; investigations and tests involving measurements of polarized

light and its application, especially in the testing, standardization, and technology of sugar, including the supervision of the sugar laboratories of the Customs Service; measure- ment of the factors which determine color, the optical transmissive and reflective properties of materials, and the color grading of light sources and materials; performance and

development of optical instruments and materials, including refractive indices and dis- persion measurements; the more general field of radiation, determination of the funda- mental constants of radiation, the development of radiometric methods and instruments,

and the determination of the emissive, reflective, and absorptive properties of materials

for thermal radiation; application of the light wave as a standard unit for high-precision

length measurements and development of interference methods; testing of photographic

materials and devices, and general photographic investigations; optical investigation, and

measuring of the physical properties of dispersoids, such as smoke, water supplies, etc.

Outstanding Accomplishments.

From the large group of varied activit'es necessarily briefly described below certain accomplishments may be cited here which are of more than ordinary interest. The International Astronomical

Union, which met during the year at Rome, adopted practically all of the bureau's measurements and recommendations concerning

prlmary and auxiliary wave length standards. One of the greatest

needs of color specialists, namely, a rigidly defined and accurately

reproductible " white light," has been met by the development of a successful method for statistically fixing by test that which observers

! agree on as " white," and it is interesting to note that this approximates very closely to noon sunlight. A scale of color temperature

ranging from the candle (approximately 1,900 centigrade absolute)

through the common artificial light sources and sunlight to that of

the blue sky (up to 24,000°) has been completed, and the same

sources have been graded according to the wave lengths of their

spectral center of gravity. The spectral energy distribution from a number of stars and several planets has been measured. Scales have

for the first time been successfully ruled using light waves directly

as measuring standards. One such, a 100-millimeter scale, was

tested by the International Bureau of Weights and Measures at Paris

; and commended as being remarkably accurate. A method for dej ciphering completely obliterated ink records on charred carbon paper

' was successfully developed.

General Condition in the Division.

Many activities have been seriously handicapped through the impossibility of obtaining adequate equipment at present-day prices.

It may be safely stated that productiveness in sugar standardization,

spectroscopy, colorimetry, and optical instruments would have been

OPTICS.

GENERAL.
104 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

distinctly greater had funds and facilities been available for obtaining needed equipment with greater dispatch.

The plan, undertaken at the beginning of the year, of merging the

optical shop Avith the optical instruments section, has reduced " lost

motion " in a satisfactory degree. With an optical instrument shop

also in this section it is believed that the productivity will be commensuratelv enhanced.

SPECTROSCOPY.

Standard Wave Lengths.

After a lapse of nine years international cooperation in the perfection of a new system of standard wave lengths was to some ex- tent revived in May, 1922, when the International Astronomical

Union met in Rome and discussed this subject. Since 1913 the spectroscopy section of this bureau has considered its major duty to lie in the direction of precision measurements of wave lengths and each

year it has contributed something along this line. It is not surprising, therefore, that this laboratory may now be credited with more

v/ork on standard wave lengths and spectra than has emanated from

all other laboratories combined. The liistory and i^ecent developments of this subject were svimmarized in two Reports on Standard

Wave Lengths, published in the Journal of the Optical Society of

America (5, p. 308; 1921, and 6, p. 135, 1922).

The International Astronomical Union has adopted practically

all of the bureau's work and suggestions, including (1) the retention

of the cadmium red line as the primary standard, (2) adoption of

neon lines as an equivalent auxiliary standard (Sci. Paper No. 329),

(3) additional measures on 12 cadmium lines suitable for secondary

standards (Sci. Paper No. 441), (4) additional measures of argon

wave lengths for secondary standards (Sci. Paper No. 414), (5)

adoption of the tables of the Bureau of Standards for reducing wavelength measurements to standard conditions and for corrections

to values in vacuo (Sci. Paper No. 327), and (6) adoption of tertiary

standards among which the bureau's interferometer values of over

300 lines in the iron arc spectrum are included (Sci Papers Nos. 251

and 274).

Certain of the secondary standards previously adopted have been

found to give slightly lower values when the light is taken from a more restricted central portion of a longer arc. The International

Commission on Wave Lengths and Solar Spectrum Tables has

changed the specifications of the iron arc as a source of secondary

standards, thus making it necessary to redetermine the wave lengths

in this spectrum. The bureau has accordingly made the required

observations by taking photographs of the interference fringes produced by cadmium, neon, and iron lines. About 50 spectrograms were

obtained with various interferometers. The range of wave lengths

under observation extends from 3.000 to 9,000A. The results will be

published during the coming year.

Investigation of Arc Spectra.

Previous annual reports and numerous publications show that this

laboratory has been partially engaged for the past six years in de-
^ REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 105 B

scribing the standard arc spectra of all the chemical elements, especially in the red and infra-red spectral regions for which special

photographic technique has been perfected by the bureau. This

work was continued during the past year, emphasis being placed

upon the less common materials, such as the rare earths and the

noble metals of the platinum family. Scientific Paper No. 421 describes the yellow, red, and infra-red arc spectra of yttrium, lanthanum, and cerium, while Scientific Paper No. 442 gives similar

information for neodymium and samarium. In the case of the last

two elements, the purest materials obtainable gave a considerable

number of lines common to both. It is suspected that these may

belong to the unknown element whose atomic number, 61, lies between

those of neodymium and samarium. In addition to the above the

arc spectra of gadolinium, dysprosium, columbium, and zirconium

have been thoroughly investigated in the longer wave regions. The

arc spectra of the entire group of platinum metals (ruthenium,

rhodium, palladium, osmium, iridium, and platinum) -have been

photographed in the yellow, red, and infra-red, using the purest

materials prepared by the chemistrj^ division of this bureau. These

results will be published in the near future.

Investigation of the red and infra-red emission spectra of oxygen

and nitrogen have enabled the bureau to identify most of the " air

lines " observed in the spectra of arcs and sparks operated in air.

Up to the present time the longer wave portions of the arc spectra of

about 75 of the chemical elements have be«n investigated.

Spectrographic Analysis.

Over 200 spectrochemical analyses were made last year on a large

variety of materials including searchlight carbons, commutator

carbons, defective platinum crucibles, bronze and brass castings,

platiniun metals, dental gold, colored glasses, precipitates and residues from reagents, etc. The spectograph has demonstrated its

great value in supplementing chemical methods of analysis, and in

certain cases it may replace the more tedious wet methods, both for

qualitative and quantitative results. A paper entitled " Practical

Spectrographic Analysis " is now in press, which describes empirical

methods and is illustrated by examples of quantitative analysis of

tin, gold, and platinum for impurities. The physical principles un- derlying spectrochemical analysis have been studied rather intensively and a paper on "The Physical Basis for Spectrographic

Analysis" is being prepared.

Spectrum Tubes.

About 70 spectrum tubes of nitrogen, helium, neon, argon, mercury,

or cadmium were prepared and furnished to various laboratories for

optical testing or spectrum standards, and many additional requests

for such tubes referred to other sources recently established in this

country. Some notes on the preparation of spectrum tubes were included in Scientific Paper No. 441 so that research laboratories

possessing the necessary equipment may be encouraged to make their

own.
]06 REPORT or DIRECTOR OF BUREAU OF STANDARDS.

POLARIMETRY.

Cooperation with United States Customs Laboratories.

The bureau has continued to assist the Treasury Department

in the maintenance and operation of its customs laboratories with

excellent results. During the year more than 1,600 exchange samples

of raw sugar were tested. Approximately 50 per cent were direct

polariscopic determinations and the remainder were tested for the

percentage of moisture in addition to sucrose content. The close

agreement of the results obtained between the several customs laboratories and the bureau demonstrates the value of control analysis.

In view of the recent opening of a large refinery by the American Sugar Refining Co. at Baltimore, Md., the division of customs

requested the bureau to design suitable laboratories and equipment

to facilitate the additional testing incident to the appraisal of imported sugars. Although the appraiser's stores, in which it was

necessary to place the laboratories, is an old building and somewhat

unsuited for this purpose, an excellent and economical plan was

devised, consisting of a chemical laboratory, polariscope laboratory, sampling and mixing room, together with suitable offices for the

sugar examiner and the chemists. It was found necessarj^ to modify

the standard equipment to meet the peculiar requirements of the

building. The installation of this equipment is well under way.

The lack of facilities necessitated the installation of a separate

boiler room in connection with the laboratories, which is equipped

with a steam boiler, hot-water heater, vacuum and compressed air

outfit, together with steam ovens for drying sugar buckets and

sample cans. At the suggestion of the bureau, an assistant chemist has been

transferred from the bureau's staff to the Baltimore laboratory. The

first cargo was received on March 17 and consisted of approximately

10,000,000 pounds of sugar. On the recommendation of the bureau, an experienced examiner was detailed from the customs service at Philadelphia to take charge of the sampling, and a member of the

bureau was detailed for several days to supervise the testing.

Supplies for the Customs Service.

Additional facilities have been provided by the bureau for maintaining a stock of tested apparatus for the customs service of the

Treasury Department. In the case of the needs of the new Baltimore laboratory it was thus possible to supply the necessary apparatus without the delay of obtaining the material and testing it. The

various other customs laboratories have been promptly supplied

with tested apparatus. A survey has been made of the weights used

in the various laboratories in the testing of sugar, and at the suggestion of the bureau a supply of analytical and sugar weights was

purchased and tested at the bureau. This permitted replacement of

an equal number of weights in use at the ports. The tests of these

replaced weights showed conclusively that frequent testing is necessary. In a number of cases the weights sent in were considerably

in error. The regulations of the customs service require that these

weights be tested at least once a year. Since this has not always

been carried out in the past, the bureau has been authorized to re-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 107

place and retest all such weights. The increased accuracy will well

repay the effort involved.

The need of a pulp balance Avhich will meet the requirements of

the cvTstoms service as well as the industry has long been recognized.

To meet this need the design of such a balance has been undertaken.

An experimental balance of this type has been constructed and tried

out in actual operation, and found to be a decided improvement over

the stock balances for sugar work.

Experiments haA^e been conducted on glass polariscope tubes of

the standard design to meet the requirements for a tube for acid so- lutions. A noncorroding metal tube has been made for the same

purpose.

Plans have been devised for increasing the scope of the bureau's

activities in connection with the precision apparatus of the customs

service. This Avork is of fundamental importance in the administration of the tariff law.

Testing of Cover Glasses.

Through the efforts of the bureau all of the cover glasses in use

in the customs service are supplied by American manufacturers.

During the year large numbers of glasses have been tested for the

above service and also for private concerns. These glasses are tested

for optical homogeneity and absence of optical activity.

Testing of Molasses.

The bureau continued to act as referee between buyers and sellers

of molasses. Since a large proportion of the molasses for manufacturing purposes is bought on the basis of total sugar content and

density, a number of manufacturers specify that settlement be made

on the bureau's analysis. During the year over 20 analyses were

made. The study of new methods of analysis has been continued

with the object of increasing the precision of determination on molasses and other low-grade products. Cooperative analyses of ash

in sirups and molasses have been made for the Association of

Official Agricultural Chemists and a report issued to their referee.

The above association voted at their last meeting to continue this

work during this year. The several methods suggested are being

further studied at various temperatures.

The Rare Sugars.

So far as the United States is concerned, the rare-sugar industry,

in relation to the commercial production of these materials, is a new

one. Until recently we were wholly dependent on Europe for our

supplies. The bureau has alreadj^ been of considerable assistance to

the industries immediately interested in this group of compounds,

and the quality and variety of the products produced have been increased. In addition, materials of a higher purity have been produced and important contributions to the knoAvledge of the sugar

group have been made.

Most of the Avork previously reported as under way has been continued. In extending this Avork it was found necessary to devote considerable time to the development of special apparatus needed for

specific purposes. Of this apparatus having general applicability
108 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

may be mentioned a vacuum still used for the concentration of sugar

solutions and allied products. The apparatus is so constructed that

is has a large capacity and at the same time concentration takes place

in glass—a necessary prerequisite for the preparation of exceptionally

pure products. A report on the design and construction of this apparatus was made at the meeting of the American Chemical Society

held at Birmingham, Ala.

Investigations have also been carried out Avith the object of developing convenient and economical methods of preparing the rare

sugars. In this connection methods have been developed for the

preparation of two more members of the sugar group, namely, mannose and fucose.

Work upon the more fundamental phases of carbohydrate chemistry

has been undertaken, and, as a result, the complete structure of fucose

has been determined. This is an important contribution, as the constitution of this sugar has heretofore been unknown. It also has a direct bearing ujDon 5 other sugars, i. e., rhodeose, the 2 methyl hexoses

from rhodeose, and the 2 methyl hexoses from fucose. This is because rhodeose is known to be the optical isomeride of fucose, and,

therefore, the knowledge of the structure of fucose gives at once the

structure of rhodeose. This leads to the structure, with the exception

of all but one point, of the other 4 sugars above mentioned. Work

upon these problems is in progress. In the course of this work the

methyl tetronic acid from fucose has been prepared and studied for

the first time. This is of importance, since it is the second sugar

derivative of this type that has been studied, and the experience

gained with it gives promise of aifording a means of determining the

structure of any other methyl sugars that may be discovered in

nature.

Raffinose in Beet-Sugar Products.

Kaffinose is a complex member of the sugar group, which occurs as an impurity in beet-sugar products of the Middle Western States. It has a disturbing effect upon the process of manufacture and frequently prevents the recovery of much sugar from the molasses in

which it has accumulated. It has long been a disputed question

whether the impurity which the prevailing analytical methods indicate as raffinose is true raffinose or a positively rotating nonsugar.

The only feasible method for the determination of true raffinose depends upon the use of the enzyme "melibiase," which is extracted

from brewer's yeast. Analyses conducted with this agent upon several

samples of beet molasses obtained from Colorado indicate that true

raffinose is present in beet molasses and that aside from the raffinose

the residual impurity is not dextro rotary, as previously supposed,

but is actually Isevo rotary.

In continuation of the research improved methods of making this

difficult analysis are being investigated.

The effect of raffinose upon the crystallization of sucrose has been

studied. It has been ascertained that a diminution of the solubility

of sucrose results in addition to a profound effect upon its crystal

form. Apparently, however, raffinose does not combine to form

" mixed crystals."
JL

REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 109

Preparation of Levulose.

Levulose is the sweetest member of the sugar group and under various forms is one of the important articles of human diet. Its diffi- culty of preparation, however, has prevented its appearance on the

market in a pure state except in small quantities and at a prohibitive

cost. If it could be prepared at a relatively low cost, it would un- doubtedly become a valuable national asset, as the material would

serve a multitude of special purposes, due to its sweetness, wholesomeness, high solubility, and other particular properties. This end, although remote, is the aim at which the bureau is striving. During

the past year a study has been made of the preparation of levulose

from cane sugar, in which it occurs combined with dextrose; and

from dahlia tubers, in which it occurs in the form of a starch known

as " inulin." The conditions necessary for the conversion of the

inulin to levulose have been studied with a view to obtaining complete

conversion and the highest possible purity. Experiments have been

made on the crystallization of the sugar from various solvents, and

in many instances promising yields of the pure substance have been

obtained.

The properties of the pure sugar have been, to some extent, studied.

Among these have been the density of solution, refractive index, and

optical rotation.

The Utilization of Molasses.

The rapid change of conditions in the sugar market during the past

two years has forced American manufacturers to consider seriously

the utilization of the waste molasses and waste waters which result in

the processes of sugar manufacture. A formerly valuable by-product

has decreased to less than one-fourth of its former value. Many valuable chemical compounds, known as nonsugars, may be produced

from these wastes under the proper conditions. Such processes are known to be in use in Germany, but as yet none have been developed

to meet the different conditions which exist in the industry in this

country. The bureau, with the strong commendation of those in the

industry, has undertaken the problem of devising means of utilizing

the waste liquors. A thorough search of the patents and literature

connected with the subject has been made and steps have been taken

to assemble the necessary equipment to carry out research on the problem. There is little or no general scientific literature on this subject

and the bureau has had to resort to the procedure of studying foreign

patents. The search has proven difficult and taken much time; The

chief difficulty has arisen from the fact that but a small fraction of

the pertinent patents are classified under the heading of molasses..

Twenty or more principal classes were found, in each of which it was

necessary to create subclasses. The search has been conducted systematically and wherever possible by examining the full individual

patent brief. It has been surprising to find that in an important

commercial field in which there is practically jno literature over 1,000

patents in German alone should be found. The unmistakable impression has been obtained that every legitimate means has been used by

foreign patentees to create as many difficulties as possible in the trailing of patents, and it is exceedingly difficult to decide when a given

patent is really of practical and specific economic importance.
110 REPORT or DIRECTOR OF BUREAU OF STANDARDS.

Molasses Formation.

Molasses is one of the greatest sources of sugar loss in the manufacture of both beet and cane sugar; hence, a study of the various

factors influencing the quantity produced is of primary importance

to the industry as well as of great importance to the country at

large. The work in this field which has been undertaken at the bureau

includes, among others, a scientific study of the equilibria of the

various complex chemical systems existing in the product. . It is

hoped that by this study a rational theory of molasses may be

developed. The work already indicates that the theory now most

widely accepted by the industry is probably inadequate to explain the

phenomena, and it seems quite possible that this theory may have

been an important factor in retarding development along certain

lines of sugar technology. The low prices of molasses during the last

year have awakened some of the beet-sugar manufacturers to the importance of such studies; and they have urgently requested the

bureau to undertake an extensive program of research on the general

problem of molasses.

Saving of Waste Sugar.

Every year huge tonnages of sugar are lost through various deficiencies in the manufacturing operations whereby the sugar from

beets and cane is extracted. One of the greatest sources of such

losses is in the molasses, which is the residual sirup obtained from the

last crystallization of sugar. It is a product from which no more

sugar can be obtained by present methods of crystallization. In a

beet-sugar factory each pound of impurities which is not eliminated

in the process before the sugar reaches the stage of crystallization

will necessitate the rehandling of some 8 or 10 pounds of sugar and

impurities in the crystallization process, and, finally, will cause the

loss of 1^ pounds of sugar in the form of molasses. Hence, any practicable increase in the quantity of impurities eliminated in the process before the crystallization stage will bring about the saving of

at least an equivalent quantity of sugar. From a sugar manufacturer's standpoint this is preferable to any known means of utilizing the equivalent quantity of molasses. Titierefore, the bureau has

undertaken an investigation in this field. The work accomplished

thus far has been confined to beet molasses. Unfortunately, the available literature on this subject is very widely scattered under different

subjects and in various languages. Much time has, therefore, been

spent during the current year in making a technical survey of existing knowledge on this subject. The collected material thus obtained

will be of special value to the American industry and will save much

time in attacking the experimental part of this work.

Commercial Production of Pure Dextrose.

In previous reports there have been given the results of the

bureau's fundamental work in making possible the commercial production on a large scale of practically 100 per cent dextrose. This

sugar, commonly known as glucose, is now produced in fine, white

crystals very similar in appearance to granulated sugar. The bureau's connection with this work is again touched upon in order to

call attention to the fact that the abstruse scientific laboratory ex-
KEPORT OF DIRECTOR OF BUREAU OF STANDARDS. Ill

periment of to-day frequently becomes of great commercial importance to-morrow. The one and one-half million dollar plant built

at Chicago for the manufacture of this material has now been completed and successfully operated, and a similar plant is in course

of erection by the same American firm in Gei'many. Once a new

material is available new uses on an extensive scale immediately

spring up. The two most recent extensive applications in the use

of dextrose are in the condensed-milk and ice-cream industries. In

these industries it satisfactorily meets the demand for a material

which heretofore has not been available.

The Laboratories of Sugar Technology.

The work of equipping these laboratories has been continued, but

they are not yet complete. They will be used extensively in the

coming year's work, however, and several pieces of work not previously attempted on account of lack of facilities will probably be

carried out. The new vacuum equipment includes a glass enameled

pan and a wet vacuum pump.

Special Sugar Apparatus.

Much of the special sugar equipment, consisting of commercial

and semicommercial units mentioned in the previous report, has

been received and partially erected during the year. Several new

designs have also been completed during this period. The equipment will be used for the purpose of obtaining scientific data re- quired for further work in certain lines of sugar technology and

will permit of carrying out laboratory-scale operations connected

with various projects.

Table Sirups of High Density.

A study of the solubilities of sugars in the presence of other

sugars has shown that a sirup of maximum solubility of a sucrose- invert-sugar mixture is obtained if it contains 33.6 per cent sucrose and 45.4 per cent invert sugar. Such a sirup may be concentrated

to 79 per cent total solids without danger of crystallization if the temperature is maintained at 30° C. This part of the investigation was

completed during the previous fiscal year. During the past year

the variation of this maximum solubility point with the temperature has been determined by computation and experiment. Many

subsidiary data have been obtained, such as the contraction of volume

upon inversion and the effect of such contraction upon the density

I of the solution.

' The question of effecting the inversion of sugar to obtain an in- crease of solubility is still under investigation. It appears evident

that when the enzyme " invertase " is available its inverting action

is the most feasible one. Where this material is not available for

isolated localities, it now appears possible that an acid method may

be applied, which, however, is valid only for " open kettle " processes.

Viscosities of Sugar Sirups.

i One of the most important properties of the ii<|ii()rs passing through

I the sugar factory is viscosity. Upon this depends, in a great meas-

' ure, the facility of filtration, boiling, centrifugal separation, and

I many other operations. There is, therefore, a need of standardiza-

' 9644—22 9
112 REPORT or DIRECTOR OF BUREAU OF STANDARDS.

tion in methods and an increased number of accurately known viscosities in order that measurements may rest on an absolute rather than

merely a comparative basis. Although there are in existence re- liable data on the viscosities of sugar at a few concentrations, these are so widely separated that interpolation is impossible. During the

past year an interpolation formula has been devised which rests upon

these few known viscosities, and it is important to establish this and

other such formulae by a greater number of accurately determined viscosities.

Decomposition of Invert Sugar in the Presence of Hydrochloric

Acid.

The experimental data acquired in the study of table sirups of high

density have made it possible to determine the time required under a given set of conditions to produce complete inversion of sucrose. It

now becomes important to ascertain the effect of an excessive time of

heating, or, in other words, the rate of decomposition of invert

sugar in the presence of acid over the range of temperatures commonly employed. This work is well under way.

Crystallization.

A delicate thermostatic-control apparatus tor growing large and

perfect crystals has been in operation for a year. It has recently

been improved in a number of details and has been successfully kept

in continuous service over a period of six months with little or no

attention. The process of growing large and perfect crystals is

necessarily a very slow one covering considerable periods of time.

The general problem of crystallization is an important one for industrial as well as purely scientific purposes. A number of relatively

large and perfect crystals of some of the rare sugars and allied substances now being produced at this bureau have been successfully

grown. An important development has resulted from the discovery

that in some cases the purity of a substance can be judged by the

character of the crystals it will produce. Rafiinose, for instance,

after purification by repeated recrystallization will readily grow in

large clear crystals, while before recrystallization it would invariably precipitate as a mass of fine white crystals. The same may be

said of mannite. Among the substances which have been grown may

be mentioned dextrose, levulose, sucrose, raffinose, rharanose, xylose,

mannite, gulonic lactone (gulose itself has never been obtained in

crystalline form), cadmium sulphate (for the production of pure

metallic cadmium), nickel sulphate, Eochelle salt, and sodium nitrate.

Diffusion Process in Sugar Manufacture.

Some work was done on this i)roblem during the year, including

the construction of a small battery. This was described before the

sugar division of the American Chemical Society at the New York

meeting in September. The experimental results thus far obtained

indicate that most of the work outlined in this field can not be completed without developing a more complete set of apparatus. Jt is planned to make some measurements of the relative diffusion rates

of certain beet constitutents, using for the purpose a series of special

glass cells which have been designed. It is believed that the result
I

EEPORT OF DIEECTOR OF BUREAU OF STANDARDS. 113

of this study when completed will provide data from which the

present commercial practice may be improved.

Standardization of Commercial Sugars.

In the previous report attention has been directed to the importance

of the problem of grading and preparing standard specifications for

the various commercial sugars produced in the United States. With

the completion of the greater portion of the experimental work incidental to this problem, the investigation has been extended during

the year to devising a system of classification which will permit the

grading of all classes of sugar products, from the highest, almost

colorless fancy grades, to the most highly colored soft sugars. The

results obtained have been satisfactory. A definite color scale, cover- ing all these products, now seems available, including the small differ- ences in tint of white sugars. The system of color grading is pliable

and gives excellent promise of a color scale suitable for the entire

sugar industry. There remains considerable work to be done in this

investigation which can only be accomplished by consultation with

representatives of the industry, to the end that the practical application may result in all cases to the benefit of the individual manufacturer.

Storage and Shipment of Sugar.

The caking of white, dry, granulated sugar during storage and

shipment is a problem of great economic importance to the sugar

industry, and while it has been studied more or less extensively with

varying degrees of success by several of the leading producers, no

satisfactory solution of the problem has been obtained. Inquiries

which have been received relative to the work previously done in this

field indicate that the various factories are still much interested and

that they regard a further study of this problem an urgent matter.

The past year's work has been confined largely to qualitative experiments and continued study of data previously obtained by one of the

manufacturers.

Color Measurement in the Sugar Industry.

The principal object of all factory operations in the manufacture

of sugar and its by-products is the ultimate removal as far as possible of all color. An accurate and convenient method of measuring the

color that remains has been a basic problem in the sugar industry for

many years. Of equal importance is the utilization of a system of

color measurement to estimate the efficiency of the various steps in

the removal of color during the progress of sugar manufacture. In

the previous report, attention was directed to the nature of these

problems, their importance, and the results which the bureau has

accomplished in its efforts to apply modern research laboratory

facilities to practical use in the industry. This work has been con- tinued with gratifying results, the investigation entering new phases

and aspects of the problem. These have compelled the acquisition of

additional precision instruments and equipment. Considerable delay

has necessarily resulted, as a part of these materials have had to be

purchased from Europe.
114 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

In summarizing 'the results accomplished thus far, it may be said

that a better definition and understanding of the nature of the color

in impure sugar products has slowly developed. There is a peculiar

intimate relationship between any color problem of the industry and

all methods pertaining to purification, filtration, and decolorization.

The additional information which has been secured as to the nature

of the color indigenous to cane and beet products is equivalent to

opening up new possibilities for the refinement and improvement

of all technical processes of manufacture. While the investigation

is proceeding by the utilization of all available scientific refinement,

it is hoped to attain the practical results in such form that they may

be directly and conveniently applicable in sugar technology. As a

valuable aid to this end, much time has already been spent in the

design of instmments of a type directly applicable to use in the factories and to the scientific laboratories connected with the sugar industry.

Gradation of Sugars by Sieve Analysis.

No further experimental work has been carried on in this investigation, but excellent progress has been made in the correlation of the

results of previous tests with other data obtained on the same samples

of sugar.

Enzymic Estimation of Sucrose.

In previous investigations the bureau has studied the Clerget

method for the analysis of sucrose and has suggested modifications

of the method to eliminate errors caused by disturbing impurities.

These methods have depended upon the inversion of sucrose by means

of hydrochloric acid. During the past year a study has been made

of the inversion of sucrose by means of the enzyme "invertase," an

active agent extracted from yeast. The invertase method, while

theoretically perfect, is apparently at present subject to greater er- rors than the acid method. A great diversity exists in the experimentally determined value of the inversion constants. The sources of these diversities have been investigated and the conclusion has

been tentatively reached that they are to be ascribed to the preparation of the enzyme. This preparation has consequently been care- fully investigated and preliminary determinations of the constants

of the invertase inversion have shown that an accurate reproducibility is possible.

The importance of this research depends not only upon its application to the invertase method itself, but as corroborative evidence of

the acid methods of analysis. The latter, when proven to be reliable

for all products, may then be used for the daily control of sugar

manufacture, and the invertase method for corroboration and examination of tlie performance of the acid method.

Decolorizing Agents.

So great is the demand for efficient decolorizing carbons in many

lines of industry, including the sugar industry, that new carbons are continually being produced in many counti"ies. The collection of

samples by the bureau has now been extended to include the European product wherever conditions have permitted of a search of
REPOKT OF DIEECTOR OF BUREAU OF STANDARDS. 115

foreign industries. In the bureau's work the study of these materials is still confined to the removal of coloring matters in prefer- ence to that of ash and organic substances. This procedure has been

followed because the decolorizing action is closely connected with

the investigation of the color in sugar and sirups, reported elsewhere. The equipment which is being accumulated directly for the

measurement of color is applicable to the present problem of estimating the performance of decolorizing carbons, and the results ac- complished in both investigations are necessarily interwoven.

A further study of technical color-measuring devices has developed the necessity of supplying industrial laboratores with precision color-measuring devices which must be reasonably priced and

simple in operation. Reliable results in decolorization practice can

not be secured by methods and instruments which merely give approximations. Deductions drawn therefrom in industrial laboratories for practical problems are invalidated' wherever such approximations are used. The technical demands for precise information have been pushed so energetically by technologists that only

precision methocts and instruments can produce the desired results.

The bureau is, therefore, engaged in presenting the sugar color problem in forthcoming publications in such manner that scientific principles in methods of analysis and in interpretation of observed re- sults will supplant the antiquated colorimetric practice, which has

been proven unsatisfactory.

Adjustment and Standardization of Saccharimeters.

The work of adjusting and standardizing saccharimeters and polariscopes has been continued. Although several excellent types of

instruments have been on the market for some time, the supply is

still limited, as is evidenced by the fact that a large proportion of the

instruments sent to this bureau for test are old types, man}'- having a

different basis of calibration from the newer ones. The bureau is

constantly called upon to furnish information regarding the lase of

these instruments and has continued to render valuable service to

the sugar industry. During the year 40 instruments were adjusted

and standardized, 29 of which v/ere submitted by various sugar companies, 5 by other Government departments, 2 by State universities,

and 4 by industrial and research labor atories.

Basis of Saccharimeter Standardization.

The rotation of the normal sugar solution, which fixes the 100°

point of the saccharimeter scale, is the most important of all polarimetric constants. In previous reports there has been chronicled the

bureau's work in the accurate determination of this value and the

discovery of an error in the accepted value of over one-tenth of a per cent. Owing to conditions which have prevailed for some years,

it has been impossible to get the International Sugar Commission

together in an effort to secure international agreement on the value

of this constant. In view of the fact that the error discovered by

the bureau was resulting in large losses to the Government from

duty not collected on imported sugars, as well as in still larger losses

to the producers of sugar, the bureau has for some time been standardizing all instruments and all quartz control plates on the cor-
116 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

reeled value. The most important development in the subject during

the 3'ear has been the publication by a prominent European authority

of an elaborate investigation on the determination of the 100°

point. This work fully confirms the results obtained by the bureau

and thereby greatly strengthens and justifies the policy previously

adopted in introducing the correction for the North American industry.

Quartz-Control Plates.

The modern saccharimeter as developed for sugar-testing purposes

is necessarily a complicated piece of apparatus and is, therefore,

likely to show variations in its reading from day to day and thereby

render inaccurate the test of a sugar. Inasmuch as all sugars are bought and sold upon the tests shown by this instrument, the highest

available accuracy and reliability are essential. All inaccuracies,

including those due to variations in temperature, can be corrected

by means of qilartz-control plates. A plate of crystalline quartz,

properly cut with regard to the crystallographic axis, has the ]5ower

of rotating the plane of polarization of a beam of polarized light in

the same manner as a sugar solution. The control plate is placed in

the saccharimeter in place of the sugar solution and the reading obtained compared to the standard value of the plate determined at

this bureau. These plates are thus of fundamental importance

throughout the sugar industry and in scientific laboratories as well.

During the year over 100 have been tested, 40 per cent of which were

rejected as being unfit for precise sugar work. Inaccuracies produced

by improper mounting of the plates were so common that the bureau

adopted the policy of remounting many that were sent in for test when such plates were already in the possession of the industry. On

the other hand, when improperly mounted plates are submitted for

test by the maker, they are rejected. The effect of this procedure

has been most satisfactory, and as a result of the bureau's work in

this field the average accuracy of the plates in use throughout the

industry has been greatly increased.

Properties of Quartz at High Temperatures.

In carrying out an investigation of the optical activity of crystalline quartz at high temperatures, it was found necessary to care- fully explore the region in the neighborhood of 573° C. At this

temperature quartz undergoes a recrystallization with a consequent

absorption of heat if the specimen is being heated, and a liberation

of heat if the specimen is being cooled. From this study it was

discovered that the transformation temperature is so sharp and re- producible that it is suitable for a fixed point on the high-temperature scale. iVll clear crystalline quartz is especially pure and the

previous experiments in this investigation were made on material

of that character. During the year a further study was made on

colored quartz of the usual type occurring in Japan. Careful experiments on the Japanese quartz showed that recrystallization occurs

at exactly the same temperature as the clear quartz, namely 573.3° C.

Owing to the importance of the utilization of quartz for the

purposes mentioned above, the effect was studied in the powdered

material. It was found to be much less suitable.
EBPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 117

" Reaction " of Sugar Products.

In the sugar industry, as in many others, it is common practice

to express an idea of the alkalinity or acidity of a product by indicating how much acid or alkali would be required to make the

product " neutral." As one might state the quantity of heat in a product without stating the temperature, so this method expresses

the quantity of acidity or alkalinity, but does not indicate its degree

of intensity. This degree or intensity is termed the " reaction " and

may be stated in terms of the 'hydrogen-ion concentration, just as temperature may be stated in terms of Fahrenheit or centigrade

scales.

The recent work of many investigators has indicated that the

behavior of a substance is controlled less often by its total quantity

of alkalinity than by its reaction. The possible application of these

facts to sugar products and processes seems to be very extensive,

ranging from improving flavor and appearance of white sugar to

better elimination of impurities in the process, and hence the production of less molasses and more sugar. Previous work in this field

by the bureau has been carried on with indicators. Electrical equipment for the purpose has recently been acquired and an extensive

program of work has been planned.

Polariscopic Determination of Double Refraction in Glass.

The usefulness of a glass is affected adversely by the presence of

strains in the material. These strains are caused by improperly an- nealing the glass or by the application of external forces, and are ac- companied by variations in the refractive index and by double refraction. Practically the only method of detecting these strains is by

means of some test for double refraction.

As it has thus far been impossible to remove all trace of such

strains by any practical method of annealing, it is necessary to determine the effect of their magnitude and distribution on the performance of the glass used in optical instruments. It is hoped eventually

to establish standards for the fitness of glass for optical purposes.

Much assistance in this work has been received from the optical glass

and instruments sections of this bureau.

Polarimetry of Oils.

Oils of all classes are often naturally active ; that is, they possess

the property of rotating a beam of plane poliarized light, and all

become active or doubly refracting in a magnetic or an electric field.

Data on these properties aid in identifying the oils and determining

their source. The commercial value of such data is great, as it is frequently possible through their use to detect adulterations and inferior

quality. Investigations in this field are progressing and the bureau

is now cooperating with those commercial laboratories where similar

work has been undertaken. Special attention is being given to developing a teehnique used in making the tests.

Refractometer in Sugar Analysis.

The refractometer serves a useful purpose in sugar analyses by

virtue of its ability to indicate in a very rapid and convenient manner

the total solid content of a sirup submitted for analysis. The re-
118 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

fractometric determination of solids is very precise when applied to

pure sugar solutions, and gives a satisfactory approximation even when the dissolved substance does not consist exclv\sively of sugar. A

necessary preliminary to the use of this instrument is that the refractive indices of sugar solutions be established with a degree of accuracy

somewhat greater than that required for laboratory control. In re- sponse to this requirement the bureau is engaged in determining with

as high a precision as possible the refractive indices of the pure sugar

solutions over the complete range of concentrations and at varied

temperatures. The available data are at present valid to the fourth

decimal. It is now proposed to extend the accuracy at least to the

fifth decimal. An improved method of measurement has been devised

by the optical instruments section of the bureau which permits precise measurement of the accurately prepared sugar solutions and allows accurate temperature control at the same time, eliminating all evident sources of error. This research is being conducted in response to a request by the

American Chemical Society which has appointed a committee to inA'estigate the technical uses of the refractometer. Application will

be made not only to the cane and beet sugar industry, but to the

glucose, maltose, and allied industries.

Rotation Dispersion of Sugars.

The necessity for additional knowledge regarding the variation in

the rotation of plane polarized light for different colors (rotation

dispersion) has long been noted from a theoretical standpoint, and

has recently become of enhanced importance owing to the recent

development of the rare-sugar industxy in the United States. The

use of the green line of the mercury spectrum as the standard individual wave-length for polariscopic constants, first proposed and

adopted by the bureau, has now been almost universally adopted by

the scientific world in place of the inferior sodium lines. It is now

used in making measurements on the various sugars and allied substances as fast as they are prepared in a sufficiently pure state, and

is always utilized as the most important wave length in all rotarydispersion measurements. During the year additional measurements

were made on raffinose, fucose, and some of the derivatives of the

latter. It is expected to continue under this investigation the ac- curate measurement of the rotary dispersion of the various sugars

which are now being produced by the bureau in a high state of purity.

Wlien this is accomplished manufacturers and investigators will have

a defined guide for the purity of their products.

Monochromatic Light Sources.

The problem of monochromatic light sources is a fundamental one

of great importance in sugar analysis and many lines of optical re- search. Such sources, as fast as they become available, are utilized in

instruments requiring special illumination, and as accessories in

other fields of practical work. There is thus needed a series of

sources of monochromatic light waves fairly equally spaced throughout the visible spectrum and of great intensity. The bureau has

made important contributions to this field from time to time. Recently a practical cadmium vapor arc lamp was developed by alloy-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 319

ing the cadmium with gallium. During the year considerable ex- perimental work has been done to develop a similar lamp, using

other materials than cadmium. Both silver and zinc have very

desirable intense lines in their spectrum, and lamps have been prepared in which they are used. Work has progressed to a point where

there is every promise of success, so far as the development of a zinc

lamp is concerned. Whether or not it is possible to produce a successful silver vapor lamp has not yet been determined, as material,

sufficiently free from zinc, has not iDeen obtained.

Saccharimeter Light Filters.

The investigation into the feasibility of substituting permanent

light filters, such as colored glass, as the standard light filter for

saccharimeters to replace the bichromate filter adopted as standard

by the International Sugar Commission has been continued. If such

a filter can be shown to give the same readings as are obtained when

using the bichromate solution, a decided improvement will have been

accomplished, as such a filter would be free from the many disadvantages inherent in the use of a solution. All observations to date

tend to confirm the conclusion indicated in last year's report that

there is no difference between the readings obtained with a standard

bichromate filter and those obtained with a glass whose spectral

transmission curve closely approximates that of the bichromate

solution. Obsen^ations have been made and more are now under

way to determine how far and in what manner the spectral transmission curve can depart from the transmission curve of the standard

bichromate solution and not introduce any error in sugar determinations. The question of a light filter for saccharimeters is an important one because of the money involved in transactions based

upon saccharimeter readings.

Standard Samples.

During the past year more than 100 samples of sucrose and about

20 samples of dextrose were distributed. These materials are used

principally for industrial and scientific purposes, and the demand

made upon the bureau for standard samples has steadily increased.

During the year, additional equipment for preparing these samples,

as well as for the issuing of samples of other sugars, has been designed and installed.

Society of Sugar Chemists and Technologists.

The national organization of sugar chemists and technologists,

in the formation of which the bureau has taken an active interest

and assisted in every way possible, has been made, during the year,

a self-governing division of the American Chemical Society. It is

known as the Division of Sugar Chemistry.

COLORIMETRY.

White Light.

For many years one of the greatest needs of color specialists has

j been a rigidly defined, accuratd.y reproducible " white light." Such

II a standard is not only very essential in the work of color analysis, but
120 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

it is indispensable to the absolute specification of certain very important color characteristics. Until the standard white can be

adopted certain other problems must remain unsolved. Involving

as it does physiological factors as well as physical, the standard

for white or gray, or the " hueless " sensation, as it is named, is

peculiarly difficult to attain. The color to be adopted must be that

which the normal (average) eye will readily recognize as without hue.

A suitable physical stimulus of the hueless sensation must fulfill

two requirements: (1) It must be exactly reproducible in the laboratory, so as to be available for those who require it; and (2) it must

conform as closely as possible to the best contributions to the knowledge of this subject. These considerations have led to the choice of

a source of light known as a complete radiator, the radiant energy

of which for any given wave length and temperature conforms to a

rigid mathematical (Planck) formula. The temperature of this source at which the energy distribution is such as to give the hueless or white sensation was found with four observers to be approximately 5,200° absolute centigrade—very like average noon sunlight

at Washington, D. C. Although there is no known terrestrial source

that can be heated to so high a temperature, the energy distribution

characteristic of this temperature can be accurately reproduced by

means of an ordinary gas-filled tungsten lamp and a proper light

filter (quartz rotatory dispersion apparatus).

The method, with preliminary data, has been published in Scientific Paper No. 417, August, 1921. An extensive series of observations

from many observers, however, is needed before this question of

standard white can be considered settled; but so great is the need

for this standard white that the preliminary data, scant as they are, have already been pressed into service by workers in color.

Color Grading of Artificial Illuminants and Daylight in Terms of

Color Temperature.

The same device used in the determination of white light for

producing a source of illumination of apparent temperature 5,200°

absolute centigrade has been the means of extending the so-called

color-temperature scale enormously. Thus the light proceeding from

the incandescent lamp, modified by the filter, can be made to assume

spectral energy distributions corresponding to those of a complete

radiator as calculated for any temperature from about 1,500 to

24,000° absolute centigrade. This has made it possible to grade, by

means of color temperature, many of the ordinary illuminants, including sky light and artificial daylight. The method is to color match

the light from the unknown source with that from the standard incandescent lamp, suitably filtered. Among the illuminants that have

been examined in this way are the Hefner lamp (the German standard candle), carbon filament lamp, vacuum-tungsten and gas-filled

tungsten lamps, 10-ampere carbon arc, sunlight, and daylight under

different conditions. When the color temperature of an incandescent

source has been determined, its spectral distribution of energy is then

known, to within farily narrow limits, in the visible part of the

.spectrum.

In this connection a great deal of work has been done on the color

grading, by means of rotatory dispersion of a number of so-called

daylight glasses. The problem of producing artificial daylight by
KEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 121

means of filtering the light from a tungsten lamp through a blue

glass, is a very important one commercially. The rotatory dispersion

method of grading these glasses is far more rapid than the spectrophotometric method; but unless the spectral distribution of energy

emerging from the glass conforms to the Planckian distribution, the

slower method must be used.

Spectral Center of Gravity Scale for Color Grading of Illuminants.

The color temperature scale, convenient though it is for color grading many illuminants and artificial illuminants, has not been found

quite as suitable as another scale, namely, the spectral center of

gravity scale. The spectral center of gravity and its relation to color

have been described in the Journal of the Optical Society of America,

September, 1920, page 389. The great advantage of this scale over

the color-temperature scale is that equal intervals on the former indicate ap2Droxim.ately the same color dilference at all points on the scale,

while on a temperature scale a very slight color difference indicates a very large temperature interval as temperatures above 6,000° absolute

centigrade are reached. A scientific paper describing in full the

color grading of illuminants in terms of color temperature is in course

of preparation.

Spectral Distribution of Energy from a Complete Radiator.

In the course of the work of color grading by means of color

temperature it was found necessary to determine, as represented

by the Planckian formula, the spectral distribution of energy for a complete radiator at various temperatures. The calculation of this

energy at every 10 millimicrons for each temperature rec[uired involved a great deal of time and labor. In order to facilitate this

work, certain curves have been plotted, with relative energy values

along one axis and temperatures along the other, one curve for each

of the required wave lengths. From these charts the reading of the

energy value for any temperature desired can now be accomplished

both rapidly and accurately. The practical use of the charts is to

determine readily the spectral distribution of energy of any illuminant subject to the following conditions : (1) That the energy distribution resembles that of a complete radiator, and (2) that its color

temperature be known.

The Visibility of Radiant Energy.

Two methods of photometry are in common use—the direct-comparison method and the flicker method. It is an open question

whether or not results obtained by the two methods are consistent

with each other. If there is a slight difference between them may this

not be a result of a difference in the spectral sensibility of the eye to

radiant energy as measured by the two methods? The exact values

of this visabiiity curve are important also in the determination of the

mechanical equivalent of light in the use of colorimeters and in other

problems.

In cooperation with the Nela research laboratory, the bureau

has made a new investigation of the visibility of radiant energy by

the so-called step-by-step method, a direct comparison method

throughout the spectrum in which the color differences are almost
122 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

eliminated. This investigation will afford an interesting comparison with a previous one by the step-by-step method made at the

Nela research laboratory and another at this bureau by the flicker

method, as several of the observers in the present investigation were

observers in one or the other of these earlier determinations. The

present investigation, with about 60 observei-s, is practically completed. The results will be published during the coming j'ear as a

iBureau of Standards Scientific Paper.

Physiologic Optics.

In cooperation with the Munsell Color Co., an extensive investigation into various outstanding problems of physiologic optics has

been started. This will comprise a continuation of the determination of a standard white or gray, a detennination of the hue sensibilitjr of the average eye, and correlative data on the visibility of

radiant energy.

The Spectral Transmissive Properties of Dyes. , The present pronounced interest in the development of the dyestuffs industry has emphasized the need of accurate and reliable data

on the properties of dyes. One of the most important properties of

a dye is, of course, its color. Like the colors of other substances,

that of a dye can be completely specified by means of its spectral

transmissive or reflective constants. The bureau is well equipped

for such specification, but has been handicapped by lack of personnel

to carry out such work. The following results have, however, been

accomplished this last year

(1) The cooperative investigation between the Bureau of Chemistry and the Bureau of Standards on the spectral transmissive properties of the seven permitted food dyes, mentioned in a previous report

(1920, p. 135), has been completed and the results published in Bureau of Standards Scientific PajDer No. 440. This publication, in

addition to giving extensive data' on the food dyes, describes in detail

the methods which have been developed at the bureau for obtaining

such data.

Four different methods have been used enabling the complete

transmittancy curves to be obtained in ultra-violet, visible, and near

infra-i-ed. This affords accurate measurements upon the location

and magnitude of the absorption bands—useful in theoretical studies

as well as in analysis and identification. In addition carefully

measured values of the specific transmissive indices for the homogeneous, visible spectral lines of mercury and helium are given,

primarily for purposes of chemical analysis. The paper also illustrates the methods—graphs and tables—by means of which the

results may be reported. Future publications will consist largely

of data presented in this way.

(2) A cooperative investigation with the Calco Chemical Co.

started the previous year has been continued. Data on about 15

dyes have been obtained in a manner similar to that used in the

study of the food dyes. Further cooperative work is planned for

the coming year.

(3) About 30 dyes have recently been prepared in the chemistry

division at the Bureau of Standards. Visual measurements with
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 123

I

the homogeneous mercury and helium spectral lines have been made

on the majority of these.

The Spectral Transmissive Properties of Vegetable Coloring Matters.

This cooperative investigation with the Bureau of Plant Industry, Department of Agriculture, referred to in the last annual re- port, has been continued. Measurements for xanthophyll, chlorophyll

and carotin have been extended into the ultra-violet, and a study of

the changes produced by oxidation is being made.

The Spectral Transmission of Spectrometers.

In connection with other investigations it has been necessary to

know the spectral transmission of spectrometers, both prism and grating instruments. This has been measured for various instruments.

Such data should be of general interest; it is, therefore, planned to

extend the measurements to still other instruments and publish the

data so obtained.

The Spectral Reflection of Enamels.

In connection with a cooperative investigation of the enameled metals section of the ceramics division, the spectral reflection of about 25

specimens of " white " enamel was measured. Eesults of the investigation will be published in a Bureau of Standards Technologic Paper.

REFRACTOMETRY AND OPTICAL INSTRUMENTS.

The Testing of Photographic Lenses.

Forty photographic lenses for use in airplane photography have

been submitted to the Bureau of Standards for investigation by the

Air Service, United States Army. These lenses are being subjected

to a complete test, and all the different aberrations are quantitatively

determined. The Air Service hopes by this means to determine

what type of lens is most suitable for use in photographic mapping

from a plane. During the course of this work new adaptations of

older methods have been developed by which the different aberrations

may be measured. The spherical aberration and departure from the

sine conditions are determined by Hartmann's method, and a special

piece of apparatus has been devised which considerably facilitates

the production of the two exposures required for the test. A further

advantage of this apparatus as constructed lies in the fact that both

exposures are made on a single 2| by 3^- plate, and a complete record

is therefore in a convenient form for filing. The other aberrations

are measured visually on an optical bench, and new nodal slides and

other attachments are under design which will facilitate this type of

work. The final results of the tests are represented graphically by

methods which enable the comparative excellence with which the aberrations are eliminated to be determined easily. As a result of this

work the bureau is accumulating a valuable record of the performance

of different types of lenses upon which a standard of excellence may

be based. In fact, some of these data have already served as a basis

for performance specifications for photographic lenses.

Silvering Apparatus.

A new apparatus for silvering glass has been installed in order

that the silvering may be accomplished without the failure and waste
124

of time incident to the old method. In the method which is now

employed the reducing solution and silvering solution drop at the

proper rate from two glass tubes into a funnel, from which the mixture flows upon the siirface to be silvered. The method has long been

einployed in commercial plants but seems to be relatively unknown

in scientific laboratories. It enables half film or opaque coatings to

be produced and appears to be much less open to the vicissitudes ac- companying the more common laboratory method.

An addendum to circular letter No. 32 has been prepared which

fully describes this apparatus.

Luminous Cross Wires.

At the request of the Navy Department, attention has been given

to methods of illuminating cross wires on reticules of telescopic

sights by means of radium luminous material. It has been found

possible to illuminate broad lines satisfactorily, but the luminous

material has not been successfully applied to the fine lines which are required in many cases. Design of a Magnifying Stereoscope.

The Coast and Geodetic Survey has requested the Bureau of

Standards to design and build a magnifying stereoscope to be used

in viewing photographs taken from airplanes for the construction

of maps. The design has been completed and the blue prints are in

the shop ready for construction to begin. The stereoscope is of the

variable power type and gives magnifications ranging from 3.3 to

10 diameters.

Design and Construction of a Field Telemeter.

This was in response to a request from the United States Geological Survey, which needs a light and easily portable instrument for

measuring the distance from a plane-table station to near landmarks

with an error not greater than 6 or 8 per cent. It consists of two

small micrometer telescopes with pentaprism attachments adapted

to be clasped, respectively, to the two ends of a stadia rod. Since

the stadia rod is already carried by the surveying party, the additional weight of the two telescopes is not much greater than that

of a pair of binoculars. With the two modified telescopes mounted

on the stadia rod, a single self-contained range finder having a selfcontained adjustment feature and a base length of 10 feet is formed.

This instrument has been completed and gave satisfactory results

when tested at the Bureau of Standards. The Geological Survey is now testing it in actual field use. Study of Spherometer.

Arising from the closer affiliation of the optical shop and the

optical instruments section, there has been a great increase in,

spherometric work. A careful investigation has been made of the

errors of the ring spherometer, and various plans are being con- sidered for increasing the precision of measurement. In particular,

it has been found that the edges of the rings soon become so rounded

that the effective diameter of the ring is a function of the curvature

of the surface to be measured. So far the rings have been calibrated
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 125

for convex surfaces over a limited range by means of the standard

steel balls in the possession of the gauge section. It is expected to

extend the calibration to concave surfaces and to surfaces of large

radii by the use of glass match plates.

Redesign of Apparatus for Measuring Transmission of Optical Glass.

A new transmission apparatus has been constructed in which a Martens photometer head is used to secure the matched fields. The

transmission of the unknown sample will be compared with the

transmission of a similar known standard instead of making the

measurement directly as has been done previously. By this method

the correction for loss of light by reflection at the two surfaces is

made more simply and all trouble due to lack of good color match

in the two fields largely eliminated.

Optical Sytem for Horizontal Angle Mcauring Instrument.

The optical instrument section has designed the optical system for

the horizontal angle measuring instrument being developed by the

aeronautical instrument section.

Modification of Special Cameras for the Navy.

Several small inclinometers for use in airplane cameras and

adapted to automatically register the inclination of cameras at time

of exposure upon the photographic plate were tested and installed

in cameras for the Navy Department. Also an airplane camera was

modified in accordance with plans prepared by the bureau to permit

two views of the horizon to be made on the plate at time of exposure

in addition to the view below the plane. From the view of the horizon the tilt of the camera may be obtained and thus data for the

rectification of the image.

Standard Prism Drawings.

These have been prepared for the different types of optical prisms

along with tables giving the proper dimensions and optical constants

for any given size. The object is to facilitate the ordering of prisms

and eliminate much computation which otherwise has to be done re- peatedly in the design of optical instruments.

Standard Laboratory Telescopes.

Twelve standard 3-power laboratory telescopes have been manufactured for the storeroom, in accordance with the design prepared

last year.

RADIOMETRY.

Roof Covering for Balloon Hangars.

Among the unusual radiation problems presented was that of the

proper covering for balloon hangars. The problem arose as to the

most effective covering for keeping the inside of the hangar at a minimum temperature. The solution is to have the outside of the

roof made of material (asbestos) which reflects a maximum of the

short wave lengths (solar radiation) and emits a maximum of long

wave length radiation (the reradiation of the roofing material as it

becomes warmed by the sun). On the other hand, it appears that
126 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

(contrary to the general belief) the inside of the roof should be

painted with a substance (aluminum) which emits a minimum of

long wave length radiation.

On actual test of roofing materials exposed to the sun it was found

that the sample which was covered with asbestos on the outside and

painted with aluminum on the inside was far better than either of

the samples having (1) both sides painted with aluminum, or (2)

both sides covered with asbestos.

Radiation Characteristics of Quartz Mercury Vapor Lamps Used for

Therapeutic Purposes.

Investigations were made for the United States Public Health

Service on the radiation intensity, etc., of quartz mercury arc burners

used for therapeutic purposes. In the air-cooled burners it was

found that the ultra-violet component as well as the total radiation

was the same for the two types of burners (the all-mercury electrode

burner and the tungsten-mercury electrode burner) when operated

on the same energy input.

The information obtained from an investigation of quartz mercury

lamps, during the past five years, was given in a paper on " Some

Physical Characteristics of the Radiation from Quartz Mercury

LamjDS," presented before the American Electrotherapeutic Association on September 9, 1921.

Stellar Radiation.

During the past year some time was spent at the Lowell Observatory, Flagstaff, Ariz., making new measurements of the total radiation from stars. In addition to this the spectral energy distribution

of 16 stars was determined by means of transmission screens (described in last year's annual report), thus obtaining for the first time

some knowledge of the radiation intensities in the complete spectrum

of a star. The results obtained verify previous observations made seven years

ago showing that the red stars emit three to four times as much

total radiation as blue stars of the same visual magnitude. The spectral radiation measurements indicate an energy distribution similar

to that of a black body at 3,000° C. for red stars to 10,000 or 13,000° G.

for blue stars.

Planetary Radiation.

By comparison of the water-cell transmission of the sun's rays

coming directly to the earth with similar measurement of the radiations coming from the planets, it was found that the water-cell transmission of the total radiation from Jupiter was the same as that of

the direct solar radiation. From this it appears that Jupiter's at- mosphere does not reradiate energy as the result of warming by

solar rays and that the atmosphere is sufficiently thick and opaque to

trap all the energy reradiated as the result of warming of its surface

by solar radiation.

The order of intensity of reradiation, as interpreted from the per

cent water-cell transmissions (Tr. of Sun=70), is as follows: Jupiter,

; Venus, 5 ; Saturn, 15 ; Mars, 30 ; and Moon, 80.

Measurements on the south and north polar regions of Mars are

different and, quantitatively, in agreement with visual observations,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 127

which show a slight cloudiness in one polar region, that would tend

to trap the reradiated energy of long-wave lengths (emanating from

the surface) thus raising the water-cell transmissions, as observed.

Photoelectrical Investigations.

As these investigations progress it becomes more and more evident

that the phenomenon of photoelectrical conduction in solids is very

complex. Each newly discovered photosensitive substance yields new

results. For example, in some substances (e. g., molybdenite and

stibnite) the photosensitivity was found most marked along the intergrowth of two bundles of acicular crystals. In certain samples of

molybdenite, radiation stimuli of certain wave lengths induce a counter e. m. f. Argentite.—An examination was made and a paper was prepared

on the " Spectrophotoelectrical Sensitivity of Argentite." This

paper, considered in connection with previously published data

(Scientific Paper No. 344) represents a study of the effect of crystal

structure upon photoelectrical sensitivity, as observed in silver sulphide, AggO, in the isometric form, argentite, and in the orthorhombic

form, acanthite. The results obtained show that crystal structure

affects the spectrophotoelectrical reaction, but is not the underlying

cause of this phenomenon. For silver sulphide appears to have a characteristic response spectrum, just as is true of selenium, cupric

oxide, etc. Bournonite and pyrargyrite.—An examination was made and a paper written on the " Spectrophotoelectrical Sensitivity of Bournonite and Pyrarg3^rite."

This paper, in connection with previously published data on

proustite (Scientific Paper No. 412), represents a study of the effect

of chemical constitution upon spectrophotoelectrical sensitivity.

In previous researches on absorption spectra it was found that the

absorption bands of a compound are not the composite of the constituents. Similarly, in spectrophotoelectrical reaction spectra, the

bands of selective reaction of the, double sulphide of silver and of

antimony (pyrargyrite) are not the sum of the spectral reactions of

the individual sulphides of silver and of antimony, which react

photoelectrically.

Various other substances.—Among other substances examined were

some lead and silver salts, also the chloride, bromide, and iodide of

thallium (some samples of which were kindly prepared by the Case

research laboratory). From the results obtained it appears that

the maximum of photoelectrical sensitivity, which is a sharp narrow

line, shifts to the long wave lengths with increase in atomic weight

of the acid element (TlCl at 0.3?[j., TlBr at 0.41iJ,, Til at 0.46[x_, and

Pblj at 0.52iJi.) . This shift of the maximum is similar to the shift of

the maximum of photoelectrical reaction in gasionic photoelectric

cells of the alkali metals (Na, K, Ca, Sr, Ba).

Experiments on the Direct Transformation of Light Into Electric

Current.

Several experiments are on record purporting to demonstrate the

direct transformation of light into electric current. But a critical

analysis of the procedure shows that the light waves were absorbed

9644—22 10
128 EEPORT OF DIRECTOE OP BUREAU OF STANDARDS.

and transformed into heat at the juncture of two dissimilar substances and that the resulting current is ascribable to the wellknown thermoelectric phenomenon.

Concerning- the generation of an electric current from direct light,

it may be said that numerous samples of molybdenite were found

which generated a small electric current without an impressed potential and without any apparent photochemical action, when exposed

to light.

These tests were made by connecting the molybdenite with a sensitive Thomson galvanometer and exposing different parts of the

sample to an equal energy spectrum. It was found that, on exposure

to some parts of the crystal (remote from the electrodes) to radiation, a small electric current is developed which is a function ot the

wave length of the light stimulus and of the thickness of the sample.

T]ie maximum effect is produced by wave lengths of 0.7 to 0.8[ji and no effect by the wave lengths greater than The effect may

be " photopositive " or " photonegative " depending upon the wave

length of the radiation stimulus, just as observed when there is an

impressed potential. It is, therefore, an interesting question whether

all photoelectrical reactions in solids are an amplification of the

effects produced without an impressed e. m. f. The actual magnitude is too small to affect the customary photoelectrical reactions

observed in molybdenite.

DISPERSOIDS.

Assistance to the District of Columbia Fire Department in SmokeMask Training.

In cooperation with the Bureau of Mines, the bureau has assisted

in testing smoke masks for the District of Columbia fire department and in training the men in their use. In training, smoke from

smoldering excelsior and fumes from an ammonia tank were used

the chief danger in fighting fires being carbon monoxide, which is

odorless. A demonstration of the removal of the odor from illuminating gas by the ordinary army canister was also made to warn the

men of the danger in using this canister, which gives practically

no protection against carbon monoxide.

Turbidimetry.

The characteristics of the Kober nephelometer have been studied

and published in the chemical press. Commercial 75 cm. turbidity

tubes have been measured, to furnish the Scientific Utilities Co.

with information for their manufacture.

The bureau is cooperating with Dr. W. G. Exton, of the Prudential Insurance Co., in placing an improved turbidimeter of the

disappearance type upon the market.

Ultramicroscopy.

In cooperation with other sections of the bureau, ultramicroscopic

examinations have been made on oils, paints, optical glass, ceramics,

sugar, etc. Samples of thermatomic carbon, precipitated coagulum

from automobile crank-case oil, " amalgam " in the Trent process

for recovering coal from low-grade ores, etc., have been examined

in the microscope and ultramicroscope.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 129

Statistical Standards.

In studying dispersoids statistical methods must be used. For

example, the large particles are graded according to size by sieves,

the smaller particles by the rate of settling. The size distribution

of ultramicroscopic particles is determined by the average displacement in Brownian movement. Such statistical methods, like any

others, need to be standardized. These mathematical standards

apply in every field of pure and applied science, so that the bureau

is called upon to advise other departments of the Government and

the public upon the general and mathematical questions involved in

estimating by sampling.

As an example of such work, a cooperative study has been made

with a biologist of the New York State Conservation Commission

of the statistical advantages of the logarithm of the number of

bacteria per liter as a standard bacterial index. This work is now

being considered by the committee on revision of the United States

Public Health Service standard of water quality.

Advice has also been given the committees of the American Society for Testing Materials, Avhich have been considering the standardization of statistical constants and methods of sampling, and

the division of vital statistics of the Census Bureau on correlation

constants.

INTERFEROMETRY.

Thermal Expansion.

The extreme sensitivity of interference methods makes it possible

to measure the dimensional changes of small samples with great

precision. The thermal expansion of samples 1 to 10 millimeters in

length can be determined with an uncertainty of not more than one- half of 1 per cent. Temperature control apparatus has been constructed with which measurements can be made in the temperature

interval —150 to -|-1,000° C. For most of the work the Fizeau

method is used, but in special cases, when it is necessary to determine

the expansivity of specimens taken from different parts of the same

sample, a method by which the expansivities of three pins can be

measured simiiltaneously is employed. During the past year tests have been made on samples of commercial and optical glass, cast

steel, amalgams, nickel, gauge steel, etc. Index of Refraction.

Several different types of interferometers have been used to determine the absolute indices of refraction and the variation of index

and dispersion with pressure, temperature, etc. Several gases, vapors,

liquids, and transparent solids have been investigated. A paper on

the changes of the index of glass with temperature is being prepared

fpr publication.

Calibration of End Standards.

During the year several redeterminations of the bureau's end

standard have been made by direct comparison with the standard

light waves. These standards are used in the calibration of pi'ecision gauges.
130 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The standards of concerns engaged in the manufacture of precision gauges have also been calibrated. Scientific Paper No. 436,

describing the methods and apparatus for calibrating gauges, has

been published during the year.

Ruling of Line Standards.

Several line scales have been ruled using a Michelson type of interferometer and the light waves as the fundamental length standard.

Different scales with 100 millimeter divisions have been ruled with

error for the total distance ranging from 0.2 to 1.0 micron. The

error of any millimeter division was too small to be detected with

the microscope. One such scale was sent to the International Bureau at Paris for calibration. The report stated that the results

of the calibration were very remarkable—the largest error being

0.27 micron.

Apparatus is now being constructed for ruling scales up to 1 meter

in length.

Dimensional Changes of Materials.

An investigation of the dimensional changes of materials with

time and the effect of different treatments upon this stability has

been undertaken. A single example of the value of such an investigation may be cited in the need of an exceedingly stable material

length standard. New apparatus has been constructed which will

measure samples at the rate of one per minute. Already quite ex- tensive measurements have been made upon gauge steel and it is

planned to extend the work to other materials.

PHOTOGRAPHIC TECHNOLOGY.

" Inertia " of Photographic Plates and Films.

Accurate speed determinations of photographic plates and films are very difficult to make because of the change of the inertia with

the growth of contrast. Potassium bromide, either in the developer

or emulsion, as is well known, causes the inertia to decrease (speed

to increase) with an increase in contrast. In practically all the

works on sensitometry it is stated or implied that the inertia remains

constant for all times of development except when bromide is present.

This, however, is not correct in all cases; in fact, with a majority

of the photographic plates and films the inertia does change with

a change in contrast, usually in just the opposite direction to the

change caused by potassium iDromide. The Bureau is of the opinion

that these inertia movements are real and are a characteristic of

the emialsion. This problem has been under investigation and the

results will be published later as a scientific paper.

" The Sensitometry of Photographic Emulsions," Scientific Paper

No. 439, has been issued. While this investigation reported two

years ago has been completed some time, the pressure of other work

prevented the preparation of the data for earlier publication.

Color Sensitizing of Photographic Plates by Bathing.

This work, mentioned in the last annual report, under the topic

photosensitizing and hypersensitizing, was carried to completion and
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 131

the results published in Scientific Paper No. 422 under the title

"Studies in Color Sensitive Photographic Plates and Methods of

Sensitizing by Bathing."

The Action of Charred Paper on the Photographic Plate.

An iijvestigation for a method of deciphering the written and

printed matter contained on papers which have been charred, shows

that good results may be had by the use of photographic plates.

If the charred papers are placed in contact with the emulsion of

fast or medium speed photographic plates, kept in this condition in

total darkness for a period of from one to two weeks, then developed

in the usual manner, it is found that the plate is blackened by the

charred paper except in those places occupied by the ink.

It appears that the gases contained in the charred paper have the

power to fog the photographic plate and that the ink acts as a screen to the emanation of the gas. Films are not nearly so well

adapted to this purpose as plates. They require a much longer ex- posure to the charred paper, about two months, and then it is found

that the ink is the active portion and the charred paper inactive

just the reverse of plates.

Washing a film in pure water for a short time and drying (all in

darkness of course) before exposure, gives results similar to the

photographic plate. Very slow plates such as " Process," and the

enlarging and printing papers are comparatively insensitive. The

results of this investigation will be published in detail under the

above title. Veterans' Bureau School of Photography.

At the request of the Veterans' Bureau, advice has been given on

a course of study, laboratory equipment, and laboratory plans for

their school of photography.

TESTING, INFORMATION, AND PUBLICATIONS.

Tests Completed During the Year.

Work of routine nature completed during the year, amounting to something over 4,500 articles tested, covered : Spectrum tubes, photosensitizing dyes, spectrochemical analyses; polariscopes and polariscope cover glasses, samples of raw sugar and molasses, quartz control plates; spectral transmission of glasses, tanning solutions,

celluloid, prisms and plant pigments; spectral reflection of talc,

paints, leather, and rope ; relative radiant power and color temperature of lamps; binoculars, telescopes, microscopes, photographic

lenses; refractive indices, dispersion and transmission of optical

glass and other substances ; refractometers, spectrographs, and prism

angles; standard sources of radiation, photoelectric cells, eye-protective glasses ; fading effects of ultra-violet light ; thermal expansion, planeness of surfaces; and calibration of end standards.

Information, Cooperation with Societies, etc.

_ An important part of the division's activities has consisted in furnishing information on scientific and technical subjects related to its

work, by extensive correspondence, reports, or directly to technical

men visiting its laboratories.
132 BBPORT OF DIRECTOR OF BUREAU OF STANDARDS,

Members of the division have cooperated in the activities of various

scientific and technical societies, including: The Optical Society of

America in the standardization of nomenclature and the compiling of

standard data needed in spectroscopy, colorimetry, and radiometry;

the International Astronomical Union in regard to standard wave

lengths; the American Chemical Society on refractive ind^ tables

for sugar solutions; and the Illuminating Engineering Society on

research.

Publications.

The following publications, relating to the work of the division,

have appeared during the year among the publications of the

Bureau of Standards, and they may be obtained from the Superintendent of Documents, Government Printing Office, Washington,

D. C:

Interference measurements in the spectra of argon, krypton, and xenon (W. F. Meggers), Sci. Paper No. 414. Wave lengths longer than 5,500 A in the arc spectra of yttrium, lanthanum

and cerium, and the preparation of pure rare earth elements (in cooperation

with the chemistry dept.. University of Illinois), (C. C. Kiess, B. S. Hopkins,

and H. C. Kremers), Sci. Paper No. 421. Studies in color sensitive photographic plates and methods of sensitizing by

bathing (in cooperation with the photographic shop of this bureau), (Francis

M. Walters, jr., and Raymond Davis), Sci. Paper No. 422. An atlas of photographic negative emulsions (in cooperation with the photographic shop), (Raymond Davis and F. M. Walters, jr.).

Notes on standard wave lengths, spectrographs and spectrum tubes (W. F. Meggers and Keivin Burns), Sci. Paper No. 441. Arc Spectra of Neodymium and samarium (C. C. Kiess), Sci. Paper No. 442. A significant exception to the principle of selection (in cooperation with the

pyroriietry section), Phil. Mag., 43, p. 659; 1922.

The excitation of the enhanced spectra of sodium and potassium in a low voltage arc (P. D. Foote, W. F. Meggers, and F. L. Mohler), Astrophy. Jour., 55,

p. 145; 1922.

1921 report of the committee on standard wave lengths (in cooperation with

a conunittee of the Optical Society of America), J. O. S. A., and R. S. I., 6, p. 135; 1922.

Practical spectrographic analysis (W. F. Meggers, C. C. Kiess, and F. J. Stimson), Sci. Paper (in press).

False spectra from diffraction gratings (Part I by W. F. Meggers and C. C. Kiess; II, by C. Runge; and III, by J. A. Anderson), to appear in the Julynumber of J. O. S. A., and R. S. I. Preparation of galactose (B. P. Clark), Sci. Paper No. 416. Note on the preparation of niannose (E. P. Clark), Sci. Paper No. 429. An improved method for preparing rafflnose (E. P. Clark), Sci. Paper No. 432. The solubility of dextrose in water (R. F. Jackison and C. G. Silsbee), Sci. Paper No. 437. The spectral distribution of energy required to evoke the gray sensation (Irwin

G. Priest), Sci. Paper No. 417. The spectral transmissive properties of dyes—I, The seven permitted food

dves ill the visible ultra-violet and infra-red (K. S. Gibson, H. J. McNicholas,

E. P. T. Tyndall, M. K. Frehafer, and W. E. Mathewson), Sci. Paper No. 440. Supplementary note on the frequencies of complementary hues (Irwin G.

Priest), .J. O. S. A., Vol. V, No. 6, pp. 513-514; 1921.

Measurement of the color temperature of the hiore efficient artificial light sources by the method of rotatory dispersion (Irwin G. Priest), J. O. S. A., Vol. VI, No. 1, pp. 27-41; 1922.

A field telemeter for approximate surveying (I. C. Gardner), J. O. S. A. (in

press )

Method of designing an objective for an astronomical telescope, Letter Circular

No. 67. Si)herical aberration in thin lenses (T. Townsend Smith), Sci. Paper (in

pre.ss).
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 133

A portable vacuum thermopile (W. W. Coblentz), Sci. Paper No. 413.

Spectroradiometric investigation of the transmission of various substances, II (W. W. Coblentz), Sci. Paper No. 418.

Tests of stellar radiometers and measurements of the energy distribution In the spectra of 16 stars (W. W. Coblentz), Sci. Paper No. 438. Spectrophotoelectrical sensitivity of argentite (W. W. Coblentz) (in press).

Spectrophotoelectrical sensitivity of bournonite and pyrargyrite (AV. W. Coblentz and J. F. Ecliford) (in press).

Some physical characteristics of the radiation from quartz mercury lamps (W.

W. Coblentz), Jour. Electrotherapeutic association, 1922.

New stellar radiation measurements (W., W. Coblentz), Astrophys. Jour.,

January, 1922.

The eifective temperature of 16 stars as estimated from the energy distribution

in the complete spectrum (W. W. Coblentz), Proc. Nat. Acad. Sci., March,

1922.

Sur I'Epaisseur des Lames Stratifiees (P. V. Wells), Annals de Physique, 16, pp. 69^110; 1921.

A simple theory of the nephelometer (P. V. Wells), J. Am. Chem. Soc, 44, pp. 267-276; 1922.

Turbidlmetry of water (P. V. Wells), Jour. Am. Water Works Ass'n.. 9, po. 488-490; 1922.

A standard bacterial index (P. V. Wells and W. F. Wells), Jour. Am. Water

Works Ass'n., 9, pp. 502-527; 1922. Interference methods for standardizing and testing precision gauge blocks (C.

G. Peters and H. S. Boyd), Sci. Paper No. 436.

A new method for the measux-ement of photographic filter factors (Raymond

Davis), Sci. Paper No. 409. The papers listed below were presented before meetings of scientific societies during the year:

Spectrographic tests for the purity of some metals, presented before the Philosophical Society of Washington, February 11, 1922. (See Jour, of Wash.

Acad, of Sciences, 12, p. 267; 1922.)

Decolorizing carbons (H. H. Peters), presented before the sugar division of

the Am., Chem. Soc, New York, N. Y., September, 1921.

An inquiry into fundamentals of sugar colorimetry (H. H. Peters), presented

before the sugar division of the Am. Chem. Soc, New York, N. Y., September,

1921.

The testing of quartz control plates (F. P. Phelps), presented before the sugar

division of the Am. Chem. Soc, New York, N. Y., September, 1921.

The estimation of raffinose and sucrose in beet products (R. F. Jackson), pre- sented before the sugar division of the Am. Chem. Soc, New York, N. Y., September, 1921.

A simple diffusion battery for laboratory and lecture room experiments (M. J. Proffltt), presented before the sugar division of the Am. Chem. Soc, New

York, N. Y., September, 1921.

Modifications in the use and application of the Hess-Ives tint photometer (H. H.

Peters and F. P. Phelps), presented before the sugar division of the Am.

Chem. Soc, Birmingham, Ala., April, 1922.

Color values of high grade sugars (W. B. Newkirk and H. H. Peters), pre- sented before the sugar division of the Am. Chem. Soc, Birmingham, Ala.,

April, 1922.

Note on a laboratory vacuum still (E. P. Clark), presented before the sugar

division of Am. Chem. Soc, Birmingham, Ala., April, 1922.

Some thermal effects observed in chilled glass (A. Q. Tool and C. G. Eichlin),

presented before the Optical Society of America, Rochester, N. Y., October,

1921.

Measurement of the color temperature of the more efficient artificial light sources by the method of rotatory dispersion (Irwin G. Priest), presented

before the Optical Society of America, Rochester, N. Y., October 26, 1921.

The complete scale of color temperature and its application to the color grading

of daylight and artificial illuminants (Irwin G. Priest), presented before the

American Physical Society, Washington, D. C, April 22, 1922.

Some physical characteristics of the radiation from quartz mercury lamps

(W. W. Coblentz), presented before the Washington meeting of the American

Electrotherapeutic Association.
134 EEPORT OF DIRECTOR OF BUREAU OE STANDARDS.

CHEMISTRY.

The work of this division includes the investigation of the chemical composition and

purity of materials, studies of chemical properties and constants, researches in connection

with methods of analysis, the preparation of specifications for technical materials for other departments of the Government and for industrial and scientific laboratories. The

chemistry division has general supervision of all chemical work at the bureau. In practically all questions of standardization or research the purity of the materials involved is an

important factor. Much of the work of this nature supervised by the chemistry division

is described under the appropriate headings elsewhere in this report.

GENERAL.

Reorganization of Sections.

The death, in September, 1921, of Mr. S. S. Voorhees, chief of a

section of the chemistry division, made advisable a reorganization

of the sectional framework of the division. The net result was a

reduction in the number of sections from nine to seven and considerable redistribution of work.

Cooperation with Technical Societies.

The chemistry division has, as in the past, cooperated extensively

with committees of technical societies. The division is represented on

many committees that are engaged in scientific woi'k and in a number

of instances its members are chairmen of committees.

ELECTROCHEMISTRY.

Included in this work are studies of electrodeposition used in

electrotyping and electroplating, the latter being made up of investigations of zinc, lead, copper, silver plating, etc.

Nickel Deposition.

During the past fiscal year the electrochemistry section has devoted its efforts especially to a study of nickel deposition. Work

has been conducted upon several phases of the subject. Some of

these have been nearly completed and others will require considerable further study. The general purpose of these investigations has

been to determine the fundamental principles regarding the operation and control of nickel depositing solutions and their application

in commercial practice. It is hoped through such studies to define

those conditions of operation which will yield the most uniformly

satisfactory results with the least expense and loss due to inferior

and defective work. In planning and conducting these studies the

bureau has benefited greatly by the advice and cooperation of members of the American Electroplaters' Society, especially from George

B. Hogaboom, electroplating adviser to the bureau, and members of

the research committee. These persons have visited the bureau,

twice during the year and on each occasion have considered care- fully the plans and progress of the bureau's researches and have

made many helpful suggestions. In addition, they have communicated information and suggestions to the bureau on numerous occasions. It is only through such willing and earnest cooperation as the bureau has received from these persons that its work can be

made directly applicable and useful to the electroplating industry.

The status of the various researches may be briefly summarized as follows
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 135

Acidity.—A simple method of measuring the acidity of nickelplating; solutions has been developed and is being tested in eight commercial plants. Results so far obtained indicate that improper

acidity is only one of several causes for defective nickel plating, but

if it is controlled other conditions can be more uniformly maintained

and other causes can be more readily detected and corrected.

Iron.—To the presence of iron in nickel deposits, defective plating

has often been attributed. It is apparent that under some conditions

the presence of iron is more detrimental than under others. A study

of the effects of iron has just been commenced.

Anodes.—In order to prepare deposits free from or containing definite amounts of iron, it is necessary to secure nickel anodes of definite composition. The effects of various impurities and of the

method of preparing nickel anodes has never been clearly established. A study of these factors is being made. From such a study

it is hoped that simple reliable specifications for nickel anodes can

be prepared.

Salts.—It is also necessary to secure nickel salts 'of reasonable commercial purity. The exact effect of each of the probable impurities

has not yet been determined. Analyses have been made of a large

number of samples and the advice and cooperation of manufacturers

and dealers has been requested, in the effort to at least exclude from

the electroplating trade salts that are grossly impure.

Conductivity.—The conductivity of solutions containing the usual

constituents of nickel baths is being determined. Such information

may be useful in permitting more rapid deposition.

Throwing power.—The ability of a plating solution to deposit uniformly on irregularly shaped articles is of great importance. Preliminary studies have led to the development of the underlying

principles, which are now being tested out experimentally.

GAS CHEMISTRY.

Methods of purification, analysis, and testing of gases, including

illuminating gas and special gases, such as hydrogen, oxygen, nitrogen, and argon, comprise the chief work of the section of gas

chemistry.

The work of the section during the past year was carried on almost exclusively with funds transferred from the Air Services of

the Army and Navy. These problems received the first attention

of the section, and the work upon each originally contemplated has

been practically completed. This work for the Air Services will

be described first.

Investigation of Methods of Producing Hydrogen for Aeronautical

Purposes.

The major problem of the section during the past year has been

that of developing a more economical method for producing hydrogen under the conditions required for military aviation. Some

time was devoted to each of eight radically different processes.

Experimental work was done upon five processes, ranging from a few days' work in the laboratory to the experimental operation of

a plant of commercial size requiring the services of approximately

10 men during four months.
136 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Oil-cracTcing process.—The process first investigated was that of

the thermal decomposition of a hydrocarbon oil by contact with a highly heated solid. The major part of the experimental work had

been done before the last annual I'eport was prepared and is partially covered in that report. The interpretation of the results and

the preparation of a technical report required much time. The re- sults of the investigation carried out in the experimental plant are covered in a report entitled " The Production of Hydrogen by the

Thermal Decomposition of Oil," which was transmitted in October,

1921. The process was shown to be a valuable one, provided suitable refractories and an adequate supply of solid fuel having the

necessary characteristics could be found. Both these requirements

were made the subject of investigations.

The location of an adequate source of supply of dense carbon

practically free from ash-forming constituents was undertaken by

correspondence. Numerous sarnples of the products of various

manufacturers were examined and satisfactory tentative proposals

were finally obtained from several concerns. The results are included in the " Progress Eeport on the Investigation of Methods

for the Production of Hydrogen," dated March 25, 1922.

The testing of refractories for use in the process presented more

serious difficulties. An effort was made in cooperation with the

ceramics division of this bureau to obtain samples of all refractories made commercially in this country which might be expected

to meet the difficult requirements of the process. Thirteen of these

products were subjected to test in a load furnace heated to temperatures as high as 1,760° C. Two refractories were found which could

be used to advantage in the hydrogen plant, and several which had

been highly recommended were definitely eliminated. The results

of these tests were issued in the report entitled " High Temperature Load Tests of Commercial Eefractory Brick," dated May 11.

1922.

A specification and drawings of a hydrogen plant employing this

process were prepared under the title " General Specification for a Hydrogen Plant to Produce a Maximum of 120,000 Cubic Feet of

Hydrogen per 24-hour Day," dated May. 13, 1922. A contract for a

plant costing approximately $40,000 to be located at Scott Field has

just been let by the Air Service under this specification.

Steam-iron process.—Without doubt more than half the time of

the section during the past year has been devoted to a study of the

steam-iron process for producing hydrogen. An improved method,

based upon the utilization of heat wasted in the older methods, has

been developed. The experiments with this process, which were made

upon a commercial scale, indicate an increase in thermal efficiency

of 30 to 50 per cent over the methods of this class now employed,

and a large saving in the cost of maintaining the plant. The

process is not well suited to intermittent operation, however, and its future usefulness must be looked for in the field of industry rather

than aviation. The report upon this process is still in preparation.

Ferrosillcon process.—Tests were made upon the first of 10 new

hydrogen generators to employ the ferrosilicon process, which were

being constructed for the Navy Department. These tests were made

to determine the capacity of the plants, the efficiencies of the cooling

11
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 137

systems under various conditions, and the characteristics of a new

feeding mechanism which was being introduced. These tests and

some supplementary experiments resulted in the development of

an entirely different method of feeding, and in a modification of

the cooling system. These changes not only improved the' generators

but accomplished a considerable financial saving to the Government

in the cost of the plants. The results are given in a report entitled

" Eeport of Tests of Ferrosilicon Hydrogen Plant," dated July

22, 1921.

A paper upon " The Production of Hydrogen by Use of Silicon

and Sodium Hydroxide" was presented by invitation at the spring

meeting of the American Electrochemical Society on April 29.

This will be published in the proceedings of the society.

Miscellaneous worh on the production of hydrogen.—kxi effort

was made to accomplish the simultaneous production of hydrogen

and of salable lampblack by the decomposition of oil in an electric

arc. The process was a complete failure because practically all of

the carbon separated in the arc is precipitated in a dense form at

the ends of the arc. This work is described in the progress report

for March 25.

An electrolytic hydrogen-oxygen generator in which the electrolyte was stirred for the purpose of freeing the electrodes from bubbles

and thereby decreasing the resistance of the cell was submitted for

test by the Air Service. This apparatus was tested with negative

results. Since the question of the practicability of decreasing the

resistance of a cell in this way had arisen several times, it seemed

worth while to make an effort to settle the question once for all

if possible. Consequently an apparatus was constructed in which the

electrodes were vigorously brushed with mechanical brushes. The

results were negative, the difference in resistance being almost inappreciable when the brushes were set in motion.

This work is described in the " Report on an Electrolytic Hydrogen

Cell with Mechanical Depolarizer," dated July 27, 1921.

Two conferences were held to consider two new methods of hydrogen production proposed by different firms of consulting engineers. One of these processes was definitely eliminated from

further consideration at the first conference. The other process is

quite promising and it is possible that experimental work will be

done upon it during the coming year if arrangements for such work

can be made without excessive cost to the Government.

Balloon Fabrics.

The work upon balloon fabrics during the past year has been

almost exclusively in the nature of routine testing. A total of 329

tests of various kinds were made upon 299 fabrics by the section

during the year.

Portable Permeability Apparatus.

A portable instrument for determining the permeability of a segment of balloon fabric without removing from the balloon has

been developed. This instrument permits a determination to be

made in about one minute. The instrument has been tested in service with satisfactory results. The first one constructed is now in

service at McCook Field. The development involved several months
138 KEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

of experimental work and the construction of four or five unsatisfactory instruments before a successful one was made.

Balloon Gas-Purity Indicator.

An instrument believed to be satisfactory for indicating the

purity of the gas in an airship has been' developed. This instrument has not yet been tried out in service, but it is now ready for a

service test. This instrument, Avhich is not heavy, will permit a. pilot to read the pLirity of his gas within a few seconds and without drawing any gas from the balloon.

Problems Not Connected with Aviation.

Auto77iatic gas analysis apparatus.—Much work has been done

upon automatic gas analysis apparatus other than the instruments

developed in connection with aviation which have already been

described.

tSulphur dioxide recorders.—Instruments were constructed for the

purpose of recording the concentration of sulphur dioxide in the

gas leaving the sulphur burners and the gas after absorption of the

sulphur trioxide in the contact process for making sulphuric acid.

These recorders were installed in the plant of the naval powder factory at Indianhead, Md., where they have been in use and have

given satisfactory service for nearly a year. Similar i-ecorders, built

according to plans furnished by this laboratory, were installed several months ago by a large industrial concern, and they have just

placed an order for a second set of instruments. The success of

these two installations is the best evidence that the apparatus of

this type can be made to give satisfactory service under plant conditions when in charge of men not especially trained for the use of

them. This should answer the principal question which has been

raised concerning the ultimate value of these instruments to industry. The possibility of using the apparatus successfully in the

laboratory for a great variety of analyses was demonstrated several

years ago.

Recording and control of composition of gases from electrolytic

generators.—An instrument for recording the purity of electrolytic

oxygen was made up and loaned to the Washington Navy Yard,

where it gave perfect service for a little over a month. It was then

brought back to this bureau because of the arrival of a much advertised recorder of another type, which the Navy had already

purchased at a cost considerably greater than that of the instrument constructed at this bureau. After using the commercial instrument for several months, the navy yard decided to discard the instrument they had purchased and requested the bureau to build one

of the thermal-conductivity type. Financial arrangements have not

yet been completed to make this possible.

As a demonstration of the possibilities of automatic control of

industrial processes, the section prepared a recorder with contacts

which would automatically vary the gas composition through a

closed cycle. Four operations were involved, each step taking place

when the composition of the gas reached a certain predetermined

figure. The entire cycle occupied about three minutes. The apparatus was sent to the Exposition of Chemical Industries at New
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 139

York, N. Y., and operated perfectly during the entire week, attracting much attention.

Some of the work which has been done along this line was described in a paper entitled " Gas Purity Recorder for Electrolytic

Oxygen and Hydrogen," published as a bulletin of the Compressed

Gas Manufacturers' Association on December 8, 1921.

Control of comtustion gases.—A considerable amount of work has

been done toward recording and controlling the composition of gases,

especially flue gases and other products of combustion, on the basis

of their oxygen content. Oxygen is really a better criterion of

efficient combustion in boilers and furnaces than is carbon dioxide

which is usually determined. In some cases where either the presence

or absence of oxygen is required for chemical reasons, it is essential.

An arrangement was made with one large industrial concern to

cooperate in the development and trial of an instrument for the

purpose of controlling the firing of a tunnel kiln, but lack of time

has prevented much progress being made by the section on this

particular problem.

In connection with the devolpment of instruments, which has been

described, several improvements have been made in the thermostating

of units, in the control of adjustment of voltagCj and in simple and

cheap methods of applying the gas analyzing units to recording and

automatic control. Some of these devices may find other applications. A paper is now in preparation which will describe several

of them.

Ahsorption of gases in liquids.—A study is being made of the

absorption of gases in liquids. This problem is of fundamental

importance in the design of scrubbers and absorbing apparatus of

all kinds employed in many industries. It is also of importance in

gas analysis. The present study is so far concerned with fundamental principles. A mathematical study was first made with the

aid of simplifying assumptions where necessary, and the various

problems reduced to simple terms involving only one important un- known quantity termed the " coefficient of absorption." A large

amount of laboratory work has been done for the purpose of determining the value of this coefficient for various cases, and the effect

of several variable conditions upon it. Some surprising phenomena

have been observed, and the problem seems to have opened up a whole field of great scientific interest as well as practical importance.

Methods of gas analysis hy combustion and hy fractionation.—

A

study of the methods of gas analysis depending upon combustion is

now being undertaken. For the purpose of this investigation it is

necessary to prepare several of the hydrocarbon gases in a fairly pure

state. This is most readily accomplished by the use of fractionation.

While using fractionation in the preparation of gases it seems worth

while also to study the use of fractionation in analysis. A considerable amount of apparatus has been designed and is now being constructed for this general purpose.

Circular on pressure-volume-temperature relations of gases.—The

receipt of numerous inquiries, from both producers and consumers

of compressed gases and from testing laboratories, which are sometimes called upon to settle disputes, led the section to initiate an

effort to fix standards for the measurement of compressed gases.
140 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The matter was taken up with other interested sections of the

bureau and with the National Compressed Gas Manufacturers' Association and the Gas Products Association. A conference was held

at the bureau at which substantial agreement was reached that compressed gases should be measured for sale on the basis of gas actually delivered at 20° C. and 760 mm. The determination of the

corrections to be made to observed pressures and temperatures to

reduce these conditions was left tentatively to the bureau. The first

step necessary is an accurate summary of the present state of knowledge of the relations between pressure, volume, and temperature for

all commercial gases. This section is endeavoring to prepare this

summary and to put it in such form that, while giving the most

accurate scientific data, it can also be easily used for making any

computation involving these quantities by the untrained man.

REAGENTS AND APPARATUS.

In this work may be mentioned the study of methods of testing

reagents and apparatus to be used in chemical apparatus, including

study of chemical glassware, porcelain, platinum, and platinum

substitutes.

Chemical Reagents and Apparatus.

Limited personnel and lack of funds have again prevented undertaking systematic work on chemical reagents. Owing to the urgent

necessity of testing the reagents used in the bureau's laboratories,

one man was assigned to this work during the last four months

of the year. In this time the following reagents were examined

Siulphuric acid, hydrochloric acid, ammoniiun hydroxide, potassium

pyrosulphate, calcium carbonate, sodium carbonate, ethyl alcohol,

potassium nitrate, potassium hydroxide, sodium hydroxide, and,

sodium sulphate.

As has been pointed out in previous repoiis, a systematic study

of " analyzed reagents " involves standards of quality and standardization of methods of test, and is therefore of direct value to science

and the industries. For this reason means should be provided for

prosecuting this work.

In the reorganization of the division which occurred in November, 1921, the branch of the bureau's work known as the preparation of pure substances was assigned to this section. Besides the

routine jDurification of mercury 200 pounds of pure benzoic acid

was prepared for issue as a standard sample. In addition, the

sodium chloride content of several aqueous solutions of this salt

was determined in cooperation with the division of weights and

measures. Platinum Metals Investigation.

The research upon the chemical and physical properties of the

platinum metals has been continued. Much of the necessarily great

amount of preliminary work on purification and preparation has

been completed and several definite projects were initiated during

the past year.

The preparation of pure platinum sponge has been reduced to a routine process and several hundred grams of such sponge were pre-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 141

pared. Much additional work on the melting and working of platinum without contamination has been done in cooperation with the

heat division and the diAdsion of metallurgy. This involved the study

of suitable refractories and the best practice in melting. Several samples of pure platinum wire have been issued to scientific laboratories

for use as standards of comparison. The heat division has substituted rare metal thermocouples made at the bureau from its own preparations of platinum and rhodium for the thermocouples hitherto used

as primary standards. The bureau has been consulted by American

and British manufacturers of pure platinum and of rare metal

thermocouples as to the methods used in the preparation of these

couples. A short paper on the preparation of pure platinum was

published in the Journal of the American Chemical Societj^ Additional data have been collected on the occurrence of calcium in platinum melted in lime.

In cooperation with the divisions previously mentioned, work was

done on the preparation of satisfactory palladium wire from the

palladium sponge previously made. Additional attention was given

to the preparation of pure osmium and a very satisfactory procedure

was developed. This will be published shortly.

Analyses were made of platinum crucibles of British, French, and

German manufacture. These were found to have much the same composition as platinum ware of domestic manufacture except that the

French crucible contained about 0.4 per cent of copper, which is

ordinarily present in traces only. The rhodium content of the French

ware was also higher than usual.

The preparation and study of alloys of the platinum metals has

been begun. Series of platinum-rhodium and platinum-iridium

alloys containing from 0.001 to 10 per cent of rhodium and iridium,

respectively, have been prepared. Their thermo-electric behavior

against platinum has been studied, and they were further used by the

optics division in the study of the partial spectrum of rhodium and

iridium.

Active work on the study of analytical methods in the platinum

group was begun during the past year. The platinum-iridium alloys

already referred to have served as material for a study of the determination of iridium in ]ilatinum alloys. This is probably the most

important determination in the platinum group. The work thus far

accomplished has been designed to determine the limitations of the

method of Deville and Stas, which, although firet used about 50 years

ago, still is the most reliable method of which the bureau has

knowledge.

Work was also undertaken on the methods of analysis for platinum

ore. Most, if not all, of the platinum ore imported into this country

(valued at over $4,000,000 in 1921 and over $7,000,000 in 1920) is sold

on analysis. The bureau's study has revealed that the methods in use

are quite lacking in accuracy and the bureau's purpose is to develop

modifications of existing methods which Avill make possible much

greater accuracy. In connection with this work the complete composition of two samples of Colombian ore has been determined.

The gold content of several Eed Cross buttons was determined for

the Society of the American Red Cross and of a sample of gold leaf

for the State of Vermont. The bureau was called upon to render an
142 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

opinion in two cases of controversy over the cause of failure of

platinum ware. By order of the Secretary of War, dated January 24, 1922, rhodium -iridium concentrates, reported to contain about 45 ounces of

rhodium and 35 ounces of iridium, were transferred to this bureau.

METAL AND ORE ANALYSIS AND STANDARD SAMPLES.

These investigations cover general methods of chemical analysis,

with special reference to methods of standardization and the preparation and analysis of standard samples of iron, steel, alloy steels,

brasses, bronzes, bearing metals, melting-point metals, ores, cements,

and pure chemicals.

Standard Analyzed Samples.

The number of standard samples called for during the fiscal year

1921-22 was 3,532, as against 4,016 in the year 1920-21. The distribution was as follows:

Irons and steels 2,019

Brass, bronze, and bearing metal 138

Metals for melting points 244

Ores 184

Cements __— 181

Sodium oxalate 247

Benzoic acid 320

Naphthalene 69

Sucrose 108

Dextrose 22

Total 3, 532

The decrease in the number of standard samples issued during the

fiscal year is due in large part to the depression in the industries,

particularly in the iron and steel trade ; this was particularly noticeable in the first half of the year ; in the latter half a nearly normal

sale was established. Another factor in the decrease was the cur- tailment of the standards normally issued to colleges and universities

necessitated by the lack of funds and equipment to carry on the

standard sample work. Steps have been taken to remedy this condition, in so far as metallurgical samples are involved, by issuing a

limited number of 1,000-gram samples for student use. These are prepared from the chips, which are not 6f the standard 20-40

mesh size issued as standard samples ; they are, however, of uniform

composition and are well suited for use in student laboratories.

The fee value of the samples issued during the last three years

has averaged close to $10,000 per year. These fees revert directly

to the Treasury and are not available for use by the bureau for any

purpose whatsoever. Consequently, when Congress discontinued

the special appropriation for the work in 1919 and again failed to

appropriate funds in 1920, the work was carried on under difficulties

and at the expense of other bureau activities. The appropriation of

$10,000 which has been made for the coming fiscal year will lighten

this burden and permit the purchase of material and the preparation

of needed standards.

One new sample was added to the list during the year—No. 54, tinbase bearing metal. Six exhausted standard samples were renewed

as follows: Acid open-hearth steel 0.2 carbon steel, 19b; acid open-
REPORT OP DIRECTOR OF BUREAU OF STANDARDS. 143

hearth 0.4 carbon steel, 20b ; basic open-hearth 0.8 carbon steel, 14b

;

chrome-vanadium steel, 30b ; cement, 46h ; and a new benzoic acid

sample, 39b, to replace the older samples 39a and 48a.

Cooperation in the Analysis of British Chemical Standards.

In addition to carrying on the analytical work dealing with the

bureau's standard samples, considerable analytical work was done

on the British chemical standards. In this work the bureau co- operated with British, Scotch, French, and Italian analysts in the

analysis of the British standard pure iron "A^," and carbon steels " U " 1.2 per cent carbon and " E, " 0.8 per cent carbon.

Cooperation in the Development of Standard Analytical Methods.

During the year the section cooperated with the American Society for Testing Materials in the revision of their standard methods

for the analysis of plain carbon steel and alloy steels and in the

preparation of tentative methods for the analysis of brass ingots,

sand castings, and bronze-bearing metal. Tlie section also co- operated with the subcommittee on analysis of the Committee for

the International Standardization of Zinc; methods for the determination of aluminum, bismuth, tin, and indium in s|)elter were

developed at the bureau and tested by the cooperating analysts.

Umpire Analyses and Standardization of Various Metallurgical Materials.

The work in this field was considerably increased during the past

year. Umpire analj^ses of several kinds were carried out where

analysts had failed to agree and the bureau was asked to settle the

dispute. The policy of the bureau of aiding firms in the standardization of material, of which no standards are available, was con- tinued and considerable analytical work was done on the prepared

samples which were submitted.

Routine Analysis of Ferrous and Nonferrous Materials.

This work includes the chemical analysis of such metallurgical

products as irons, steel, alloy steel, ferros, brass, bronze-bearing

metal, type metal, boiler plugs, solder, pure metal, and coated metals

such as tin plate, galvanized metal, and silverware. Much routine

work was done for a number of branches of the Government service.

Cooperation with the American Society for Testing Materials.

The following methods of analysis, in the compilation of which

the section largely cooperated, are now published as preprints by the

American Society for Testing Materials and will appear in the Proceedings for 1922 : Proposed Tentative Methods of Chemical Analysis

of Plain Carbon Steel; Proposed Tentative Methods of Chemical

Analysis of Alloy Steels; Proposed Tentative Methods of Chemical

Analysis of Brass Ingots and Sand Castings; and Proposed Tentative Methods of Chemical Analysis of Bronze Bearing Metal.

LUBRICATING OILS, RUBBER, PAPER, TEXTILES, INK, AND GLUE.

This section is concerned with chemical analysis and investigations of oils, rubber, paper, textiles, ink, glue, airplane dopes, etc.,

with special reference to meeting particular requirements.

9644—22 11
144 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Airplane Dopes.

For nearl}^ four years there has been comparatiA^ely little activity

in the study of these nnaterials. However, samples are received

from time to time, and a few were tested during the year.

Balloon Fabrics.

The routine chemical examination of rubberized balloon fabrics

continued throughout the year, but the number of samples was not

A^ery large.

In last year's report mention was made of the attempt to prepare

a material for coating balloon cloth which would possess the best

features of both rubber and goldbeaters' skin.

Rubber Chemistry.

During the year the rubber laboratory was never without samples

that must be analyzed for one or another branch of the Government,

yet time was found for work on analytical methods. This investigational work was largely in cooperation with the committee on methods of anah'sis of the rubber division, Ameiican Chemical Society.

One of the chemists of this bureau is chairman of this committee.

It is gratifying to note that at the April. 1922, meeting of the

Chemical Societ}' the rubber division accepted the report of the

above committee, which recommended with onlj^ a few changes the

methods of analysis given in the fourth edition of Circular 38 of this

bureau.

Textile Chemistry.

Even in the routine examination of textiles there is considerable

variety in the tests made. The following determinations are made

on one or more kinds of materials : Composition of wool-cotton mixture, percentage of starch or sizing in cotton goods, fastness of dyes

to light, crocking, water and washing, oil content of rope and twine,

color test for manila fiber, shrinkage of window shades, resistance

of duck to the penetration of water, copper content of cloth intended

for rubberized raincoats, absorptive power of mops and absorbent

cotton, and percentage of asbestos in packings.

Sealskins.

In the annual report for 1921, page 153, mention was made of

the examination of certain sealskins to determine how they had been

dyed. The object was to obtain evidence in connection with a suit

brought by an English corporation against certain individuals and

firms in this country, who had established the business of dyeing

the skins. The English dyers claimed their process as a secret one,

imparted in confidence to their head dyer, and wrongfully used in

this country when he was employed here. This dyer asserted that

the process was his OAvn secret, which he had never divulged, and that

after he left them the English were forced to find a new one. The

work done by the Bureau of Standards showed unmistakable differences in the dyes and mordants used. Afterward four of its

chemists were witnesses at the trial before the United States District

Court in September, 1921. The decision handed down in June, 1922,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 145

was in favor of the Americans, but it would probably have gone

against them if it had not been for the chemical analyses made by

this bureau.

Dyes,

In furtherance of a program for work on dyes, including their

standardization by spectrophotometric measurements, a series of

typical dyes of known purity was prepared. It is planned to continue this work.

Writing and Copying Inks.

Most of the many samples tested were received with bids made to

the General Supply Committee and the Post Office Department.

Comparatively few delivery samples were received for test during

the year.

Stamping, Marking, and Related Inks.

Inks for use on stamp pads ; for numbering, canceling, and duplicating machines ; and for marking and stenciling were tested to determine their suitability for the purposes intended.

Typewriter and Similar Ribbons.

Large numbers of these were tested to aid the General Supply

Committee and the Post Office Department in awarding contracts,

as well as to check deliveries when purchases were made. Most of

the ribbons were for typewriters.

Carbon Paper.

Many samples were examined during the year. Carbon paper is

used in so many ways and under so many different conditions that

no one grade is suitable for all purposes. A given grade may be

entirely suitable for making only 1 or 2 copies on relatively heavy

paper, and not do at all for 10 or 20 copies on very thin paper. Still

another grade may be best for use with pen or pencil. In the latest

proposals of the General Supply Committee more attention than

! ever before is paid to this phase of the subject. This makes the work

' of testing easier and should enable purchasers to secure the grades

best suited to their needs.

Glue, Mucilage, and Paste.

Numerous samples of these were tested during the year. Many of

the samples of paste and some of the mucilage were found to be very

I susceptible to the growth of mold. In some cases the trouble was

due to the use of formaldehyde, an excellent antiseptic but one not

suitable for this purpose. It is so volatile that it soon escapes from

the surface layers of the paste. This is where it is most needed in

I order to kill or prevent the growth of mold spores that settle upon

ij' the paste when it is exposed to the air. Salicylic acid, sodium benzoate, thymol, and j^henol are all more effective than formaldehj'de

because they are but slightly, or not at all, volatile. The essential

I oils, such as wintergreen, clove, and sassafras, have antiseptic prop1 erties. They can be used alone, or to mask the less pleasing odor of

thymol or phenol.
146 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Fingerprinting Device.

For various reasons a system of fingerprinting is used as a means

of identification hj the Postal Savings Division of the Post office

Department. There are objections to inking the fingers, and the

department was considering the purchase of special equipment which

would cost a great deal in the aggregate. This bureau Avas asked to

study the subject and if possible devise some easy and convenient

way to make the prints. After some experimentation this was ac- complished by an adaptation of the equipment which the department had been considering. This bureau's device is so convenient

and cleanly, and costs so little, that a request was made for 12 sets to be given a practical trial in various post offices.

The fingers are first imperceptibly oiled by pressing them upon a

sheet of heavy paper impregnated with mineral oil. Prints are then

made upon the necessary documents, developed by dusting them with

lamjDblack, and fixed by spraying them with a dilute solution of

shellac from an atomizer. The improvement is to do away with the

camel's-hair pencil for applying the black, and to use instead a small

ball of absorbent cotton coated with lampblack or gas black, and tied

Bp in a cover of organdie. When the oily prints, at first nearly invisible, are dabbed with this, enough black comes through the

organdie to make them visible and to develop their characteristics.

The slight excess of black is then blown away and the prints are

fixed by spraying them with the shellac solution.

Lubricants.

The final test of a lubricating oil or grease is how well it reduces

friction and how long it lasts without serious deterioration when

used on the machine for which it is intended. In examining a series

of samjDles in the laboratory it is not possible to study their behavior

in actual use. The best that can be done is to make a number of

physical and chemical tests that indicate, but do not prove, whether

or not the lubricants are likely to be satisfactory.

During the year the usual large number of lubricants was analyzed

for different branches of the Government service. In connection

with investigations in progress in another division of the bureau, oils

were tested and samples of oil sludge and of carbon deposits were

analyzed.

Further progress was made in the study of the oxidation of

petroleum oils. Oxidation is one of the causes, and possibly the chief

cause, of the deterioration of oils in use. A paper on the effect of

metals and their oxides upon the rate of oxidation of oils was mentioned in last year's report. It was published in the October, 1921,

number of the Journal of Industrial and Engineering Chemistry,

under the title "Catalytic oxidation of petroleum oils." A related

paper on " Sulphur compounds and the oxidation of petroleimi oils " appeared in the July, 1922, number of the same journal.

Specifications.

Members of the section cooperated with interdepartmental committees in drawing up specifications for rubber goods and specifications and methods of testing petroleum oils.

li
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 147

PHH' DETERGENTS, CEMENTS, CORROSION, ETC.

W' The field covered by this section includes the chemical analysis

and testing of detergents, cement, lime, gypsum, coated metals (such

as tin plate and galvanized metals), waters, etc.

Detergents.

Routine tests.—Many samples of soaps, washing sodas, cleansers,

polishes, etc., were examined to guide the various Government departments in making awards to contractors. Throughout the year

many delivery samples were also examined. Several materials were

analyzed for the Federal Trade Commission.

Soap speci-ficatiom.—In April, 1921, in response to an inquiry

regarding the revision of soap specifications, a prominent soap manufacturer was advised that the bureau would welcome the cooperation

of a small authoritative committee who could represent the soap

manufacturers. Nothing definite was heard from this suggestion,

until August, 1921, when the bureau was advised that the soap sec- tion of the American Specialty Manufacturers' Association, said to

represent 90 per cent of the soap manufacturers of the country, had

appointed a committee to confer with the bureau relative to the

revision of soap specifications as outlined by the Government. Although considerable correspondence was held with the committees

nothing definite was accomplished until the Federal Specifications

Board was organized. The manufacturers' committee olfei*ed their

services to the board, and the latter appointed a technical subcommittee, with a member of the bureau staff as chairman, to take the

matter up. A conference of the two technical committees was held

at this bureau, and it was agreed that the specifications listed below

would give material of suitable quality to cover the general needs

of the Government service and at the same time conform to commercial practice. Specifications for the following materials were

submitted to the Federal Specifications Board and have been promulgated as United States Government standards : White floating soap,

liquid soap, soap powder, salt-water soap, chip soap, ordinary laundry soap, automobile soap, grit cake soap, scouring compounds, and

hand grit soap. These specifications are being printed as circulars

of this bureau.

In addition to the specifications listed above, the manufacturers'

committee submitted specifications for special grade laundry soap,

hard-water grade laundry soap, and milled toilet soap. These specifications have not been recommended for adoption as Government

standards, as there appears to be no demand at this time for such

soaps by the various branches of the Government service. However,

the specifications are believed to be satisfactory for the grades of

soap indicated and will be included in a forthcoming revision of

Circular 62. The methods of sampling and analysis given in the

various specifications are essentially the same as those prepared by

a committee of the American Chemical Society, but not yet promulgated. These methods were prepared by the American Chemical

Society committee in cooperation with the two technical committees

mentioned above.
148 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Cements, Etc.

Interdepartmental conference on chemical lime.—After publication of the modified Scaife method for the determination of available lime in quick and hydrated limes (Chem. and Met. Eng., October 19, 1921) various comments were received. Additional tests were made where further information was required, and objections

were apparently satisfactorily met. The method appears to be very

generally aj^proved, has been formally adopted by the Technical

Association of the Pulp and Paper Industry, and recommended for

publication as a tentative standard by the American Society for

Testing Materials. At the request of the conference, tests were made

which indicate that this method m^y be used for the determination

of overburned lime.

Investigations.—Considerable work of a miscellaneous nature was

done in cooperation with the structural materials division, consisting largely of furnishing special data for their investigations. This

work included the analyses of samples of Canadian feldspar, alkali

water and soil, waterproofing and composition flooring compounds,

trass for hydraulic cement, jDroprietary cement compounds, and comparative analyses of Belgian, Italian, and other foreign Portland

cements. Studies of certain analytical procedures were also car- ried out.

Corrosion, Waters, etc. Cooperative tests.—Cooperative work on the "total immersion"

tests of the committee on the corrosion of iron and steel of the

American Society for Testing Materials, conducted in part at this

bureavi and begun nearly two years ago, is still in progress. The

iron and steel sheets under test at this bureau, while considerably

corroded and somewhat thinner, have as yet shown no failures.

Reports of these tests will be found in the proceedings of the abovementioned society.

Metallic coatings.—Owing to press of other work, no investigational work was done on methods of testing metallic coatings. Indications are that the salt spray test, as described in Circular No. 80,

is still regarded as a valuable accelerated test. Numerous tests were

made for the Government departments of zinc coatings, oxide coatings, lead-coated steel, and copper-clad steel. Preliminary tests indicated that, for the same thickness of coating, cadmium offers

greater protection than zinc. For stripping cadmium-coated metal,

warm ammonium nitrate solution Avas found more satisfactory than

the baths in common use for other types of coating.

IVaters.—The work done on watei's consisted of the mineral analyses

of waters submitted to determine the advisability of purification for

industrial use and the means to be adopted ; and after the installation

of purification equipment, analyses of the treated waters to determine whether specification requirements have been met. Of the

latter, the installations in Government hospitals at Chicago, 111., and

Dawsonsprings, Ky., may be cited. Periodic examinations of the

treated waters are made. Analyses were made of waters from various

localities for the Treasury and War Departments and the United

States Shipping Board. At the request of the Secretary of the Treasury, a member of the bureau staflF was designated to serve as a member
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 149

of an advisory committee on drinking water standards for common

carriers. The bureau, however, does not test waters as to potability.

Miscellaneous Work.

A large number of samples of materials was tested for the Steamboat Inspection Service to determine their fire hazard. A report was

made to the Navy Department showing the amounts of the standard

Navy boiler compound to be added to various mixtures of condensation and sea water, in order to give a definite degree of alkalinity.

Advice was given the Post Office Department regarding metals suitable for use in the construction of street letter boxes. Various materials were examined for the Government departments—for ex- ample, graphite, insulating compositions, boiler compounds, chemicals for water purification, fire-extinguishing liquids, antifreezing

solutions for automobile radiators, so-called carbon removers and

gasoline accelerators, nondrying oils, etc. Cooperative work was

done with the American Society for Testing Materials on the distillation test of gasoline. A tentative specification was prepared for

plumbago for facing foundry molds. A specification for fire ex- tinguishing liquid (carbon tetrachloride base) was prepared by a

technical committee with a member of the bureau staff as chairman.

This specification has been adopted by the Federal Specifications

Board and will be published as a bureau circular.

PAINT, VARNISH, AND BITUMINOUS MATERIALS.

This section handles the analysis and testing of a great variety

of paint and varnish materials and of bituminous materials for

waterproofing and roofing purposes. It prepares specifications for

such materials and collects infoi'mation relative to the service that

may be expected from them.

As in past years, the greater part of the work done by this section

consisted in the testing of paints, varnishes, and bituminous materials submitted by various branches of the Government service.

The major part of this work in the fiscal year just past came from

the Shipping Board, whose first estimate of the amount of work

to be expected from it was more than five times exceeded in the

amount actually sent.

Federal Specifications Board.

The committee formerly known as interdepartmental committee on

paint specification standardization has been made the technical committee on paint materials by the Federal Specifications Board, and

the various paint specifications published as Bureau of Standards

circulars have been adopted as United States Government specifications. Representatives of this section of the chemistry division are

also serving on the technical committees on (a) bituminous roofing,

and (b) floor coverings—nontextile.

American Society for Testing Materials.

Cooperation has continued with the society's committee on protective coatings for structural materials. The report of that committee for the year 1922 contains contributions from more than one

section of the chemistry division. The revised " tentative specifica-
150 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

tions " of the society for a number of pigments and paints are all

based on the bureau's specifications.

The bureau cooperated actively also with the society's committee

on waterproofing materials and to some extent with the committee

on drain tile.

Researches.

Some improvements in the technique of testing paints were made,

and work on the physical properties of paint was vicrorously prosecuted. The field is almost untouched but the progress made is en- couraging.

Investigation of built-up roofing has occupied much time. At the

request of the Board of Education of Cleveland, Ohio, much of the

information collected by the bureau on this subject was made available

in preparing specifications for roofing for school buildings in Cleveland.

Experimental work on waterproofing shotgun shells for the War

Department indicated that a coat of shellac was quite efficient. A

number of shells so treated have been returned to the War Department for a service test. The work on concrete drain tile, mentioned in last year's report,

was continued but no conclusions have been reached. The work on

mastic flooring, also mentioned last year, was continued and specifications have been prepared for regular mastic to be submitted to

the Federal Specifications Board technical committee on floor cover- ings—nontextile and acid-proof mastic.

Considerable work has been done toward providing material for a circular of general information on bituminous waterproofing of

concrete and masonry structures.

CHEMICAL TESTING.

The number of chemical tests made in the chemical laboratories

during the fiscal year was 8,4-95. Distributed by types of materials

the tests were as follows: Ferrous metals (irons and steels), 596;

nonferrous metals, alloys, and coated metals, 649 ; cement and cement

materials, 814; bituminous products (including creosotes, etc.), 488;

varnish materials (including shellacs), 445; paint materials, 1,131;

lubricants, 608; soaps, nondrying oils, and metal polishes, 614; inks

and related office supplies, 1,068; balloon fabrics, 223; rubber, 667;

textiles, 571 ; and miscellaneous, 621.

'' The tests were made for very many Government bureaus and establishments and for States, municipalities, and private parties, as follows: Agriculture, 20; Commerce, 2,967 (this includes samples re- ceived from other divisions of the bureau for chemical tests) ; Interior, 21: Labor, 5; Navy, 425; Post Office, 973; Treasury, 521;

War, 464; United States commissions and committees, 1,500 (including United States Shipping Board, 1,310) ; General Supply Committee, 778 ; Panama Canal, 391 ; other independent establishments,

311 ; State and municipal institutions, 41 ; and private parties, 78.

PUBLICATIONS.

The following papers emanating wholly or in part from the chemistry division were published during the year:
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 151

Technologic Paper No. 195, Zinc cyanide plating solutions.

Circular No. 38, fourth edition, The testing of rubber goods.

Circular No. 90, second edition, United States Government specification for

red lead. Circular No. 97, second edition, United States Government specification for

green paint, semipaste, and ready mixed.

Circular No. 103, second edition. United States Government specification for

water-resisting spar varnish.

Circular No. 111. Recommended specification for flat interior lithopone paint

white and light tints. Circular No. 114, Reconmiended specification for cotton rubber-lined fire hose.

Circular No. 115, Recommended specification for pneumatic tires, solid tires,

and inner tubes.

Circular No. 117, Unitecl States Government specification for interior varnish.

Some physical properties^of paints, Proc. A. S. T. M.. 1922.

Determination of the acid number of tung and other vegetable oils, published

in Jour. Ind. and Eng. Chem., 14, p. 57, 1922.

Abietic acid and certain metallic abietates, published in Jour. Am. Chem. Soc,

44, p. 1383, 1922.

Catalytic oxidation of petroleum oils, published in Jour. Ind. Eng. Chem., 13,

p. 901, 1921.

Sulphur compounds and the oxidation of petroleum oils, published in Jour.

Ind. Eng. Chem., 14, p. 725, 1922.

Determination of available quicklime and hydrated lime, published in Chem.

Met. Eng., 25, p. 740, 1921. Equilibria in the systems carbon disulphide ; methyl alcohol and carbon disulphide ; ethyl alcohol, published in Jour. Am. Chem. Soc, 44, p. 105, 1922.

Gas purity recorder for electrolytic oxygen and hydrogen, published in Bull.

Comp. Gas Mfrs.' Assn., December 8, 1921. The production of hydrogen by the use of silicon and sodium Tiydroxide, published in Trans. Am. Electrochem. Soc, 41, p. 15, 1922.

The electrodeposition of lead-tin alloys, published in Trans. Am. Electrochem.

Soc, 40, p. 147, 1921.

The stnictiire and properties of alternately deposited metals, published in Trans.

Am. Electrochem. Soc, 40, p. 137, 1921.

The acidity of nickel depositing solutions, published in Trans. Am. Electrochem.

Soc, 41, p. 233 1922.

The electrolytic reproduction of engraved printing plates, published in Chem.

and Met. Eng., 25, p. 320, 1921.

Coprecipitation of vanadium with ammonium phosphomolj'bdate, published in Jour. Am. Chem. Soc, 43 p. 2.552, 1922.

Notes on the analysis of cast bronze, published in Jour. Ind. Eng. Chem., 14,

p. 426, 1922.

Modified method for the determination of iron and vanadium after reduction

by hydrogen sulphide, published in Jour. Am. Chem. Soc, 43, p. 1560 1921.

The determination of aluminum as phosphate, published in Jour. Ind. Eng.

Chem., 14, 1922.

The following are in preparation or in press

:

The analysis of chrome-vanadium steel. Notes on the determination of phosphorus.

Quantitative precipitation by ammonia of phosphorus pentoxide in combination

with aluminum hydroxide.

Specifications for soap. Standardization of solutions employed in the evolution method for sulphur.

Specifications for rubber goods.

ENGINEERING PHYSICS.

Investigations relating to mechanics, sound, and properties of matter; testing and de- velopment of engineering instruments; performance standards of mechanical appliances; sound ranging;/* investigation of soundproofing properties of building materials; analysis

and correction of acoustical defects of assembly rooms; elastic properties of diaphragms

and springs ; investigation, testing, and experimental development of aircraft instruments;

ballistics; and aerodynamical testing and research. GENERAL.

The engineering physics division includes sections dealing with (1)

engineering instruments and mechanical appliances, (2) sound in-
152 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

vestigations, (3) aeronautic instrnments, and (4) aerodynamical

phj^sics. In addition, special experimental and theoretical researches

are carried on by a staff of engineering physicists. The activities of

the division in testing and research are described in the following

pages. An equally important feature of the work is to be found in

the advisory relationships which have been established with other

technical branches of the Government and with the industries. This

is illustrated by the participation by the bureau (1) in the formulation of several of the power-test codes of the American Society of

Mechanical Engineers, and in the work of the American Engineering

Standards Committee and the A. S. M. E. Fluid Meters Research

Committee; (2) in the work of the aerodynamics committee of the

National Advisory Committee for Aeronautics; and (3) in numerous

conferences with representatives of the Army and Navv, particularly

in connection with problems in aerodynamics, ballistics, and aerial

navigation.

ENGINEERING INSTRUMENTS AND APPLIANCES.

Current Meter Rating Station.

An adequate installation for the accurate calibration of water

current meters used in measuring the discharge of rivers and other

open channels is too extensive and costly to be provided by private

enterprise. A hydraulic laboratory, designed and equipped especially for this purpose and housed in so as to be available throughout the year is maintained by the bureau to supply this necessary

service. During the past fiscal year 376 current meters of various

types were calibrated for the engineering bureaus of the Government, instrument manufacturers, and engineers in private practice.

Calibration of Instruments.

During the past fiscal year 601 instruments were tested, including pressure gauges of various descriptions, current meters, anemometers, speedometers, and miscellaneous engineering instruments.

Fire Extinguishers.

At the request of the Steamboat Inspection Service the investigation and testing of chemical fire extinguishers submitted to that

bureau for its approval for use on vessels under its jurisdiction

was continued. During the past year 25 fire extinguishers, including one 40-gallon chemical engine, were investigated. Several of

the devices tested represented new principles of construction and

operation.

Radiator Return-Line Valves.

The successful operation of the heating systems generally employed in 23ublic buildings is principally dependent on thermostatic

valves placed at the outlet of each radiator. At the request of the

Supervising Architect of the Treasury Department performance

tests are made of all such devices presented to that office for its approval for use in buildings under its jurisdiction. Nine A^alves

of this description were tested during the past year for compliance

with performance standards previously developed.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 153

Miscellaneous Engineering Tests.

A variety of miscellaneous engineerino- tests were made, such aa hydrostatic tests of condenser tubing, tests to determine the towline tension of sounding apparatus, tests of high pressure gas cylinder- vah^es, discharge tests of a radiator modulation valve, tests of

a safety device for gasoline containers, and the like.

Safety Release Devices for Hydrogen Cylinders.

At the request of the Chief of the Air Service of the Army, an

investigation was undertaken of the safety devices used on hydrogen cylinders to safeguard them against explosion should extraordinary pressures be developed within the cylinder. The devices

now in use successfully perform this function but frequently fail

under ordinary service conditions, causing an appreciable loss of

hydrogen. An investigation of the possibilities of a modification

of the present form of safety cap for use with a fusible alloy plug

has been completed, resulting in a design of a device of this description which promises to meet the needs of the service. An experimental study of frangible copper disks has been concurrently in

progress. The necessary preliminary work in determining the separate etfect on the bursting strength of the disk, under the conditions of use, of the dimensions of the disk and orifice and of the

quality of the copper, has been completed and the investigation of

the effect of continued loading on the bursting strength of the

disk was in progress at the close of the fiscal year.

Investigation of Elevator Safety Devices.

A survey of available statistics shows that approximately 74 per

cent of all fatal elevator accidents to the public occur at the hoistway door. A well-designed reliable interlocking device should

practically eliminate all such accidents. An investigation of the

interlocking devices now available was recently undertaken for the

purpose of determining their reliability and of developing performance specifications for use in connection with elevator safety codes.

The design and construction of automatically operated testing apparatus has been practically completed and the testing of commercial

devices will be shortly under way.

SOUND MEASUREMENTS.

Sound Sources.

The electrical system devised last year as a sound source has been

improved to provide for more ready control. The energy losses in

the loud-speaking telephone instrument have been studied for systematic measurement under varying conditions of operation. Sound

absorption and transmission are functions of the intensity. Sound

intensity at a given position relative to the source is determined by

(a) the emitting mechanism, (h) the environment of the source,

and (c) the reaction of the environment upon the emitting mechanism.

It is, therefore, important that the output of the source should be

measured in a series of experiments which involve alterations in its

environment. A method has been devised and apparatvis is being

developed for this purpose.
154 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Sound-Intensity Measurements.

The apparatus and method described last year has been further

developed so as to cover a much wider intensity range. A substitution method has been devised which will make the intensity measure- ments comparable, regardless of changes which may have been made

in the measuring apparatus, or of the variations in the amplifier

system between experiments.

Sound Chamber.

In response to the widespread demand from associations of building material manufacturers and other building interests, a sound

chamber has been designed and constructed for the jDurpose of providing suitable facilities for making sound-transmission measurements. Data on sound transmission and absorption in order to be

really valuable to the architect and builder should include at least

the more common materials and constructions. The data now available provide only a very limited amount of this information.

The sound chamber is built massively of concrete. Two measuring rooms are located, respectively, above and beside- a source room,

the latter being separated from the remaining structure by air space.

Panel openings are so designed that the transmitting panels when

sealed into position form the only bond between the two parts of the

structure, excepting the common ground on which they stand. The

vertical panel opening is to be used for the studj^ of wall structures,

the horizontal panel opening for the study of floor and ceiling structures. The panels are to be built 6 feet by 7 feet 6 inches. When

sealed into position, the effective transmission area will be 6 feet by

6 feet 6 inches. These panels are larger than any for which transmission data have so far been found. The arrangements and the

program of M'ork are such that information covering a wide range

of materials and construction can be developed rather rapidly after

the preliminary difficulties have been cleared up.

Auditorium Acoustics.

Analyses have been made of the acoustical conditions in the auditoria of a number of public buildings and recommendations made

for their improvement. In a few cases analyses of plans have been

made in advance of construction. The preponderance of the former

cases over the latter indicates clearly that architects and builders do

not appreciate the importance of providing for satisfactory acoustics or do not know that they may be planned nearly if not quite as definitely as ventilation, illumination, and other essentials of an entirely

satisfactory building.

Voice-Tube Experiments.

A series of experiments has been begun in cooperation with the

Bureau of Construction and Eepair of the Navy Department to

determine the causes of difficulties encountered in voice-tube communication on vessels of the Navy and to develop information of

value in designing installations of this kind. This work is still in

the preliminary stages.
M.

REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 155

I Fog-Landing Experiments.

In cooperation with the Air Service of the United States Army,

some experiments have been made to determine the feasibility of

determining altitude of aircraft above ground level by means of

sound reflections from the ground as an aid in landing in foggy

I ^ weather.

IP The interval between the transmission of a sound pulse from a ' plane and its reception after reflection from the ground would proi,K vide a means of estimating the ground disturbance. The difficulty

I p lies in the reception of the feeble reflected sounds in the presence of

I the noises attending air navigation. A selective sound-receiving

1 system has been developed with a view to overcoming this, but the

j service trials thus far made have not been ygvj promising.

j Sound Ranging.

The sound laboratory has continued to cooperate with the Signal

Corps in the development of apparatus for artillery sound ranging.

A sound-ranging system has been developed for the technical staff

|, of the Army Ordnance Department and installed at the Aberdeen

|f Proving Grounds. This system is designed to secure the muzzle

i velocity, range, and time of flight of each projectile from a machine

' gun during a burst of fire. The method has the further advantage

that the three quantities are all obtained for the same shot instead

I of obtaining them separately from different rounds. The installation combines the desirable features of several sound-ranging sysI terns developed during the World War and is believed to be superior

to any apparatus available at that time. The field work is still in

i progress.

High-Speed Oscillograph Camera.

j Several of the projects on which work has been done in the sound

laboratory have involved the use of a high-speed oscillograph camera. Such a camera was developed last year. During the

present year the tuning-fork time-scale apparatus was made an integral part of the camera, so that it is available for use with any

type of oscillograph. This obviates the necessity of equipping each

oscillograph in the laboratory with a time-scale apparatus.

I' In the 4-inch camera referred to above the exposure is limited to a half-inch strip if it is to be prolonged beyond a single revolution.

An 8-inch camera has been developed which increases this strip

width to 2 inches. In this development the laboratory had the

effective cooperation of Maj. W. P. Wilson of the Coast Artillery,

to whom the bureau is indebted for many ^essential features of the

design.

Precision Time Scale for Oscillograph Measurements.

i A G. E. oscillograph vibrator with the axis horizontal is tuned to

j! the frequency of a 500-cycle fork. The vibrator is operated by cur- rent derived from the plate circuit of a 500-cycle tuning fork, the

vibrations of which are maintained by means of the electron-tube

drive. The light beam sweeps past the cylindrical lens of the oscilj| lograph camera at its maximum speed and sharp time index marks

(I result on the moving film. A number of vibrators can be operated

from the same fork. This affords a means of correlating oscillograms obtained simultaneously on a number of oscillographs.

i
156 REPORT or DIRECTOR OF BUREAU OF STANDARDS.

The sound laboratory has cooperated with six other sections of the

bureau by providing suitable time-scale apparatus involving the use of tuning forks for both mechanical and photographic recording

systems.

Radio Time Recorder.

In cooperation with the United States Coast and Geodetic Survey

two radio time-recording sets have been developed and built for their

longitude work. These instruments are now in the field.

Solenoid Chronograph,

The development of this apparatus for the technical staff. Army

Ordnance, has been continued. The instrument provides a means of

measuring projectile speeds with an accuracy at least ten times as great as any hitherto available in America. An automatic device

has been added to the 2:>hotographic instrument which makes it possible to make velocity firings more rapidly than with any of the

chronograph types currently used.

Experimental work aiming at the elimination of the photographic

method of recording has been progressing slowly and no definite

results can be reported at this time.

Pressures in Guns.

The piezo-electric gauge developed last year has been subjected

to actual test in a gun. The results obtained are in satisfactory

agreement with other data obtained at the same time. The feasibility of the method and the adequateness of the apparatus have,

therefore, been established.

A carbon disk gauge for measuring pressures in guns is being developed in cooperation with the electrical division of this bureau.

It is an adaptation of the strain gauges and other telemetric devices similar in principle which have been developed in that division

during the last year or two.

In connection with the program of interior and exterior ballistics

being worked out by the technical staff at the Aberdeen Proving

Grounds, considerable time has been given to the development of

apparatus and the oscillographic recording of various events incident to the firing of the gun.

Small-Arms Projectiles.

A suitable method and apparatus for the convenient experimental

determination of the principal moment of inertia of small-arms

projectiles have been developed. Such measurements are of importance in estimating the stability of experimental projectiles. The

apparatus may also be used to determine the degree of uniformity

of a random selection of projectiles of the same type.

Yaw Instrument.

It is customary to study the yaw motion of a projectile by firing

through suitable screens and measuring the maximum diameter of

the perforation. An instrument for establishing the relation between

this magnitude and the yaw angle for any projectile type has been

constructed, and provides a convenient means for establishing the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 157

relation betAveen the measured quantity and the sio^nificant yaw

angle, from which calibration curves may be plotted for each type

of projectile.

Measurement of Linear and Angular Speeds and of Torsional Oscillations.

An instrument is being constructed for the purjiose of recording

instantaneous values of linear and angular speed. It is of the homopolar dynamo type in which the electromotive force is strictly proportional to the speed at any instant. This instrument is designed

to replace instruments used for obtaining time-displacement relations from which time velocity and time acceleration curves are usually deduced by graphical differentiation. The precise direct

recording of a time-velocity curve has obvious advantages both in

convenience and accuracy. It is proposed to use a pair of such instruments attached to opposite ends of a rotating shaft to record

simultaneously the angular speed of the rotating system and the

period and amplitude of existing torsional oscillations.

AERONAUTIC INSTRUMENTS.

The research and development work which the aeronautic instruments section has been carrying on for several years with the Army,

the Navy, and the National Advisory Committee for Aeronautics

on funds furnished by these organizations has been continued, to- gether with a more limited program with other Government departments and private concerns. In addition a large amount of

routine work on instruments submitted for tests has been carried

out. In this report the research work which involves the experimental investigation of the fundamental principles of instrument

design will be described first, followed by the development work

which concerns the practical design and construction of ncAv types

of aircraft instruments.

Altitude Effect on Air-Speed Indicators.

A second report on the effect of altitude on air-speed indicator

readings has been submitted to the National Advisory Committee for

Aeronautics for publication. In this report are presented the re- sults of tests in a specially constructed low-pressure wind tunnel

on the Venturi and Pitot-Venturi air-speed nozzles in common use. The tests were conducted at air pressures ranging from atmospheric

pressure to approximately 220 millimeters of mercury, which corre- sponds to an isothermal altitude of 33,000 feet. Curves giving the

density and viscosity corrections for the Zahm Pitot-Venturi nozzles

used by the United States Army and Navy are included in this

report. The viscosity correction, which this work has made available for the first time, is particularly important in connection with

the low-speed flight of dirigibles where serious errors might be made

if the density correction alone were applied, as has been done in

the past. It is also shown in this report that the effect of compressibility of the atmosphere on the performance of Venturi nozzles can be neglected over the speed range of present day aircraft. A

cup anemometer air-speed indicator was tested in the low-pressure

wind tunnel and was found to have approximately a 3 per cent altitude effect at an altitude of 33,000 feet.
158 BEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

Diaphragm Investigation.

The investigation of instrument diaphragms has been continued.

Further information has been obtained as to the laws of deflection

of corrugated diaphragms. It is found that the corrugations make

a diaphragm much more flexible than a flat diaphragm of the

same size. Apparatus for measuring the drift and hysteresis of

metallic diaphragms has been developed. Hysteresis loops have

been accurately measured for flat and corrugated diaphragms of

various diameters and thicknesses of different materials, and for

different ranges of loading. Evidence has been obtained tending

to support the view that dii'ectional hysteresis, as distinguished from

elastic hysteresis, exists. It is found that corrugated diaphragms

exhibit much less hysteresis than do flat diaphragms under the same

conditions. The investigation of materials for use in nonmetallic

diaphragms has been continued. The effect of temperature and

humidity on a number of leathers, rubberized and treated fabrics,

and on rubber dam have been studied. The theory of the performance of Sylphon diaphragms has been developed and published as a

technical note of the National Advisory Committee for Aeronautics.

Tension Experiments on Metallic Strips.

In connection with the investigation of the elastic properties of

metals suitable for instrument diaphragms, measurements of the

drift and recovery characteristics of metallic ribbons under tension

have been continued and extended to include other metals and a wider range of loading. An interferometer method was used. The

samples tested include German silver, nickel, silver, duralumin,

phosphor bronze, and brass. The results indicate that German silver

and nickel are the most suitable of the materials tested for instrument diaphragms. Phosphor bronze and brass show the least satisfactory results.

Bourdon Tubes.

The mathematical treatment of the deflection of Bourdon tubes

as presented in various published papers has been coordinated and

amplified for publication in a single report. Apparatus for measuring the deflection and hysteresis of Bourdon tubes has been developed in which an optical-lever method is used to obtain the required

magnification.

Compass Investigation.

Extensive laboratory tests have been made on 43 types of airplane

compasses comprising British, French, German, Italian, and American service and experimental instruments. Flight tests are in progress on each of the different types, the object being to determine by

actual comparative tests which is the most desirable for use on aircraft. A careful magnetic survey of each available type of airplane

is also being made. These data are very important and must be

known before intelligent compass development can be imdertaken.

Laboratory investigations are in progress on the theory of compass

performance, the damping effect of various liquids, card markings

and interior bowl finishes, magnet steels, and pivots.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 159

Ground Speed and Drift Indicator.

A ground speed and drift indicator of the optical-synchronized

type has been completed and tested both in the laboratory and in

flight. The instrument is easy to install and operate and no difficulty

has been experienced in making satisfactory observations at altitudes

above 3,000 feet. A new model embodying certain modifications of

the mechanical drive system is now under construction,

Air-Speed Indicator.

The cup anemometer type air-speed indicator which was developed

at this-bureau for dirigibles has been improved and adapted for use on airplanes. The cixps have been replaced by a small propeller,

since it is found possible by this means to make the instrument start

at a much lower air speed. Four of these air-speed indicators have

now been built at the Bureau of Standards, two for the United States

Navy and two for the United States Army. Tests of one of these

instruments at altitudes up to 17,500 feet have revealed no measurable altitude effect ; in other words, the instrument reads the true air

speed at all altitudes up to this limit and probably still higher. A

simple voltage adjustment corrects for the effect on the readings of

changing the position of the instrument propeller on the airplane.

Water-Speed Indicator.

An instrument for measuring the taking-off and landing speeds of

sea planes has been developed. This instrument consists of a small

stream-lined body carrying a propeller which is rotated by the motion of the water relative to the plane. The propeller shaft carries a commutator which closes an electrical circuit each time the shaft

revolves, thus operating a chronograph. The exposed parts of the

instrument are constructed entirely of monel metal to avoid corrosion

from immersion in sea water.

Turn Indicators.

A new electrically driven gyroscopic-turn indicator has been designed and made. It consists of a small, specially constructed battery motor in which the armature rotates about the field on ball

bearings, forming the rotor of a gyroscope. The gyroscope is

mounted in such a way that it may precess about only one axis, fore

and aft, when mounted in the airplane. The turning movement of

the airplane causes precession about this axis which is indicated on

the dial by a suitable mechanism. The instrument has the advantage over the air-driven types that it operates always at the same

sensitivity regardless of air speed, whereas the air-driven type does

not perform satisfactorily at speeds lower than 50 miles per hour.

It is much more compact and simple than other types of electricturn indicators. The investigation of existing types of turn indicators has been continued. Tests on a propeller pump for driving

turn and pitching indicators proved this device to be unsatisfactory.

Turn Meters.

Preliminary work on the design of a turn meter has been completed. The purpose of this instrument is to indicate quantitatively

the rate at which the aircraft is turning from a given course. 9644—22 12
160 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Angle of Incidence Recorder.

This instrument gives a permanent record of the angles of incidence of an airplane during flight. It consists of a specially constructed multiple surface wind vane which operates a series of electrical contacts in circuit with a set of minature electric lamps in the

recording apparatus. These lamps record on a moving photographic

film the angle of incidence, the lamp lighted at a given moment being determined by the position of the wind vane element. The vane

is located on one of the airplane struts. The recording device is placed in the cockpit.

Precision Barometer.

An improved model of precision barometer has been completed

and delivered. This instrument was given a number of flight tests which showed the desirability of making certain changes, particularly in the indicating mechanism. These modifications have been

carried out and the instrument will soon be ready for further flight

tests. Temperature-Compensated Altimeter.

This instrument, which corrects automatically for the effect of air

temperature on the altitude readings, has been completed and given

laboratory and flight tests. These tests indicate that the method of

temperature compensation used causes an appreciable amount of

thermometric lag, and it is proposed in futui"e instruments to provide an external thermal pressure element such as a Bourdon tube

for air temperature compensation instead of the bimetallic device

used in this instrument.

Temperature-Compensated Thermobarograph.

This instrument is similar in principle to the temperature-compensated altimeter described above, but is pi-ovided in addition Avith

a recording mechanism. It gives a record of the altitude corrected

for air temperature and in addition a record of the air temperature

itself. The air temperature correction is computed on the assumption

that the average temperature of the air column from the ground to

the instrument is equal to the arithmetic mean of the temperature

at the ground and at the altitude where the instrument is situated.

Temperature-Compensated Barograph.

This instrument is similar to the temperature-compensated thermobarograph, except that it is not provided with the temperaturerecording element.

Precision Barograph.

Laboratory tests on this instrument indicate a satisfactory ])erformance and show that it gives much more precise readings than

ordinary barograi)hs. As a result of this development it has been

found to be possible to make a combined altimeter and barograph

provided Avith an indicating dial like an ordinary altimeter and a recording device similar to that of the precision barograph. The

pilot would thus be able to read the indication of the instrument as

h'e would that of the altimeter and at the same time obtain a per-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 161

manent record on the chart of the altitude throughout the flight.

This combined instrument would obviate the necessity of carrying

both an altimeter and barograph.

Statoscope.

A new type of statoscope has been designed in which an automatic electrically operated valve is substituted for the breaking

bubble or hand operated valve ordinarily used in statoscopes. This

method is much more accurate than that of using a breaking bubble

and automatically protects the instrument against excessive pres- sure such as would occur if the pilot is careless in the use of the handoperated valve. The electric current required is supplied by a dry

battery inclosed in the case of the instrument itself.

Combined Statoscope and Rate-of-Climb Indicator.

This instrument is a combination of the automatic electrically operated valve statoscope described above and an improved rate-ofclimb indicator which uses a Sylphon diaphragm for the rate-ofclimb indicating element. When the instrument operates as a statoscope the air chamber and capillary leak tube are shut off from the

Sylphon diaphragm by a valve which is operated from outside the

case. At the same time a subdial Avith the legend " Statoscope " printed on it is rotated to expose this word through a slot in the

dial thus indicating that the instrument is operating as a statoscope.

When used as a rate-of-climb indicator the capillary tube is con- nected to the outside air, the air chamber connected to the Sylphon

element, the contact device, which controls the electrically operated

device, shifted so as to be thrown out of action and the subdial

rotated so that the legend " Rate-of-climb indicator " shows that the

instrument is functioning as a rate-of-climb indicator. The change

is accomplished by simpl}^ turning a knurled knob.

Rate-of-Climb Recorder.

An improved type of rate-of-climb recorder has been constructed,

which is more compact than the model referred to in last year's re- port. The film-propelling mechanism has been changed to permit

the use of a long film which is of ordinary post-card camera size.

This is effected by rolling the film by clockwork from one bobbin to

another. Means are also provided for varying the speed of the film

from one-half to 2 centimeters per minute.

Astronomical-Position Finder.

An exi^erimental model of this instrument, the fundamental principles of which were suggested by the Air Service, has been designed

and constructed to study the feasibility of an aircraft instrument of

this type for indicating geographical position directly by the

simultaneous observation of any two stars. Extended tests have

been made with this experimental instrument. The essential features

of an aircraft instrument have been determined and the design is

now in progress.

Aircraft Sextants.

In connection with the instrument-development program, practically every type of aircraft sextant has been studied and tested.
162 REPORT or DIRECTOR OF BUREAU OE STANDARDS.

An investigation of the properties of bubble levels and pendulums,

regarding their use as artificial horizons for aircraft sextants, has

been completed. A new bubble sextant has been constructed and

the design of an improved model is now under consideration.

Airplane Compasses.

An experimental compass of new design has been made and tested

in the laboratory and in flight. A novel feature of the instrument

is the card element which is very light (weight 3 grams) and which

is damped by radial supporting wires. This card recovers quickly,

the time being 12.5 seconds for a deflection of 45° from its position

of rest, with but one swing through zero.

Distant Reading Compass.

A study has been made of methods of indicating at a distance the

readings of the magnetic compass. The problem is a very difficult one since no power whatever is available directly, the directive force

of the compass magnets being so small that the least friction causes

serious error. Systems employing selenium and other photoelectric

cells and thermoelectric units have been tried but have not as yet

proven entirely satisfactory. A method now being tested experimentally is one in which a high-tension spark jumps a gap on a

repeater, the position of the spark corresponding to the position of

the compass card. In connection with this method it is necessary to

develop a suitable air-damped compass.

Earth Inductor Compass.

A model for airplane use has been produced and satisfactorily

tested in flight. The inductor consists of a cross-shaped armature

carrying a closed coil of wire which is rapidly revolved in the magnetic field of the earth, thus generating a current, the intensity of

which depends upon the orientation of the coil with respect to the

magnetic field. The pilot has before him on his instrument board

a movable dial bearing compass graduations on which the desired

compass coui-se is set off. When the airplane is on this course the

needle of a small galvanometer on the instrument board continuously points to zero. A deflection of the needle to one side or the

other indicates a corresponding deviation from the predetermined

course. The earth inductor itself is located in the fuselage back of

the rear cockpit where it is free from magnetic disturbances due to

the engine. It is driven by a small cup propeller projecting through

the fuselage.

For this device the American Philosophical Society has awarded

its Magellan medal to the two members of the bureau staff con- cerned in its development. Experiments are now being carried out

with a view to producing an earth inductor compass suitable for

ship use.

Latitude Indicator for Airplanes.

Study has been given the problem of the determination of latitude

in airplane flights by the measurement of the magnetic dip. Considerable progress has been made but the difficulties of such measure- ments are obvious. A special form of dip needle seems to be, the

most promising type of instrument.
KEPOKT OF DIRECTOR OF B.UREAU OF STANDARDS, 163

Altitude and Azimuth Indicator.

The problem of a complete determination of position by observation of a single star, the sun for example, is being studied. Several

apparently promising methods have been eliminated as impracticable.

The studies are being continued.

Maps, Map Boards, and Methods of Reducing Observations.

Since the nautical methods of finding position from astronomical

observations demand rather involved computations requiring considerable time, the problem of devising some simple mechanical or graphical method for aircraft use is under consideration. A study of

all the more promising methods which have been proposed is nearing

completion. The related question of maps is also being studied, as well as the necessary equipment of map boards, map cases, and plotting instruments.

Horizontal-Angle Indicator.

An instrmnent for measuring horizontal angles between any two

I points, and simultaneously the depression angles to each point, is

|, needed in range finding from captive balloons and dirigibles. A

i\; number of alternative designs have been worked out and from a comparative study of these, the most promising selected. Complete working drawings have been prepared and an instrument is now under

construction and rapidly nearing completion.

Bomb Sights.

A comprehensive study of existing types of bomb siglits has been

made and an optical sight is in process of design. Attention is being

' directed toward making the operation of the instriunent as simple as

1 possible, thus giving the bomber more time for such adjustments as

] must be made. Plans for adjustment of the optical ground speed and

drift indicator to the instrument have been developed. Experiments

i are also now in progress on a new type of gyro for the bomb sight,

compensated by magnetic means for the effects of acceleration and

the earth's rotation.

Aircraft Electric-Resistance Thermometer.

This instrument was designed primarily to determine the gas and

I air temperature in lighter-than-air craft. The temperature elements

! consist of resistance coils of fine nickel wire. The indicating element

is an ohm meter graduated directly in degrees centigrade. Several

resistance elements located at different parts of the ship may be con- nected to the indicator and the temperature at each point determined

in succession by pressing a button on the indicator.

Ballonet Volume Indicator for Dirigibles.

j The purpose of this instrument is to indicate the volume of air in

jl the ballonets on nonrigid dirigible balloons. It is particularly desirI able to have such an instrument on ships inflated with helium gas,

V since it will tend to prevent waste of this comparatively expensive

j gas by keeping the pilot informed as to the volume of air in his ballonets. The theory of a volume indicator based on the difference in

pressure between the ballonet and the ga^ bag has been developed
164 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

and has been confirmed by tests on the ballonets of several dirigibles.

The development of a manometer for measuring extremely small

pressures will be required for this purpose.

Balloon and Airship Manometers.

An investigation of the available mechanical types of balloon

manometers has been conducted. As these instruments make use of

nonraetallic diaphragms and these diaphragms are responsible for

the most serious defects of the instruments, it has been found neces- sary to conduct an investigation of the materials available for use

in this connection. Tests to determine the porosity of the material

and the effect of temperature and humidity have been conducted.

Kymograph or Airplane Oscillation Recorder.

The purpose of this instrument is to record the oscillations of

an airplane in flight by focusing the sun's rays on a moving photographic film in the instrument. An improved type of instrument

has been developed which gives an exceptionally sharp, narrow

trace. The film is driven by an electric motor and the bobbins have

sufficient capacit}' for 3 meters of moving-picture film, which cor- responds to a flight of three hours.

Standard Testing Sets.

A set of standard airplane instruments has been prepared for field use. This is made up of carefully calibrated instruments to be used

in checking other similar instruments in the field. It contains an

altimeter, an "air-speed indicator, a tachometer, an oil pressure gauge,

an air pressure gauge, a radiator thermometer, a cockpit thermometer, and a set of correction curves. The instruments are all ar- ranged conveniently for transportation in a mahogany case.

Aircraft Chronograph.

A chronograpli for use on airplanes has been extensively modified

and improved. The record is made on motion-picture film. Electromagnetic shutters are provided to intercept the beam of light from

a miniature electric lamp. The record consists of spots or short

dashes on the film which is driven by a small electric motor. There

is also an electromagnetic timing device for the film. Twenty-five

impressions per second can easily be recorded with this instrument.

Sphygmomanometers.

The investigation of sphygmomanometers has been continued and

standard tests and tolerances have been established for these instruments. The testing apparatus has been improved so that large

numbers of instruments can be handled.

Routine Testing.

The usual amount of routine testing work on aeronautic instruments submitted for test by Government departments and private concerns has been carried out. This includes tests on 26 altimeters,

24 air-speed indicators, 16 tachometers. 11 turn indicators, 10 rateof-climb indicators, 10 aneroid barometers, 5 barographs, 3 mercurial

barometers, 3 airplane thermometers, 1 manometer, 1 oil pressure

gauge, 1 air pressure gauge, and 5 sphygmomanometers.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 165

Flight Tests on Aeronautic Instruments.

A large number of flight tests have been carried out by members

of the bureau in connection with the development of new types of

instruments. These have been made possible through the courtesy

of the Army and Navy, who have provided the necessary facilities

in both lighter and heavier than air craft for these tests.

Aeronautic Instrument Collection.

The collection of aeronautic instruments maintained by the Bureau

of Standards, which is very complete and contains representative

instruments of all the principal types from most of the more prominent manufacturers, not only in this country but also abroad, has

been further extended by the addition of new instruments, including

a Wimperis course-setting sight, a Power position finder, a Bygrave

calculator, a Goerz course calculator, tAvo sextants, a turn indicator, a maximum altimeter, a statoscope, and a rate-of-climb indicator.

AERODYNAMICAL PHYSICS.

Three wind tunnels are now available at the bureau for aero- dynamical work. The tunnels differ in size and speed range and

are adapted to a great variety of work.

The 54-inch tunnel, located in the wind-tunnel building, is of the

British National Physical Laboratory type, octagonal in cross section, the 54-inch dimension being between opposite faces. The faired

entrance of the tunnel is about 4 feet long, the parallel portion 25

feet long, and the exhaust cone 15 feet long. The diameter at the

propeller end is 9 feet. The tunnel room is 68.4 feet long, 28.5 feet

wide, and 18 feet high. The room is divided transversely near the

exit end of the tunnel by a wall honeycomb, consisting of pasteboard

tubes 1.5 inches in diameter and 4 inches long, packed in a light

framework, which is covered on both sides by mosquito bar. This

open honeycomb structure serves to damp out the swirl and eddies

in the air stream as it returns from the fan to the tunnel entrance.

A speed range of 17 to 90 miles per hour is attained in the tunnel

with the expenditure of from 2 to 90 horsepower. Two balances

are available, the first being a modified N. P. L. balance with an

auxiliary balance for pitching moments, used chiefly for work on

aerofoils and airplane models; the second balance is designed for

very heavy models, such as radiator sections, engine cylinders, etc.,

and is adapted chiefly to head-resistance measurements. For very

accurate work at low speeds storage battery current may be used.

The 36-inch tunnel is of the Venturi type, circular in cross section.

The entrance cone is 12 feet long, the worldng portion 6 feet long,

and the exit cone 33 feet long. The diameter at the end of the exit cone and the front of the entrance cone is 7 feet. The tunnel I'oom

is 106.7 feet long, 25.2 feet wide, and 10.2 feet high. Two wall

honeycombs, consisting of hollow tile covered with mosquito bar,

extend entirely across the room in the path of the returning air

stream. A speed range of 11 to 180 miles per hour may be attained

in this tunnel with an expenditure of from 1 to 110 horsepower.

Speeds over 150 miles per liour may be maintained for short intervals of time only. The tunnel is steady and relatively free from
166 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

turbulence. A modified National Physical Laboratory balance is available, but deflection methods have been much used in the past.

The tunnel is well adapted to the calibration of airplane instruments at airplane speeds and to the investigation of devices functioning in a wind stream of high speed.

The third tunnel is 10 feet in diameter and is not housed. The

faired entrance is 4 feet long, the parallel portion 50 feet long, and

the exit cone 34 feet long. It is of circular section, 14 feet in

diameter at the propeller end. A maximum speed of 75 miles per

hour has been obtained with an expenditure of 250 horsepower.

Apparatus is thus available for practically all kinds of aero- dynamic testing except propeller and windmill torque and thrust

measurements.

Aerodynamical Characteristics of Aircraft Bombs. > The general investigation of the aerodynamical properties of aircraft bombs has been in progress for three years. An excellent

series of aluminum models of ogives and bodies was delivered by

the Ordnance Department in the early part of last year and these

models have been supplemented by models of fins of various areas and shapes. Progress this year has been along two lines, namely,

the investigation of the damping of an oscillating bomb and measurements of the forces, moments, and damping on certain models

equipped with the various forms of fins. The first investigation re- quired the development of the necessary apparatus, various difficulties

being met and overcome in new designs. The apparatus in present

use consists of two seven-sixteenths inch rods attached to the bomb in

the same line passing through the center of gravity and connected to

the supports on the tunnel walls by thin steel strips. The strips

have sufficient stillness to cause the bomb to oscillate. The frictional damping is very small. The fin form tests have progressed

sufficiently far as to enable very definite statements to be made as

to the desirability of the use of various forms.

In addition to the general program a finned trench mortar projectile was carried through the same tests as the bomb models. The

projectile was then modified in various ways in an attempt to improve its stability.

Forces on an Airship Shielded hy Wind Screens.

The preliminary work on this problem was reported last year, in

which tests were made in cooperation with the balloon and airship

division of the Air Service of the fliow about models placed in the 54-

inch wind tunnel. This past year experiments were made in cooperation with the engineering division of the Air Service in the open air,

first in the slip stream of a propeller driven by a Liberty motor, sec- ondly, in a natural wind at Langley Field, Va., and finally in the

stream from an electrically driven propeller. Force measurements

were found practicable only in the last-mentioned stream. The general flow was studied by means of anemometers and fine threads.

Enough data were secured to specify the general design of a fullscale wind screen which with proper maneuvering of the airship

would enable landing and ascents in high winds. The forces on the

ship when shielded are a very small percentage of the unshielded

values.
1^^^ EEPORT OF DIEECTOE OF BUEEAU OF STANDARDS. 167

1 Resistance of Ice-Coated Electric Wires to Wind.

In connection with the preparation of safety codes and for the

purpose of providing data for the specification of proper loading

factoids to be used in design, a series of tests was made on a smooth

1-inch cylinder, which represents approximately the form of an icecoated electric wire, at various angles to the wind.

Studies of Wind Tunnel Air Streams.

At the request of the National Advisory Committee for Aeronautics,

a number of studies have been made of the air streams of the wind

tunnels. The two principal investigations concern the effects of

turbulence and the absolute measurement of velocity.

An absolute measurement of velocity has been made by the use of

hydrogen-filled balloons of the same average clensitj^ as air, which

were allowed to float in the air stream. The balloons traversed a beam of light reflected across the stream three times, the times taken

to traverse the distances between successive reflections being meas- ured by means of the camera developed by the sound section. Time

j signals were obtained from a tuning fork previously calibrated

j against a standard clock. The speed determined from Pitot tube

readings was found to equal the speed of the balloons to within one- half of 1 per cent, the accuracy being limited by the unsteadiness of

the air stream.

j The turbulence tests were made on a stream-line model. "Wire

} screens have been used previously as a source of artificial turbulence,

I but recent tests have shown the velocity distribution behind such

' screens to be extremely irregular and unsteady. The work was interrupted due to the pressure of other tests. One attempt was made to measure the temperature of the air

I stream by means of thermocouple junctions placed parallel to the

j stream. The few measurements made show that the air does not

ii undergo adiabatic expansion, but that the heat transfer due to turbu-

^ lence is an important factor.

Cooperative Tests with Weather Bureau.

Assistance has been given to representatives of the Weather Bureau

in the calibration of existing types of Robinson anemometers used

at official stations for recording wind speeds. The corrections of

these instruments at very high speeds are not well known. Some

development work on new types designed to give a more constant

} correction factor has also been done.

! Resistance Measurements in a High-Speed Air Stream.

' Work for the Ordnance Department on the head resistance and

cross-wind forces of models of projectiles and aircraft bombs in a wind stream of high velocity has been continued. These measurements have been ntade possible through the courtesy of the General

Electric Co., which has provided facilities for carrying on the work

in connection with the testing of large centrifugal air compressors

II at Lynn, Mass. A fairly steady air stream of high velocity is ob-

!jl tained by allowing the compressed air to escape continuously through

an orifice 12 inches in diameter. The models are supported in this

air stream on suitably designed balances of various types. Resist-
168 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

ance measurements for air speeds up to 1,200 feet per second have

been obtained in this way.

Jet Propulsion for Airplanes.

A theoretical investigation of this subject was undertaken and a report prepared about two years ago at the request of the Army

Air Service. This investigation has now been revised and made

more complete, and the results have been prepared for publication

by the National Advisory Committee for Aeronautics.

There is no present prospect that jet propulsion can be used successfully and the publication of these results may px'event engi- neers or inventors from attempting impossibilities.

Orifice Meter Investigations.

Flow meters of the differential pressure type are of constantly increasing importance in the commercial measurement of water, oil,

gas, etc., and many requests are received for information regarding

them. In particular, very large quantities of natural gas are sold

on the basis of orifice meter readings, and the Government is interested as receiving large royalties, determined in this way, from

gas produced on public lands.

A considerable part of the literature on flow meters has been ex- amined, in connection with preliminary reports prepared by the

A. S. M. E. Fluid Meters Committee, and a further report has been

submitted to that committee.

At present the division of engineering physics and the division

of weights and measures are starting an experimental research on

orifice gas meters. This is in answer to various requests and has the

cordial approval, accompanied by offers of cooperation, of the Natural Gas Association and numerous meter manufacturers.

GENERAL INVESTIGATIONS.

Plumbing Investigations.

The plumbing subcommittee of the building code committee of

the Department of Commerce is engaged in the formulation of

simplified plumbing practices and regulations, especially as applied

to small-house installations. Experimental work has been carried

on at the bureau to determine the effectiveness of various simplified

systems of venting and the effectiveness of smaller sizes of soil

and drain pipes than are now commonly employed, with a view

to reducing the cost of plumbing installations. Experiments have

been conducted on the determination of rates of discharge from

various plumbing fixtures with different methods of water supply

on the carrying capacities of the 3-inch soil stack and 4-inch house

drain; on designs for the installation of plumbing fixtures on the

stack system; on the variation of air pressure and air flow within

the stacks and branch drains during service ; and* on the effect of

external conditions, such as frost closure of stack tops, wind over

stack tops, and rain water in a combined sewer system. Plumbing

installations, employing 3-inch soil stacks, representative of different

types of dwelling house construction, have also been erected and

tested.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 169

Conclusions from the experiments and tests have been made the

basis of a preliminary report covering dwelling house construction

by the plumbing subcommittee. The work is being continued with

a view to publishing a final complete report during the ensuing year.

Hardware Standardization.

The purpose of this work is to accelerate the standardization of

hardware for Government as well as private use ; to carry out such

laboratory tests as may be necessary to insure the adoption of articles

having requisite characteristics regarding durability and performance; and to make surveys of hardware as manufactured in order

that the items adopted as standard will be those found in general

commercial production. Special attention has been given toward

furthering the work of the interdepartmental advisory committee on

standardization of hardware, appointed by the Federal Specifications

Board. Illustrated specifications for 279 items of builders' hardware

are now ready for submission to manufacturers for comment and

criticism. A survey was made of the methods used by manufacturers

in measuring the length of nails, tacks, and screws, and a digest of

the replies was sent to the industries concerned. Several irregularities in the methods of measuring lengths have been eliminated.

Following the above survey two conferences were held at the bu- reau with representatives of the wood-screw manufacturers, at which

dimensional standards for wood screws were adopted and the number of sizes manufactured as standard were very materially reduced.

The new standard sizes have been put into effect by the makers and

the trade notified accordingly. A specification for wood screws embodying the new standards has been written by the advisoi-y committee on standardization of hardware for adoption by the Federal

Specifications Board.

Plasticity of Soft Materials.

The determination of plasticity is of technical importance for

specifying such materials as clays, paints, and greases, but no satisfactory methods have been developed. This subject has been under

investigation in connection with experimental work in other divisions of the bureau. A paper on the subject is in preparation.

PUBLICATIONS.

The following papers have been published during the year

:

N. A. C. A. Report No. 125, general classificatiuii of instruments and problems

(M. D. Hersey).

N. A. C. A. Report No. 126, altimeters and barographs (A. H. Mears, H. B. Henrickson, and W. G. Brorabacher).

Precision altimeter design (.J. B. Peterson and .T. R. Freeman, jr.).

Statoscopes and rate-of-climb indicator (A. H. Mears).

Aerographic instruments (J. A. C. Warner).

N. A. C. A. Report No. 127, air-speed indicators (F. L. Hunt).

Testing methods for air-speed indicators (H. O. Stearns).

Principles of ground-speed measurement (F. L. Hunt).

N. A. C. A. Report No. 128, inclinometers and banking indicators (W. S. Franklin and M. H. Stillman).

Aircraft compasses and turn indicators (J. A. C. Warner).

Testing of magnetic compasses (R. L. Sanford).*

' Contribution from electrical division.
170 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

N. A. C. A. Report No. 129, aircraft tachometers (G. E. Washburn).

Testing methods for ta^^hometers (R. C. Sylvander).

Thernionieters for aircraft engines (E. F. Mueller and R. M. Wilhelm).*

Air pressure and oil pressure gauges (H. N. Eaton).

Gasoline-deptli gauges and flow meters (J. A. C. Warner).

N. A. C. A. Report No. 130, oxygen instruments (F. L. Hunt).

N. A. C. A. Report No. 131, navigating instruments (H. N. Eaton).

N. A. C. A. Report No. 132, recent developments in aeronautic instruments

(F. L. Hunt).

N. A. C. A. Technical Notes No. 90, sylphon diaphragms, a method for predicting

their performance for purposes of instrument design (H. N. Eaton and

G. H. Keulegan).

Experiments on the recording and reproduction of cardiac and respiratory

sounds (F. L. Hunt and M. J. Myres), Science, October, 1921.

A precision high-speed oscillograph camera, the precise measurement of small

time intervals (E. A. Eckhardt), Jour. Frank. Inst., July, 1922.

A Piezo-electric method for the instantaneous measurement of high pressures

(J. C. Kavcher), Sci. Paper, in press. On plastic flow through capillary tubes (E. Buckingham), Proc. A. S. T. M.,

V. 21, 1921.

Notes on the method of dimensions (E. Buckingham), Phil. Mag., V. 42, p. 696,

1921.

The earth inductor compass (P. R. Heyl and L. J. Briggs), Proc. Am. Phil. Soc,

1922, in press. Measurement of gravity at sea, a review (L. J. Briggs), Bull. 17, Nat. Research

Council, 1922.

STRUCTURAL, ENGINEERING, AND MISCELLANEOUS

MATERIALS.

This division is concerned with the investigation of the properties, uses, design, and fabrication of structural, engineering, and miscellaneous materials. This includes metal of

all kinds, and v/ood, especially when fabricated into structures or structural parts, cement,

concrete, lime, gypsum, sand, stone, and sand-lime brick. Under miscellaneous materials

are included leather, rubber, and composition materials used in place of these, textiles, paper, and lubricating oils. To make the study of these products complete it is desirable

to take into consideration the processes by which they are manufactured. Hence, the equipment includes an experimental rubber mill, textile mill, paper machine, cement plant,

etc. The division is also concerned in the improvement of the present and the develop- ment of new methods of testing and the establishment of standards covering the use of

the materials concerned. GENERAL.

The outstanding feature of the year has been the marked increase

in the contacts which have been secured with the industries interested

in the various lines of work covered by this division. This interest

has been brought about by the increased activity in the matter of

standardization. The war activities demanded the concentration of

efforts along either routine testing or investigational lines to develop

a definite product. The vast fund of information thus obtained has

been of inestimable value in bringing to the attention of both producers and consumers the qualities of the products on the market and

the possibilities of their improvement.

At the same time both the producing and consuming public have

appreciated the need of extensive standardization as a result of the

voluntary efforts in that line during the war. When, therefore, the

matter of the extension and amplification of these had been brought

to their attention, there was a very gratifying cooperation shown by

all concerned. The producing interests have, through their representative organizations, appointed special committees on standards

or technical problems. These have met with the experts of the

bureau on the respective problems and gone thoroughly into the sug-

« Contribution from heat division.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 171

gested standard—in certain cases approving it as prepared, in other

cases taking it under advisement and study in private laboratories of

the industry, and in still other cases drawing up a program of further

cooperative research.

The bringing together of the producing and consuming interests

concerned in any product has resulted in either party obtaining the

other's viewpoint. The producers have learned that the consumer is interested in the manufacture of the commodity he uses, especially in

liow the materials entering into it and the methods of production

aifect the service, and the consumer has learned that the producer is

just as interested in how different phases of service affect the manufacture. This mutual understanding of the problem by all concerned,

when brought together on mutual ground, has been of very marked

value to both and has hastened the work and the obtaining of results

materially.

The bureau, in bringing together the interested parties, acts not

only as a neutral agent or arbiter, but also to a certain extent as the

representati^^e of the Government as a consumer, always, however,

with the advice and cooperation of those governmental departments

actively interested in the product under consideration.

More detailed examples of this more active cooperation along

technical lines and the preparing of standards, especially in the

paper, textile, leather, and rubber industries, will be found under

these respective headings.

STRUCTURAL AND ENGINEERING MATERIALS.

In these laboratories measurements are made of the resistance of

engineering materials, particularly of metals and wood when fabricated into structural units, under tensile, compressive, and torsional

stresses. The fatigue and impact resistance of materials, as well as their hardness, are subjects of careful study. Special attention is

given to the design of testing apparatus and to testing methods in

general in order that these may be improved. The properties of new

materials are determined so that they may be used successfully by

all branches of the Government and by American industries. Attention is given to the alloys of aluminum having low weight because of

their importance in the construction of aircraft. Engineering structures are also designed and tested to determine the construction most

suitable for a^ given purpose. Many of these are loaded to observe

the behavior of their parts. Tests of this kind are made upon

machine and airplane parts as well as on buildings and cranes. Theory of Columns.

The design of columns or compression members in steel structures,

such as bridges or steel-frame buildings, is in a much less satisfactory

condition than the design of tension members or of girders. Instead of rational column formulae giving the column strength in

terms of the dimensions of the column and the properties of the

material, it is the general practice to use empirical formulae whose

constants have been determined from tests on actual columns, and

which are as a rule not related to the properties of the material of

which the columns are made. As a consequence compression members are often designed with an unduly large factor of safety re-
172 REPORT OP DIRECTOR OF BUREAU OF STANDARDS.

suiting in waste of material, and sometimes are of inadequate

strength, resulting in failure.

This unsatisfactory condition has been due to the lack of an

adequate theory of column behavior, verified by a sufficiently wide

range of expex'imental data.

The work of other investigators in this field has been reviewed

hj the bureau, especial attention being paid to the work in foreign

laboratories, and much valuable information has been obtained.

A mathematical analysis of the problem has been made and it seems probable that some of the results will be of practical application.

This theoretical work has been compared with the results of

column tests made at the bureau, as well as those reported by other

laboratories and in all cases where sufficient data were available

the exjierimental results are consistent with the theory.

In order to verify the general applicability of the theory, a series

of tests on small comj^ression members has been undertaken. A

wide range of physical properties of the material has been obtained

by securing, through the courtesy of a number of manufacturers,

specimens of ingot irons, carbon and alloy steel, brass, and monel

metal. These will be tested in widely varying lengths to cover the

slenderness ratios usual in practice, from the ordinary structural

column to the slender latticing used in tower construction and the

struts used in aircraft.

Fatigue Resistance of Metals.

The investigation to determine the fatig-ue resistance of sheet

metals has been continued throughout the year. The metals used

are those suitable for aircraft construction, the thickness varying

from 0.020 to 0.120 inch.

Flexvral fatigue.—Four machines have been designed and constructed for the work on flexural fatigue of thin sheet duralumin.

They have many features which are novel and which may be found

to have advantages for fatigue tests on thicker specimens.

The specimen, a small rectangular piece of the rolled sheet, is held

along ojDposite edges by clamps. The bending stress is set up in the

specimen by a lever and connecting rod driven by a variable speed

electric motor.

The bending moment in the specimen is measured by the torsional

deformation of flat steel springs held at their ends and to the middle

of which the specimen is attached. The deformation of the springs is

measured by a simple optical system consisting of a single filament

electric lamp, a concave mirror attached to the springs near the specimen, and a graduated glass scale. A counter recoi'ds the number of

revolutions made b}' the motor before rupture occurs, as the motor

is automatically stopped when the sj)ecimen breaks.

Preliminary tests on these machines indicated that their rigid construction, which it was believed would entirely eliminate undesirable

vibrations, had not entirely accomplished its object. The dynamometer and ci'ank system was, therefore, progressively redesigned to

obtain the highest possible free frequencies consistent with the

requisite sensibility. After setting up the machines as redesigned a preliminary series of tests on very thin material was made at rela-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 173

tively high stresses to see if the machines were giving consistent results. The first results showed considerable variation for the same

stress range. It was found that the clamping stresses were responsible for the lower readings. After reducing the clamping stresses to

a negligible amount further tests gave residts well within the limits

of variation of fatigue requirements.

The investigation has not been carried far enough to allow any

conclusions to be drawn as to the magnitude of the endurance limit or even as to the probability of its existence in this thin slieet duralumin. Although specimens have been run for more than 10,000,000

alternations of stress without failure, other investigations have shown

that it is not safe to draw general conclusions for series stopping

short of 100,000,000 alternations of stress. Thei'e is no reason to believe that the work will not proceed

smoothly. Because of the speed limits imposed by the thinness of

the si^ecimens the tests will necessarily take a considerable length of

time, but this difficulty is inherent in all fatigue testing.

Impact fatigue.—The machines designed for this investigation

consist of heavy cast-iron anvils mounted on blocks of concrete. The

specimens clamped at their ends are struck at the middle by a tilting

hammer raised by a cam and which falls freely from a fixed height.

The height of fail and the weight of the hammer can both be varied.

Three of these machines were set up on separate bases of concrete to

prevent the vibrations from one machine affecting the results obtained on another.

A number of preliminary tests have been made on specimens of the

bureau's tentative standard size. It is proposed to use hammers

whose weights are proportioned to the thickness of the material

! tested. .\ The three machines can apparently be used interchangeably as the

I results of most of the tests indicate little difference between them.

I The machines can now be used satisfactorily for the thinner sheet

metal, and with the solution of problems connected with methods of

bending the machines will be ready for continuous use in securing

data on this important problem.

I Verification of Testing Machines.

: A careful study of this problem is being made and much valuable

II information has been obtained, some of it from European labora-

; tories. Because of the interest in this subject and its importance in

I commercial work committee E-1 on methods of testing of the AmeriI can Society for Testing Materials undertook a revision of their

standard methods of calibration, which have never proven entirely

satisfactory. At the invitation of the chairman members of the

I bureau's staff attended meetings of this committee and were requested

to submit a revision of the portion of the tentative report dealing

with this subject. The experience of the bureau's engineers in the

use of testing machines and particularly with commercial and other

weighing scales was of great assistance in tliis work. The report met

with the approval of the committee after some revision.

Machines have been designed for applying dead loads to apparatus

for verifying testing machines. Several portable instnmients have

also been designed, and it is probable that experience with these will

lead to the design of an instrument which will be practicable for

verifying commercial machines.
174 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Investigation o£ the Physical Properties of Dental Alloys.

Although dental science has probably been carried further in

this country than elsewhere, much difficulty has been found with the

metallic alloys used for fillings, inlays, crowns, and bridges. Many

of these alloys now in use by the Public Health Service fail, due

to deformation in use. This makes it necessary to replace the

damaged ones at frequent intervals, with the great economic loss

which this involves.

Tests of the physical properties of these alloys are not usually

made and little is known about the relative merits of the alloys

now on the market.

In cooperation with the thermal expansion laboratory this sec- tion is undertaking tests of these materials, which will give reliable

information on their properties.

A Francke flexural testing machine has been donated for this

work, and has the advantage that it allows a very small specimen

to be used and is very sensitive. Loading the specimen as a beam

approximates service conditions and makes it practicable to test wire, sheet, and other forms of the material in the form in which

it is used for dental work. The tests on the Francke machine will be

supplemented by tensile hardness and other tests whenever possible.

It is believed that this is the first investigation of this kind

the results of which will be generally available.

Crinkling Stresses in Steel Tubing.

In cooperation with the Bureau of Aeronautics of the Navy

Department the bureau is investigating the axial compressive loads

which will cause failure of the steel tubing used for airplanes.

Special compression blocks have been constructed having many small

steel balls between the spherical end block for the tube and its seat

in the testing machine. Tubes of different diameters and wall

thicloiesses and of different lengths have been tested and the results

compared with theory and also with the experimental work of

others. This investigation will allow the strength of tubular struts

for airplanes to be computed for design purposes if the material is

uniform.

Shrapnel Diaphragms.

At the request of the Bureau of Ordnance of the Navy Department, tests have been made of the steel diaphragms used in shrapnel

shells.

These diaphragms are placed between the shrapnel and the ex- plosive charge in the base of the shell. If too thin they deform when

the gun is fired, and the charge in the base of the shell may also

explode. The diaphragms were loaded in special fixtures and the

deflection at the center measured. The tests showed that a thinner

diaphragin could be safely used.

Marine Glue Specifications.

Marine glue is used in the construction of the pontoons of flying

boats to cement the fabric used between the inner and the outer

skin and elsewhere.
EEPORT OF DIRECTOE OF BUREAU OF STANDARDS. 175

To supplement a large amount of investigational work done by

the chemistry division on these glues, this section made a large

number of experiments to determine the most practicable tests for the physical properties of this material.

Tungsten Carbide Balls for Brinell Hardness Tests.

For measuring the hardness of metals the Brinell test, using a

ball to indent the material, is the most reliable and practicable. The

ordinary hardened steel ball, such as is used for ball bearings, is satisfactory if the hardness of the material being tested does not

exceed 500 Brinell hardness number. If the hardness exceeds this

value the ball is deformed and the hardness is not accurately determined.

In an attempt to secure harder and stronger balls, tungsten

carbide has been secured in small quantities, and its suitability for

this work studied. Although this material appears to have some

advantages over steel, the samples so far obtained have not been

III entirely satisfactory.

Investigation of Motor-Truck Wheels.

li^ An investigation of the strength of several types of motor-truck

wheels was made for the motor transport division of the Quartermaster Department, Camp Holabird, Baltimore, Md. The wheels

tested in this investigation were a standard wood wheel, a cushion

wood wheel, a cast-steel wheel, a special steel disk wheel, and an

aluminum wheel. The tests made on the wheels were a static radial

compression and a static side-thrust test, a wheel of each type being

used for each test. From the results, the proportional limit, the

strength, resiliency, stiffness, and other physical properties were

obtained under static loading. The determination of these properties makes possible a comparison of the different types of wheels.

Tests of Oil-Well Material.

In the drilling of oil wells or in the salvaging of the fittings in

exhausted wells it sometimes happens that the joints of the casing

may separate at the couplings entailing considerable delay and financial loss. As the weak point in a string of casing is at the threads

where they are joined by pipe couplings, tensile tests were made in

cooperation with oil companies and manufacturers to obtain information on this important point. Apparently the strength of the threads

could be increased to advantage. The material used is also an important factor in the strength of these casings.

Strength of Large Columns of H-Shaped Cross Section.

A report of the tests of large steel columns made at Pittsburgh was

prepared and submitted for criticism to persons interested in the

manufacture of these columns. As a result a number of conferences

were held and it was decided to make further tests of large columns

before publication of these results. In cooperation with the Bethlehem Steel Co. material of low and high yield point is being

selected meeting American Society for Testing Materials and American Steel Manufacturers' Association, class B, specifications, re- spectively.

9644—22 13
176 REPORT OF DIRECTOR OF BUEBAU OF STANDARDS.

Seventy-two columns will be tested, including heavy and light

comparable H-shaped sections of solid rolled and fabricated (plate

and angle) construction of approximately 85 and 36 square inches

cross-sectional area, respectively, and carrying loads up to 4,000,000

poimds.

The properties of the material used are being carefully determined

by means of tests on a large number of coupons cut from the columns

averaging over 10 specimens per column. These coupon results will

be compared with the results of the column tests. Twelve of the

columns have already been tested at the Pittsburgh laboratory, giving

results consistent with those previously obtained. The tests will be

continued during the coming year.

Investigation of the Strength o£ Brick Walls.

In cooperation with the Common Brick Manufacturers' Association of America and other interested organizations the bureau has

made tests on the strength of brick walls. The program included

many variables which are of practical importance in building construction. To avoid the criticism that laboratory tests of brickwork

are usually made on specimens which are very much better than commercial brickwork, every effort was used to obtain average material

and workmanship. The brick from the Cleveland district were of

ordinary quality, and their physical properties have been carefully

determined, both flatwise and on edge. The mortars used were

cement, lime and cement, and lime. The walls were 8 inches thick

in most cases and all of them 9 feet high by 6 feet long. The tests included compression, both axial and eccentric, and transverse tests

to measure the resistance to lateral loads such as wind pressure.

Tests of Girder Hooks.

In cooperation with the American Bridge Co. tests have been made

on the steel hooks used in handling rolled I beams and other structural shapes during fabrication.

The methods at present in use for the design of these hooks are not considered satisfactorj?^, and the tests were undertaken to determine the actual strength of the hooks being used and, if possible,

to obtain formulas which can be used for design.

Three each of the 5, 10, and 15 ton hooks were tested, many straingauge readings being obtained to show the behavior of the material.

These hooks are an important case of the curved beam and it is

believed that the measurement of the stress by means of the straingauge will allow a comparison to be made between the actual and the

theoretical stresses. Welded Structural Members.

In cooperation with the American Bridge Co. tests have been made

of columns, girders, and tensile specimens fabricated from structural

steel. For the columns and girders three of each were riveted and

three of each were electric spot welded. A large number of tensile

specimens were made. All specimens were tested so as to show the

relative strength and other properties of the members. A direct

comparison in this way of members which are used in actual con- struction is very valuable in determining the suitability of a new
KBPORT OF DIKECTOR OF BUREAU OF STANDARDS. 177

method of fastening such as this. More elaborate experiments can

then be planned to obtain additional information.

The results are very encouraging, as the strength of the welded

specimen was, in most cases, at least, equal to the strength of those

which had been riveted. It is probable that in the future both electric spot welding and also gas and electric fusion welding will be

used for many purposes for which other processes are now employed.

Before this is done, however, it should be proven that their use is not

dangerous.

Cooperation.

The bureau has been cooperating actively with the various scientific

and technical societies, assisting in the preparation of specifications,

safety codes, and in the standardization of methods of testing.

CEMENT, CONCRETE, STONE, GRAVEL, AND SAND.

j Specifications for Concrete and Reinforced Concrete.

Publication of the tentative specifications of the Joint Committee

I on Concrete and Reinforced Concrete, .referred to in( the annual

) report for 1921, page 185, has brought out severe criticism of certain

I parts of the report, especially those dealing with (a) the methods

of proportioning the ingredients of concrete, (b) the use of re- inforcing bars rolled from old rails, and (c) tha use for waterj proofing purposes of admixtures in concrete. A number of largely

I attended sessions of the American Society of Civil Engineers, the

American Concrete Institute, and American Society for Testing

Materials have been devoted to the discussion of these questions.

The Bureau of Standards has participated in this standardization

I work, and a member of the staff is serving on committees which have

prepared programs of investigation intended to settle the questions

j regarding proportioning of concrete and the use of rerolled bars as

I reinforcement.

[ Floor-Slab Tests.

The concrete and hollow-tile floor slab tested at Waynesboro, Ohio,

is still under loads of 1,413, 1,184, and 920 pounds per square foot

on three panels, respectively, as described in the annual report for

1921, page 185. It is reported, however, that these loads have

recently caused severe deflections and cracking of the slabs. This

is to be expected, since the loads applied are many times as great as are permitted by present standards. The report of the showing

from this test up to October 21, 1921, forms the basis of a technologic

paper, which has gone to press.

Effect of Direction of Reinforcement on Strength of Slabs Supported

on Two Edges.

A technologic paper has been prepared in which is included (a) an

analysis of the stresses and deflections of slab beams in which the

reinforcement makes an angle with the direction of the span, and

(&) results of tests of such beams using bars and of beams using

expanded metal as reinforcement. The analysis indicates a smaller

strength and a greater deflection for the beams with diagonal re^
178 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

inforcement than for beams having reinforcement parallel to the

direction of the span. The slab beams tested were very shallovr and

the reinforcement was in two layers in all cases. The thinness of

the slabs causes small errors in placing the reinforcement and in

measuring its position to assume considerable importance in the test

results. The fact that the reinforcement was in two layers offers

opportunity for the entrance of errors in interpretation of the results. The tests show a distinct trend in the direction indicated by

the analysis, but for final conclusions as to the effect of variation in

details of the reinforcement on the behavior of the beams more tests are necessary,

ReroUed Steel Investigation.

Owing to the fact that concrete reinforcement made from salvaged

steel, usually old rails, is prohibited in nearly all public and private

work now going on, an investigation was made to determine the

suitability of such reinforcement. One of the main objections en- tered against rerolled steel is that it is subject to too much breakage

in handling, and the tests made were such as would show brittleness, lack of ductility and i;he tensile properties of the materials.

Lots of steel from 10 different sources—5 rerolled steel and 5

bought under the specification that they be hard-grade new billet

steel—were tested. The tests made were: (1) Tension tests of

straight specimens; (2) and (3) tension tests of bent specimens;

(4) impact tests; (5) bend tests made in an Olsen cold-bend testing

machine; and (6) bend tests in a special bending machine. The

tension tests of bent specimens were made on specimens from the

same bars but bent in different bending machines to study the

effect of the manner of bending on the strength of the steel.

With the exception of one lot of bars the rerolled st>eel showed

tensile strengths which met the A. S. T. M. specifications for such

material. The yield points and tensile strength of the new billet

steel were generally too low to classify them as hard grade. The

method of bending appeared to have generally only a small effect

on the tensile strength and was generally less for specimens bent

in the special bending machine than for those bent in the ordinary

way. Only one lot of |^-inch square rail steel bars failed to meet

the' bend test. Out of 21 bars of the lot nine broke before bending

through 90°. The impact test was used to test the bars for brittle- ness. The blow used was sufficient to stress the bars well beyond

their yield points. In no case did the bars break, but after the

impact each showed a decided bend at the point where the blow was

applied. The amount of the measured permanent deflection was

approximately inversely proportional to the square of the yield

point of the bars.

From the tests made it appeared that either rerolled or new billet

steel with yield points up to 60,000 pounds per square inch which

meets the tension and bend tests would be satisfactory for concrete

reinforcement. From these tests it appears doubtful if rerolled steel

having a yield point greater than 60,000 pounds per square inch can be bent to meet conditions in practice, but reinforcement not re- quired to be bent should be satisfactory if it meets the tension test and suitable impact or bending tests to detect brittleness. No data
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 179

were secured which indicated whether or not the same conclusion

would apply to new billet steel of high yield point. While the tests were quite clear in their indications, the finality of the conclusions

is limited by the fact that steel bars from only 10 sources were

tested. To justify a more positive statement it is desirable that an

investigation be made on specimens from a large number of sources.

Durability of Concrete in Alkali and Sea Water.

The third progress report on Durability of Cement Drain Tile

in Concrete and Alkali Soils was issued as Technologic Paper No.

214 at the close of the fiscal year. This paper is now available for

distribution.

An opportunity was taken during the year to inspect some of the

concrete structures in sea water on the Pacific coast; the experimental concrete blocks installed in alkali sloughs at Montrose and

Grand Junction, Col., in 1915, were also examined. The present

condition of these blocks, as well as of the sea-water concrete, indicates the marked superiority of strong, impermeable concrete in

resisting attack by these destructive agencies.

General Investigation of Building Stones.

Several years ago the bureau started an investigation to determine

the physical properties of all the important stone deposits in this

country. The object of tliis study is to establish reliable data on

the various types, deposits, etc., for use in specifications. This work

has necessarily proceeded rather slowly, due to the fact that only a limited amount of time could be given the subject. Considerable

work has been done on limestone, sandstone, and marble.

The greatest problem in connection with the testing of stone is

that of preparing the test specimens from the rough quarry blocks

which are submitted as samples. Recently some very important

improvements have been made in the bureau's stone-cutting equipment which makes possible the preparation of specimens with more

facility, hence the cost of this part of the work is considerably re- duced and the tests can be accomplished more expeditiously.

The work done during the past year has been concerned principally with granite, slate, and limestone. About 30 specimens of

slate from the slate district of Pennsylvania have been tested for

transverse strength, elasticity in bending, absorption, and effect of

freezing. Granites from the following localities have been tested

:

Eion and Mount Airy, S. C. ; Salisbury and Ealeigh, N. C. ; Lithonia,

Pine Mountain, and Stone Mountain, Ga. ; St. Cloud, Minn. ; West

Compton, N. H. ; Graniteville, Mo. ; Lincolnville and Vinal Haven,

Me.; Prescott, Ariz.; Bethesda, Md. ; and Cheland, Wash.

Freezing tests have been made on a considerable number of limestone samples. In these tests a sufficient number of freezings were

made to practically destroy the stone. Some of the weaker specimens were disintegrated by 100 freezings, while others were not

visibly affected by 600 freezings.

Another problem which has been started in connection with building stones is the cause and effect of efflorescence on masonry. Cases

have been noted where disintegration occurred in connection with

efflorescence, and it is believed that this is due to the formation of
180 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

crystals in the pores of the stone near the surface. The effect of

allowing a few different salts to crystallize in the pores of the stone

has been studied and all have shown a tendency to disintegrate the

stone.

Exposure Tests on Colorless Waterproofing Materials.

This class of materials is used principally for exterior application to masonry walls where it is desirable to prevent the penetration of water. There are numerous brands of these materials on

the market and the bureau is frequently called upon for information

concerning their value and relative merits. More than a year ago

a series of tests was started to determine their effectiveness on limestone and their relative durability when exposed to the weather. A

report was published on this series after six months exposure and

the tests are still in progress. Eecently the scope of the work has

been extended to include three types of sandstone which vary in

texture from coarse-grained stone to very fine-grained, compact

stone. The object of this study is to determine if a given waterproofing material is equally effective on different textures or if it is necessary to vary the composition to suit the texture of the stone.

Elastic Pointing and Calking Materials.

These materials are for the purpose of permanently sealing up

joints in*masonry which are subject to slight movements from settlement of the building or thermal expansion. Ordinary Portland

cement or lime mortars usually crack under such conditions, thus

permitting the entrance of water. Seven commercial compounds

which are claimed to remain plastic enough to take care of such

structural movements are being tested on panels of limestone which

are continually exposed to the weather. One course of the stone

is so arranged that small relative movements can be produced, thus

bringing a stress upon the pointing material. These tests are made

on the exposed panels about once each month and the effect on the

materials is noted. Other observations are made on the materials,

such as their tendency to stain the stone, their ability to maintain

a waterproof joint, weathering qualities, and general appearance.

Discoloration of Indiana Limestone.

The frequent occurrence of ugly discolorations on new limestone

buildings has long been a source of annoyance to users as well as the

producers of this popular building material. While it is not of

general occurrence, its effect in marring the beauty of the structure

has greatly detracted from the value of the stone, in the opinion of

many architects. This bureau has been carrying out various experiments in the laboratory and on exposed panels of the stone for the

past two years trying to determine a practical method of overcoming

the trouble. The bureau's work along this line has developed some

important facts in connection with the stain, as follows

1. The brown discolorations which are frequently called iron stains are really due to the organic impurities in the limestone.

2. The impurities in the stone which give rise to the stains are not

uniformly distributed throughout the entire limestone deposits or even in one ledge or one quarry. Hence, it is not possible to say that

certain quarries produce stone which will not stain.
HEPORT OF DIRECTOR OP BUREAU OF STANDARDS. 181

3. Some properties of the cement used in setting up the stone are

largely responsible for the appearance of the staining element on the

surface of the stone.

4. So-called nonstaining cements sometimes possess this property

to a greater degree than normal cements.

5. Stains do not occur to an appreciable extent if water is prevented from leaching through the masonry.

The work along this line is now concerned with : (a) The study

of the properties of various types of cement, (h) the feasibility of

preventing the leaching process by means of colorless waterproofing

materials, and (<?) the study of the chemical phases of the staining

process. The bureau's experiments indicate that the trouble may

be overcome by the use of colorless waterproofing materials, but a more economical solution may possibly be found in a specially prepared or treated cement for setting the stone.

Concrete Tanks for Oil Storage.

This investigation was brought to a close in the early part of the

fiscal year owing to lack of funds for its further continuance. The

chief aim of the work, however, was acocmplished and reported

briefly in the last annual report. Further work of value in connection with oilproofing treatments might have been carried out, but

aside from a few long-time tests on one or two special treatments,

the test of oilproofings was abandoned.

Stucco.

An investigation of the comparative value of various types of

metal lath and wire fabric as a base of stucco has been undertaken

during this fiscal year. Ten of the large stucco panels erected in

1916 have been replaced with new panels, on which an extensive

series of strain-gauge measurements are being made. Some very

interesting results have been obtained from these measurements, but

a complete report will not be made until the panels are a year old.

As a matter of interest it may be stated that a few minute cracks

have developed on the new panels in such manner as to indicate that

they result from strains set up by the movement of the underlying

diagonal sheathing, notwithstanding the fact that the frame and

sheathing were erected six years ago and are now thoroughly sea- soned. This furnishes additional evidence in support of the bureau's

recommendation that sheathing of frame houses which are to be cov- ered with stucco should not be laid diagonally.

Study of Concrete-House Construction.

Supplementing the activities of the division of housing, the bureau

has made an extensive study of concrete-house construction. The

majority of the larger projects have been visited, and numerous

smaller projects and individual houses have been inspected. The

data are now largely at hand for a comprehensive report on the subject, in which the advantages and disadvantages of the concrete

house will be fully discussed. From the information which has

been gathered it is believed that the concrete house is worthy of

more general consideration on the part of architects, owners, and

builders, and that within the next few years the merits of this type

of construction will be widely recognized.
182 EEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

Investigation of Sewer Pipe in the City of Los Angeles.

In the latter part of the fiscal year the bureau began an investigation of the condition of sewer pipes in the city of Los Angeles for

the purpose of studying the effects of sewage and sewer gases on

clay and cement pipes, both of which are now being extensively used

in that city. In this work it is cooperating with the clay and cement

pipe manufacturers and the office of the city engineer.

The program of the investigation involves the excavation and

inspection of sections of pipe from laterals in various parts of the

city, and the replacement of these with tested pipe for further ex- amination. The major part of the work, however, consists in the

installation of small sections of pipe in manholes in such manner

that a part of the specimens will be submerged in the sewage and a part exposed only to the action of server gases. The exposure points

have been selected in such manner as to cover typical conditions

throughout the system, and at these points periodic analyses of the

sewage and sewer gases will be made for the purpose of determining

the concentration of ingredients which may be injurious to the pipes.

The real object of the investigation is to determine, from the

chemical survey as outlined above, general relations between rate or extent of deterioration of pipes and concentration of damaging

elements in the sewage and gases. The problem is a difficult one,

not only on account of the extent of the work involved but more

particularly because the field which it enters is as yet unexplored.

Air Analyzer.

The modified form of air analyzer as described in the last annual

report has been found to extend the range of fineness determinations

to a minimum size of separation of 0.01 mm. The most important

work carried out during the year with the apparatus was the mechanical analysis of a series of English and American whitings for

the ceramic division of the bureau.

United States Standard Sieve Series.

Some progress has been made in the selection of a suitable material

for checking up the " sieving values " of the finer sieves of the series

to supplement the microscopic measurements of the sieve cloth. It

is probable that the standard cement-fineness samples will be entirely

satisfactory for sieves finer than the No. 200. For sieves coarser than the No. 200 it has been found that samples of fine quartz sand

can be prepared with the necessary uniformity, but the desirable

range in gradation has not yet been established with certainty. The

new circular describing these sieves will probably be issued during

the coming year and will contain matter descriptive of their manufacture, use, and testing.

Standard Samples.

The bureau prepares and keeps on hand for issue standard-fineness

samples of cement for checking up No. 200 sieves. They are supplied in two degrees of fineness and are issued in sealed glass jars,

each jar containing about 160 grams, enough for three 50-gram sieve

tests. Each sample is accompanied by full directions for its use. A

nominal price of 50 cents, sufficient only to cover the cost of prepa-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 183

ration, is charged for each jar. With these samples No. 200 sieves

may be compared with the standards of the Government and cor- rection factors determined. These samples are also used by the

bureau in checking up its own sieves and in the standardization of

No. 200 sieves submitted for certification. The two samples on hand

at present are 46h-78.6 per cent passing the No. 200 sieve and

47c-89.2 per cent passing the No. 200 sieve. While there has been

in the last year a decrease in the number of No. 200 sieves submitted

for standardization, there has been a 50 per cent increase in the

number of standard cement-fineness samples issued. This would

indicate that the users of sieves are taking advantage of the standard samples to make their own standardization tests.

Caustic Magnesia Cement.

The calcinations of certain lots of foreign and domestic magnesites

referred to in last year's report was completed during the early part

of this j^ear. All specimens were made and all but a few of the longtime specimens have been tested. All results confirm the earlier conclusions of the sensitiveness of this cement to the action of the aggregates. They also show that until a satisfactory regulator of

setting has been developed it will be necessary to overcalcine the ore,

as an ore calcined at such a low temperature as to produce maximum

activity reacts so energetically with the chloride solution as to be

valueless for cementing purposes.

During the year five large test panels of commercial magnesite

stuccos were erected and are under observation. While being placed,

laboratory test pieces of the stucco as used were made as well as test

pieces made of the dry mixtures used, but gauged with 22° Baume

chloride solution in the laboratory.

All of the manufacturers known to the bureau were also requested

to furnish samples of the various floorings manufactured by them

which were to be lased in determining the various physical properties

of the commercial floorings. A generous reply was received and a large number of samples were obtained, on which all test pieces have

been made. They are now being tested, and from the results it is

hoped it will be possible to prepare specifications for resilient composition floorings.

Constitution of Portland Cement.

Some few tests were made on admixtures of calcium monoaluminate

with Portland cement. It was thought that as the former had the

property of very rapid hardening with a consequent high early

strength, it would materially increase the early strength of the Portland cement. However, it was found that until about equal amounts

of the two were used, the Portland cement gave the mixture a flash

set unless about twice the usual amount of gypsum was used. "When

the latter procedure was followed in using a 90 per cent Portland and

10 per cent monoaluminate mixture, it was possible to increase the 24-

hour strength of a Portland cement mortar about 100 per cent.

An investigation is now under way at a commercial cement plant

in which the conditions of burning in one 125-foot kiln are being

closely observed and at the same time the composition is being varied over wide limits. The resulting cement, if it meets the specifications.
184 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

is going in with the other output of the plant. At the same time a large number and A^ariety of test pieces are being made at the plant

and duplicates will be made at different later periods at the bureau.

The entire investigation is an attempt to study the effect of different

degrees of burning in bringing about a different constitution from

raw mixes of the same composition and to study the effects of the

different constitutions and compositions on the physical properties

of the cement.

General Concrete Investigations.

In cooperation with eight other laboratories and the American

Society for Testing Materials an extensive series of concrete tests has

been made to determine the effects of various accelerators. The one- year tests will be completed this summer.

The San Francisco branch has cooperated with the Bureau of

Public Eoads in studies of alkali soils and their effect on concrete

roads. In particular, an intensive study was made of the Glenn

County, Calif., alkali district, and a special report thereon was prepared for the Bureau of Public Eoads.

Extensive tests have been made in studying the effect of hydrated

lime in concrete subjected to various storage conditions. The results

were embodied in a paper presented before the National Lime Association in June, 1922.

Test pieces have been made of various clays mixed with a special

cement which has been placed on the market as a cement suitable for

building roads from roadside clays. This test has not been completed.

Periodic examinations are being made of mortar specimens prepared last year from an aggregate of partially decomposed feldspar.

This aggregate gave satisfactory tests at the end of the usual 28-day

period, but at the end of one year the disintegration of some of the

specimens is becoming very marked.

Various laboratories have requested information and working

drawings of the flow table, an apparatus designed to measure the

consistency of concrete mixtures. Further investigations are planned

with a view to improving this device, and a table embodying certain

new and desirable features is now being constructed.

Testing and Shipment of Cement for Government Purposes.

The quantity of certified cement packed and shipped under the

supervision of the bureau's inspectors to Government projects was

smaller than in the preceding year. The cement was used in con- nection with the usual building operations of the Government, such

as river development, irrigation projects, bridges. Army camps and

buildings, naval bases, Panama Canal, island possessions, hospitals,

educational institutions, fisheries, public roads, lighthouses, scientific

buildings, and District of Columbia construction.

Among the branches of the Government served were: The War,

Navy, Treasury, Interior, Agricultural, Commerce, and Labor Departments; the Marine Corps; the Office of Public Buildings and

Groimds ; the government of the District of Columbia ; the Panama

Canal ; the Shipping Board ; the Piscataqua River Bridge Commission ; and the Smithsonian Institution.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 185

Shipments of Tested Cement (Barrels).

Month. 1919-20 1920-21 1921-22

July . . 144,421

168, 141

1 ^ft IRA 133,462

118,648

80,939

79, 894

66,28,5

70, 835

75, ,590 53, 798 56,605

99,849

63,625

52 460 93^532

75, .305 59, 389

24, 890

29, 605

57, 515 54,054

59, 129 89,698

71,416

63, 853

67 528 72|355 46,809

44, 625 27,624

21,476 42,969

43, 970

45, 1.56 46,064

August . September

October November. .

January

February ,

Anril

Total 1,186,782

125,919

759,051 86,652 593,845

1 51,124

1 In addition, 6,200 barrels were withdrawn by manufacturers when the early test results were available. Inspection was made at 40 shipping points located in the District

of Columbia and the following 15 States : California, Colorado, Indiana, Iowa, Maryland, Montana, New Jersey, New York, Oklahoma,

Pennsylvania, Texas, Utah, Virgmia, Washington, and West Virginia.

The foregoing inspection does not cover all the mills furnishing

cement on Government orders, but only those where conditions and

location permit the service.

In addition to the approximately 1.100 samples tested in connection

with the foregoing inspection, the laboratories tested 186 samples

submitted by Government offices for specification tests. Ten samples

were received for comparative tests and special investigations. Two

imported cements and 10 special cements were tested.

Samples of cement submitted from an official source represented

,

several large lots of cement which had been in storage for some

months. A portion of these samples developed a tensile strength

considerably below the specification requirements. On the assumption that the cement was satisfactory when purchased, this case emphasizes the need of making a retest after any considerable storage period.

LIME, GYPSUM, AND SAND-LIME BRICK.

Hydrated Lime in Concrete.

The outstanding feature of the year's work on this subject is the

determination of the fact that when lime, but no water, is added to

concrete the strength is increased and the flow is decreased. These

effects are exactly the opposite of those obtained when water, but no

lime, is added. When both lime and water are added, they tend to

neutralize each other, so that the net effect may be plus, minus, or

zero. This work has been done in cooperation with the cement sec- tion. A new machine for measuring the effect of lime on the workability of concrete has been developed and turned over to the cement

section for further experiment.

Panel Tests of Lime Plaster.

In order to ascertain the impurities which may cause unsoundness

of plaster, several suspected materials were prepared and screened
186 EE PORT OF DIRECTOR OF BUREAU OF STANDARDS.

to predetermined sizes. These were then mixed with hydrated lime

and used as the finish coats of plaster panels. Ninety-eight such

panels have been erected and are now under observation at the bureau. The materials for this work were furnished by the National

Lime Association, the labor by the International Plasterers Union^

and the supervision by the National Association of Plastering Contractors.

Measurement of Plasticity.

The plasticimeter designed by the bureau to measure the plasticity

of lime is now on the market. Four of these instruments have been

sold, to date, and the bureau is calibrating them.

Measurement of Sand-Carrying Capacity.

Where sand is added to lime to make plaster or mortar, it is the

usual custom to continue adding sand until the mixture " feels right."

The plasticity of the mortar seems to be the final criterion. The

plasticimeter has therefore been made use of as a means of measuring the sand-carrying capacity of lime. The results obtained to date

are quite satisfactory, so that all that now remains is to obtain a

sufficient quantity of data to warrant a recommendation.

Making Hydrate Plastic.

Hydrates which are sufficiently plastic to be used for finish coats

differ in plasticity only from those which are not so plastic; no

chemical or physical differences can be detected. The bureau has

found that by grinding a nonplastic hydrate with 1 per cent of a

desiccating agent, such as quicklime, it can be made plastic. A

patent on this method, taken out by F. C. Welch, has been dedicated

to the free use of the public.

The Constitution of Hydrated Lime.

It is known that the maximum temperature reached during the

slaking of lime has a profound effect on the physical properties of

the hydrate. An investigation has been undertaken to ascertain

whether the properties noted are dependent upon the way in which

the water is contained in the hydrate. No results are available as

yet. i

Properties of Commercial Limes.

In order that the bureau may assist manufacturers by giving them

a fair report on the quality of their products, and assist the users

in the proper selection of the material they need, the bureau has

undertaken to measiire the more important physical properties of all

commercial limes. These properties include plasticity, sand-carrying capacity, time of set, yield, shrinkage, and tensile strength.

Some 20 samples have been tested to date.

Action of Lime on Clay.

It is known that lime sometimes changes the properties of a clay

soil so that it will not bake when dry or get sticky when wet. This

reaction is being investigated to see if it can be brought under effi- cient control.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 187

Properties of Lime-Cement-Sand Mortars.

The addition of lime to cement mortars is becoming quite cus- tomary, but how much lime to use is still an open question. To

answer it, measurements are being made of the plasticity, time of

set, yield, shrinkage, and tensile strength of mixtures of lime, cement,

and sand in many different proportions.

Quick Setting of Lime Plaster.

It is sometimes desirable to be able to exercise some control over

the time of set of lime plaster. Five or six ways of doing this have

been worked out, and are now being investigated as to their relative

costs and the keeping qualities of the product.

Adhesion of Gypsum Plaster to Concrete.

Preliminary investigations led to the belief that any lack of adhesion of gypsum plaster to concrete is probably due to a difference

in the coefficients of expansion of the two materials. A study of the

expansion of gypsum plaster as affected by its content of sand, its

consistency, and other factors was, therefore, made. The data so obtained made possible the production of a gypsum plaster having

the same expansion as a given concrete. Such a plaster has been

applied to concrete and is now being tested to see that it adheres

properly.

Effect of Temperature of Calcination on the Properties of Calcined

Gypsum.

This research has been under way for some years. This year it has taken the form of an investigation of the properties of deadburned gypsum. Under the name of Estrich gypsum this material

is widely used in Europe, but the nearest approach to it on the

United States market is Keene's cement. Further information about

this material may lead to the development of its manufacture in this

country.

Pottery Plaster,

This is a form of calcined gypsum which is used in making molds

for casting pottery. Some time ago the bureau was asked by a user of this plaster to develop a way to utilize his worn-out molds. This

can be done by regrinding and recalcining the material, but, under

ordinary conditions, it is cheaper to buy fresh material than to work

up the old. The problem was, therefore, transformed into one of

" casehardening " the molds, to make them last longer. Several

methods of doing this have been developed and are now being tried

out in the ceramic division.

Determination of Anhydrite.

Anhydrite is an impurity frequently found in gypsum, but the

quantity of it is not accurately indicated by ordinary chemical

analysis. Since small amounts of it may be quite harmful where the

gypsum is to be used for certain purposes, a simple and accurate

means for its determination becomes desirable. The heavy liquid

method of separation, and also the petrographic estimation, are being

tried.
188 REPORT OF DIRECTOR OE BUREAU OE STANDARDS.

Effect of Clay in Gypsum.

It is the custom in some localities to add a small amount of clay to

calcined gyj)sum in the manufacture of wall plaster in order to make

it work more smoothly. Opponents of this practice claim that the

clay is deleterious to the quality of the hardened plaster. The bureau

has undertaken to ascertain the facts in the case. Measurement of Consistency.

There are almost as many ways of measuring the consistency of a

plastic material as there are materials. Much confusion would be

eliminated if one instrument could be used for this test, even though

the different consistencies desired might require different readings on

the instrument. Furthermore, it is generally conceded that no instrument now in use measures consistency only, but always consistency

plus something else. Under these circumstances, the need for standardization is obvious and the bureau is engaged in a preliminary

study of the subject.

Weatherproof Gypsum.

Gypsum has been used for exterior work, but is not recommended

for permanent structures. A great many ways of making it weather

proof have been developed, and samples treated in these ways are now

exposed to the weather.

Tests of Gypsum Plaster Boards and Wall Boards.

In order to obtain the data necessary to prepare specifications for

these materials samples from nearly every manufacturer were collected and tested for strength, weight, and thickness.

Properties of Plastering Sands.

The attempt to write a specification for plastering sand was finally

abandoned as economically futile. Instead the bureau has undertaken

an investigation of the properties of plastering sands, with a view

toward guiding the contractor in the best utilization of the materials

available. This has led to the measurement of the physical properties of lime and gypsum plasters, made with different kinds of sand.

Cooperation.

American Society for Testing Materials.—This section holds the

secretaryship of the brick committee of the American Society for

Testing Materials, and the incumbent was designated to represent the

society at the conference of the Department of Commerce on the

simplification of sizes and types of paving brick.

The lime committee, in which this section holds two subcommittee

chairmanships, has revised its specifications for structural quicklime

and structural hydrate, and brought out five new specifications for

different kinds of chemical lime.

This section holds the chair of the gypsum committee, which has

this year revised all of the seven specifications it has issued, and has

started an investigation of the use of anhydrite in Portland cement,

and of the fire resistance of gypsum products. One of the meetings

of the committee was held at the bureau.
KEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 189

As a member of the committee on testing methods, this section has

taken an active part in the discussion of the measurement of consistency.

Bureau of Standards plastering conference.—This body, composed

of representatives of the various industries involved in plastering,

was formed to assist the bureau in the preparation of a national

plastering code. A great deal of correspondence, and several meetings, placed much valuable information at the bureau's disposal.

This year this information has been worked up into a report, which

is nearly ready to be submitted in tentative form to the members.

Interdepartmental conference on chemical lime.—This body, composed of Government employees from the various bureaus interested,

is organized to assist the Bureau of Standards in preparing specifications for, and collecting information about, the quality of lime re- cjuired for different chemical uses. It has published two specifications, has five or six more in preparation, and has commenced the

preparation of four technical articles.

National Lime Association.—The bureau keeps in close touch with

this association of manufacturers, which maintains a fellowship in

the laboratory. Their board of directors met here in December. A

member of the section attended their annual meeting in Cleveland

in June.

Gypsum Industries Association.—The fellowship which this asso- ciation maintains at the bureau assures close cooperation between the

two organizations. Many of the members of the association are

active in the work of the gypsum committee of the American Society

for Testing Materials, which met at the bureau in October, and in

conjunction with a monthly meeting of the association in Chicago in

March.

Sand-lime Brich Association.—Contact with this association has

been maintained through the brick committee of the American Society for Testing Materials and through the attendance of a representative of this section at the annual meeting of the association at

Dayton in February.

Visits to plants.—During the year members of the section have

visited 1 lime plant, 4 gypsum plants, and 2 sand-lime brick plants.

RUBBER.

New Equipment.

The bureau's experimental rubber mixing mill was inadequate for

the amount of work necessary, and a mill with a much greater ca- acity is now being installed. This addition will make it possible to o experimental compounding on a much larger and more accurate

scale.

A sifting machine was installed so that all the ingredients used can be of the proper fineness.

A new machine for buffing rubber samples was installed, which

was designed in the laboratory and built at the bureau. It is now

possible to prepare test samples of all grades of rubber goods sat- isfactorily and more efficiently.
190 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Power Losses in Automobile Tires.

The investigation of the power losses in automobile tires has been

continued. A preliminary report covering the results obtained will

be published as Technologic Paper No. 213.

An endurance tire-testing machine has been installed and is in

continuous operation. Data are being compiled from the results of

the dynamometer and endurance machine tests with the intention of

working out a sei-vice test for tires which can be incorporated in

the Government specifications.

This work is being done in cooperation with a committee representing the Rubber Association of America,

Asbestos Packing.

At the request of the Panama Canal the properties of compressed

asbestos sheet packing were studied. The results are to be used by

the Federal Specifications Board in preparing specifications for this

class of material.

Insulating Tape.

An investigation of the properties of rubber and cloth-frictioned

tape is now being made in conjunction with the electrical division.

The results of all this work are to be used in cooperation with the

Federal Specifications Board for the development of standard specifications.

Insulated Wire.

The Signal Corps of the Army requested that a complete study of

insulated wire be made, and this work is in progress.

Kubber Heels and Soles.

In cooperation with the leather section standard heel and sole compounds made at the bureau are being compared with commei-cial

samples. A complete series of artificial and normal aging tests is being conducted.

Rubber Tubing.

The experimental rubber laboratory has been very successful in

malring all sizes of tubing to meet the bureau's needs. About 500

pounds was made this last year. In addition, this work has made

it possible to accumulate data of value in the drawing up of standard

specifications for rubber tubing.

Jar Rings for Canning.

This investigation is now continuing into the second year. Its

object is to determine the aging qualities of jar rings in actual use and in storage, and to revise the existing specifications as found

necessary. This work is being done in cooperation with the States

Relations Service, Department of Agriculture, and a graphical report

of the results to date was sent out to the cooperating manufacturers.

Compounding Ingredients.

One of the most vital problems that confront the rubber manufacturers is to find a rapid method for determining the life of a rubber

.. t 1
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 191

comjDound. About eight years ago the bureau started some work on

the Geer test, which consists in exposing samples to the effect of heat

in a properly ventilated oven for varying periods. The results,

which are contained in the new edition of Circular 38, The Testing

of Rubber Goods, indicate that it is desirable to continue this work.

As a result the bureau has planned an extensive investigation of

the properties of rubber and the effect of ingredients on the life of

rubber compounds, under various conditions of storage. Some preliminary work was started in which the value of some substances

that have not been used in the compounding of rubber is to be determined. One of these is slate dust, submitted by the Bureau of

Mines, Department of the Interior. A preliminary report was made,

which indicates that it can be used as a rubber filler. Rubber Analysis.

An important part of the bureau's work is the analysis of rubber

goods purchased by the various Government departments. The

number of substances that can be used is constantly increasing. The

properties of many of these are such that the usual methods of

analysis give incorrect results, thus necessitating additions to or

revisions of the existing methods.

The bureau has done considerable work the past few years in

attempting to evolve a method of analysis which will give accurate

results in all cases. It is hoped to find a solvent which will dissolve

the rubber compound and permit of the separation of the fillers

unchanged. At first cresol was used, but, in addition to being poisonous, inaccurate results were obtained. Later cymene was used and

much better results obtained. At the present time a mixture of oils

seems to be most satisfactory.

In cooperation with the committee on methods of analysis of the

rubber division, American Chemical Society, the bureau has been

doing considerable work on the determination of alcoholic-alkali

extracts and the proper drying temperature for the different extracts.

The bureau's methods formed the basis of those recommended by the

cormnittee for adoption by the rubber division and eventually by

the society.

Miscellaneous Materials.

Under this heading are included not only a large number of rubber

articles, such as hose of various kinds, belting, valves, packings,

rubber-covered wire, jar rings, rubber bands, etc., but also many materials other than rubber. As typical examples of the latter may be

mentioned asbestos gaskets, canvas belting, linoleum, flax shot lines

used by the Coast Guard, sash cords, hack-saw blades, shoe laces, etc. Special equipment has been developed for testing some of these materials and in such cases similar tests are made for manufacturers

upon request. The usual tests of miscellaneous materials were made

for the General Supply Committee, the results being used as a basis

for the award of contracts covering the fiscal year 1922-23. At the

present time the bureau is cooperating with the rubber committees

of the Federal Specifications Board.

9644—22 14
192 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Cooperation.

It is the bureau's policy to cooperate to the fullest extent with

manufacturers with the view of having the requirements of specifications conform in every way to the best manufacturing practice.

When all available sources of information have been utilized a

specification is prepared in tentative form and presented for discussion and final adoption at a conference of the Federal Specifications

Board. In this way the requirements of a specification when approved are such as to insure a commercial product of satisfactory

quality and well adapted to meet the conditions of service imposed by

the Government.

The following examples illustrate the service rendered the various

Government offices by the bureau acting in an advisory capacity.

The bureau has been cooperating with the Bureau of Engraving

and Printing in the development of more suitable rubber-covered

inking rolls. Considerable work was done for the Chemical Warfare Service on the artificial aging of gas-mask material. An investigation of the necessary properties of teat-cup rubbers has been

started for the Dairy Division, Department of Agriculture.

In addition the bureau works in close cooperation with the Eubber

Association of America.

Specifications.

Bureau of Standards Circular No. 165, Specifications for Pneumatic Tires, Solid Tires, and Inner Tubes, was adopted by the Federal Specifications Board for use by all Government departments.

The bureau assisted the Federal Specification Board in drawing

up the following specifications:

General specifications for mechanical rubber goods.

Cotton rubber-lined flre hose.

Rubber bands.

Rubber tubing.

Rubber jar rings.

Water and wash deck hose.

Gas hose:

a-. Acetylene-hydrogen hose.

b. Oxygen hose.

Engine tender hose.

Air-brake and signal hose and gaskets.

Steam hose.

Suction hose.

Pneumatic hose

a. Rock-drill hose.

b. Pneumatic-tool hose.

Diver's liose. Dredging sleeves. Chemical engine hose.

Spray hose.

LEATHER.

Sole Leather.

The investigation to determine the comparative durability of sole

leather filled with sulphite cellulose extrEKjt and sole leather filled

with the ordinary tanning materials was completed and the results

will be published as Technologic Paper No. 215.

As a result of these tests the following observations can be made

regarding the sulphite cellulose extracts used in this investigation
BEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 193

as fillers for sole leathers. (1) Leather filled either partially or

entirely with sulphite cellulose extract is as durable as leather filled

with the ordinary tanning materials, such as chestnut and quebracho.

(2) As reflected by the chemical analyses this extract is as firmly

fixed in the leather as these vegetable tanning materials. (3) The

use of such a material instead of chestnut and quebracho would

conserve these materials for use in the actual tanning process for

which they are suitable and for which sulphite cellulose extract has

not been successfully used. (4) It is probable that this material could

be used as a filler in place of the more soluble glucose, thereby producing a more waterproof leather. (5) Leather filled with this material can be made of as light and uniform color as leather filled

with the ordinary materials. This was the case for lots Nos. 1 and 2. There was a slight difference in the color in lots Nos. 3 and 4, the

leather filled with sulphite cellulose extract was a little darker. (6)

Using this material as a filler has no more effect on the aging of

the leather than the ordinary materials, since samples of these

leathers, which have been in the laboratory for over two years, are

still in a satisfactory and pliable condition.

A detailed study is being made of the relative merits of chrometanned and vegetable-tanned sole leather. This investigation has

included the securing of information and data regarding the water

resisting qualities of differently treated chrome sole leathers, the

abilit}'^ to take an edge finish, comparative yields for the two types

of leather, and a study of the variation in chemical composition of

chrome sole leather. In addition, a large number of service tests are in progress to determine: (1) The comparative durability of

vegetable and untreated chrome sole leather tanned from the same

hides; (2) the comparative durability of untreated chrome sole

leather and the same leather treated with paraffin; (3) the comparative durability of vegetable leather and chrome sole leather

treated with paraffin; and (4) the comparative durability of vegetable-tanned sole leather and chrome-tanned sole leather made from

the same hides when the latter is filled with greases and mineral

matter.

Additional machines have been secured during the fiscal year so that it is now possible to receive the whole sides of sole leather for

test and die out, skive, and attach the soles to shoes under close

laboratory observation. An expert repair man has been employed

in the laljoratory during the greater part of the year.

Synthetic Tanning Materials.

Investigations were started to determine the suitabilit}' of vari- ous synthetic tanning materials for use in the making of leather.

This work is being done by actual tanning experiments. Among

the points being considered are the soluble effects of the various

materials, their evaluation, penetration under different conditions,

and their effects upon the physical quality of different leathers.

Shark Leather.

The work on this subject has been completed and the results are

to be published as a joint publication with the Bureau of Fisheries.

It is considered that the purpose of this work has been accomplished
194 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

and the facts will be presented for such commercial application as may seem desirable to those interested. As a general conclusion it can be stated that the shark leather has considerable merit.

Rubber Heels.

The use of rubber heels on shoes has increased to such an extent

that the matter is of vital interest to the shoe manufacturer. At

the request of manufacturers the matter of the standardization of

shapes and sizes for rubber heels was proposed by this bureau.

Through its efforts the rubber heel manufacturers and shoe manufacturers have been brought together and considerable progress

has been made toward standardization.

Experimental Tannery,

During the year laboratory tanning equipment has been designed

and built at the bureau. This equipment consists of 20 rockers, 30

layaway vats, 4 paddles, 4 drums, beam, soaks, drying loft, and

miscellaneous materials. Pieces of heavy leather 8 by 10 inches can

be used in experiments and whole skins can be used for experiment

with light leathers.

Specifications.

Specifications for shoulder straps and carrier's tie straps were

developed for the Post Office Department.

A specification for vegetable-tanned leather belting developed in

cooperation with the manufacturers was presented to the Federal

Specifications Board. After some revision by the subcommittee on

leather it has been adopted for use by the departments and independent establishments of the Government. In connection with the

development of this specification considerable data were obtained

regarding the physical properties of belting leather hfid the re- quirements of existing specifications were studied. It is hoped that

large corporations and municipalities will seriously consider the

use of this specification as a step toward standardization.

Specifications for lace leather and upholstery leather are now being developed.

Sole leather is a difficult product to cover satisfactorily by a

specification. Work has been started on the subject in cooperation

with the tanners, and special leather is being furnished by the

Tanners' Council for investigations in this connection.

Cooperation.

The Tanners' Council, the Leather Belting Exchange, the National Boot and Shoe Manufacturers' Association, and the Kubber

Heel Club of America have actively cooperated with the bureau

during the fiscal year.

Committee work on the analysis of chrome leather has been done

in cooperation with the American Leather Chemists' Association.

In addition, a large number of manufacturers and tanners have

furnished materials for use in the experimental tannery and also

furnished leather for special investigations. This cooperation has

been greatly appreciated.

1
EEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 195

TEXTILES.

Standardization of Textiles.

The progress made on work classified under this general heading

was very satisfactory, considering the number of items taken up, due

to the degree of cooperation extended by the manufacturers and users of the materials. It is necessary to view the subject from the

standpoint of the individual materials in the textile trade, hence

no one group of manufacturers could materially assist in the standardization of textiles in general. The materials under consideration

were selected either as a result of the direct requests of a group

of manufacturers or to assist the Government in the purchase of

textile materials. In either case the first move has been to establish

direct contact between the user and manufacturer, so that their

opinions could be collected and an outline of the work established

which would be of maximum helpfulness. This, in itself, hasj

been a difficult task in some cases because of the necessity of obtaining unanimity of opinion as to what is desired and required.

Approximately 10 committees have been named especially by the

manufacturers to work with the bureau on this subject, while others are being developed.

Aside from the projects for standardization discussed in the subsequent pages, the following products have been considered but

have not progressed to the same degree of completion : Knit goods,

electrical cotton yarn, cement bags, sugar bags, shade cloth, brushes

and brooms, and sash cord. The work on these projects will, of

necessity, continue until more data are available and until some

of the work almost completed can be finished.

Generally speaking, the project of standardization has been taken

very favorably by the entire trade.

Numbered Duck.

The first material considered for standardization was numbered

duck. A committee was appointed from the Cotton Duck Association ; samples were submitted from the stock of a number of manufacturers; these samples were tested at the bureau; and results of

tests were made available for a series of conferences held at the

bureau. Specifications were finally drawn up which were considered ideal for both commercial and GTovernment purchases. These

specifications have been finished and accepted both by this bureau

and the Cotton Duck Association and are now ready for the printer.

The specifications will be presented to the Federal Specifications

Board for adoption, completing final action by the Government as a whole on these specifications. The Cotton Duck Association has

taken the initiative in having the general form of the specifications

and results of tests accepted by the entire trade. The final work

along this line will produce specifications and methods of test

! which will be considered standard, giving, perhaps, the only good

example of combined standard material and test in the textile trade.

Hosiery.

Hosiery is next in importance in the standardization project, considered from the standpoint of the amount of work performed and
196 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the degree of cooperation and interest shown throughout the trade.

The National Association of Hosiery and Underwear Manufacturers

welcomed the project and are following the matter very closely.

Due to the* present condition of the trade, in which no methods of

test and no information on the technical manufacture of hosiery are now available, the project will take considerable time for investigation before satisfactory standards can be adopted.

Cordage.

A direct request from the Cordage Institute, which includes about

85 per cent of the hard-fiber manufacturers, led the bureau to take

up the standardization of cordage. This work will cover standard

specifications for commercial and Government use, standard methods

of test, and development and standardization of a series of further

tests to indicate the performance of the rope in actual service. This

work will not only bring about satisfactory standardization, but it is a step toward proper selection of a material for a definite service.

Sheeting.

From direct contact with the manufacturers, users, and laundries

it was found that the question of the standardization of sheetings

was very important and vital to those interested. At a conference

held in New York there were represented organizations of manufacturers, laundries, selling agents, dyers and cleaners, and hotel men.

The meeting was not successful in the formation of a joint committee

to consider the problem. The laundry men are especially interested

in improving the quality of domestic sheeting in conjunction with

the effort of the Government to standardize sheetings bought by

the GoA^ernment. The manufacturers have submitted a large number

of samples as individuals, which have been tested. A recheck is now being made on the physical properties. Results of these tests will enable the Government to draw up a satisfactory specification

for Government use. A suggested problem in connection with this work is the development of a standard test to indicate the probable life or number of

washings that any one sheeting can stand. This is being done in

cooperation with the Laundry Owners' National Association.

The American Home Economics Association is interested in the

project for educational reasdhs.

Press Cloth.

The results of the bureau's work on the determination of standards of moisture content and oil percentage of hair press cloths

which were requested by a large user of this cloth were presented to a committee of manufacturers and users appointed by the president

of the Interstate Cotton Seed Crushers' Association, the membership

of which includes most of the users and manufacturers of this

product. The members of this committee were located at different

parts of the country and at first the work was carried on through

correspondence, which lengthened the time required to bring the

problem to a close. In an effort to settle the matter, the bureau

invited the committee to come to its laboratory for a conference.

Their work was correlated and submitted to the annual meeting of
KEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 197

the association. The bureau's final report, which was later prepared,

reviews the need for the problem, the difficulties involved, then outlines a method of procedure, and suggests standards for oil and

moisture content. It also presents a form for insertion in contracts

which will enable adjusting pensdties for noncompliance in accord- ance with the use and price.

Conveyor Belting.

This work was taken up at the request of the Post Office Department in order to obtain data which would enable the Postal Service

to select the most suitable belting for their service. The question of

the number of stitches, the stretch, and surface impregnation appears

to be of great importance.

In connection with the purchase of 7 miles of belting for the

Chicago post office by the Post Office Department, samples were submitted to determine a few of their physical properties. The results

of this work will be of great assistance in connection with the whole

subject.

Heat-Retaining Properties of Fabrics.

Apparatus has been designed and set up in the bureau's humidity

room for determining the comforting value of blankets. So far it lias been found necessary not only to measure heat transmission but

also air permeability and water-vapor permeability of the specimens,

for each has an important bearing on the final solution of the problems involved. Thus apparatus of new design, which has been

planned to eliminate errors of former apparatus and for greater

range of application and flexibility of use, has been set up for obtaining data on all three of these interrelated properties of blankets.

Among the features of this apparatus is provision for compensating for edge and bottom heat loss, tensioning the specimen under

test to bring it to a state of tautness which will make the results on

different specimens comparable, and adjustability for testing in

liorizontal, vertical, or other positions. This latter provision has

much to do with the freedom of mobility of the enmeshed air.

Blankets or textile products should be thought of as being relatively loosely constructed fabrics, enmeshing air and a certain degree

of moisture content, which is relatively free to move or circulate,

thus causing the different fabrics to vary widely in their capacity to

retain heat or transmit heat.

The outstanding considerations which have been borne in mind

dealing with this research fall into three phases of the problem, viz.,

(1) the human side in which the natural temperature of, and matter

and heat dissipated from, the human body has to be reckoned upon

as governing the comfort of the individual; (2) the weather or humidity conditions from without, which have to be insulated effectively from rendering discomfort to the individual; and (3) the

blanket, covering, or fabric itself, which acts as the protector or

insulator between the body and the elements, has to be studied

physically and structurally to obtain the reason for its characteristic

functioning in rendering its service as bedding or clothing. A cor- relation of data obtained on these three phases of the subject will

lead finally to a satisfactory solution of the problems involved and to
198 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

ratings which manufacturer or mechant may cite as standards in

disposing of his products.

Thus far this research has been more useful in the direction of

standardization of apparatus for deA^eloping satisfactory test methods

than in the furnishing of results which can be applied immediately

for purposes of the industry.

However, certain fundamental considerations have been studied

and cared for in the new apparatus which have been partially or

totally omitted in similar investigations heretofore conducted and

will undoubtedly lead to more concordant results in the future. A

preliminary publication is being worked up at present which will

present the plan, progress, and some test data pertaining to this subject. The investigation is of wide commercial and domestic importance.

Physics of Balloon Fabrics.

At the request of the engineering division of the Air Service an

investigation was carried out on the physical properties of cotton

cloth to determine what factors in the manufacturing processes

affect such properties as are of importance in a cloth to be used in

the production of balloon fabrics. In the course of the work, 70

different specimens of cotton cloth were woven in the experimental

cotton mill, where the details of manufacture could be completely

supervised.

The same fiber was used to spin yarns, differing in yarn size, ply,

and twist, and these yarns were woven into cloths containing various

numbers of threads to the inch. The effect of these various factors

on the properties of the cloth was studied and applied as far as possible to the present standard grades of balloon cloth.

Low-Grade Cotton.

The progi'ess on the investigation of uses for low-grade cotton can

be considered very satisfactory, as the problem is a difficult one and

requires not only laboratory tests but the cooperation of the producer, machine builder, manufacturer, and user. It is now the practice in some foreign countries to use not only the by-product of the

manufacturing processes but also the low-grade material produced

in the fields, and for several years past there have been unsuccessful

efforts made to introduce it in this country. The principal reason

for failure is a lack of understanding of the possibilities of this

material, brought about because the parties interested have never come together as a unit to discuss the problem.

A number of fabrics have been made from low-grade cotton introduced for different purposes, but these have failed because of the

price of the material, which has been manufactured on the same

machines and with the identical organizations used for high-grade

fabrics. The cost of manufacturing, which is one of the important

factors, thus became prohibitive.

The preliminary work in the laboratory can be considered complete. The bureau's plan is to secure large quantities of the materials to be manufactured in a commercial way. At first considerable lack of cooperation was manifested on the part of the grower;

accordingly the work has been delayed so that it will be necessary
BEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 199

to continue it into the next fiscal yeai\ The bureau has now obtained the aid of the cotton growers through the Interstate Cotton

Seed Crushers' Association.

Tent and Awning Duck.

In line with the bureau's policy of aiding in settling disputes

caused by misunderstandings between various industrial organizations, the Cotton Duck Association and the National Association of

Tent and Awning Manufacturers were asked to attend a joint con- ference in Washington to clear up a misunderstanding w*hich has

existed for some time on the question of a standard method of ex- pressing the weight of a fabric. The existing method of expressing

weight has caused considerable confusion to the tent and aAvning

manufacturers, and they have attempted to secure legislation which

would enable them to base the weight of material on their standard

width of 29 inches. Keports of the two conferences which these

associations have held in New York following the conference in

Washington indicate that the suggestion of the bureau to adopt a standard basis of 36 inches for width would be accepted.

Pima Cotton.

A direct request was received from growers of Arizona Egyptian

cotton (usually called Pima cotton) for physical tests and actual

manufacturing data. Such information would enable them not only

to submit facts to prospective users but also lead to an understanding

as to just what their fibers were capable of, and probably to improved methods of growing. This unusual request indicated the

desire of this group of growers to improve and to understand their

material. The investigation is a long one and will probably continue

for a period of two years. Such an investigation must take into

consideration all other fibers, domestic and foreign, and any other

facts which are likely to be of value.

The bureau's preliminary investigation was started using the fiber

in a material and in a place where actual data could be collected.

The fibers were spun and fabric made in the experimental cotton

mill, producing a duck made according to the specifications of the

Post Office Department. The material is now undergoing a service

test for one year as railway package pouches. The purpose of this

investigation in connection with the Post Office Department is to

get a relation between the serviceability of the usual average staple

cotton and this long-staple Pima cotton. The construction of the

two materials is identical, the only variable being the length of the

fiber. This will give a relative value in regard to the increased

serviceability obtainable with increase in staple length.

The second step taken in this investigation was to obtain relative

figures on the spinnability and serviceability of yarns of very high

yarn numbers. The bureau succeeded in reaching a 200s yarn, though

of course yarn of this number has no commercial value. The usual

limit of ring-spun yarns in this country is approximately 80s, and

this has been reduced in recent years to approximately 60s, the limit

of fineness being determined by the desire of the public for fine

materials.

The objectionable feature of this material has been the neppy nature of the yarns when spun. It is noted that the matter of settings.
200 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

speeds, and adjustment of machine parts affects to a very large extent

the degree of neppiness of these yams, making it necessary for the

manufacturer to have exact information on the organization (machine adjustments, etc.) for this particular cotton. Actual figures are now being obtained.

Data are being collected from mills now using this cotton which

it is hoped will in another year enable the bureau to submit a report

containing experimental and commercial data and a standard outline

for testing the uniformity of and degree of satisfaction which can

be obtained from all long-staple cottons.

Abrasion of Fabrics.

An investigation of the workability of the design of apparatus

used for obtaining the abrasive properties of fabrics is now under

way and facts concerning the machine are being obtained. Most of

these data are not of a sufficiently exhaustive nature to warrant

definite conclusions. Few of the bureau's developments in the line

of testing have caused such widespread interest as this abrasion test,

and, because of this interest, it is thought that only work of an ex- haustive character should be published. It is found that the abrasion

test, besides forming an individual study itself, may be combined

with a number of other investigations, thus securing additional facts.

The first publication on the subject will be prepared and submitted

to a technical committee for criticism and for a discussion of the

advisability of adopting it as a standard abrasion test.

Cloth for Federal Trade Commission.

In the course of the fiscal year the Federal Trade Commission

requested determination of the actual per cent cotton and wool in

approximately 1,100 samples of clothing material. The samples were

collected by the Federal Trade Commission from various manufacturers and retailers in different parts of the country. The reason

for the collection of the data is not definitely known, but it is understood that the Federal Trade Commission is desirous" of obtaining

data on the actual amount of mixed and pure wool goods now made

and purchased by the public.

Cartridge Bag Cloth.

An investigation was made on a large quantity of silk fabric used

in cartridge bags to determine whether or not the stock held by the

Government would deteriorate in storage. Information was needed

as to whether the material should be held to avoid great financial

loss because of the lack of a sufficient market, or Avhether it should

be sold at a very low figure because of future deterioration. Approximately 9,000,000 yards, worth $6,000,000, were involved. No

conclusions were drawn from the material because the samples submitted were not taken at periods sufficiently far apart to indicate

whether or not the material would deteriorate. In December a large

number of tests were made on the material, and it was suggested

that further tests be made in six months and in a year. It is ex- pected that additional samples will be received for test, and at that

time exact statements as to the deterioration of the material can be

made.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 201

Fishlines.

At the request of the Bureau of Fisheries a short study was made

to find a better treatment of fish nets to increase the resistance to

water deterioration and to develop technique for testing the relative

merits of the various preservatives. The investigation included

shrinkage, stiffness or pliability, increase in weight, stretch, strength,

and wearing qualities. A number of these tests are being made in

the laboratoi-y of the Bureau of Fisheries, where the data will be

compiled. This study should result in a better quality of net as well

as a financial saving to the fishing industry.

Fasteners for Cartridge Belts.

As the request of the Quartermaster General of the Army an investigation was carried out to determine the usefulness of two types

of cartridge-belt fasteners. The essential difference in the two types

was in the formation of the spring. Special apparatus was designed

to reproduce the actual action of fastening and unfastening the two

parts in service. Results of tests showed that one type was greatly

superior to the other in respect to the total number of fastenings and

unfastenings. This investigation points out the great value of special

tests and actual investigation before reaching conclusions.

Lead Lines.

Another short investigation was carried out in cooperation with

the Coast and Geodetic Survey on the comparative endurance of

several types of lead lines used in that service. These lead lines are usually made from flax fiber and are used to obtain soundings

when a ship is entering a port or coming to anchor. Very complete

tests were made to indicate the construction and physical properties

under different conditions.

Effect of Washing on Sheeting.

An investigation was made for the American Laundry Machinery

Co. to determine the effect of sours used in the laundering process

on the physical properties of sheeting. The tests were for construction, breaking strength, and resistance to tear for different types

of sours and for 3, 5, 10, 15, and 20 treatments. Results of this work

are to be compiled by the company as a purely research matter.

A second part of the investigation was to determine if the joint use of sizing with the sours had any greatly deteriorating effect on

the physical properties. Because of the great distortion of the samples submitted no definite conclusions could be derived.

Suiting.

A short investigation for a large manufacturer of suitings was

made to determine the effect on woolen fabrics of sponging and drying at high temperatures. The investigation was made to ascertain

if it was possible to decrease the time necessary for sponging and

drying by increasing the temperature of the dryers. The maximum

temperature used was 220^ F., and results showed that no marked

depreciation in properties of the material had taken place. A re- port was sent showing the results of tests, methods of test, and

conclusions.
202 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Printers' Blankets.

This investigation was started during the last fiscal year to devise

some method of measurement which would assist the Bureau of

Engraving and Printing to describe the desirable properties of felts

used for the printing of paper money. The specifications at that

time did not call for a test which would indicate performance of

the material, for the specifications were drawn up from an analysis

of the construction and fiber content of the material. The resili- ence test formulated showed that an index could be obtained which

would measure the property of suitability for the purpose of printing, and that this would vary for different mixtures. It was then

]DOssible to use this index as a measure of practicability of the material. Results were submitted to the Bureau of Engraving and

Printing about the middle of the fiscal year.

Bandages.

At a request from the Surgeon General's Office an investigation

was made on the variation in length of a large number of 2, 2^,

and 3 inch gauze bandages which were purchased during the war. This department had available for sale after the war an enormous

amount of bandages which were declared surplus. On selling to

private individuals it was found that there was a wide variation in

length, some coming materially short of the length stamped on the

package wrapping.

The purchaser took the stand that he was defrauding his customers

by selling materials which were not as represented on the label and

accordingly took steps to return the material to the Government.

The Government in turn went back to the original manufacturer

seeking adjustments and corrections. Results of the investigation

showed variation in care and exactness in cutting bandages by the

different manufacturers, also lack of information as to exact toler- ances and effect of humidity on such material. The investigation

involved the consideration of approximately $1,000,000 worth of

bandages and illustrates the importance of the bureau's work to

other Government departments.

Conferences.

The following textile conferences in which the bureau took part

were held during the year at the places indicated

Conference on- Date. Place.

Standardization of numbered duck

Standardization of sheeting

Standardization of cordage

Standardization of hosiery

Textile research committee Tent and awning duck

Standardization of shade cloth Press cloth

Dec. Mar.

Apr.

Apr.

Aug. 1, 1921 Mar. 15,1922 June 14,1922 Nov., 1921 Feb. 3,1922

21,1921 9,1922

18, 1922

19, 1922 Apr. 26,1922 May 26,1922 May 1-7, 1922 May 15,1922 June 14,1922 Apr. 20,1922 Apr. 19,1922 Apr. 21,1922 Apr. 24,1922

Bureau of Standards. Do. New York, N. Y.

Do.

Do. Bureau of Standards. Do.

Do.

Do.

Do. New York, N. Y.

Philadelphia, Pa.; Chicago, 111.; Reading, Pa.; and Milwaukee, Wis.

Philadelphia, Pa. New York, N. Y. Bureau of Standards. Do.

Do. Do.
KEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 203

PAPER.

The functions of this section are the study and development of

methods of testing paper, the investigation of paper-making materials, the experimental production of special types of paper, the

study of paper-making processes, the development of standards and

specifications for papers and the testing of paper, both for the Government and for the public.

General Conditions.

It has not been necessary to purchase any large pieces of equipment

during the year and there has been little change in the facilities for

this work. Minor pieces of apparatus have been obtained, for the

testing laboratories and especially for the paper mill, such as an

electric conditioning oven, centrifuge, wire guide, large deckle straps,

new lower press roll, torsion balance, glarimeter, etc. Every effort

has been made to concentrate on the testing apparatus and equipment

available and to standardize test methods as much as possible. The

flexibility of the conditioning apparatus in the physical testing

laboratory was demonstrated during a series of tests under conditions

of relative humidity varying from 15 to 85 per cent. Some difficulties

are, however, still experienced in maintaining exactly 70° temperature in the hot part of the summer, due to lack of insulation of the

walls of the test room. The power supply has improved and there

have been less delays due to that cause.

Tearing Strength of Paper.

As indicated in the last annual report, two studies were continued

during the year in regard to the tearing strength of paper. Two

publications (Technologic Paper No. 194, and Paper Trade Journal,

March 9, 1922) have been issued, giving the resvilts of these studies.

It has not been possible as yet to recommend a standard method for

determining this quality of paper, chiefly because of certain unknown

factors introduced when more than one sheet is torn at one time. It

is believed that the apparatus available at this time will give important information in connection with mill-control work and that

each of the types are of some such value. It is doubtful, however,

whether any results are of an absolute nature, and it is thought desirable to continue this study in the hope that a method may be developed which will give a true value to the tearing quality of paper.

This quality is of very great importance in connection with wrapping

and envelope paper and also in the case of paper for books, magazines?

etc. However, the chief reason for continuing this research is to develop a method which compares with the common practice of tearing

a corner of a sheet of paper to determine its quality and to have a check on the other test methods which do not give sufficient information. It is believed that a suitable test may be developed to give a true

value of the tearing streng-th of a single sheet of paper.

Thickness of Paper.

In cooperation with the gauge section, an investigation of commercial dial micrometers for measuring the thickness of paper has been

completed. This problem was taken up because of the differences

existing at this time in the various types available and because of the
204 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

fact that check results can not be obtained in many cases, when usingmicrometers of different types. For this reason conti'oversies have

arisen and it was believed necessary to thoroughly investigate the

subject in order that definite data might be available. This study

was made of the mechanism and performance of 12 different micrometers, with 14 different kinds of paper. Measurements were

made of the area and parallelism of the contact surfaces and the static

contact pressures of the instruments. It was found that there were

radical differences in the various types of micrometers and that the

thickness of paper as measured by various instrmnents was in some

cases quite different. These differences were most apparent where a bulky, loosely formed sheet was used, due to the differences of the

static pressure in the various types of micrometers. It has been

possible to develop specifications for a standard instrument and for a procedure to determine the mean thickness of paper samples. Such

an instrument should be of great value, because of the varying compressibility of different papers and the different pressures exerted by

the various types of dial micrometei*s now used for determining the

thickness of paper.

Blotting Quality of Paper,

Considerable difficulty has been experienced in determining the

blotting quality of paper by the Klemm strip method, which does

not sufficiently take into account the thiclaiess of the sample, nor

the value of the sample in connection with repeated blottings. In

the case of some papers, a high initial absorption will be obtained

but subsequent application of the sample to ink will often produce a

blot, due to lack of further absorption. Twelve samples of commercial blotting papers were examined and tested by four different

methods. These results were studied in connection with the bulk of

the sample, the fiber content, and the amoimt of ash present- It was

found that, although the amount of bulk is an indication of the

value of the sample, the fiber content and the amount of ash present

are of great importance and should be considered. The best results

were obtained with samples having less than 10 per cent of ash

present and with a high percentage of cotton or rag fiber. The

absorptive value of the paper is due to the air spaces between and

within the fibers and, since the long rag fibers are cut up in the beater,

there are a large number of ends to permit absorption within the

fiber. The fibers of the broad leaf woods are bulky but are short

and have not so many open ends, which probably accounts for their

lesser absorptive quality. For determining the value of a blotting

paper, a practical test was developed which will give relative results

and also indicates which of several samples may be considered the

best. It should be noted that the samples used in this investigation

were those to be used for blotting writing inks and were not the type

of paper used as desk covers, which are less absorptive, more compact, and more durable.

Effect of Relative Humidity on Paper.

Data appearing in various publications and developed by different

laboratories have indicated that it is necessary to control the atmospheric conditions in the testing laboratory, in order to obtain accu-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 205

rate and reliable information as to the physical qualities of paper.

This is due to the fact that changes of relative humidity markedly

affect the moisture content of paper, which in turn affects most of

the physical characteristics of a sheet. In order to check work done

at this bureau 10 years ago and to widen the scope of the information, a series of tests on 11 samples of different kinds of paper were

made at relative humidities from 15 to 85 per cent. These tests

included weight, bursting strength, moisture content, folding endurance, breaking strength, tearing strength, expansion, and stretch.

An examination of these data indicate that the bursting and breaking

strength increase with increase of relative himiidity from 15 to 35

per cent and decrease as the relative humidity increases from 35 to

85 per cent. Weight and moisture content increase regularly with

increase of relative humidity, as do the stretch of the paper under

load and the expansion without load. Both the tearing and folding

qualities of paper are markedly affected by changes of relative

humidity, increasing in value with increase of relative humidity

;

however, this effect is not so regular with the different kinds of

paper. It is shown by the data obtained that the tendencies indicated above are not the same for all kinds of paper and that it is

probably impossible to develop a suitable conversion factor for the

various tests. It is recommended, however, whenever possible, that

some definite conditions of relative humidity be maintained within

close limits, in order that test data obtained on similar samples of

paper may be comparable. A full report of the data obtained in

this investigation will be published in the near future.

Paper for Cement Bags.

In connection with specifications for paper for lime and cement

bags, published in Technologic Paper No. 187, tests were made on

10 samples of bags obtained from several shipments of cement to

determine whether commercial bags conform to these specifications. Complete tests were made on these samples, and it was

found that only 1 bag would entirelj^ conform to the specifications.

Nine bags had a bursting strength equal to the specifications, 5 bags

had the necessary ratio of bursting strength to weight, 7 bags contained 50 per cent or more of manila and jute stock, 8 bags passed

the folding endurance specification, 5 bags had a breaking strength

equal or greater than the specifications, but only 2 bags conformed

to the breaking strength specifications. Data are being collected as

to the value of the bags under service conditions of shipment, and

a study of these data will indicate whether the specifications as developed will be satisfactory for paper for this purpose.

Blue-Print Paper.

For several years paper manufacturers in this country have been

developing a paper for blue-print purposes which has seemed to

give complete satisfaction. The requirements for this type of paper

are somewhat severe, for it must properly absorb the sensitizing

solution, must resist rough handling when the blue print is in use, and must have sufficient strength when wet to permit of handling in

the washing bath. In order to determine the relative value of such

paper made in this country and abroad, a number of samples were

obtained and complete tests are being made. A comparison of the
206 REPOKT OF DIEECTOE OF BUREAU OF STANDARDS.

test data with specifications coverinjy various uses of blue-print paper

will indicate whether commercial papers are equal to these specifications and whether foreign-made papers have any superior qualities over such paper made in this country.

Carbon Paper.

As indicated in the last annual report, a study of carbon paper

was being made in cooperation with the chemistry division. It

has not been found possible to specify any but a practical test to

indicate the value of carbon paper, but it has been possible to

standardize the method of making this test in order to obtain relative values of carbon paper. For the purpose of Government specifications, carbon paper was divided into three classes or weights in

connection with the number of copies to be made at one time cm

the typeAvriter. The kind and quality of paper to be used in

making these tests have also been specified, as well as the kind of

typewriter, type, etc. Data obtained in this manner on a large

number of samples and correlation with actual use in the Government service should permit the development of definite specification

of carbon paper for use with the typewriter.

Sizing Quality of Paper.

Over a year's study of the electrical conductivity methods of meas- uring the sizing quality of paper indicates that, although the data curves obtained are consistent and regular, it is not possible to evaluate these curves in order to obtain a numerical value for this quality.

The problem is of considerable importance, since there is little or no

uniformity in determining this quality and the present methods used

do not give results that indicate the true value of the sample. A

reliable method is essential before an investigation of the sizing

process can be undertaken. A new method has been developed and

published in a trade journal which has the advantage of requiring

very little equipment and of giving consistent results which may be

given a numerical value. The test depends on the time of curl

of a small sample of the paper floating on water at a definite temperature. This time of curl is very consistent for a given sample of

paper and by properly taking into consideration the thickness of the

sample when completely saturated with water a numerical value is obtained which indicates the degree of resistance to absorption of

the sample. This method is being tried out by several paper-mill

laboratories and such data will aid in determining its actual value.

Herzberg Stain.

In the microscopic examination of paper to determine the proportions of the various fibers of which it is composed, it has been

customary to make use of a selective stain composed of zinc chloride,

potassium iodide, and iodine. The stain has the property of coloring cotton, chemical wood pulp, and mechanical pulp differently,

which permits of greater ease in differentiating these fibers. Considerable difficulty has been experienced, however, in preparing this

stain so that the color differences are correct and it is the general

practice to " doctor " the stain to get the proper colors with known

fibers. A careful study of this problem has developed a formula

and manipulation which produces the necessary color differences and
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 207

• has eliminated the necessity of modifying, from time to time, the

proportions of the ingredients of the stain. Such a formula is of

great value to the various paper-testing laboratories which are equipped to make misroscopic examinations and will assist in obtaining greater accuracy, due to greater uniformity of color.

Photomicrography.

During the past two or three years extensive data have been collected on methods of making photomicrographs of vegetable fibers

used in the manufacture of paper. An increasing number of technical laboratory workers and others are availing themselves of the

possibilities of this means of studying problems and it is believed

I that a publication on this subject would be timely. Various phases

of this subject are considered in a report that is now in press

which gives data and methods of manipulation as follows : Source

of illumination, light filters, use of condensers, use of substage diaphragm, choice of camera and objective, photographic plates and

their development, value of representative field of fibers, value of

staining, and photomicrographs as permanent records. The publication is replete with diagrams and photomicrographs which illustrate the various points to be brought out.

] Color of Paper.

There has been a demand for a method which would satisfactorily

measure and give a numerical value for the color of paper. Apparatus of this character is of importance in the study of such

problems as the use of various clays as fillers in paper and also in

! connection with the color values and bleaching of the various pulps

used in white printing and writing paper. Likewise a means of

: measuring the color of paper would be of great importance in

I assisting manufacturers to maintain uniformity of color, something of great importance in making fine papers. Through the

j cooperation and assistance of the optics division, an apparatus has

been installed, the chief portion of which is a spectrophotometer,

j Delays in securing the parts necessary for this apparatus have

j made it impossible to determine at this time whether such an equipment will be satisfactory for slight differences of tints of white

paper but with certain modifications, a suitable method for distinct

color differences is being developed.

Flax Straw and Tow.

1 Many attempts, both laboratory and commercial, have been made

! to utilize the million tons of seed flax straw which are produced

annually in this country and of which 80 per cent are wasted. Most

of the attempts have had in mind the production of a strong paper

from the bast fiber attached to the straw, by the elimination of the

woody straw fiber, which is short and of little strength. Mechanical separation of the woody straw fiber from the long bast fiber is

I necessary, as well as a solvent for the ligneous and pectous binding

compounds which will not weaken the bast fibers. In most cases,

j alkaline solvents, such as milk of lime, caustic soda, etc., have been

i( used, but it has not been possible to eliminate all the woody shive

by these processes. In the work carried on at the bureau, the " sulI 9644—22 15
208 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

phate " process of cooking wood was used, both in the preliminary

experimental work and the cooking trials under mill conditions. The

process was found satisfactory for the separation of the bast fibers,

and paper Avas made both from the flax straw and the flax tow which

had a strength equal to a good grade of wrapping paper and bond

paper. Difficulty was experienced in eliminating extraneous dirt

which had been introduced by careless handling of the tow and

straw and because of unfavorable conditions during the cooking

trials under mill conditions. No difficulty was experienced, however, in handling the stock on the paper machine at the Bureau of

Standards where all the cooked fiber was converted into paper, both

that produced in the experimental rotary and in the mill cooking

trials. Complete data are not yet available as to the actual yield of

paper from the straw and tow, but about 7 tons of whole flax straw

are required for 1 ton of pulp for wrapping purposes. In general,

it may be said that a fair quality of wrapping paper can be made

from whole seed flax straw, that a good quality of writing paper

can be made from seed flax tow, provided especial care is taken to

eliminate specks, that pulp prepared from seed flax tow can be

readily bleached, that the chemical consumption for the preparation

of pulp from the whole straw is about double that required for wood,

that the chemical consumption for the pulping of a good quality of

seed flax tow is only slightly in excess of that required for wood, and

that, at the present time, it is not economically feasible to use seed

flax f'ber for the making of paper unless a solvent can be developed

which will not weaken the bast fiber during the process of separation from the pectous and ligno-cellulose material combined with it. A full report of this investigation is in preparation and will be

published in the near future.

Clay in Paper as Filler.

In cooperation with the ceramic division, an investigation was

undertaken as to the relative value of foreign and domestic clays

when used as fillers in printing papers. This material is added to

the fiber stock during the process of manufacture of paper to produce a smooth, even surface, by filling up the interstices between the

fibers, to permit of half-tone printing, etc. Foreign clays, chiefly

from Cornwall, are used to a large extent for this purpose in this

country, and this investigation was undertaken to determine what

qualities of the foreign clays produced the better results. In general,

color, grit, and retention on the paper machine are the factors to be

considered. Complete physical tests have been finished by the

ceramic division on a number of domestic and foreign clays, and

preliminary work on the paper machine is under way to standardize

the conditions of making the comparative runs. A considerable

amount of preliminary work has been necessary to determine the

closeness of check runs and a suitable method of determining the

value for retention of filler. The problem has been made more

difficult by the shortness of the runs and by the lack of uniformity

among the paper mills as to a method of determining retention.

This Avork will, however, be continued, and as soon as definite data

are available, which may be used as the basis for tentative conclusions, cooperative tests are to be made with several book paper mills

under commercial conditions.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 209

Clay for Coating Wall Paper.

The bureau cooperated in a series of mill experiments in which

four domestic clays were used successively in connection with the

coating for wall paper. The problem under consideration was

whether these domestic clays would be satisfactory when used with

a special gum as adhesive. The tests indicated that all four clays

worked satisfactorily, and difficulties experienced in this connection

are probably due to" lack of care in heating the gum or in obtaining

the proper proportions.

Standardization of Paper.

During the past year the question of the standardization of paper

has been taken up with representative manufacturers and users. In

view of the very large number of kinds of paper and uses for paper,

certain general phases of the subject are being considered by several

committees which are collecting information and data on which to

base recommendations. Because of the necessity for obtaining a uniform classification of the kinds of paper for the purpose of properly tabulating statistics, a grouping of the various similar types of

paper is being accomplished. Such a classification will be of great

value to all agencies engaged in the collection of statistics of the

paper industry and should make it possible to compare accurately

data obtained through different sources. The use of terms and names

of kinds and grades of paper is very indefinite in many cases. Definitions are being developed for about 600 such terms and names, and

this is being done with the a&sistance of manufacturers, users, and

technical men of the industry. The acceptance of such terms and

their arrangement in the form of a glossary or dictionary Avill be of

great assistance in eliminating certain misunderstandings between

buyer and seller and will have considerable significance in connection

with export trade. A large economy may be obtained by the reduction in the number of sizes and qualities of paper, both as to the

large-size sheets as sold and in the number of sizes of printed matter.

An exhaustive survey is now well under way by a committee of

large users of paper and a report and recommendations will be

available in the near future. This phase of the subject is of great

1 economic importance and will result in benefits to the manufacturer,

distributor, and user of paper. A technical committee is considering

the following subjects: Specifications of quality, standard methods

j of testing and sampling, and tolerance to be permitted on deliveries.

I Because of the lack of such standardization these phases of the subI ject must first be considered in a general way and later particular

kinds of paper can be considered in relation to their uses. This inj vestigation will progress more rapidly after some of these general

i aspects of the problem have been settled.

j Government Specifications.

I Assistance has been given various Government offices in connecI tion with the development of proper specifications for the purchase

of paper. In many cases a large number of tests were necessary, but

in this work an attempt has been made to bring more closely together

the specifications as used in the various bureaus and offices. Changes
210 EEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

have been recommended in the standards for the District of Columbia, with special reference to terminology and conformity to good

practice. Recommendations have been made in connection with the

specifications used by the Government Printing Office, although the

necessary changes in them are minor in charaLter at this time, with

the exception of light-weight printing paper used in the bureau's

publications. It has, however, been suggested from time to time

that the tolerances as to weight should conform somewhat more

closely to good commercial practice. In connection with the General

Supply Commitee, some additional items have been placed under the

" standard sample " group. Such an arrangement permits the prospective bidder to have definite information as to the kind of paper

desired. The specifications of the Post Office Department for official

envelopes, shipping tags, and stamped envelopes have been revised.

It has been possible to have included standard samples for color and

finish for the paper for official envelopes, which will provide greater

uniformit}^ and also a closer match between the envelope and the

contents.

Lime for Sulphite Pulp.

In connection with the Interdepartmental Conference on Chemical

Lime, specifications were prepared for a suitable lime and limestone

used in the preparation of the liquor used for cooking wood chips by

the " sulphite " process. These specifications were based largely on

data obtained during the war from a questionnaire and reflects the

opinion of experienced technical men of the pulp industry.

LUBRICATING OILS.

Reclaiming Used Petroleum Lubricating Oils.

An investigation has been started on the methods necessary to

restore used lubricating oils to a condition in which they may be of

further service. It has been found that the completeness as well as the rapidity of separation of an oil from an emulsion with water

must be considered, as the relation between emulsification and organic

acidity is important. Some work has already been done in this connection. The metliods of making the emulsion and demulsibility

tests have been modified accordingly.

Standardization of Viscosimeters,

In continuation of the work of standardization of viscosimeters,

equations and conversion tables have been derived for three additional instruments—the Saybolt Furol and Redwood Admiralty for

measuring the viscosity of fuel oil, and the Redwood No. 1 for test- ing lubricating oils. The Redwood instruments are standard in

Enirland and are of importance in the export trade.

Closely related to this work were investigations of the drainage

error in the Bingham viscometer, and the change in viscosity of

oils with temperatui-e, upon which papers have been prepared for

outside publication. The Bingham instrument is an especially accurate instrviment for determining the viscosity of liquids used to calibrate the technical instruments in everyday use.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 211

An improved viscosimeter, with interchangeable outlet tubes has

been designed and adopted for use in determining " Saybolt viscosity." The novel features are the stainless steel outlet tubes and the

enlargement of the oil tube to permit leaving the thermometer in

place during the run.

Oil Friction Testing Machine.

As a result of many tests on an oil friction testing machine with

a journal partly surrounded by the bearing, the conclusion was

reached that a machine of this type was unsatisfactory because the

smootliness of the rubbing surfaces could not be kept constant.

Tests were accordingly discontinued, and a new machine was designed, using flat rubbing surfaces, and is now being built. A journal can not be polished without changing the radius of cui-vature,

but flat disks may be polished when necessary.

Cooperative Work.

Work has been continued on the consistency of fats used in cooking, in cooperation with the Bureau of Home Economics, Department

of Agriculture.

Members of the division have cooperated in the activities of vari- ous societies and associations, including the xVmerican Society for

Testing Materials, the National Electric Light Association, the

American Petroleum Institute, and the Society of Automotive Engineers. All these societies are vitally interested in standai*d methods

of testing and specifications for lubricants.

TESTING INFORMATION AND PUBLICATIONS.

Tests Completed During the Year.

During the year, the following tests have been completed by the

various sections of this divisioii

:

Structural and miscellaneous materials.—The amount of test work

of a routine nature completed during the fiscal year is listed below.

The list includes materials tested for other divisions of the bureau,

other Government departments, and for the general public.

Summary of Tests : Material.

Number of Iron and steel : v specimens.

Malleable iron 12

Steel 330

342

Aliiminimi and aluminum alloys

:

Aluminum alloy 8

Aluminum alloy, duralumin 40

48

Copper, brass, and bronze:

Brass 11

Bronze 22

Copper 3

36
212 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Summary of Tests : Material—Continued.

Number of Miscellaneous metals and alloys : specimens.

Dental amalgam 24

Monel metal 9

Magna metal 4

87

Fiber rope and wire rope

Rope, fiber 60

Rope, wire 6

66

Calibration or Testing Machines.

Riehle, 50,000 pounds 1 Riehle, 100,000 pounds 1

Miscbsxaneous.

Asbestos sheet packing 16

Bearings 10

Bolts and nuts 5

Bomb points 7 Bomb lugs 2

Bfnes, bog 21

Cans ^ . 2

Chain 1 Cups 2

Crayons 12

Fiber, hard 4

Crlass, wire insei'ted ; 12

Gears 15

Insulator, porcelain 1 Jacks 3

Lead lines 6

Metal, lead clad 15

Nails : 6

Nickel 2

Pipe sections, threaded 48

Rubber hard 48

Shackles, anchor chair 4

Spoons, aluminum 9

Springs, automobile 4

Tubes, condenser . 28

Tubes, boiler ' 2

Tubes, copper 2

Webbing 6

Wire, magnet 1 Wire, monel : 1 Wire, sounding 4 Wood, storage battery separators 160

Wheels, roller-skate 2

Wheels truck 12

Wheels, veneer disk 3

Veneer, 3-ply for airplanes . 140

617

Cement, concrete, stone, gravel, and sand.—In addition to sampling

and testing approximately 600,000 barrels of cement for Government purchases, tests were made of more than 200 samples of miscellaneous materials, comprising silica sands, concrete fence posts,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 213

accelerators for concrete, building stones and slates, disintegrated

stone, rock for riprap, special cements for stonework, concrete building blocks, floor hardeners, concrete aggregates, cement brick, clay

brick, elastic cements, clay tile, trass, waterproofing materials, paints

and coatings, filter sands, drinking water, boiler water, paints, limes,

galvanized coatings, steel, copper, reinforcing rods, culvert pipe,

lubricating oils, alkali, miscellaneous fine materials for separation

by the air analyzer. The tests of aggregate included study of the

materials submitted by some of the reclamation projects and a hospital project. In addition to the tests, inspection was made of a shipment of 540 feet of metal culvert pipe. Numerous specimens of

concrete were tested for the United States Engineer projects, for one

of which there were tested 561 specimens. From another there were

received 1,242 specimens, some of which are for long time tests. Some of the other miscellaneous materials were submitted by Reclamation Service, Army, Bureau of Lighthouses, Public Eoads, Navy,

State Highways, Panama Canal, Forest Service, District of Columbia, and Supervising Architect.

Lime, gypsum, and sand-lime hrich.—During this fiscal year this

section has made routine tests on 5 samples of lime for other

branches of the Government, and on 65 samples of lime, 18 samples

of gypsum, and 12 samples of sand-lime brick for private individuals.

Rubl)er.—Seven hundred and seventy-six samples of miscellaneous

materials, including pneumatic tires, inner tubes, solid tires, hose

of all kinds, rubber bands, rubber rings, dredging sleeves, and rubber hospital equipment were tested for the Post Office Department,

War Department, Panama Canal, General Supply Committee, Marine Corps, and other Government departments.

Leather.—Eighty-two samples of leather were tested for the vari- ous Government departments during the year. These included sole,

flat and round belting, bookbinding and chamois leathers, also ledger

binding straps, leather leggins, strap leathers, and leather preservatives. One item in the above consisted of the inspection of 400 pairs

of leather leggins for the Porto Rican Government.

Textiles.—Ahout 4,500 samples were tested for the various Government departments, chiefly the Panama Canal, Post Office Department, Federal Trade Commission, and Navy Department. The

work done for these departments consisted of the testing of duck,

twine, aircraft cloth, and suiting materials.

Paper.—Although the chief functions in connection with paper

are the development of standard test methods and specifications of

quality, a considerable amount of time is devoted to the testing of

paper to determine the quality of such paper when delivery is made

on contract to the Government. In addition to this, a certain limited

amount of testing is done for the public, but this work is kept at a minimum, as there are several reputable commercial testing laboratories equipped for this type of work. All tests of this nature are

Government samples

Bureau investisations.

Non-Government

Totai 5, 810
214 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

made by the bureau at 65 pei* cent relative humidity and 70° temperature.

Number of samples.

Government Printing Office 1, 331

Post Office Department 777

General Supply Committee 404

New York State 149

Department of Commerce 1.55 Interior Department 50

Department of Agriculture . 30

War Department 23

Panama Canal 21

Treasury Department 14

District of Columbia 12

Library of Congress 4

Navy Department 4

Department of Labor 2

Bureau of Standards 422

For the public 206

Summary.

For the Government , 3,398

For the public 206

Grand total 3,604

Lubricating oils.—During the year routine tests were made on 551

samples for Government departments. Special tests for private

parties included determinations of viscosity on 64 samples, demulsibility on 29, and the examination of 33 viscosimeter tubes. These

tubes were all of the Saybolt type, with the exception of one Engler.

Id order to increase the accuracy of standardization of viscosimeters,

and to obtain better agreement between different laboratories, a new

form of certificate has been adopted based upon flow tests, instead

of upon the less accurate measurement of the diameter of the outlet

tube. (See report of committee D-2, Proceedings American Society

for Testing Materials, 1922.)

Cooperation.

The division has continued to cooperate with the industries

through their organizations and members of its staff have held positions on numerous important committees. A list of the societies interested in structural and other materials with which the bureau has

cooperated is as follows:

American Concrete Institute.

American Society for Testing Materials.

American Society of Mechanical Engineers.

American Bureau of Welding.

National Research Council.

American Engineering Standards Committee.

National Advisory Committee for Aeronautics.

American Society of Civil Engineers.

American Association of Engineers.

Engineering Foundation.

Associated General Contractors.

Joint Committee on Concrete and Reinforced Concrete.

National Lime Association.

Gypsum Industries Association.

Sand-Lime Brick Association.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 215

National Electric Light Assocatlon.

American Petroleum Institute.

Society of Aiitomot ve Engineers.

United TypothetEe of America.

National Paper Trade Association.

American Paper and Pulp Association.

Technical Association of Paper and Pulp Industries.

Association of National Advertisers.

National Association of Purchasing Agents.

Book Paper Manufacturing Association.

Tanners' Council.

Leather Belting Exchange.

National Boot and Shoe Manufacturers' Association.

Rubber Association of America.

Rubber Heel Club.

American Leather Chemists' Association.

Cordage Institute.

Cotton Duck Association.

National Association of Hosiery and Underwear Manufacturers.

American Home Economics Association.

Inter-State Cotton Seed Crushers' Association.

National A.ssociation of Tent and Awn.ng Manufacturers.

Publications.

During the fiscal year the following material has appeared as publications of the Bureau of Standards

:

Investigation of oxy-acetylene welding and cutting blowpipes, Tech. Paper

200 (R. S. .lohnston).

The friction and carrying capacity of ball and roller bearings, Tech. Paper

201 (H. L. AVhittemore and S. N. Petrenko).

Results of some tests of raanila rope. Tech. Paper 198 (A. H. Stang and L. R.

Strickenberg).

Durability of cement drain tile and concrete in alkali soils. Tech. Paper 214

(G. M. Williams).

Cementing qualities of the calcium aluminates. Tech. Paper 197 (P. H. Bates).

Preliminary report of exposure tests on colorless waterproofing materials

mimeographed circul.ir—published in .Tour. Am. Inst, of Architects ; October,

1921.

Blast-furnace slag as concrete aggregate—mimeographed circular.

A preliminary study of tearing instruments and tearing-test methods for paper

testing. Tech. Paper 194 (P. L. Houston).

The Redwood viscosimeter. Tech. Paper 210 (Winslow H. Herschel).

Recommended specifications for limestone, quicklime, and hydrated lime for use in the manufacture of glass. Circular 118. The testing of rubber goods (4th edition), Circular 38. Specification for cotton rubber-lined fire hose. Circular 114. Specifications for pneumatic tires, solid tires, and inner tubes. Circular 115. Power losses in automobile tires, Tech. Paper 213 (W. L. Holt and P. L. Wormeley )

.

The durability of sole leather filled with sulphite cellulose extract. Tech.

Paper 21.5 (Roy C. Bowker) ; also published in Hide and Leather Magazine;

April 22, 1922.

The following are in press and will shortly be available

:

Specifications for numbered duck for commercial and Govei'nmeut use.—Circular. Was prepared for publication and has been submitted to the edi- torial committee.

A study of commercial dial micrometers for measuring the thickness of paper

(P. L. Houston and D. R. Miller).

The photomicrography of paper fibers (R. E. Lofton),

The following papers by members of the bureau's staff have appeared in outside journals

:

Tests of rotary-drill pipes, Iron Age ; September 29, 1921, and February 2, 1922.

(A, H. Stang.)
216 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Experimental use of liquid air and explosives for tightening body-bound bolts,

Auiencan MaoUinist ; Apr.i 6, lt)22. (ti. L.. Nvnittemoi-e.

)

Moments and stresses in slabs, reprint and circular series of the National Research Council, No. 32. (H. M. Westergard and W. A. Slater.)

Concrete by strength—Austrian speciiications, translation and comments. Concrete, 19, 231; December, 1921. (\V. A. Slater.)

Girderless floors in Malmo, Sweden, translation and comments, Concrete, 20,

264; June, 1922. (W. A. Slater.)

The application of the fundamental knowledge of Portland cement to its manufacture and use.—Reprinted from the Journal of the Franklin Institute, March,

1922. (P. H. Bates.)

Standardization of textiles (F. R. McGowan). This was presented to the National Association of Cotton Manufacturers and will appear in their bulletin.

It has been published in most of the textile periodicals.

Standardization of cordage (F. R. Mc(iowan). This was published in the Cord

Age.

Tentative outline of Bureau of Standards Textile Committee on Cooperation

and Research (F. R. McGowan). This was written for the July issue of the

Manufacturers' Club of Philadelphia.

The btanuardization or paper, Paper Trade Journal; October 27, 1921. (F. A.

Curtis.)

A supplementary study of commercial instruments for determining the tearing

streii.^tn oi paper. Paper Tratle Journal; March 9, 1922. (P. L. Houston.)

The test ng oj blotting paper, PaiHjr Trade Journal; November 10, 1921. (P. L. Houston and R. Ledig.)

The oete uui.ation of sizing quality, Paper Trade Journal; April 6, 1922.

(F. T. Carson.)

Improvements in methods of making the Herzberg stain used in fiber analysis. Paper Trade Journal. (M. F. Merritt.)

Viscosity and friction, Jour. S. A. E., 10, pp. 31, 369; 1922. (Winslow H.

Herschel.)

Fuel oil vis'cosimeters, Chem. and Met. Eng., 26, p. 1175; 1922. (Winslow H.

Herschel.)

Elfect of grading of sand upon absorption and transverse strength of sandlime br.ck, Rock Products; January 28, 1922. (Emley and .Johnson.)

Manufacture of lime, Proc. Sand-Lime Brick Assn. (1922), p. 52. (W. E. Emley.

)

Sampling of leather for chemical analysis. Jour, of Am. Leather Chemists' Assn.,

May. 1922. (Roy C. Bowker and E. L. Wallace.)

METALLURGY.

The metallurgical division concerns itself with research, investigation, and testing as

related to metals and alloys, except built-up metal structures and the processes of extraction of metals from their ores. Its functions include the production of metals and alloys, both of the highest attainable purity and of commercial grades; the preparation and study

of auxiliary metallurgical products such as slags, inc\,uded gases, molding sands, refractories and deoxidizers; the development of apparatus, instruments, and manufacturing

appliances for metallurgical processes, research, and testing; the formulation and maintenance of those standards and specifications of interest to metallurgy; the determination

of metallurgical constants and properties; the investigation of the performance of manufacturing units; the determination of the causes of failure and the study of the improve- ment of metal products; and the development of economical metal substitutes. The division has equipment for metallographic examinations of metals such as microscopic analyses,

including determinations of constitution, structure, and causes of failure; for thermal

analyses including determination of heating and cooling curves for location of critical points; for the various heat treatments such as annealing, quenching, cementation, tempering; for various operations for the hot and cold working of metals such as forging, roll- ing, and drawing, and for miscellaneous physical tests; for the usual foundry operations of molding and casting ferrous and nonferrous metals; and for other metallurgical processes such as production of pure metals, electrodeposition and plating, welding, and determination of gases in metals. GENERAL.

Among the important problems which have engaged the attention

of the metallurgical division during the past year may be mentioned

a study of the methods of analysis for gases in metals and a deterr

mination of the effect of these entrained gases on the behavior of

metals at various stages of manufacture and on the properties of the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 217

finished metal products. The main object of this work has been to

devise procedures suitable for the elimination of the harmful effects

of gases in metals. This was accompanied by a study of deoxidation

processes in steel and iron manufacture.

Work on several problems relating to railroad materials has been

completed, particularly the investigation of thermal stresses in chilled

iron and steel car wheels, a problem of great importance in connection with wheel design, weight of cars, and speed of trains. The

effect of using titanium in the manufacture of steel rails has been

studied, and there was also published the results of the investigation

on sound ingot practice.

The present program relating to bearing metals has been completed,

and methods of abrasion testing will next be considered. Papers

have been published on alloy steels containing zirconivmi and other

elements, properties of steels at elevated temperatures, and tests of

centrifugally cast steel; the development of methods of metallographic etch ng for various m.etals has been studied, and there were

prepared for publication several papers dealing with microconstituents and structures.

Ihe investigation being carried out by a joint committee on the

effect of sulphur on several grades of steel has led to a preliminary

publication deal ng wuth the relation of the sulphur content to the

properties of rivet steel. A study of the rolling characteristics of

medium carbon steel, the properties of pure alloys of iron, carbon,

and manganese, and the testing of wrought iron is ready for publication. The standard tests for molding sands are being developed

with a joint committee representing the industry.

Some of the investigations started are the corrosion of rust-resisting chromium and other steels ; a comparison of the cutting qualities

of high-speed steels, the preparation of platinum alloys of the highest

purity, and several investigations principally of military interest.

Mention should also be made of the work of the research associates

in metallurgy, relating to investigations in nickel and monel metal,

malleable iron embrittlement by sherardizing, magnetic estimation of

iron in brass, and tlie hot working of ingot iron as affected ])y sulphur, oxygen, and copper.

A notable event was the estabrshment of a committee advisory to

the bureau on ferrous metals. This committee consists of delegates

from technical societies interested in steel and iron and is representative of the entire industry, and will enable the bureau to keep in

closer touch with the needs of industry.

The organization of a committee on metals under the Federal Specifications Board, in which the metallurgical division is taking an active part, was also an important matter.

Other activities started the past year through the instrumentality

of joint committees are investigat ons relating to gauge steels, mine

drill steels, molding sands, welded rail joints, and thermal stresses in

steel wheels.

The most important instrumental development was the design and

construction of an automatic apparatus for thermal analysis, permitting the elimination of one operator in tak.ng heating and cooling

curves.
218 REPORT OF DIRECTOR OE BUREAU OF STANDARDS.

RESEARCHES IN COOPERATION WITH TECHNICAL COMMITTEES.

Investigation of the Ef¥ect of Sulphur and Phosphorus in Steel.

The joint committee on this subject, of which committee the chief

of the division of metalhirgy is chairman, has finished its program

relat ng to the effect of sulphur on rivet steel, and the bureau released

for publication a preliminar)' report presented at the June meeting

of the American Society for Testing Materials. The complete re- port will be issued as a technologic paper of the Bureau of Standards.

In this investigation of rivet steels, material was used from fourteen 75-ton heats of sulphur contents ranging from 0.03 to 0.18 per

cent. There were 19 kinds of tests made, amounting to 5,230 physical tests and over 1,000 chemical analyses, mostly at Watertown and

Annapolis. Progress also has been made on tests of sheet steel of

various sulphur content, as well as on a series of steels so made as to compare the effects of residual and added sulphur. The work is being extended to include forging steels for the coming year.

Molding Sand Research.

The bureau is actively represented on the joint committee on molding sand research recently organized by the American Foundrymen's

Associat on and the National Research Council, and in cooperation

with this committee is engaged in an investigation on the establishment of standard tests for molding sands. This work requires a considerable amount of experimental research; substantial progress has

been made the past year in specifying the details of physical tests,

the work on fineness and cohesiveness being practically completed.

Welded Rail Joints.

*

There was organized the past year by the American Bureau of

Welding, at the suggestion of the committee on way matters of the

American Electric Railway Association, a committee with the chief

of the division of metallurgy as chairman, for the study and improvement of the several types of welded rail joints. The committee is composed of some 36 representatives of street railways,

manufacturers of welding ajopliances, steel companies' engineers,

and the Bureau of Standards. By means of meetings and success- fully conducted questionnaires there has been mapped out a research

program relating to types of weld such as cast iron, electric resistance, including bar and butt welds, seam, both carbon, and metallic

arc, and thermite welds.

The bureau has also carried out some experimental work along

lines of interest in development of these welding problems.

Bearing Metals.

The program of tests, to be executed by the bureau, as mapped out

by the nonferrous advisory committee and committee B-2 of the

American Society for Testing Materials has been completed and re- ported through a paper at the June meeting of the American Society

for Testing Materials. The following properties of the 12 tentative standard white metal bearing alloys of the American Society

for Testing Materials have been determined : Compressive strength

and Brinell hardness at normal temperature and 100° C, the melt-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 219

ing point and temperature of complete liquation. The Brinell hardness at both temperatures was also determined on two series of alloys

made up to meet the proposed specifications by two independent

manufacturers in order to compare them to the similar series of

alloys prepared at the bureau under careful laboratory control from

pure metals.

Car-Wheel Investigations.

The investigation of thermal stresses in chilled-iron car wheels,

outlined in cooperation with representatives of the Association of

Manufacturers of Chilled Iron Car Wheels, has been completed and

published as Technologic Paper 209. Further work is being planned

on the properties at ordinary and elevated temperatures of irons of

car-wheel composition with a view to providing data for the establishment of chemical specifications for chilled-iron wheels.

In cooperation with a group representing all the manufacturers

of steel railway wheels an investigation has been completed and is

ready for publication on thermal stresses developed in steel wheels

by the heat caused by brake applications. The behavior of all the

types of steel wheels in use was studied along the identical lines

followed in the investigation of iron wheels, except it was found

possible to reach higher temperatures with the steel without harmful

effects. Both of these investigations are of interest in relation to design and weight of wheels, weight, speed, and braking of trains.

Corrosion of Metals.

The bureau is represented on the newly formed correlating committee on corrosion organized by the National Research Council and

on the nonferrous corrosion committee of the American Society for

Testing Materials and expects to conduct its researches in this subject along lines to best fit in with the programs now being outlined.

Gauge Steels.

The construction of all high-grade machines of precision depends

on the use of gauges whose metallurgical and geometrical requirements are very severe, and which have not as yet been satisfactorily

met. A joint committee has been formed consisting of representatives of all the manufacturers of gauges, certain steel manufacturers

and large users, the Ordnance Department of the Army and the

Bureau of .Ordnance of the Navy, as well as the Bureau of Standards.

A survey has been taken of the situation and a start made on a comprehensive program of research at the bureau in cooperation with the

other interested parties under the joint committee's supervision.

The funds for work at the bureau are provided in part from an

allotment from the War Department. The main features of the

problem involve a study of the properties and behavior of a selected

series of steels, including the technique of manufacture into gauges,

especially the relation of heat treatment to permanence of dimensions,

resistance to abrasion, and corrosion.

Mine-Drill Steel.

A committee advisory to the Bureaus of Mines and Standards has

been formed on the subject of mining-drill steels, their composition,

treatment, thermal and mechanical, and reclamation, together with
220 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

causes of breakage as related to standardization of design and practice, properties, manufacture, and preparation, with the object of

eliminating waste and delays in mining operations. Several meetings have been held, a preliminary program mapped out, and the

bureau has made a survey of drill-steel practice in the. metal mines

of some 10 Western States, obtaining data which will be of use in

suggestions as to standardization of design, heat treatment, and

practice generally as relating to drills and auxiliary mining machinery. Reports of this survey are in preparation.

Deoxidation of Steel.

The committee of the National Research Council on this subject

is being reorganized, and the advisory committee to the bureau on

ferrous metals approved the bureau studying " the general principles,

physical and chemical, of the cause .and prevention of oxidation of

steel."

Metals Committee, Federal Specifications Board.

Under this board there has been organized a committee on metals,

with the chief of the division of metallurgy as chairman and the chief

of the section on mechanical metallurgy as technical secretary, with

representatives from the various Government departments, which

has undertaken the task of preparing unified Government specifications for metal products. It is planned, where possible, to use existing specifications, whether governmental or of the technical societies, with the purpose of bringing about as complete uniformity as practicable. The subjects are being taken up in the order, generally,

of ingot, cast, wrought, fabricated, and special metal products.

Conferences.

The committee advisory to the bureau on nonferrous alloys held

two meetings at the bureau, going over in detail the bureau's work in

that field.

On June 2 was held the first meeting of the newly organized advisory commitee on ferrous metals, at which were, present all but

two of the official delegates apointed by the several technical societies interested in steel and iron.

Several conferences were held with the representatives of the manufacturers of iron and steel wheels, and one on metallurgical refractories.

Committee Memberships.

A large part of the work of the metallurgical division is planned

by keep'ng in touch, through membership in technical societies and

committees, with the needs of science and industry as expressed by

these activities. The following is a list of such cooperating bodies:

The National Advisory Committee for Aeronautics, National Research Council, American Institute of Mining and Metallurgical

Engineers, American Society for Testing Materials, Joint Committee on Sulphur and Phosphorus in Steel, American Physical

Society, American Engineering Standards Committee, Society of Automotive Engineers, American Society for Steel Treating, American

Foundrymen's Association, and Advisory Committee on the Critical

Table of Constants.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 221

Circulars of Information.

iThe circulars of information, dealing with the properties of

different metals and with other metallurgical subjects, which have

been issued from time to time during the i^ast few years have proved

to be among the most useful of the division's publications. During

the past year two new ones were added. Circular 42 on metal lographic testing summarizes in a general way the bureau's activities

along the line of physical metallurgy. Circular 113 on the structure and related properties of metals is based upon the bureau's

experience in the microscopy of metals and shows by the means

of typical examinations the need for and the use of such examinations in the study of engineering and metallurgical problems.

Several of the other circulars have received considerable revision.

Circular 58 on invar and related nickel steels has been largely

rewritten and a good deal of new material included. Circular 73

on copper and Circular 80 on protective metallic coat'ngs for the

rustproofing of iron and steel have been revised and brought up to

date. Circular 76 on aluminum is under revision at the present

time.

OPTICAL METALLURGY.

Crystallinity in Wrought Iron.

Most specifications for wrought iron require specimens of the

material to pass satisfactorily a " nick-bend " test, the absence or

the occurrence of crystalline areas in the fracture being the criterion

by which the material is to be judged. Numerous requests have

been received from time to time concerning this test, and in order

to furnish reliable information for answering such requests a study

was made of the behavior of different grades of wrought iron,

donated for the purpose by five manufacturers, when tested in

various manners after nicking. The results were presented before the American Society for Testing Materials at its last annual

meeting, the aim being to show that the clause covering; this test

in most current American specifications should be rewritten so as to define this test more strictly. A nicked bar of wrought iron

subjected to impact stresses usually shows a crystalline brealc upon

fracturing, whereas the same material moderately stressed will show

a fibrous appearance. The presence of " steel " in wrought iron

is usually conducive to a crystalline fracture, although the converse is not necessarily true. Two types of crystalline are^s are often found in the fractures of wrought-iron bars after the " nickbend " test; one, which is the result of transcrystalline fracture

usually by impact, is to be considered as revealing certain characteristics of the iron, whereas the second, which always occurs on the

side of the tested specimen which is in compression during the test,

results from the plastic deformation of the gra-ns by compression

and should be considered as a characteristic of the method of test- ing rather than of the material.

Corrosion of Special Steels.

The increasing use of " noncorrodible " steels and irons and the

lack of information concerning the behavior and limitations of the

various grades, as evidenced by the numerous requests received by the
222 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

bureau for information, appeared to warrant a rather extensive investigation of this subject. During the past year various grades of

chromium steels, differing in tlaeir relative carbon and chromium

contents—carbon, 0.04 to 1.07 per cent; chromimum, 3.9 to 13.7

per cent—were prepared and tested. Small ingots of the alloys

were melted in the high-frequency induction furnace, rolled into

plates and cut into suitable size for corrosion tests. The behavior of

these specimens, when subjected to hydrochloric-acid corrosion and

in a simulated weather test, was studied. In general, the order of

resistance of the alloys to acid attack was found to be quite different

from that under atmospheric corrosion. A relatively high chromium

content is necessary for the latter, whereas in the series of simple

chromium steels subjected to acid the high-chromium specimens were

the least resistant.

Further tests are being made in the endeavor to show the influence

of added elements in chromium steels, such as nickel, silicon, and

manganese. Apparatus is also being constructed for the oxidation

tests so that the conditions can be much more carefully controlled

than hitherto. By an automatic arrangement the specimens will be

alternately immersed in the corroding medium and then withdrawn

into the air. The results of the experiments are being published

from time to time.

Microstructural Changes Accompanying the Tempering of Martensitic Steels.

This investigation was completed during the year and the results

assembled for publication. The structure of martensite, as illustrated

by quenched steels varying in carbon content from 0.07 to 1.12 per

cent, and the visible microstructural changes which occur during the

tempering of such steels are described by means of typical micrographs. A structural change corresponding to the transformation at

approximately 250° C. as determined by thermal analysis and other

means of investigation was shown to exist. The variation in the

mechanical properties corresponding to different structural conditions was determined by means of scleroscope hardness measurements.

Metallographic Etching Reagents for Nonferrous Alloys.

During the past year the second scientific paper summarizing re- sults obtained in this investigation was published. This dealt with

the common alloys of copper and with nickel and its alloys. The

etching characteristics of aluminum and its alloys have also received

attention during the past year. As material for study and for the

preparation of necessary alloys, aluminum of an exceptionally high

degree of purity (99.97 per cent), furnished by the manufacturers

for the pxirpose, was used. In the preparation of the various alloys,

preference was giA^en to those which have some industrial use. The

results Avill be published shortly.

Metallographic Etching for the Identification of Carbides, Tungstides, and Other Compounds in Alloy Steels.

When etching alloy steels with the acid reagents usually employed

for steels, no apparent distinction is obtained between the carbides,

tungstides, and other compounds that may be present in the free or undissolved state, in the microstructure developed by the etching.
REPORT OF DIRECTOR OF BUREAU OE STANDARDS. 223

Various investigators had in the past proposed special etching re- agents, some of them being known to be present. It appeared, however, that coordination among these results was lacking and no clearh'

established rationale underlay the procedure. This investigation has

been undertaken in the endeavor to establish upon a systematic basis

the identification of the A'arious constituents of alloy steels by means

of comparative results obtained on the constituent in question with

the already known etching reagents and any new ones or methods

of etching that might suggest themselves during the course of the

investigation. It Avas seen early in the work tliat solutions of an

alkaline nature did not offer much hope in this dii'ection. Attention

has been directed to the rationale of the behavior of the several alkaline solutions used to the various constituents of the chromium, tungsten, and plain carbon steels. Ternary alloy steels, containing varying amounts of carbon and the alloying element as chromium or

tungsten, have been in part prepared in the laboratory and in part

obtained from steel manufacturers. Other special substances, such

as tungsten carbide, have been prepared for study. Specimens of

these steels have been given different heat treatments as quenching

from a high temperature to retain in solid solution as much as practicable of the constituent, ordinary furnace cooling, and extremely

slow cooling from a high temperature to precipitate as far as possible

the constituents out of solid solution and at the same time agglomerate them into larger masses for the easier concentration of the etching

effects upon the otherwise very small-sized constituents. A method

of sequence etching, involving the etching of the microsection with

two or more different etching reagents in succession without any re- polishing of the section being undertaken between the etchings, has

been developed for high speed steels, and the results obtained so far

indicate that there are at least three diffei-ent constituents present

in this complex alloy which may be identified from one another, although their identity has not yet been established with certainty.

The investigation is in progress, and it is proposed to extend the work

to include in the study molybdenum, vanadium, and possibly other

alloying elements.

Embrittlement of Steel by Hydrogen.

Low-carbon steel of the grade used as boiler plate at times becomes embrittled in service so that cracks develop and leaks in the

boiler occur. The explanation is now very generally accepted that

the concentration of the " caustic products " resulting from the

" treatment " of the boiler water, or initially present in the feed

water is responsible for the failure of the steel, the evolved hydrogen

being the immediate cause. Several cases of failure of this kind were

submitted for metal lographic examination during the past year. A

means for the metallographic determination of steel aifected in this

way is being sought at present.

Graphitization of White and Gray Cast Iron.

These experiments were conducted to determine the maximum

allowable temperature for the annealing or " pitting " of cast-iron car

wheels. The wheels should be annealed at the highest temperature

that will not cause any graphitization of the chilled treads. Pre964-^22 16
224 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

viously it was p^enerally supposed that no graphitization occurred

below 700° C. The work of the bureau, however, has shown that for

periods of annealing as long as 12 days there is appreciable graphitization at temperatures as low as 600° C. Because of the excessive

time required for graphitization at 600° C. the actual practice in the

annealing of car wheels may not be affected. The results, however,

are of considerable theoretical interest, as they may aid in explaining

the mechanism of graphitization, which phenomenon is extremely

complicated and Avhich must be understood to control exactly such

processes as the annealing of chilled-iron car wheels and the production of malleable castings. Micrographs were taken showing

the progressive changes in microstructure of white and gray castiron with variations in time and temperature of annealing.

Relation of Grain Size to the Mechanical Properties of Steel.

The subject of the shock-resisting properties of annealed steel

received some attention during the past year and it will be continued

during the coming year. It seems that this particular property of

steel is profoundly affected by the size of grain—much more so than

any other' mechanical property.

Microphotographic Work.

In the study of the structure of metals by means of the microscope,

permanent records are made by means of photographs. During the

past year 2,1 18 micrographs were taken for this piirpose. Of these,

409 related to materials submitted for examination, and 1,709 were

taken in connection Avith the various research problems in progress

in the division of metallurgy.

Investigations Continued and Proposed.

The study of the corrosion of A^arious types of " noncorrodible

steels will be continued during the coming year.

The iuA^esftigation of the crystallinity of Avrought iron as reA^ealed

by the " nick-bend " test Avill also receive some further attention.

In connection Avith the general study of the "enameling properties " of cast iron, it is expected that considerable microscopic study

will be necessary, particularly in connection with the blistering of

enamels Avhen applied to- certain grades of cast iron.

Further investigation of the relation between the grain size of

steel and the shock-resisting and other mechanical properties has

been planned.

THERMAL METALLURGY.

Thermal Analysis.

Neiv chronogra'ph for thermal nnali/sis.—The neAv recording chronograph for the inverse rate method of thermal analysis has been

placed in satisfactory operation, and it has been possible to carry

out routine and research Avork with equal or greater accuracy and

a time saving of 30 to 60 per cent. A report covering the constniction and application of this apparatus has been comipleted.

Magnetic m,ethod of determining critical ranges in ferrous alloys.—

Additional Avork has been done with magnetic methods for determining critical ranges in steels with varying degrees of success.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 225

^^Tiile no results of special interest can be reported, there are indications that even the simple apparatus now available will be of value

as an addition to present thermal equipment for determining transformations in special steels.

Mechanical Properties of Steels at High Temperatures.

TemUe tests.—Following the completion of the two reports re- ferred to in 1921 tests were made of quite a number of commercial

carbon and alloy steels and metals of special composition throughout the range 20 to 550° C. Among the most important of these

are the following : .

(«) Normalized carbon steels containing 0.2, 0.4. and 0.6 per cent carbon.

(h) Quenched and also quenched nnd tempered carbon steels,

(c) One and one-quarter per cent manganese steel (used for ordnance) —nor- malized.

((7) Cobalt steel (5 per cent Co, 0.60 C) —normalized.

{€) Normalized and also quenched and tempered chromium-molybdenum steel. {f) Stainless steel, heat treated in various ways (three series).

{g) Chromium vanadium steel (3 per cent Cr. 0.20 per cent V, 0.5 per cent

C) —air cooled.

(h) Normalized tungsten finishing tool steels (two series).

(i) Twenty-eight per cent nickel steel. {]) Special chromium steels containing 3, 5, and 10 per cent chromium.

A "stiffening" (that is, increased strength with decreased datility) at hiffh temperatures between about 850-550° C. is produced

by the addition of such elements as chromium and tungsten, while

nickel in small proportions (3 per cent) has little or no effect on the

tensile properties, ond large amounts (28 per cent) produce a very

soft and weak metal. Tests of a series of uranium steels are also now

in progress

While it is desired to accumulate test data for commercial steels,

one of the principal functions of this work is to determine effects of

various alloying elements in order that special alloys of high strength

in various temperature ranges may be produced. The reports cov- ering various phases of this work have been prepared.

Compression tests.—At the request of a manufacturer of forging

equipment a special apparatus for compression tests at high temperatures was constructed, and to date one series of tests up to 700° C.

has been completed. This work will be extended, and it is hoped to

obtain data up to 1,000° C. for a number of the most commonly used

" forging steels."

Effect of Heat Treatment on Properties of Structural Steels,

Tests of some of the newer alloy steels, referred to in the 1921

report, have been continued. Two reports were completed. One

of these deals with the heat treatment of 1 per cent carbon (spring)

steel, while the other considers carbon-molybdenum and chromiummolybdenum steels.

In this latter report an extended discussion is given of effects of

various heat treatments on the tensile and impact properties, hardness and microstructure of two molybdenum steels. Parti ular at- tention is paid to comparison of oil and water hardening for production 'of definite strengths and certain peculiarities in beliavior,

considered to be the result of a molybdenum change, are described.
226 REPORT OF DIRECTOR OF BUREAU OF STANDARDS,

Surrounding Atmosphere in Heat Treatment and Gases in Steels.

The progi-am of 1921 was modihed and extended and some interesting results obtained for steels treated in hydrogen, nitrogen, etc. In studying the variations in mechanical properties between electricfurnace and open-hearth silico-manganese spring steels when subjected to the same heat treatments it was found that the proportion

of nitrogen in the electric steel, which in the rolled bars was about

twice that in the open-hearth heats, was also dependent upon the

heat treatment. This work is being continued to include more observations on the relation of nitrogen to heat treatment.

High-Speed Tool Steels.

Quite a large number of lathe-cutting tests of various high-speed

tool steels were made in cooperation with the Navy Department and

a report is now in preparation. The work may be described as a

critical examination of the severe breakdown test more or less generalh^ used of late for high-speed tool steels and also a comparison

of the perfoi'mance of modern types under varjdng conditions of

service. Examination of fracture, secondary hardness determinations, power input, fracture tests, and niiscrostructure are additional

factors considered.

Dimensional Changes in Hardening Steels.

As a result of reports of difficulties encountered by a number of

firms in the control of dimensional changes, while hardening steel

for tools and dies, some work was undertaken to determine the magnitude of these changes resulting from variations in rate of heating,

time at hardening temperature, temperature and rate of cooling.

Relatively small changes in any of these factors may produce large

differences in the dimensional changes found in the hardened steel. In some cases dimensional changes onlj' are obtained while in others

volume changes as well are observed. Sufficient work has already

been carried out to show the complexity of the problem and the

difficulty of reproducing results. The question is, however, of great

practical interest and imj^ortance and the work will be continued.

Proposed New Investigations.

It is planned to continue work on high-speed tool steels, the control

of dimensional changes in hardening and high-temperature investigation relating to special alloys. In addition it is hoped to be able

to begin work on several of the following investigations: (a) Temperature variation in large masses during quenching, (5) artificial

seasoning of cast irons, (<:) stress corrosion tests of boiler plate at

high temperatures, {d) effect of heat treatment on certain nonferrous

light alloys, and (a) study of quenching media.

MECHANICAL METALLURGY.

Titanium Treated and Untreated Rails.

The experimental work of this investigation, mentioned, in last

year's report, has been completed. Sections of rails from several

heats of steel with and without titanium treatment were taken from
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 227

A-rails and a survey made of the chemical homogeneity, soundness,

and uniformity of mechanical properties. The results have been compiled and will be reported as a Technologic Paper.

Corrosion of Iron-Silicon Alloys.

The experimental work of this investigation has been completed

and reports submitted to the manufacturers who cooperated by

furnishing material.

Effect of Rolling Conditions on the Properties of a Medium Carbon

Steel.

The additional work on this report has been completed and the

results have been compiled, which it is anticipiated will be issued soon

as a Technologic Paper.

Equilibria of Tin-Rich Ternary Alloys.

This work, mentioned in last year's report, has been continued.

One point of considerable interest is the detection of a preliminary

lowering of the melting point of tin by the addition of 0.3 per cent

antimony. All previous investigators have reported an immediate

rise in melting point with the addition of antimony which was admittedly contrary to theory. This point is being investigated further.

Wear Testing.

There is a continued call from the industries for information on

the wearing qualities and resistance to abrasion of steels and nonferrous alloys. Apparatus for studying the wearing qualities of

metals has been obtained and work is actively in progress. The first

phase of the work will be a study to determine if any relation exists

between hardness and resistance to wear. Particular attention will

also at first be given to steels suitable for gauges.

Invar Tape and Shapes.

The United States Coast and Geodetic Survey has use for and need

of invar surveyor's shapes because of its low thermal coefficient of

expansion. Since the war the Coast and Geodetic Survey has been

unable, except with great difficulty, to obtain invar tape er shapes,

either in the United States or abroad. The bureau is, therefore,

making a general study of the manufacture, mechanical working of

invar, and its thermal characteristics, in order to make possible the

obtaining of invar products of known and guaranteed minimum

thermal expansivity.

Properties of Large Crystals.

A method has been devised for obtaining very large crystals of

pure lead and possibly other pure metals. The method also provides

a means of studying the solidification of pure metals under unusual

conditions. Briefly, the method consists of drawing a lai^ge stalactite of metal out of a molten bath. A study of these large crystals

and the processes of solidification it is hoped will help to interpret

the physical and mechanical properties of cast metals, as well as prove of great academic value.
228 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Foreign Travel and Exchange of Research Personnel.

During the past year a member of the staff visited the principal metallurgical laboratories of France, Switzerland, Germany, and England, and also many large metallurgical establishments. A member

of the staff also worked for over two months in the metallurgical

department of the National Physical Laboratory of Great Britain,

inaugurating an exchange of results between the metallurgical departments of the British and American national research laboratories.

Miscellaneous.

Apart from the major investigations which have been mentioned,

this section is interested in several other problems such as a study

of the causes of shrinkage of electrotype plates, the testing and development of aluminum solders, the preparation of pure alloys for

standards of spectroanalysis, the determination of the melting point

of nonferrous alloys.

The rolling mill, foi'ging, and wire drawing equipment has been

used a great deal in rolling, forging, or drawing special alloys and

shapes for use in connection with research work within the bureau

and also for other laboratories and in special work for other Government departments.

Metal Specifications.

This section has been particularly active during the past year in

assisting in the formulation of metal specifications. This is best

evidenced by the number of specification committees of the Government and national societies on which members of its staff are serving.

CHEMICAL METALLURGY.

Gases in Metals.

The appreciation of the practical importance of gases in metals

and their probable relation to many of the hitherto inexplicable differences in quality and service of metals and alloys of supposedly

identical composition has grown rapidly during the past year. Both

in this country and abroad this phase of metallurgy has come to be

regarded as of prime importance. Both the ferrous and nonferrous

metallurgical industries are cooperating with the bureau to the full- est extent in all phases of this investigation.

Method for Total Gases in Metals.

The principles of the vacuum fusion method for the determination of gases in metals were outlined in last year's report. Three

modifications of the method of fusing the metal samples in the highfrequency induction furnaces have been tested: (1) Melting the

metal sample with a gas-free alloy, which lowers the melting point

of the original metal and may at the same time throw carbon out of

its solution in the metal, (2) melting the metal sample in a refractory

oxide crucible by direct induction in the metal itself and (3) melting

the sample in a graphite crucible. The second method is satisfactory

in the case of carbon-free metals. However, with metals containing

carbon there is in most cases an appreciable reduction of the oxide, of
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 229

the crucible, a reduction sometimes so great as to completely decarburize the metal sample, and as a consequence there are obtained

results for carbon monoxide and oxygen which are valueless. Satisfactory results for total gas on carbon-free metals by the second

method are duplicated by the first method—for example, melting

electrolytic iron with an alloy of antimony tin. The antimony tin

alloy procedure (originally developed by Sorens) when used with

steels or cast irons has the advantage that carbon is thrown out of

solution when the metals fuse. In this latter condition the carbon is

much less reactive toward crucible refractories than when in solution

in the iron or steel. Tests are now being carried out with the third

method of melting, viz, in a graphite crucible, in the attempt to

develop the procedure as a method for determining oxygen in carbonbearing metals such as steel, pig iron, and cast iron.

Two forms of Nitrogen in Steel.

During the examination of samples of open-hearth and electricfurnace silico-manganese spring steels for gases it was found that the

amount of nitrogen as determined by the Allen or acid-solution

method was very noticeably increased after certain heat treatments

of the electric furnace steel. No similar change in nitrogen took

place in the open-hearth, steel after identical heat treatments. Similar increases in nitrogen were found in a plain carbon steel from a sec- tion of an autoclave, and also in a series of small electrolytic iron

ingots. The only form of nitrogen determined in iron and steel by the

Allen method is combined nitrogen, probably existing as nitride of

iron, or such minor constituents as manganese, aluminum, or titanium.

It is probable that the increase in combined nitrogen with heat treatment observed in these classes of material was the result of the conversion of uncombined nitrogen to nitride nitrogen, and that nitrogen

in two forms was present in the samples in which the increase took

place. It is believed that such behavior of nitrogen in steel has riot

previously been reported.

Direct Method for Nitrogen.

This method has been reported previously as applicable to the

determination of nitrogen in mixtures with oxygen and hydrogen.

-During the past year tests of the accviracy of the method for nitrogen-carbon-dioxide mixtures were completed. It is possible to determine 93 per cent of the nitrogen present in mixtures of air and carbon

dioxide with the carbon dioxide as high as 75 per cent. With less

carbon dioxide present the recovery of nitrogen is still higher. In

the absence of carbon dioxide 98 to 99 per cent recovery of nitrogen

is obtained. This method of analysis was developed for use in the

absorption of nitrogen evolved from metals fused in vacuum.

The Decarburization of Ferrochromium by Hydrogen.

The recent development of " stainless " or " rustless " iron, con- taining chromium in about the same proportions as stainless steel,

but with the carbon content in the neighborhood of, or less than, 0.1

per cent, has emphasized the need of low-carbon ferrochromium.

The bureau has carried out preliminary experiments to determine the

feasibility of a proposed method for the decarburization of com-
230 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

mercial grades of ferrochromium by means of hydrogen. . It was

found that moist hydrogen at 1,000° C. reduced the carbon content

of ferrochromium but also oxidized the ferro-alloy somewhat. Dry

hj'drogen reduced the carbon very slowl}^ if at all, at 900° C; at

1,100° C. the reduction was appreciable; at temperatures close to

the melting point of 8 per cent ferrochromium the reduction in carbon

was still greater and was much more rapid at a temperature slightly

above than at one slightly below the melting point. The most rapid

reduction in carbon was obtained by bubbling hydrogen through

molten ferrochromium at somewhat above 1,500° C. At a higher

temperature and in the presence of silica the loss in carbon was

partly due to the reduction of silica to silicon.

The preliminary tests made indicated that while the decarburization of high-carbon ferrochromium by means of hydrogen takes

place to some extent at temperatures below the melting point of the

alloy, the most promising condition for refining high-carbon feriochromium by this method is probably blowing the molten alloy in a converter with a blast of hydrogen.

The Effect of Carbon and Manganese on the Mechanical Properties

of Iron.

A paper in press describes the preparation and mechanical properties of a series of veiy pure vacuum-fused alloys of electrolytic

iron, carbon, and manganese, whose compositions were chosen so as

to bring out the specific effects on pure iron of additions of carbon

and of manganese separately and of carbon and manganese to- gether in varying relative proportions. The maximum amount each

of carbon and manganese was about 1.5 per cent.

Carbon increased the ultimate strength of the iron at an average

rate of 1,000 pounds per square inch for each 0.01 per cent carbon,

up to a content of about 0.85 to 1 per cent, the rate increasing with

the increase in manganese. The proportionate increase in Brinell

hardness was about the same as that for ultimate strength. The

proportional limits were less affected by carbon than were the ultimate strengths. Elongation and reduction of area were rapidly re- duced as the carbon increased.

Manganese, in the absence of carbon, had ver}^ little effect on the

mechanical properties of iron. With the addition of carbon its effect was increased proportionately with the carbon content, raising

the ultimate strength from 90 to 250 pounds per square inch for each

0.01 per cent manganese. Brinell hardness was increased in about

the same manner. The proportional limit was increased more by

manganese than was the ultimate strength. The effect of manganese

on ductility was negligible.

Invar (36 Per Cent Nickel-Iron Alloys).

Several departments of the Government have been interested in

obtaining small amounts and special shapes of the nickel-iron alloy

known as invar. This alloy has a very low coefficient of thermal

expansion. The better grades of this material have in the past been

obtained from European sources. During the past year several

ingots of this alloy have been made in a high-frequency induction

fui-nace, some ingots containing carbon and manganese in proportions found in commercial invar, and others free from both carbon
KEPOKT OF DIEECTOR OF BUREAU OF STANDARDS. 231

and manganese. It was found possible easily to prepare this alloy

of a quality suitable for precision-instrument material free from car- bon and manganese and it has been cast in chill molds and successfully

forged. The coefficient of thermal expansion of the alloy as forged

varied from 0.8X10"'' to 1.1 XlO"" for the range 20 to 100° C. One

sample as forged had a coefficient of 0.4X10"" for the range 20 to

60° C. Sand castings of invar gave, after annealing, a coefficient

of expansion of 1.2X10"« between 20 and 100° C.

Platinum and Platinum-Metal Alloys.

A considerable amount of work has been done on the melting and

working of palladium, phitiniun, and rliodium of very high purity.

These raefals are fused by direct induction in the higli-freciuency

induction furnace in special refractories—usually thorium oxide.

The purest platinimi in the possession of the bureau and noAV used

as the standard in the thermoelectric test for the quality of thermoelement platinum was prepared in the course of this work. This

sample is 55 microvolts negative to (more pure than) the best sample of Haraeus thermoelement platinum in the bureau's possession

at the beginning of the present investigation. Palladium of higher

purity than the bureau's previous standard has been melted and

drawn to wire by the same procedure. A number of platintim -metal

alloys have been prepared for stan'dards for chemical and spectroscopic methods of analysis. Platinum and platinum-rhodium wire

has been ])repared and furnished to various divisions of the bureau

and to other research laboratories for precision thermocouples and

resistance thermometers.

It is hoped that it will be possible to undertake the preparation

and investigation of the properties of a number of platinum and

pliitinum-metal alloys with particular reference to improving the

quality of platinum laboratory ware.

Special Alloys and Castings.

The bureau's equipment in the line of electric vacuum and highfrequency induction fiu-naces enables it to make a great variety of

special metals, alloys, and castings. Among those made during the

past year may be mentioijed vacuum-fused electrolytic iron wire and

sheets, " staiidess " steel and " rustless " iron castings and forgings,

manganese-steel castings, carbon-free iron-tungsten alloys, fused

tungsten cai'bide, vacuum-fused cobalt, and cobalt-iron castings.

Proposed New Work.

It is pro]>ose'l to lay special emphasis during the coming year on

the study of the relation of gases in metals to variations in commercial practice in melting, refining, and working; to dilferences in

quality or service of metals of apparently identical composition apart

from contained gases. The continuation of the work on platinum

metals in the direction mentioned above, viz, the development of

better alloys for platinum laboratory ware, should also recei%'e particular attention. Studies of equilibria in systems involving metals

and gases at high temperatures, and the specific heats and thermal

conductivities of metals and metallurgical refractories at high temperatures are proposed new lines of investigation.
232 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

EXPERIMENTAL FOUNDRY.

Production of Castings.

The foundry has continued to serve the bureau and certain other

Government departments in the production of castings, mainlj^ for

instrument parts and in connection with research material. The

?ast year there were made 1,881 castings from 15 kinds of metal,

t is planned to install a cupola during the coming year for the more

convenient production of cast-iron castings.

Molding-Sand Tests and Investigations.

Various samples of molding sand have been tested for State sur- veys, producers, and foundries. The research work on molding sands

has been largely carried out in cooperation with a joint committee

representing the industry. A new type of permeability apparatus

has been developed and is under investigation. The research work

relating to standard tests of fineness and cohesiveness has been practically completed. A muller is being installed for the preparation

of synthetic sands.

PROBLEMS OF MILITARY INTEREST.

Erosion of Special Machine-Gun-Barrel Steels.

Twenty alloy steels which were recommended by members of the

bureau. War Department, and sources outside of the Government

departments, for service as machine-gun-barrel steels were prepared

for metallurgical and service tests. The bureau has been engaged in obtaining physical data upon

these steels pertinent to the erosion problem. One of the arsenals

of the War Department has been active in the manufacture and

service testing of the barrels. The testing of the final lot of barrels is now in progress. The project has progressed through 80 per

cent of its course and should be completed during the coming year.

During the year the bureau has replaced six of the special alloys

when the supply for the experimental Avork had given out. Eeports

have been distributed on (a) the degree of fiberization and segregation in the special steels, (b) the thermal expansion and contraction

of the special steels, and (c) the attempted electrodeposition of

erosion-resisting coatings.

In connection with the work above an investigation has been begun

of the possibility of impregnating a steel surface with a refractory

element suitable for resisting corrosion.

Development of Light Armor Plate.

In conjunction with the War Department the bureau has undertaken the problem of developing light armor plate and of preparing specifications expressing in physical terms those properties of

armor plate which are at j^resent expressed in ballistic terms.

The first portion of the work allotted to the bureau, namely, the

preparation by a special process of a series of plates, has been completed and the plates shipped to one of the proving grounds for ballistic tests. Other work in connection with this problem has been

outlined but held pending the results of the firing tests.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 233

Reports have been submitted on (a) the change in properties with

heat treatment of two typical compositions of armor plate, (h)

effectiveness of different commercial carburizers upon armor-plate

steel, (c) effectiveness of different cleaning methods, (d) rate of

carbon penetration, and (e) efficiency of various coatings for selective carburization.

Work on the correlation of ballistic properties with physical properties has been outlined with the purpose in view of determining the

properties necessary in a successful plate. The drawing up of

specifications which recommend the manufacturing procedure and

demand certain physical properties is expected to remove the mystery

connected with the ballistic requirements, which provoked antagonism among manufacturers.

Corrosion of Metals by Ammonia and Its Constituent Gases.

In cooperation with the bureau, the Fixed Nitrogen Research Laboratory has been engaged in an investigation of materials suitable for use in the nitrogen-fixation apparatus. A special high-pressure,

high-temperature corrosion imit has been built at their laboratory

and put into operation.

A series of 50 steels and nonferrous alloys have been exposed to

the action of the gases and their mechanical properties and structure

before and after test studied.

The initial program is roughly 50 per cent completed. The deA'elopment of satisfactory materials for the fixation work is expected

to follow.

During the year a compilation of all data in connection with 30

of the alloys has been made. A report on the occurrence of nitrides

and oxides in boiler-tube steel and a I'eport on the mechanical properties of a series of chrome-vanadium steels have been published.

Reports which have been submitted on other phases of the work

will be revised for publication.

Investigations associated with the principal problem are under

way, namely, (a) the deterioration of tubing in ammonia at high

temperatures, (b) the corrosion of iron under stress in ammonia gas,

(c) strength of certain steels at the operating temperatures, and

(d) the structure and properties of metallic-base catalysts.

Miscellaneous Investigations.

A number of minor problems and special tests associated with

the work above have been undertaken and reported upon to the

individuals concerned.

RESEARCH ASSOCIATES.

The same research associates as last j'ear. representing mettallurgical industries, have continued their Avork in the metallurgical division. The following is an account of their accomplishments

:

Iron in Brass.

The research on the effect of small percentages of iron on the magnetic properties of cast red brass has been completed. It was found

that no simple relationship existed either in the cast or annealed condition between the iron content and the magnetic properties of the
234 EEPOET OF DIEECrOK OF BUREAU OF STANDARDS.

brass. Heat treatment of the alloy produced marked changes in the

magnetic effects. Less than 0.14 per cent iron went into solid solution in the brass (82 copper, 15 zinc, 3 tin).

Sherardizing.

The sherardizing process was investigated further. The factor of

the fineness of the zinc dust employed was given the chief consideration. The results showed that the rate of deposition is materially

affected by the state of Subdivision of the dust, but the amount

and distribution of zinc oxide present is so intimately bound up with

this variable that more study will have to be given the problem

before more definite conclusions can be drawn.

Embrittlement of Malleable Iron by Galvanizing.

During the ^^ear an investigation was started to study the embrittlement of malleable iron in galvanizing. It has been found in

practice that malleable iron that was not abnormally brittle as it came from the malleableizing oven frequently became so on coating

with zinc by dipping in the molten metal. The work to date has

shown that the embrittlement is probablj^ entirely due to the heat

treatment the iron receives The fact that the metal becomes coated

with zinc has little effe t on the shock resistance of the metal, but

the circumstance that the iron becomes heated to about 450° C.

on being immersed in the molten zinc, followed by rapid cooling,

is the real cause of the embrittlement. Some malleable iron does

not seriously deteriorate under these conditions. There seems to be

a rough proportionality between the silicon content (0.5 to 0.9 per

cent) and the embrittlement produced. That silicon is probably

not the sole cause of this harmful effect is shown by the fact that

commercially pure iron to which varying amounts of silicon up to

1 per cent had been added was not seriously influenced by the heat

treatment. On varying the temperature from which samples of

malleable iron were rapidly cooled it was found that up to 450°

C. the resulting metal was increasinglj' brittle. At somewhat higher

temperatures, however, the resistance returned and even increased over that of the untreated iron, so that at about 600° C. the metal

became one and one-half times as resistant to shock as it was before

treatment. Unfortunately the brittle range coincides with that used

in hot-dip galvanizing. There appear so far to be two ways to

overcome this embrittlement. One is to anneal the galvanized pieces

at a low temperature (160° C.) for four hours or more. The second

is to heat the malleable iron to a temperature above the brittle

range (say 625° C.) and quench. This metal can then be galvanized

without serious loss of resistance. Further data as to the cause of

the embrittlement are now being secured.

Deoxidation of Iron and Steel.

During the past year considerable improvement has been made

in the technique of laboratory Avork on deoxidation. Improved methods of making the magnesia crucibles used in the work have been

of great help. These are now made by tamping the moistened

magnesia into a paper mailing case of suitable size, using a wood

mandrel for the core. The crucibles are then baked in an oven and
REPOET OF DIEECTOR OF BUEEAU OF STAiSTDARDS. 235

burned in lots of 12 or 14 in a large gas furnace at about 1,500° C.

Such crucibles are very satisfactory for use in the induction furnace.

Most of the laboratory deoxidation tests are now carried out in

the induction furnace, since it has been found during the previous

experiments that the atmosphere of an Arsem vacuum furnace

causes reduction of iron oxide whether a deoxidizer is present or

not; moreover a melt made in an Arsem furnace gives a sound

ingot with or without a deoxidizer. This is due to the fact that the

gases causing unsoundness are removed by the vacuum, and no deoxidizer is needed for such purpose when melts are made in vacuo. When carrying out the melts in the induction furnace it has been

found that a very considerable amount of oxidation occurs by ac- tion of the air on the molten ingot iron, and this is being further

investigated. It is believed that some of this oxidation is due to

the porosity of the crucible which allows air to enter and oxidizes

the metal. This matter has been investigated by making melts under

hydrogen and nitrogen in such crucibles. Although the air is thus

excluded quite completely from the surface of the melt, there is nevertheless some oxidation, and this must be due to the porosity of the

crucible. It is expected that this difficulty in the "preparation of a standard material for testing deoxidizers will be eliminated by

melting in a vacuum, then introducing enough air to give a definite

oxide content in the metal, then adding the deoxidizer and pouring

or allowing to solidify in the crucible. As soon as this latter part

of the work is completed a paper is to be prepared giving the details of a method which has been developed for testing the ironoxide removing power of various deoxidizers.

Considerable progress has been made in the endeavor to correlate

laboratory deoxidation experiments with those on a larger scale.

From the parallel sets of experiments which have been conducted

thus far it is evident that the proportion of deoxidizer needed to

accomplish a given result increases progressively in the order : Laboratory experiment, large ingot experiment, small ladle experiment,

and large ladle experiment. The causes for this variation are now

being investigated; they seem to lie partly in the reaction of the

deoxidizer with the slag, in the mechanical difficulties, and in the

variation of the gas content of the metal in the different pieces. It

is hoped to follow some of this work by gas analyses of the various

products in order to get more information on the fundamental laws

involved.

Hot Shortness of Ingot Iron.

The various ingots made to test the effect of different elements on

the hot forging properties of iron have been assembled and completely analyzed. A few more ingots are to be prepared to check

the results already obtained and the results will then be published

in a paper giving experiments and conclusions on the effect of oxygen, sulphur, manganese, and copper on the red shortness of lowcarbon iron.

The Trent Process. ^

In order to test the products made by the Trent process of direct re- duction of iron ores, several experiments were carried out in which

the various factors of the process such as the fuel and ore used, vari-
236 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

ous temperatures, time of reaction, etc., were varied. This gave cor- responding variations in the products made by this process.

Although this work has not been completed it has been found that

there is an optimum temperature range for each ore and eacli reducing material. If the temperature s carried too high there is considerable slagging of the reduced iron with impurities in the

ore. If the temperature is too low the reduction to metallic

iron is not complete. In all cases it has been found exceedingly important to protect the reduced material from oxidation while

it is cooling to ordinary temperatures. If this precaution is not

taken the air or the products of combustion of a fuel-fired furnace

will completely oxidize the reduced iron. It was found in these ex- periments that a gaseous reducing agent is much more convenient

and effective in general than a solid one. In carrying out the magnet c separation phase of the Trent method

it was found that not less than 90 per cent of the magnetic material

was recovered and oftentimes as h gh as 95 per cent. Here again

it was found desirable to control the reaction temperatures very

closely.

Some examinations have been made of " amalgam," using dyes

to color the oil and water used in making this product. The format'on of the product under the microscope has also been observed.

From such examinations it has been concluded that the " amalgam "

consists essentially of oil-coated particles in clusters with water on

the outside and in the inner spaces of the clusters. There also seems

to be a certain amount of water in the interior of the oil -coated

particles. During the process of formation of the " amalgam " it can

be seen under the microscope that the water in the interior of the

oil-coated particles tends to migrate out of the interior but probably

not all of it gets out when equilibrium is reached.

Effect of Cold Rolling on Some Mechanical Properties of Monel

Metal Sheet.

Tensile and hardness tests were made on a number of monel metal

sheets Avith various amounts of cold-rolling, followed by annealing

at various temperatures. The following conclusions could be drawn

from these tests

1. Cold rolling up to about 80 per cent reduction in thickness in- creases tlie hardness of monel metal. With greater cold rolling this

material gives lower hardness values both for Brinell and scleroscope.

2. A temperature of 800° C. is required to thoroughly anneal

Monel metal Avhich has been cold rolled to about 80 per cent reduction

in thickness.

3. Monel metal cold rolled above 85 per cent reduction in thickness

is not thoroughly annealed at 900° C.

4. Increased cold rolling up to about 60 per cent reduction in

thickness increases the tensile strength and decreases the elongation

5. Cold rolling beyond 20 per cent reduction in thickness followed

bv annealing at 700° C. or above produces a decrease in both tensile

strength and elongatfon.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 237

Equilibria of Nickel-Nickel Oxide.

Nickle oxide has been shown to be practically insoluble in solid

nickel. It forms a eutectic mixture containing 0.47 per cent oxygen,

corresponding to 2.2 per cent NiO. The melting point of this eutectic is 1,438° C. The melting point of nickel oxide in air has been

found to be 1,660° C. It remains to be proved that the composition

of the oxide in nickel is NiO and that this is stable up to its melting

point, 1,660° C.

Stress Corrosion Test on Monel Metal.

Several specimens of monel metal stressed in tension above their

yield point have been alternately exposed to air and immersed in

water from the city water supply of Washington. These specimens

have been under stress for eight months and have shown no indication of failure.

A specimen of monel metal was stressed in tension above its yield

point and remained immersed in aqua ammonia for two months without showing any signs of local corrosion or season cracking. The

ultimate strength and elongation of this specimen was not affected

by this treatment.

The Effect of Impurities on the Malleability of Nickel.

It has been shown that nickel containing carbon, nickel oxide,

hydrogen, or carbon monoxide and only traces of sulphur is malleable. Nickel containing a very small amount of sulphur, 0.01 per

cent or more, will crack on forging, either hot or cold. The addition

of magnesium to nickel containing sulphur renders it malleable.

The bureau is unable to identify the sulphur constituent in nickel

which contains as low as 0.01 per cent sulphur. The addition of

manganese does not change its appearance, while the addition of

magnesium does. The sulphur constituent of nickel to which magnesium has been added has not been identified.

The effect of sulphur in nickel will be determined with conditions

resembling commercial practice.

TESTS.

Fusible Boiler Plugs.

There were tested during the year 446 fusible boiler plugs, 440

being tested for the Steamboat Inspection Service, 2 for the Panama

'Canal, 1 for United States Lighthouse Service, Detroit, Mich., 1 for

United States Engineering Office, St. Louis, Mo., and 2 for the Walworth Manufacturing Co. Of these 142 were rejected, 27 on account

of copper content being more than 0.3 per cent, 26 on account of the

lead content being more than 0.1 per cent, 26 on account of the copper content being more than 0.3 per cent and the lead content being

more than 0.1 per cent, 3 on account of the iron content being more

than 0.1 per cent, 1 on account of the zinc content being more than

0.1 per pent, 32 on account of the total impurity content being more

than 0.3 per cent ; 15 on account of the tin fillings being loose, 9 on

account of the casings not being bronze, 2 on account of failures

in mechanical specifications, and 1 on account of the melting point of

1
238 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

tin filling being less than 230° C. Seven plugs were reported as haying loose fillings. One plug tested was taken from the boiler

which exploded on the steamer Omer D. Conger. Tests shoAved that

the copper content at the small end of the bore was greater than at

the large end, the chemical analysis giving copper content at small

end 2.68 jjer cent, while at large end 0.18 per cent.

Tests Involving the Microscopy of Metals.

The following cases are given as typical of examinations of this

kind which the division has been asked to make during the past year.

Tests of this kind are largely investigational in character. They are of great variety and each requires individual treatment.

Steel from Knickerbocker Theater.

Of more than simply technical interest was the examination of

samples of steel from the trusses of the Knickerbocker Theater. The

steel did not differ materially from the usual grade of structural steel.

There were no structural features found which would lead to its

being regarded as defective.

Failed Parts, Subject to Stress.

The following are examples of failed parts subjected^to liigh re- feated stress

A drive shaft from a Government Quartermaster Corps truck

broke, causing an accident involving the death of a soldier. It was

found that most probably the primary cause of the failure was the

result of mechanical causes rather than in the inherent character of

the metals used. However, the fracture occurred in the weld between

the hollow shafting and the solid end, showing that this was a Aveak

point. It was found that the tubing was of low carbon steel and

seemed to be unsuitable for a part subject to high stress. Two somewhat similar failures from a 4-wheel-drive truck were

also examined.

Forged-steel anchor bolts varying widely in composition and mechanical properties but all of which showed fractures of the fatigue

type all failed in the same relative position in the bolt. This indicated strongly that the fault did not lie in tlie material of the bolts

but in the mechanical design.

A broken crank shaft from a 10-ton ammonia refrigeration machine was found to be of a chemical composition often used for such

parts. Microscopic examination showed, however, that the material

was porous and had received insufficient forging. There was also

evidence that surface defects had been filled in with fused iron,

probably by a fusion welding process. The internal discontinuities

reduced the ductility very materially, so that the metal offered relatively low resistance to fatigue stresses, and the fractiire once started

by the surface defect easily progressed through the unsound metal.

Duralumin Forms.

These shapes were to be used in the construction of an all-metal

seaplane. They showed a number of surface markings designated

as crude spots, scale blisters, oxide spots, hard spots, etc. Since they

occurred usually at the sharp bend of the specimens, it appeared that
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 239

they were the result of preexisting defects which were made prominent by the shaping of the specimens.

Welded Sheet Aluminum.

Two grades were submitted ; one was claimed to have welded satisfactorily, the other showed cracks adjacent to the welds. It was

found that the satisfactory material was a much purer metal and

also that it had been rather severely cold rolled, so that its tensile

strength was greater. The immediate cause of the cracks was un- doubtedly the high local stresses resulting from the high shrinkage

of aluminum upon cooling from the welding temperatures. It is still an open question whether to attribute the superior welding

properties of the satisfactory sheet to the ability of this material to

withstand such stresses because of its higher yield point and tensile

strength or to the absence in this metal of the network of the constituent resulting from impurities (iron and silicon). Further

investigation is needed on this point.

Corroded Copper Tubing.

This tubing was from a heating and cooling coil of a milk pasteurizer. Iced brine is used as a cooling agent and this, together with

the action of the steam upon the heating, had badly pitted the tube

and completely perforated it in places. The copper was found to be

of high quality, so that the trouble could not be attributed to any

defect in the metal but rather to the conditions under which it was

used.

Brass Condenser Tubing.

A large number of new and used brass condenser tubes were tested,

the new ones in accordance with the specifications of the United

States Shipping Board. These require a grain-size determination

and mercurous-nitrate solution test among others. Many of the old

corroded tubes that were examined consisted of the two-constituent,

alpha-beta brass which corroded much more easily than the oneconstituent, alpha brass, particularly if the latter contains 1 per cent

tin called for in the present specifications.

Special Rolled Steel.

This material, submitted by the inventor, was prepared by pressing

machine turnings into briquets, heating and rolling to shape. The

metal is not melted. This process is claimed to have a decided commercial value. The amount of oxide was found to be greatly in excess of what is ordinarily found even in low-grade steels. This would

limit the material to those uses for which, the cheaper and lower

grades of steel are generally employed.

Cooperative Tests.

A large number of microstructural examinations were made in

connection with the following investigations of the bureau which are described elsewhere: Study of magnetic properties of the microconstituents of hardened and tempered carbon steel, Schoop spray

process for coating metals, enameling of sheet steel, deoxidation

of monel metal, special deoxidizers for steel, effect of mechanical

9644—22 17
240 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

working on properties of steel, and study of iron-carbon-manganese

alloys.

Effect of Hot Gases Upon Steel.

The examination of a steel used in the construction of an autoclave

used in the Haber process for nitrogen fixation showed that the

metal underwent very decided changes in composition and properties

in contact with the hot gases (principally the hydrogen) . The carbon

was removed to a large extent and the metal developed very pronounced " blisters. " An alloy steel of the chrome-vanadium type

was recommended in place of the simple carbon steel previously

used.

Chart of Tests.

There is attached a chart giving a summary of the tests carried out

in the division during the past year, the estimated value of which is $12,662.

Tests Completed During Fiscal Yeae 1922.

Heat treat- ment and

thermal

analysis.

Mctallographic (including

physical, chemical, and

corrosion tests). Fusible plugs.

Castings.

Total.

Irons and

steels.

Nonferrous metals.Irons and

steels.

Alumi- num

alloys.

Brass and

bronze.

Miscellane- ous.

Ferrous.

Nonfer- rous.

For the Government:

-'.grioulture Department 1 14

9

4

1 3,729

214

446

25

4533

1

1

289

27

Bureau of Standards 2,056 67 1,592

9 3

Steamboat Inspection

446 War Department 18 7

1

1 Treasury Department 248

3

i U. S. Shipping Board 4

Foreign and Domestic

1

1 Government Printing OfCoast and Geodetic Sur- vey 289 General Supply Commit27

Total For the public

2,074

1,512 675 66

43

9

13 564 526

446 289 1,592 4,604 1,603

3,586 72 109 22 60 31 446 289 1,592 6,207

PUBLICATIONS.

Publications Issued During the Year.

Publications by members of the metallurgical staff appearing

during the year are as follows

The manufacture and properties of steel plates containing zirconium and

other elements (G. K. Burgess and R. W. Woodward), Tech. Paper 207. Thermal stresses in chilled iron car wheels (G. K. Burgess and R. W. Woodward), Tech. Paper 209. Tests of centrifugally cast steel (G. K. Burgess), Tech. Paper 192. The Government laboratory and industrial research (G. K. Burgess), Trans.

Am. See. for Steel Treating, 1, p. 91, and Scientific Monthly ; December, 1921.
KEPORT OF DIEECTOR OF BUREAU OF STANDARDS. 241

Effect of sulphur on rivet steel (G. K. Burgess and C. L. Warwick), Preliminary report of the joJit committee on phosphorus and sulphur in steel, Proc

Am. Soc. for Test. Mat., 22 ; 1922.

The structure and related properties of metals (H. S. Rawdon), Circular 113. Metallograpliic testing (re\ised e'lition) (H. S. Rawdon), Circular 42. Chemical and mechanical properties of arc-fused steel (H. S. Rawdon), Proc. Am. Welding Soc, Vol. III. The micros; opic study of the structure of metals (H. S. Rawdon), Am. Machinist, 55, p. 659. Fusion weld ng—a new use for castings (H. S. Rawdon). (Contribution to dis- cussion of fusion we. ding. ) Year Book, Am. Iron and Steel Inst., pp. 340-348 ; 1921.

Metal] ographic factors in carburization. Discussion of "Effect of quality of

steel on case carburizing results" (H. S. Rawdon), Trans. Am. Inst, of

M'n. and Met. Engineers; 1922.

Corrosion patterns on cold worked tin and z'nc (H. S. Rawdon, A. I. Krynitsky,

and J. F. T. Berliner) . Chem. and Met. Eng., 26, p. 212 ; 1922.

Br'ttleness developed in pure lead by stress and corrosion (H. S. Rawdon, A.

I. Krynitsky, and J. F. T. Berl ner), Chem. and Met. Eng., 26, p. 109; 1922. Brittleness developed in aluminum and duralumin by stress and corrosion (H. S. Rawdon A. I. Krynitsky, and J. F. T. Berliner), Chem. and Met. Eng., 26, p. 154; 1922. Metallographic etching reagents, II, for copper alloys, n'ckel and the alpha

alloys of nickel (H. S. Rawdon and M. G. Lorentz), Sci. Paper 435. Contrast etching for metallographic spec'mens (H. S. Rawdon and M. G. Lorentz), Chem. and Mef-. Eng., 25, p. 915; 1921. Metal Industry, 18, p. 25. Concenti'ated hydrochloric acid as a metallographic etching reagent for nickel

(H. S. Rawdon and M. G. Lorentz), Chem. and Met. Eng., 25, p. 955; 1921.

Some observat ons on the " nick-bend " test for wrought iron (H. S. Rawdon and

S. Epste n), Proc. Am. Soc. for Test. Mate.. 22; 1922.

The effect of phosphorus upon the structure of low carbon open-hearth steels (E. C. Groe.sbeck). Tech. Paper 203. Tensile properties of some structural alloy steels at high temperatures (H. J. French), Tech. Paper 205. Trans. Am. Soc. for Steel Treating, Vol. II, p. 409 ; 1922.

The effect of heat treatment on the mechan'cal properties of a carbon-molybdenum and a chrom uni-mol.vbdenum steel (H J. French), Trans. Am. Soc. for Steel Treating. Vol. II, p. 769; June. 1922. The elements of heat treatment of steel (H. J. French), Amercian Machinist,

55, pp. 907, 960. Experiments on the art ficial seasoning of gage steels (H. J. French), Chem.

and Met. Eng., 25, p. 155; 1921.

Discus.sion of paper by R. S. MacPherran on Steels at high temperatures (H.

J. French), Proc. Am. Soc. for Test. Mate., 21. p. 861 ; 1921. The effect of heat treatment upon the properties of one per cent carbon steels (H. J. French and G. W. Johnson), Tech. Paper 206. Trans. Am. Soc. for

S eel Treating, Vol. II, p. 467; 1922.

Discussion of paper by MacQuaid and Ehn on " Effect of quality of steel on

case carburiz ng results" (H. J. French and L. Jordan), Trans. Am. Inst. Min. and Met. Engineers; 1922.

Strength and elast city of boiler plate at high temperatures (H. J. French),

Chem. and Me . Eng.. 26, p. 1207; 1922.

Discussion of "The spontaneous formation of martensite from austenite " (H.

Scott), Chem. and Met. Eng., 26, p. 1154; 1922.

Mechan'cal properties of metals and alloys (R. W. Woodward), American

Machinist 55. p. 596. Note on the properties of antimonial lead (J. S. Hromatko and L. Gurevich),

Chem. and Met. Eng., 25, p. 62 ; 1921.

Nitrides and ox'des in boiler tube steels (J. S. Vanick and A. E. White), Trans.

Am. Soc. for Steel Treating, Vol. II, p. 323 ; 1922.

Some mechanical properties of hot-rolled Monel metal (P. D. Merica and R. G. Waltenberg), Proc. Am. Soc. for Test. Ma e., 21. p. 922; 1921.

Note on notched-bar impact tests and toughness of Monel metal (R. G. Waltenberg) , Chem. Met. Eng., 25, p. 322 ; Metal Industry, London, 19, p. 229 ; 1921.
242 REPORT OF DIRECTOR OF BUREAU OP STANDARDS.

Graphitization of white cast-iron below the Ai transformation (S. Epstein),

con'ribution to the discussion of " Malleableizing of white cast iron," Trans.

Am. Inst, of Min. and Met. Engineers ; February, 1922.

Contribution to discussion of " Experiments with sherardizing " (L. H, Marshall), Trans. Am. Inst, of Min. and Met En.2;ineers ; February, 1922. The Coprecipitatiou of vanadic acid with ammoniura phospliomolvbdate (J. 11. Cain and J. C. Hosteiter), Jour. Am. Chem. Soc, 43, pp. 2552-2.562; 1921.

Publications in Press.

Comparison of titanium treated and uuti"eated steel rails (G. K. Burgess and

Willard Quick).

Thermal stresses in steel wheels (G. K. Burgess and Willard Quick).

Discussion of Sir Eobert Hadfield's paper on " Corrosion of ferrous metals,"

Brit. Inst, of Civ. Eng., 1922. (G. K. Burgess.)

The structure of niar ensitic carbon steels and the changes which occur upon

tempering (H. S. Rawdon and S. Epstein), Scientific Paper.

Some observations on the corrosion of various types of clironiium steels (H. S. Rawdon and A. I. Krynitsky), Chem. and Met. Eng.

Deterioration of alloys by internal oxidation. Conti'ibution to discussion of

" The effect of impurities on the oxidation and swelling of zinc-aluminum

alloys" (H. S. Rawdon), June (1922) meeting, Institute of Metals, Am. Inst. of Min. and Met. Engineers.

Some metallographic features of aluminum-bronze. Contribution to discussion

of " Occurrence of blue constituent in high-strength manganese bronze

(H. S. Rawdon), .Tune (1922) meeting. Institute of Metals, Am. Inst, of

Min. and Met. Engineers.

Effect of grain-size in low-carbon steel on the results of impact tests. Contribution to discussion of "Effect of sulphur in rivet steel" (H. S. Rawdon),

June (1923) meeting. Am. Soc. for Test. Mate.

Contributory factors in corrosion. Contribution to discussion of " Preliminary

notes on corrosion" (H. S. Rawdon), June (1922) meeting. Am. Soc. for Test. Mate.

Copper, Circular 73 (revision) (H. S. Rawdon).

Protective metallic coatings for the rust-proofing of iron and steel, Circular 80

(revision) (H. S. Rawdon).

Invar and related nickel steels. Circular 58 (revision) (E. C. Groesbeck).

Effect of temperature, deformation, and rate of loading on the tensile properties of low-carbon steels below the thermal critical range (H. J. French),

Tech. Paper.

The decomposition of martensite into troostite in alloy steels (H. Scott), forging and heat treatment. On precision altimeter design (,T. R. Freeman and J. B. Peterson), Report No.

126 of National Advisory Committee for Aeronautics ; 1922.

Mechanical properties of chrome-vanadium steels (J. S. Vanick), Am. Soc. for

Steel Treating.

The magnetic susceptibility and iron content of tin-red-brass (L. H. Marshall

and R. L. Sanford), Tech. Paper.

The decarburization of ferrochromium by hydrogen (L. .lordan and F. B. Swindells).

The preparation of iron-carbon-manganese alloys and the effect of carbon and

manganese on the mechanical properties of steel (R. P. Neville and J. R. Cain), Scientific Paper.

Drill steel investigation ; summary of observations, Survey of April-June, 1922

(Clayton, Burnholtz, and Foley).

Drill steel investigation : Hardness and heat treatment of mine drill steel shanks (Clayton).

The physical properties of the A. S. T. M. tentative standard white metal bearing alloys (J. R. Freeman, jr.), appendix to report of Com. B-2, A. S. T. M.

Proceedings, vol. 22; 1922.
REPORT OF DIKECTOE OF BUREAU OF STANDARDS, 243

CERAMICS.

The work in connection with ceramics deals with standards of quality, methods of test, and specifications for ceramic materials and products; the study of problems relating to the preparation and utilization of ceramic materials and to the manufacture of ceramic

products; the elimination of waste by supplying definite guides to purchasers, govern- mental and private, and by obtaining and disseminating to rnanufacturers scientific in- formation of assistance in the improvement of products and in increasing the efficiency of methods. The products embraced in this work include building materials, such as brick,

hollow tile, wall tile, and architectural terra cotta; drainage materials, such as sewer

pipe and draintile; paving materials, such as paving brick and floor tiles; refractory materials required for the lining of metallurgical and other furnaces; pottery and porcelains,

including dishes, sanitary ware, electrical porcelain, and chemical porcelain; glass products, including window glass, glass containers, and optical glass; and products made by

the enameling of sheet iron or sheet steelj cast iron, and other metals.

GENERAL.

The assistance which the bureau can render to both the consumer

and producer of ceramic products has never been more appreciated

than during the past year. This has been shown both in the demands

which these interests have made on the bureau for technical help,

and the amount of time which representatives of individual corporations or of organizations have spent in conferences with representatives of the division. Two strilring examples of this are in the co- operative work under way dealing with refractories and white ware

(tableware).

In the former case a strong demand was made both by the public

and certain Government departments for a more discriminating

set of specifications for refractories for various uses. A rather too

marked attitude of indiiference on the part of both the con- suming and producing interests and a lack of interest in and

appreciation of the problems of each other was quickly removed

at the first joint conference of all concerned. A Yevy comprehensive investigative outline was prepared which is now being carried

out by the bureau with the hearty cooperation of all interested.

The National Government and the various State and large municipal governments are larger consumers of tableware than is

generally appreciated. That they should have presented to the

bureau the need of specifications for the purchase of this ware

should not be surprising. They have been accustomed to make

purchases on the sole requirement of equalit}^ to a certain brand

or make or that the ware should be " fully vitrified." This latter

request, while fully justified, on account of the need of a nonabsorptive dish in the various municipal or other Government hosgitals and institutions, does not in itself secure the end in view,

imple as the term may seem, it does not serve to define the amount

of absorption desired or allowable. Also this is but one of the

properties which such a product should have; equal important are the resistance to breaking, or chipping, or crazing, or

cutlery making. These features have been considered of but

secondary importance by the manufacturer when compared with

the general appearance and the cost of production of the ware as

affected by different raw materials or procedures in manufacture.

When the importance of these factors was recognized at conferences, a very broad investigation was outlined, in the carrying out

of which a representative of the bureau visited all the plants making

" vitrified " tableware and prepared special test pieces at all but

two plants. These specimens will later be tested at the bureau.
244 BEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

Preliminary work done at the bureau on finished ware has shown

that on the average domestic ware of this type is superior in these

points to imported ware. Such problems as the above, dealing with the properties of finished ware, immediately bring to the attention of the manufacturer the question of the quality and effect of the raw materials

on their products. With the example before them of the methods

of investigating the finished product used by the bureau and

having seen the equipment available for such lines of work, they

have brought many of their individual manufacturing problems

and difficulties to the bureau for solution.

The two examples cited above are both typical of the work which

is being done for the other branches of ceramics, as : The enameled

ware industry; the glass industry (particularly glass containers

and sheet glass) ; hollow tile, architectural terra cotta, and heavy

clay products industries.

CLAY PRODUCTS.

Development of Methods of Tests and Specifications for Vitrified

China and Semiporcelain Tableware.

Several departments of the Government which are large purchasers of tableware, as well as large private purchasers, have felt the

need of adequate tests to enable them to distinguish between different

makes of chinaware which, while similar in appearance, differed

widely in cost, the claim being made that the higher priced wares

were superior in qualities essential to satisfactory service. In order

to satisfy the needs of these purchasers and at the same time place

the purchase of chinaware on a basis more satisfactory to those

manufacturers who are producing, or preparing to produce, goods

of high quality, the bureau has undertaken the development of tests for the most essential qualities. These are : Freedom from tendency to craze, resistance to acids and alkalies, nonabsorbent quality

of body, and resistance to mechanical injury. As the result of a large

amount of experimental work, methods of test, applicable particularly to hotel china, have been developed for absorption, resistance

to breakage, to chipping and crazing. A series of chemical tests demonstrated the fact that none of the hotel china now on the

market in this country is affected by such acids and alkalies as are

likely to be encountered in actual service, and consequently no method

for chemical test has been adopted. Attempts to develop a satisfactory test for ability to withstand the abrasion of table cutlery and

other wear incident to washing and handling have not been successful, and this test will require further work as it is important.

The tests so far adopted have been applied to 35 brands of ware, part

of which were of foreign make. American manufacturers cooperated

heartily in the work by supplying samples for test. The results of

these tests, which have been published, show that American-made

hotel china is superior to the best imported brands in several respects,

particularly in resistance to breakage and chipping and to sudden

temperature changes.

The United States Potters Association and the American Vitrified

China Manufacturers Association are cooperating with the bureau in

1 1 ir
BEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 245

the work of preparing specifications to be based on the information

obtained and to be obtained by additional studies that have been

outlined.

Physical Properties of Hotel China Bodies.

This is one of the additional studies referred to above in connection

with the work on specifications. One of the factors which complicate

the situation and on which it is necessary to obtain definite, quantitative information is the effect of the differences in heat treatment

secured in different parts of the commercial pottery kiln on wares of

different body compositions. Test pieces have now been made up in

11 of the American factories producing vitrified china, and these are being fired in different portions of the kilns; in order that these

pieces might all be made up in the same way and be fully comparable a representative of the bureau visited the various factories

and personally prepared the test pieces. They will be shipped to the

bureau, where a systematic comparison of their properties will be

made and the results made available to the manufacturers cooperating

in the work.

Effect of Thickness of Plates on Resistance to Impact.

This is another problem which has arisen in connection with the

work on specifications and which has been taken up in cooperation

with the manufacturers. Producers are making plates of various

types in several different thicknesses and sending them to the bureau

to be tested for resistance to breakage by impact. It is hoped that it will be possible from the data obtained in this study to establish

relations between thickness of plates and resistance to impact and to

determine approximately what thicknesses are most advantageous,

particularly in plates.

Properties of Foreign and Domestic Ball Clays.

The question of ball clays is one which has given potters and other

manufacturers of white ceramic products a great deal of trouble.

This is due to the fact that ball clays from different sources vary

to an important extent in their essential properties and that there

has been no complete information as to the properties of the various

clays. In changing from one claj^ to another, the potter was likely,

in secui'ing proper working properties in his body, to encounter bad

firing qualities and to suffer such losses as tended to discourage all

changes that could be avoided. This has had the effect of retarding

the adoption of the American ball clays and at the present time the

English clays are used in much greater quantities by American manufacturers than are the domestic materials, although large deposits

of the latter are available.

A comprehensive investigation of all the American and English

clays in use in the manufacture of china, earthenware, electrical

porcelain, sanitary Avare, and floor and wall tile has been completed

and is now ready for publication. Among the properties studied

were water of plasticity and drying shrinkage relations, strength in

the plastic condition, strength when dried, viscosity of slips of the

clays, oxidation behavior, volume and porosity changes in firing over a wide range of temperatures, and color in a standard body.
246 REPORT OF DIRECTOR OF BUREAU OF STANDARDS,

It has been found that while the English clays have a greater strength

in the dried state, and a more desirable behavior in firing, the American clays contain less coarse mineral matter and carbonaceous material, and fire in general to a better color. The data obtained in

this work Mall serve as a guide to the manufacturer in making

changes in the ball-clay content of his ware and will thus facilitate

the greater use of domestic clays than heretofore.

Comparison of Foreign and Domestic Clays as Fillers for Paper.

A large tonnage of high-grade clays is used in the United States

as fillers for various grades of paper, particularly in the line of

book papers. A very large part of this material is imported, due

to the fact that the domestic clays that are available are not con- sidered as satisfactory as the foreign grades. With a view to obtaining definite information as to what properties of clays detei'mine

their suitability for this purpose an investigation consisting of a combination of laboratory studies and factory experiments is being

carried out. Samples of 18 foreign and 22 domestic clays were obtained and these have been tested for grit, color, and plasticity.

Eight of the 40 clays were selected to be tried out in actual factory

production in order to establish the relations between their physical

properties and their suitability for commercial use. On these eight

clays the following physical properties were determined: (1) Volume

shrinkage, (2) slaking behavior, (3) transverse strength of clay in

dry state, (4) ratio of pore water to shrinkage water, (5) viscosity

water relations after treatment with various percentages of sodium

hydroxide and alum, (6) fineness as indicated by rate of settling in

water, (7) fineness as determined by elutriation, (8) specific gravity,

(9) gi'it content, and (10) plasticity. The phj'sical testing has been

completed; the mill runs are still in progress.

In this connection, aclcnowledgment should be made of the hearty

cooperation accorded the bureau by paper manufacturers, not only

in carrying out in the mill operations which necessarily interfere

with normal production, but also in contributing liberally of their

time and the information at their disposal.

Clays for Coating Paper.

The situation in regard to coating clays is similar to the filler

clay situation, most of the material being imported although domestic clays for the purpose are on the market. An investigation

is accordingly being made for the purpose of obtaining information

which will serve as a guide to paper manufacturers in the purchase

of coating clays and if possible promote the more general use of

the domestic clays.

The usefulness of a clay for this purpose depends on: (1) Color,

(2) freedom from grit, and (3) fluidity of the clay slip when mixed

with a sizing material. This last property is very necessary and

different clays differ greatly in their behavior in this respect. Considerable work has been done in an attempt to connect this essential

property, or t&ndency of clay suitable for coating paper with some

readily measurable property or properties of clays. The Bingham

plastometer has been used in connection with this work and some

promising results have been obtained. The work is still in progress.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 247

Plasticity of Clays.

One of the most essential properties of clays and the one which

makes it possible to form a wide variety of commercial articles from

them by practical methods is plasticity. While this is a property

common to almost all useful clays, it is one which is difficult to define and still more difficult to measure. Because of the need for a better understanding of plasticity and of means for determining it

quantitatively, so that this property may be included in practical

commercial specifications for clays for specific uses and that it may

be studied more intelligently in relation to other characteristics, a study is being made of various methods that have been proposed

for measuring it. During the year an experimental study has been

made of the results that may be obtained by the use of the Bingham

plastometer. By virtue of the principles involved in the operation

of this instrument it resolves the property plasticity into two components—yield value and mobility. The work with the plastic flow

of clay slips has shown that these slips do not behave like plastic

substances that have previously been investigated. The equation

for reducing the two components, yield value and mobility, to values

independent of the capillary does not apply to the flow of clay slips

through capillary tubes. It has not so far been possible to formulate

equations reducing these components to absolute values independent

of the capillary, but by using the same capillary with different slips

it is probable that approximate comparisons of the values for different clays may be made.

Cooperative Investigation of Water Smoking and Dehydration of

Clays,

This work is being done in cooperation with a group of manufacturers' organizations, including the American Face Brick Association,

Hollow Building Tile Association, Common Brick Manufacturers'

Association of America, and National Paving Brick Manufacturers'

Association. Both the water smoking and the dehydration of clays are processes which have long been recognized as marking essential

stages in the burning of clay products, but definite information as

to the temperature limits within which each takes place, the rates

at which the water is eliminated at different temperatures, and the

safe rate of heating, at different stages for different types of clay,

has been meager. The rapid development in new types of kilns

for the burning of heavy clay products that is now in progress and

in prospect adds greatly to the present importance of such information because some of the most vital problems involved in the design

and operation of continuous kilns are those connected with these

stages of the burning.

The method adopted for obtaining quantitative data in this investigation has been to make up samples of the various clays to be

studied in the form of 4-inch cubes and to pass these through the

initial stages of burning at different rates in a special electric fur- nace which is so constructed that the loss in weight taking place in

the specimen can be observed continuously. The furnace is equipped

for testing two cubes at once. The cubes are prepared with small

holes running through them at different depths, so that by means of

thermocouples in tubes extending through these holes the tempera-
248 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

tures at different points in the interior of the pieces can be determined.

The data obtained up to this time indicate that important progress can be made in the reduction of time necessary for burning

and in fuel economy. One of the points that has been brought out is that with many clays the safe rate at which the material can be taken

through the dehydration period depends on the rate at which the

oxidation can be accomplished. Provision is being made for determining, separately, the loss of weight by dehydration and that by

oxidation at different temperatures.

GLASS.

Specifications for Glass Products.

1. Tumblers.—The attention of the bureau was first directed to the

matter of specifications for tumblers by a* complaint from a manufacturer in regard to the specifications of one of the Government

departments. As a result of inquiry into this matter for the manufacturer, it was learned that the department concerned would welcome an effort, on the part of the bureau, to prepare specifications

for fflass tumblers which would secure the character of tumbler

required by the service for which it was intended and at the same

time admit as many bidders as possible to competition for the business. Tlie matter was taken up in a systematic wav and simple but

reliable tests by which the quality of tumblers could be determined

were developed. Specifications for lime-flint glass tumblers were

then written and these have been adopted by the War and Navy Departments, the Public Health Service, and the General Supply Committee. Som'^ of the producers have also adopted the tests in^^luded

in these specifications as routine factory tests. It has been reported

by one of the departments of the Government that satisfactory tumblers have been secured by the use of these specifications, at a much

lower price than previously.

2. Glass tablenmre and containers.—Methods of test for these products are being developed along the same general lines as those that

have been adopted for tumblers. Some of these are now in use as factorv control tests.

3. Window and plate glass.—Not only the Government departments but also architects and jobbers feel the need of specifications

which will make it possible to identify the various grades of window

glass and plate glass when they are delivered. The production of

these wares in the United States is on a high plane, and the factory

grading, done bA^ skilled men, is generally accurate and satisfactory.

However, due to the lack of suitable specifications, it is extremely

difficult for the builder to tell with certainty whether he has received

the grade ordered or a lower and cheaper grade. This gives opportunity for unfair practice on the pai't of the unscrupulous dealer,

with possibilities of unnecessary expense to the purchaser and loss

of business on the part of the high-class distributer. A representative advisory committee has been organized to cooperate with the

bureau in undertaking to prepare specifications which will place the

pizrchase of this line of materials on a more satisfactory basis. This

committte is made up of representatives of the glass manufacturers,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 249

the American Institute of Architects, the National Glass Distributers

Association, the Wholesale Sash and Door Association, and interested

Government departments. Four conferences have been held and considerable work on classification and definitions and tentative specifications has been done. It can be said with assurance that understandings already arrived at will go far toward eliminating the most

serious cause of confusion and trouble in the window-glass business.

Standardization of Milk Bottles.

The lack of uniformity of State and municipal laws in regard

to the marking and the capacity of milk bottles imposes a serious

hardship on manufacturers on account of the large variety of sizes,

j shapes, and identification marks required. The additional equipment, additional stocks, and added production cost result in the

end in a tax on the consumer. The bureau has undertaken to co- operate in the matter of obtaining relief from this condition. The

needs of the milk-bottle manufacturers were brought to the attention of the annual Weights and Measures Conference, which was

held at the Bureau of Standards in April, and resolutions favorable

' to the request for action made hy the milk-bottle manufacturers

were passed by the conference. Later a conference of bottle manufacturers, dairy supply dealers, milk dealers, and food inspectors

was held and an organization for proceeding with the work of se- curing the standardization of laws regarding milk bottles, and of

j various essential details of milk bottles themselves, was effected.

i

i Specifications for Lime for Glass Making.

A study of the requirements for lime for glass-making purposes

has been made and specifications for lime for such purposes have

been prepared. These have been adopted by the Interdepartmental

Conference on Chemical Lime, which is made up of representatives

: of various interested Government departments. The specifications

have been issued as Circular 11, and the demand for them has necessitated the printing of a second edition within the year.

Strength of Window Glass.

As a part of the studies preliminary to the preparation of specifications for these materials more than 5,000 samples of plate glass

and window glass have been tested for transverse strength and rei sistance to impact in order to obtain data on the strength of a wide

11 variety of tj^pes.

Study of Disintegration of Glass in Water.

The deterioration of glass containers which are repeatedly subjected to treatment in hot water, especially in the process of sterilization, has become a matter of importance because of the tremendous

, increase in the use of such articles, and a study has been made of

' the causes of such deterioration and of differences in the ability

j of containers of different compositions to resist it. A part of this

work consists in the development of methods of test to determine

the suitability of glass containers for various purposes. The exI perimental study of the relation between composition of glass and
250 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

solubility in water is nearing completion, as is the development of

a standard methcd for determinino- the alkaline solubility of glass.

Ampoule Glass.

In response to inquiries as to the necessary qualities of glass for

use in special containers for packing vaccines and intravenous solutions a study of this problem has been made and recommendations

submitted.

Glass Containers' Association Fellowship.

The above association of glass manufacturers, food packers, and

associated industries now maintains a fellowship at the bureau for

I'esearch on problems relating to the glass industry. The chief

problem now being investigated is " the scumming of bottles," a rather important and troublesome defect which develops while the

empt}^ article is in storage and causes considerable loss. This

trouble develops more extensively in himiid climates, such as exist

in parts of South America, and methods of prevention would be

very valuable in developing South American trade. A progress

report on this work has been written and circulated among the manufacturers of glass, in which is given a simple method for removing

this defect from bottles by a washing process. This method, heretofore regarded as impracticable, is proving of considerable practical value.

Optical Glass.

This work consists of investigations relating to (1) the making of

optical glass; (2) the molding of opt cal shapes, such as blanks for

prisms, lenses, and optical flats; (3) the annealing of optical glass;

(4) the testing of optical glass; and (5) the development and improvement of specifications for (a) materials from which optical

glass is made, and (h) for finished optical glass.

Melting.—During the past year 27 experimental melts of various

kinds of optical glass were made. These melts gave approximately

29,000 pounds of glass as follows

Pounds.

Boro-silicate crown (Nd=l. 52) 15,500

Light barium crown (Nd=l. 57) 2,300

Dense barium crown (Nd=l. 60) 1, 500

Medium flint (Nd=l. 62 ) 6, 750

Dense flint (Nd=l. 65) 3,000

Molding.—The technique of molding blanks for optical purposes

has been decidedly improved. Blanks ranging in weight from a few

grams to 1,500 grams are now made quite readily by the "sticking

up " process, while slabs about 20 by 30 by 10 cm are easily made by

melting large pieces of glass in clay boxes.

Annealing.—In nearly all cases strains affecting the optical properties of glass or inducing breakage in it can be removed by proper

annealing. This is a process of heating the glass to suffic'ent temperature and holding it there for a certain time, after which it is cooled

slowly. To outline the technique of the best annealing procedure

involves the study of many of the properties of glass. Certain problems involved stfQ being investigated by this section in cooperation

with the optics and heat divisions.
KEPOKT OF DIEECTOE OF BUREAU OF STANDARDS. 251

The electric furnace for annealing optical glass, which, was completed early this year, has given very satisfactory results. A system for the automatic control of the temperature of this furnace is being developed in order to insure satisfactory annealing in the

shortest time possible; this is difficult to accomplish without such

control.

Thermal Properties of Glass.

The problem of producing glass free from strain is of major importance in the commercial production of this material but the available

scientific knowledge in this field has long been extremely meager. In

the production of optical glass for scientific purposes the elimination

of strain as far as possible is indispensable. In the temperature region

where glass becomes practically rigid there is, on cooling, an excessive

evolution of heat while on heating through this same region there is an abnormal absorption of heat. Through the investigation of these

phenomena it has been found that rapidly cooling the glass from a high temperature appears to suppress some molecular transformation which normally takes place. Reheating the glass and annealing

it appears to allow the suppressed transformation to proceed, thereby

liberating heat to a degree depending on the temperature and an- nealing time. New data have been collected on this phase of thf

problem in order to determine the significance of these phenomena

and their relation to the general problem of glass annealing.

Hardened Glass.

The resistance of glass to mechanical shock can be increased many

times by hardening processes. These processes are practically the

opposite of those followed in annealing, the object in annealing being

to eliminate as far as possible all strain, while in hardening certain

strains properly distributed must be introduced. Glass so hardened

is very valuable in the production of protective goggles and other

glass which are subjected to extreme shocks. During the year a quantity of glass has been hardened under as wide a variety of procedure as possible. The relative resistance of the various samples has

been measured with the object of determining the effect of the variation in the molecular transformation due to various heat treatments.

It is expected that the above procedure will lead to an improved

process of hardening.

Cooperation vsrith the Navy Department.

One of the fundamental purposes of the work on optical glass is to assure a domestic source of optical glass for scientific and military

purposes. The experimental melts of glass often yield considerable

quantities of first-quality glass. By special arrangement this glass

is molded into optical shapes and delivered to the Navy Department

for use in the construction and repair of various optical instruments

used in naval service, and performance of such glass is then investigated. This arrangement gives ample opportunity to study the

effect of various conditions and defects, such as strain, striso, etc., on

optical performance under actual service conditions. The information thus obtained should eventually become a satisfactory basis for

definite specifications for optical glass.
252 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

During the past year this bureau has delivered to the naval optical shoj) glass as follows:

Pounds.

Meclium flint lens blanks 124. 23

Light barium crown lens blanks 378. 5

Boro-sil cate crown prism blanks 1,021. 5 Boro-silicate crown slabs, etc 1, 122. 75

Total 2, 647. GO

In addition to the above, the requirements for optical glass used in

research work of this bureau have been supplied.

Burning Glass Pots and Stirring Rods.

A decided improvement in the quality of glass pots has been ob- ' tained by heating the pots very slowly up to 300° C. and then burning

them to a temperature at which they begin to soften (about 1,425° C.)

which is about 50° higher than the bureau's previous practice. It

should also be noted that the pots are completely burned in pot arches

instead of a iDreliminary burn in arches with a final burn in the melting furnace, as is ordinary practice in optical-glass plants.

The slow initial heating and the higher final burning in the pot

arch produce pots that are relatively free from cracks and are more

resistant to the corrosive action of melted glass.

A decided economy in gas has been effected by burning the stirring

rods with the pots instead of in a separate furnace, as is ordinary

practice.

Inspection.

The detection of striae in irregular pieces of glass and molded blanks

hy the immersion method has been found to be greatly influenced by

the intensity of the light used. Fine striae are invisible in strong light,

but become visible when the intensity is reduced.

Chemical.

A study of the relations between composition and optical properties of optical glass is in progress. The information available as

to these relations is incomplete and the purpose of this work is

to supplement that which has already been obtained by various

investigators.

REFRACTORIES.

Specifications for Refractories.

In connection with the work of the Federal Specifications Board,

a conference was held at the Bureau of Standards at which those

departments of the Federal Government which are large purchasers

of refractories were represented. It was brought out at this conference that different departments employ different methods in the

purchase of refractories and that the matter could be placed on a

better basis if specifications which would be satisfactory to all departments could be established for use in the purchase of refractories

for varioiis purposes. The action of the conference took the form

of a request to the Bureau of Standards to prepare such a set of

specifications.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 253

Realizing, to some extent, the magnitude of this undertaking, the

bureau brought about the formation of an advisory committee on

which are represented the commercial organizations and technical

societies most interested in refractories. Two conferences of this

advisory committee have been held at the bureau. At the first, the

entire question of tests for refractoiies was considered, all of the

tests that have attained any recognized status being discussed. In

the second conference, an attempt was made to prepare tentative

specifications for fire brick for the linings of the furnaces of stokerfired boilers. Test requirements for fire-clay brick for this purpose

and for the fire cement to be used with them were written but because

of a lack of assurance that they would be effective in drawing a

definite line between suitable and unsuitable fire brick it has been

considered necessary to carry out an extended investigation in which

a systematic comparison of test results with service records of a large number of brands of fire brick should be made. One of the

members of the advisory committee has undertaken to secure service

records from varioiis sources as well as samples of the brands of

brick on which these reports are obtained. These records and samples

are being obtained from all the important industrial districts of the

United States. The samples are to be subjected not only to the tests

in the new tentative specifications, but to other recognized tests for

refractories, including (I) 72-hour reheating at 1,450° C, (a) on end

without load, (b) supported at ends and loaded for bending; (II)

quen-hing tests, (a) after reheating five hours at 1,400° C.—(1)

quenching from 1,350° C, (2) quenching from 1,100° C., (3) quenching from 850° C, (&) after T2-hour reheating at 1,450° C. ; (III) load

test, (a) standard load test, (&) standard load test except maximum

temperature held longer than in present test, (<?) ball impression

test; and (IV) softening-point test. It is possible that a test method

may be developed which will give essential information that is not

obtained by any of the present tests. An unusual feature of this investigation is that the samples for

test are being obtained from the user instead of from the producer.

The advantage of testing samples taken from shipments is obvious,

and the fact that a considerable number of consumers (practically

all of those who have been asked to cooperate) are willing to go to

the trouble and expense necessary to ship, charges prepaid, 40 bricks

of each brand asked for seems to be indicative of an interest in this

undertaking.

The testing is now under way and will extend over a period of

several months.

Glass Pots for Use in Experimental Optical Glass Making.

Glass pots large enough to contain approximately 1,000 pounds

of optical glass are made in the laboratory by the casting process

developed by the bureau. While the primary purpose of this work

is to supply pots to the glass plant, it affords an opportunity to do

full-scale experimenting in the study of glass-pot bodies. During

the year 25 pots have been made. Trial was made of the substitution of grog made from kaolin and ball clay for the pottery bisque

that has ordinarily been used and of other modifications of the body

composition that were made as the result of indications obtained
254 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

from a small-scale investigation. The introduction of gallic acid

as a deflocculating agent was tried out in 10 of these pots, this material being substituted for a part of the sodium silicate in varying

proportions, from 1 part acid to 9 parts silicate, to 5 parts acid to 5

parts silicate. It was found that the use of 1 part of gallic acid

to 8 parts of sodium silicate assisted materially in producing a

slip of good working or flowing qualities. The pot cast from this

slip attained the rigidity necessary for safe handling in an unusually

short time.

Resistance of Glass Pots to Corrosion.

While important work has already been done, in this bureau and

elsewhere, in the study of relations existing between body composition and resistance to the attack of corrosive glasses at high temperatures, our knowledge as to these relations is still incomplete, so that

it is not possible to say with assurance what is the best silicaalumina ratio for pots for use in making, for example, dense barium

crown optical glass. Since this is an important matter, not only in

connection with the manufacture of optical glass but also in its

bearing on the best compositions for other glass refractories, a some- what comprehensive investigation has been undertaken in which a wide range of variations of kaolin, ball clay, flint, and feldspar is to

be covered. To date 216 experimental pots of about 25 cubic inches

capacity have been made and burned. These and others of other

compositions are to be subjected to the action of corrosive glass at

high temperatures. It is the intention to select promising compositions for trial in full-size glass pots in the optical glass plant.

TERRA COTTA.

Cooperative Investigation of Problems Relating to Architectural

Terra Cotta.

This work, which is carried on in cooperation with the National

Terra Cotta Society, has included during the past year extended work

on the actual freezing of burned samples of terra-cotta bodies made

by the different manufacturers. Small bars were first used in the

freezing tests and after observing the results of these freezings

pieces 4 by 4 by 1 inch were subjected to this test for comparison.

A study has been made of the types of pore systems of a series of

bodies made from materials of widely different types with a view to

classifying terra-cotta bodies on a basis of the nature of their pore

systems and to determining relations between the type of pore system

and other physical properties of the body. In the work done so far

the rates of absorption of a series of synthetic bodies have been compared with the total absorption and the transverse strength.

A short laboratory study has been made of the effect of rate of

cooling of terra-cotta pieces on their tendency to develop cracks or other defects after being removed from the kiln. Three-inch cubes

made from bodies of five different types were cooled at widely different rates and afterwards quenched in running water to obtain indications as to the resultant states of strain. The results obtained, while

interesting, can not be definitely interpreted in terms of the factory

cooling of large commercial pieces of terra cotta. Future work will
REPORT OF DIRECTOR OE BUREAU OF STANDARDS, 255

be in the form of an investigation to be made partly in the factories

and partly in the laboratories of the bureau.

ENAMELED METALS.

Wet-Process Enamels for Cast Iron.

While enamels of this type have been applied on cast-iron kitchen

utensils for many years,' the literature on the subject is very limited

and indefinite. There has been a great demand in the past few years

for wet-process enamels for cast-iron stove parts, as dry-process

enameling is not especially adapted to the many sizes and ty^^es of

castings used, and repeated requests have come to the bureau from

manufacturers for information on the compositions and application

of this type of enamel.

The bureau has therefore conducted an extended investigation of

this subject and has developed some very satisfactory compositions

and has secured information on the limits of composition and te ;hnic

in the preparation and application of the enamels. White and colored

enamels requiring a ground coat and those used without a ground

have been developed. The laboratorj^ results have been checked in one of the large enameling plants, and several of the compositions

suggested by the bureau are now being successfully used in a number of enameling plants throughout the country.

A preliminary report of this work will appear in a forthcoming

number of the Journal of the American Ceramic Society, and the

final report is being compiled for publication as a technologic paper.

Fish Scaling of Enamels on Sheet Iron and Steel.

The defect known as "fish scaling" is the spontaneous chipping

of minute portions of the enamel from the surface of the ware. The

fractures are usually in the shape of a half moon and can thus be

dilferentiated from those caused by impact. This defect has been

one of the most costly and probabty the most elusive one encountered

by the enameled-metal-ware industry. An extended investigation

has shown that the defect is due primarily to the flifference in contraction of the enamel and the metal to which it is applied, and

that it can be eliminated by the development of enamels which have

a coefficient of expansion more closely approximating that of steel

and iron than is true of the usual commercial enamels.

It has been shown that the surface condition of the metal is an

important secondary factor in the reduction of fish scaling and that

mechanical treatment of the steel is effective in preventing the development of the defect. This explains the tendency of the un- worked portions of an enameled vessel to fish scale, while the " spun " (curved) portions almost invariably are free from the defect.

In order to check the laboratory results on this phase of the

bureau's findings, the cooperation of both sheet-steel producers and

enamel-ware manufactures has been enlisted. Several tons of enameling steel which has been given two and three passes through the

cold rolls have been especially prepared by one of the steel companies. This stock has been fabricated and enameled under factory

conditions by several manufacturers of kitchen ware. While the

general results indicate that this treatment was beneficial, further

9644—22 18
256 REPORT OF DIRECTOR OF BUREAU OF STANDARDS,

extended experimentation must be done before definite conclusions can be drawn as to the commercial value of this method of preparing

enameling stock.

The question has been raised as to whether cold rolling, while

eliminating the tendency to fish scale, might introduce new diffi- culties, such as the tendency of the enamel to flake from the steel over large areas. Tests of some of the ware manufactured from the

cold-pass steel has shown, however, that the adherence of the enamel

to this stock is equal to and in some cases superior to that of the

same enamel applied to ware made from enameling stock prepared

by the usual methods.

It is of interest to note that recent work of enamel investigators

has confirmed the bureau's original conclusions in regard to the

causes and control of fish scaling. A cooperative investigation of

enamels for sheet steel now being conducted in this laboratory is also givina: further definite information as to the direct I'elation

between fish scaling and the relative contraction of the enamels and

the steel base.

A preliminary report of this investigation has appeared in the

Journal of the American Ceramic Society (vol. 4, No. 8), and the

final report is now being compiled for publication as a technologic

paper by this bureau.

Specifications, for Enameled Kitchen Ware.

The subject of specifications for enameled kitchen ware is of importance to the departments of the Government and to private parties interested in the purchase of enameled kitchen ware as well

as to the manufacturers in attaining and maintaining high standards of their product.

Through the cooperation of the Sheet Metal Ware Association

the bureau has had the opportunity of testing some 20 different

brands of kitchen ware, as well as some foreign ware which was

obtained through jobbers and dealers. Standard tests have been

developed in this investigation for the resistance to impact, to

thermal shock, and to dilute acids. It was found that American

ware was equal and in some cases superior to that of foreign

manufacture.

Tentative specifications based on these tests have been prepared

and submitted to a conference of the manufacturers' association held

at this bureau and at New York, N. Y. A representative has also

conferred with the technical committee of the Sheet Metal Ware

Association and revised tentative specifications have received their

approval and have been referred to the association for their action.

Relation of Composition and Properties of Sheet-Steel Enamels.

This investigation is being conducted in cooperation with a manufacturer of enameled kitchen ware to determine tlie relation of composition of the enamels to resistance to impact, to thermal shock, and

to acids. While this work has only been under way a short time,

some very interesting information has been obtained on the relation

between the fit of the enamel to the steel base and resistance to impact and thermal shock. The relative contraction of the several coats

of enamel applied to the steel also appears to be very important. The
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 257

preliminar}^ results indicate that, as the investigation proceeds, information of impoitance to the manufacturers of sheet steel enameled

ware will be obtained.

Cooperative Investigations.

The enamel division of the American Ceramic Society is cooperating with the bureau in a study of suitable iron for enameled castiron ware. Samples of commercial irons will be obtained from representative plants and tested at this bureau for chemical composition,

physical and enameling properties.

Similar cooperative Avork is being conducted with the same organization in an investigation of the warpage of sheet iron and steel in

the enameling process. This organization has also cooperated in the

investigation of fish scaling of enamels on sheet steel.

^ TESTING AND INFORMATION.

A significant indication as to the progress of the work of the division of ceramics is to be found in the increase in the scope of the

testing that has been done for other Government departments and

for outside parties. In previous years, a very large part of the test- ing has been on fire brick. During the past year the testing of re- fractories has continued but since methods of test have been developed for vitreous china tableware and for glass tumblers and glass

containers, there have been calls for tests of dishes and glassware

that show not only an interest in the differences in quality in these

wares, but a need for practical test requirements covering them. It

is also significant that the first calls for tests have come from the

manufacturers themselves. Even before test methods have been

fully developed for a given product, manufacturers have sent in

samples of their standard product and also samples made up from

other bodies with which they had been experimenting in order to

obtain comparisons. In one case the bureau was able to determine

for a manufacturer that a new body which had been developed and

which was about to be adopted for quantity production made a product inferior to the one in regular use. Manufacturers of glass

products have shown a constructive interest in the work. Some of

the tests made indicate that glassware of very inferior quality, in

point of resistance to the effects of boiling and sterilization, has been

made unnecessarily simply because of the lack of practical tests by

which to measure this quality. The manufacturer could have produced high quality ware without increase in cost if he had known

what composition to adopt to get the best results.

Next to the manufacturers themselves, and in some cases preceding them, the Government departments using these wares have

called for tests to secure information for guidance in the placing

of contracts in order to determine which articles possessed the

qualities necessitated by their specific conditions and to avoid the

possibility of paying a premium for imaginary superiority. This

applies particularly to the purchase of hotel china ; tests for quality

have been needed to do away with the old but somewhat persistent belief that chinaware made in Europe must necessarily be

superior to that made in the United States.
258 REPORT OF DIEECTOR OF BUREAU OF STANDARDS.

Numerous samples of matei'ial have been received from individuals in various parts of the United States with requests that

these samples be analyzed and tested in other ways to determine

whether they are suitable for the manufacture of certain products.

In some cases these parties need the services of a consulting en- gineer to investigate not only the material but also the property

in question, but in most instances little more than a casual examination is needed to determine that the material is not of such a character that it could be marketed profitably. In svich cases the

bureau is able to give information which unquestionably avoids

unnecessary expenditures for tests; in some instances it is apparent

that materials are worthy of thorough investigation and the bu- reau is able to direct the interested parties to competent and re- liable persons or firms who are in a position to do the work in a commercial way.

As a result of the work on specifications there has been an unusually large number of inquiries during the past year for information regarding proper test requirements for materials for various purposes. The requests for specifications for refractories have

been particularly numerous, and in several cases the bureau has

been asked by users of refractories for advice in regard to specifications for their use in purchasing and in testing materials delivered. Similar requests have been received from large purchasers

of tableware. The bureau's own work along these lines has progressed to such an extent that in all cases information has been given

which would keep those consulting the bureau from working along

unpromising lines and possibly adopting undesirable specifications.

Cooperation vi^ith Technical Societies,

A number of the senior members of the staff of the division have

continued to do important work as members and officers of committees of technical societies. However, the most essential committee work in which the division is taking part is that done by

the committees which have been formed to assist the bureau in the

work of establishing standards and specifications. The usual order

is reversed and the technical societies are finding representation on

the bureau's committees instead of members of the bureau's staff

working on outside committees whose lines of activity are not

directly controlled by the bureau. The following technical societies

and commercial organizations are cooperating with the bureau in one

way and another, some in investigative work on specific problems but

the majority in committee work on the broader problems of standardization and establishment of specifications: American Institute

of Architects, American Society for Testing Materials, American

Society of Mechanical Engineers, American Ceramic Society, American Iron and Steel Institute, American Electric Light Association,

National Terra Cotta Society, United States Potters Association,

American Vitrified China Manufacturers Association, Hollow Building Tile Association, Refractories Manufacturers Association, American Face Brick Manufacturers Association, Common Brick Manuiacturers Association of America^ National Paving Brick Manufacturers Association, Wall Tile Manufacturers Association, American Stokers Association, National Glass Distributors Association,

TTTT
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 259

Wliolesale Sash and Door Association, and Sheet Metal Ware Association.

Special acknowledgement should be made of the cooperation that

is being received, in the work referred to above, by other Government departments whose representatives participate in the bureau's

conferences.

Publications.

During the year the following reports of work done in the division have been published

:

Technologic Paper No. 190, High fire porcelain glazes (H. H. Sortwell).

Kote on the hardness of glazes (G. Blumenthal, jr.), Jour. Am. Cer. Soc, 4, No. 11, p. 896. Earthenware bodies and glazes (H. H. Sortwell), Jour. Am. Cer. Soc, 4, No.

12, p. 990. The properties of some ball clays (H. H. Sortwell), The Ceramist, 2, No. 1, p. 5. Comparative tests of American and foreign tableware (H. H, Sortwell), Jour. Am. Cer. Soc, 5, No. 6, p. 276. Plasticity of clays (F. P. Hall), Jour. Am. Cer. Soc, 5. No. 6, p. 346. Causes and prevention of scumming (Arthur E. Williams and K. L. Ford),

printed and distributed by Glass Containers' Association to manufacturers.

Specifications and standard methods of testing glass (Arthur E. Williams),

The Glass Industry, March, 1922.

The disintegration of soda lime glasses in water (Arthur E. Williams) (at

the printers to appear in Jour. Am. Cer. Soc, August, 1922).

Recommended specification for limestone, quicklime and hydrated lime for

glass making, Circular No. 118. Specifications for lime flint glass tumblers. Circular No. 119. Refractories for the steel plant, (W. A. Hull), Year Book of American Iron

and Steel Institute (1922), p. 470. Causes and control of fish scaling of enamels for sheet iron and steel. (R. R,

Danielson and W. H. Souder), Jour. Am. Cer. Soc, 4, No. 8, p. 620. Production of some white enamels for copper, (R. R. Danielson and H. P. Reinecker), Jour. Am. Cer. Soc, 4, No. 10, p. 827.

Some relations of composition to solubility of enamels in acids (H. F. Staley), Jour. Am. Cer. Soc, 4, No. 9, p. 703. BUILDING AND HOUSING.

The work of this division includes the collection and dissemination of scientific, practical, statistical, and other information tending to encourage, cheapen, and improve construction and housing. It covers investigations for use in framing local building and

plumbing codes, and a study of problems connected with city zoning. Information on the

prices, production, consumption, and stocks of building materials, and on building activity

is collected, analyzed, and distributed. Examinations are made of some special aspects

of the housing problem. The work includes studies in building practice, and cooperation

with the efforts to eliminate waste which are being made by different parts of the con- struction industry.

GENERAL.

Scope of the Work on Building and Housing.

The construction industry is one of the largest and most important to the people of the United States, and it is a function of the

division of building and housing to study the needs of the industry

and their relation to the public welfare. It endeavors to see that

these needs are met, partly through its own efforts, and by enlisting

the aid of other branches of the Federal Government whose work

can be of constructive value, and partly by presenting its conclusions

to the industry itself, through the trade press, trade associations, and

individuals in the industry.

The division of building and housing is the only agency of the

Federal Government whose duty it is to survey the entire field of
260 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

construction from the jDoint of view of the general welfare. The

work of the division, as pursued during the first year of its activities,

has fallen into four general groups.

One group includes siDecialized investigations aiming to improve

the relations between the different local governments throughout

the United States and the construction industry. The work under

this heading includes the formulation of recommendations for local

building and plumbing codes and an analysis of city zoning regulations.

The second main group of work lies in the collection and coordination of current statistical information connected with the building

industry. This includes gathering building-material prices as paid

by contractors in different cities, publication of figures on building

activity, building costs and building materials, and handling of

inquiries in regard to statistics in these fields.

Under the third group of activities come economic and statistical

studies related to the building industr}' and to the housing problems

of the American people.

The fourth group of the division's work has been in the way of

elimination of waste and service to individual home builders. Under

this heading come the work on building practice, and cooperation

with the Architects Small House Service Bureau, a nonprofit-making

organization, in its work of preparing and distributing improved

small-house plans.

General Condition in the Division.

The division of building and housing was organized under the

provision of a supplemental appropriation item, which was made

available July 1, 1921. Preparations for the work of the division

had been made by Franklin T. Miller, who had been assistant to

the Select Committee on Reconstruction and production of the Senate of the Sixty-sixth Congress, and who was therefore in close

touch with current conditions in housing and the construction industry.

By July 1, 1921, the work on building codes had already been under

way for several weeks, and was transferred to this division at that

time. The direction of the division's activities had to be determined,

and building up a staff required some time. The difficult problems

before the construction industry at the time, and the acute national

shortage in housing, which amounted to about 1,000,000 homes, made

it a question of choosing from among the many activities suggested.

The effort was made to meet the most pressing needs that promised

the greatest results for the efforts expended and at the same time

to cover a sufficient range of problems to keep the division in touch

with the principal elements of the construction industry, for only

by so doing could the division get the proper perspective and be

in a position to get support to accomplish results in matters in which

the cooperation of several groups was required.

In taking up the work on building and plumbing codes and on

city zoning, it was felt that, while the staff of the division could do

a part of the technical work, the assistance of outside authorities

in the sifting and weighing of material would be invaluable, and

accordingly the work of the advisory committee on building codes.
KEPORT OF DIEECTOR OF BUREAU OF STANDARDS. 261

which had been appointed prior to the fiscal year, was continued,

and special committees were appointed on plumbing codes and zonThese committees consist of seven or eight members each, and

represent the leading technical bodies interested in each field. Thus

the advisory committee on building codes consists of two architects,

three engineers, a building official, and the head of the section of

timber mechanics of the United States Forest Products Laboratory.

The zoning committee includes men designated by the National

Conference on City Planning, National Municipal League, American

Civic Association, National Association of Real Estate Boards, and

the National Housing Association, while the n)embers individually

represent such professions as law, landscape architecture, civil engineering, and municipal engineering, and occupy important positions

in such organizations as the United States Chamber of Commerce

and the American Society of Landscape Architects.

TECHNICAL SERVICE FOR MUNICIPALITIES.

Building Codes.

The lack of uniformity in local building regulations, and their technical backwardness in many cities, were noted by the Select Committee on Reconstruction and Production of the Senate of the Sixtysixth Congress, and were declared to exercise a retarding influence

j on construction activities and the best interest of many cities. The

I differences in the codes are much wider than different climatic and

other conditions justify. Most of the studies that have been undertaken in connection with building codes have been made with special

reference to conditions prevailing in a particular city, and at the same

time, some of the most fundamental problems, and those most important from the point of view of cost of construction and health and

j, safety have never been thoroughly investigated.

1^

The aim of the work on building codes is not to force the adoption

P

of uniform regulations covering all classes of construction in cities

throughout the United States, where conditions vary. It is simply

, to i^rovide the State and city officials charged with framing codes,

1 and the local organizations and associations who ordinarily assist

j them in this work, with certain of the basic data which they require,

and which have either not been available at all, or at least not in

authoritative form. There are, however, certain sections which

could be made uniform throughout the country with advantage to

I everyone.

It was felt that the provisions of codes affecting small houses were,

perhaps, most in need of revision, and that, in view of the present

housing shortage, a revision of these sections in the light of modern

methods and the results obtained with present-day types of buildings,

i would be of greatest value at the present time, as directly affecting

the better housing of the American people. Accordingly, an exhaustive investigation of sections of building codes relating to small

1 houses in cities throughout the United States, was undertaken, and

the views of building officials, architects, fire chiefs, engineers, experts

ij in the use of different building materials, and of professional societies and associations connected with the building industry, and the

production of building materials were obtained.
262 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Not the least important part of the committee's work has been

the systematic polling of the most expert opinion available on cer- tain matters, which, either through lack of scientific investigation or from their very nature, must be decided according to the best judgement of experts. This condition applies to some of the most basic

parts of the building code, such as sections governing minimum

thickness of masonry walls, the floor loads to be provided for in small

houses and other stiTictures, and the amount of protection necessary

to prevent chimneys from constituting an undue fire hazard.

About the end of April, 1922, a preliminary set of recommended

provisions governing small-house construction was sent out to practically all those individuals and organizations with which the committee had been in contact, for comment and criticism. At the close

of the fiscal year, these recommendations were being revised for publication in the light of the comment submitted.

Plumbing Codes.

The work on plumbing codes followed rather closely the lines outlined for work on building codes proper. The advisory subcommittee

on this subject, appointed in August, 1921, likewise decided to concentrate its attention on problems connected with small-house plumbing

systems. In this case, a special series of tests with actual plumbing

installations, was undertaken by the bureau, and the results obtained

were of great value in preparing a preliminary report which was completed just before the end of the fiscal year, and which was to be sent

out for comment and criticism by several hundred interested parties

throughout the country.

Zoning for Towns and Cities.

The rapid spread of zoning in American cities, and the popular

interest in the measure as a possible means of eliminating great

wastes, providing for the orderly development of cities, and protecting the property of home owners and other holders of real estate,

caused a number of national organizations to request that the Department of Commerce make a study of the problem, and such work was

initiated after a careful survey of the field.

The advisory board on zoning was organized in November, 1921^

and its work so far has included a study of State acts enabling cities

to zone, and of city zoning ordinances, together with a survey of

the literature on the subject. A selected bibliography of zoning, con- taining references to the more important articles on the subject was

issued in mimeograph form, and has been circulated throughout the

United States to zoning commissions, city plan commissions, and

others specially interested, and in response to requests received by

mail from nearly evez^y State in the Union. " A Zoning Primer," ex- plaining the elements of zoning in popular style was issued as a department publication, and in addition to being reprinted extensively

in real estate sections of newspapers and in the construction and real

estate press, has been purchased in large quantity from the Government Printing Office by such organizations as the United States

Chamber of Commerce and its local bodies, the American Civic Association, and local city planning commissions.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 263

CURRENT STATISTICS.

The principal original material collected by the division is a monthly table of building material prices for 24 items, as paid by

contractors in about 60 cities. It was felt that the gap in existing

current statistics was greatest at this point, and the division has had

the support of a number of associations in the work of collecting these

prices and circulating them.

The division is also cooperating with the editor of the Survey of

Current Business in obtaining figures on budding activity, building

costs, and the production, consumption, and stocks on hand of the

principal building materials. Several pages of this Department of

Commerce publication are devoted to these figures each month, and it therefore serves as an invaluable statistical guide to conditions for

those in the industry, as well as for those interested in it indirectly.

Some of the more important figures, which are believed to be of

greatest value as an index to conditions, are j)lotted in graph cal

form, and receive wide distribution through republication in trade

papers of the construction industry and allied fields.

The division has also served as a clear ng house for inquiries in re- gard to statistics collected by other Government departments that re- late to building and building materials, and it has been possible to

answer several hundjccd requests involving information collected

elsewhere, either directly or by reference to the proper bureau.

ECONOMIC AND STATISTICAL STUDIES.

Th's work has included investigations of the extent and nature of

the housing shortage, of the proportion of family income usually

paid for rent, a study of the census figures showing home ownership^

of the number of families as compared with the number of dwellings,

and surveys of the facilities for financing home building.

An original report on the materials of which houses are built, by

districts throughout the country, is also under way. Investigations

of price movements of building materials, and the relation of apparent supply to demand, have also been made from time to time, and the

results given out in addresses or statements in the press.

ELIMINATION OF WASTE AND SERVICE TO HOME BUILDERS.

Elimination of Waste.

j The work outlined under " Technical Service for Municipalities "

I aims at the ebmination of waste, but is treated separately. There

i are certain other activities of the division, however, which fall

I mainly under this heading. The need for standardization of building materials has been widely manifested, and the division is enj deavoring to call the attention of the industry to the savings possible

I through greater simplification and elimination of dimensional va-

} rieties. This work was carried on independently by the division

until the formation of the division of simplified practice, and since

I that time the division has cooperated with the division of simplified

I practice in connection with building materials.

I Standards of building practice also vary widely from city to city,

and an effort has been made to ascertain what could be done to pro-
264 KEPOET OF DIKECTOR OF BUREAU OF STANDARDS.

mote wider use of the best methods of construct'on and workmanship,

and in the way of obtaining some of the fundamental data which

every contractor and builder should have in order to compare the

efficiency of the dillerent parts of his own organization with general

standards.

Along this line, an im-estigation of the proport'onate cost of separate building materials to the total cost of materials entering into

the construction of small brick and frame houses was made, and the

results set forth in a simple table. Similarly, the proportionate d s- tribution of wage bills for small houses to the different trades was

determined. The results of these two studies have been extensively

published in trade papers, newspapers, and accounting journals.

Service to Individual Home Builders.

The division has been able to refer large numbers of 'ndividuals

requesting information on dwelling construction to available pamphlets issued b}^ Government bureaus. In order to assist the people

in obtaining better house plans for economical and livable homes, the

Architects' Small-House Serv'ce Bureau, a nonprofit-making organization fostered by public spirited architects throughout the country,

has been indorsed by the department, and is working in close harmony with the division of building and housing.

At the close of the year, a " F nancial PrirS^r " for home owners

was in course of preparation, and is expected to embody the results

of some of the economic and statistical studies mentioned above.

COOPERATION, INFORMATION, AND PUBLICATIONS.

Cooperation with Public Bodies and Societies.

As noted above, the division has obtained the valuable cooperation

of different architectural, engineering, and trade associations, and

public officials, both in obtaining material for technical investigations

and statistics and for distr'buting it generally.

An important part of the division's work has consisted in supplying local community conferences that have been endeavoring to " clean

up" the building industry in d'fferent cities, with necessary statistical information and reports on what other cities have done along

similar lines. Thus, the information obtained on methods of financing home buUders has been frequently called for by cities in different sections of the- country.

The chief of the division was executive secretary of the committee

on construction industries of the President's Conference on Unemployment, which was held in Washington September 26 to October 13,

1921. The staff of the division was, as far as possible, placed at the

service of this committee for the period of the conference, and has

kept in touch with the conunittee on construction development, which,

in accordance with the instructions of the conference was appointed by

the Secretary of Commerce to follow up the recommendations of this

committee.

The chief of the division was also a member of the Distrist housing committee, appointed by the Commissioners of the D' strict of Columbia, and served as chairman of the subcommittee on building materials. He is also on the board of governors of the newly formed

American Construction Council, and on its executive board.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 265

Members of the staff have addressed meetings of the American

Civil Association, American Construction Council, American Society

of Civil Engineers, Baltimore Real Estate Board, National Association of Builders Exchanges, Nat'onal Federation of Construction

Industries, National Municipal League, Special Libraries Association,

and the Women's City Club of Washington.

In addition to the organizations mentioned above, the division has

important contacts, among others, with the American Civic Association, American Institute of Architects, includ'ng local and State chapters; American Society of Civil Engineers; Associated General Contractors ; Chamber of Commerce of the United States ; National Association of Builders' Exchanges; National Association of Real Estate Boards, including many local boards ; and United States League

of Building and Loan Associations.

The methods of distributing mformation have varied with the different branches of work. Charts and other material issued by the

division have appeared in nearly all classes of trade papers connected

with building; building materials; real estate; in the Building and

Loan Associat on News; in the house organs of local organizations,

such as chambers of commerce, real estate boards and builders ex- changes; in the monthly bulletins of Federal reserve banks; in the

real estate sections of newspapers; and in the proceedings of professional societies. In addition, the Survey of Current Business is widely used as a source of statistics on conditions in the building

industry.

Publications.

A zoning primer (Advisory Committee on Zoning), Dept. of Com. Pub.; 1922.

The papers listed below have appeared in current publications:

Stabilization of prices of materials, etc. (Jolm M. Gries), New York Evening

Post, December 31, 1921, and syndicate of newspapers.

Housing—broad economic aspects (.John M. Gries), Proc. Am. Soc. of Civ. Eng.,

March. 1922.

Standai-dization in the building industry (.John M. Gries), American Contractor,

March 25, 1922 ; The Permanent Builder, .Tune, 1922 ; The Nation's Business,

April, 1922 ; and elsewhere.

SIMPLIFIED PRACTICE.

This division is cooperating with American industries with the object of furthering a

nation-wide program for the elimination of waste in commerce and industry, through the

reduction in the number of sizes and types of standard products, the abandonment of useless varieties, and the concentration of the attention of manufacturers upon articles of the greatest interchangeability.

GENERAL.

The new division of simplified practice, which was organized in

January, 1922, is vigorously engaged on a basis of cooperation with

American business groups, in developing a nation-wide program

with a view to lending the hand of the Government to the elimination

of collective wastes in commerce and industry. These wastes, it is

estimated, result in a loss of 30 per cent of America's energies.

The experience of this country during the war, followed by the

report Waste in Industry, prepared by the Federated American

Engineering Societies, proved conclusively the urgent necessity of

utilizing standardization, of eliminating freak varieties, and of con-
266 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

centrating the processes of manufacturing and distribution upon

articles of the greatest interchangeability. Accordingly, the division of simplified practice was established as one of the units in a general program for eliminating industrial and commercial wastes^

for stabilizing employment, developing our foreign commerce, increasing the quantity of American products, and, in general, secur- ing for every American citizen a higher standard of living.

The chief function of the division of simplified practice is to

supplement the work heretofore carried on by other divisions of the

bureau, by setting up a centralized agency to bring producers, distributors, and users of specific commodities together, and to support

the recommendations of those interested when they shall mutually

agree upon a certain program of simplification of benefit to the industries and the public concerned.

ELIMINATION OF USELESS SIZES.

Paving Brick.

Excellent illustrations of the opportunity for simplified practice

are found in the work already done by several national industries.

The National Paving Brick Manufacturers' Association called the

attention of the division to the need of simplifying the number and

sizes of paving bricks. They estimated that there were about 30

sizes and varieties. After a preliminary conference with the department they undertook in the name of the department an exact survey

of the field, and found that instead of 30 there were 66 sizes and

varieties of paving brick actually being manufactured and sold.

As a result of that survey, the department called a conference of

the manufacturers, municipal engineers, various associations in the

ceramic industry representing engineers, architects, and buyers, as well as the manufacturers of laricks. In a one-day meeting 30 representatives of organizations reduced the sizes and styles of paving

brick by mutual consent from 66 to 11, and recommended that these

sizes be adopted by their various associations and groups as recognized sizes in the paving-brick industry.

At a later conference of the standing committee appointed by the

first conference, a further reduction from 11 to 7 was effected.

Metal and Wood Beds.

The metal and wood bed industry, together with the spring and

mattress groups, realizing the advantages to be gained through simplification, asked the cooperation of the department in aiding their

industry, and upon completion of surveys by the several associations, a general conference was called of representative manufacturers, distributors and users, and again in a single day, four sizes of beds of

one standard length were adopted as recognized sizes in that particular industry. It was also agreed at the same time that the

mattress and spring manufacturers should have their products con- form to the sizes agreed upon by the bed industry.

The results of these conferences have been published in a Simplified Practice Recommendation of the Department of Commerce.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 267

Preparatory Surveys of the Field.

Surveys preparatory to calling conferences for the elimination of

excess varieties and sizes are now being conducted by parent associations in the following industrial fields: Warehouse commercial

forms; lumber; hardware; paints and varnish; sash, door, and millwork ; clay products ; cigar boxes ; metal lath ; common brick ; storage

batteries; spark plugs; automobile tires; ball bearings; milk bottle

openings and caps ; and hollow building tile.

SIMPLIFICATION OF DIMENSIONAL SIZE AND VARIETIES.

Work Now Under Way.

Opportunities similar to those just mentioned for simplification of

dimensional size and varieties exist in hundreds of lines, and although the division has only been operating for six months, contacts have been made with more than 65 industries, most prominent

of which are those manufacturing farming equipment, electrical

lighting fixtures, cordage, railway car wheels, stoves, machine tools,

boxes and food containers, refrigerators, barrels, pianos and musical

instruments, copper and brass products, structural slate, small tools,

jute products, safes and vaults, tents and awnings, fabricated structural steel, metal culverts, flags, linoleum, and sheet glass.

Requests for Assistance.

Initial requests for action by this division come from all branches

of the trades. In some cases programs for simplification come from

groups of retailers, and others are submitted by the manufacturers.

In general, these programs look to reducing the amount of capital

tied up in inventories by both manufacturers and retailers, reducing

the unit cost of manufacturing by making possible the introduction

of mass-production methods, and the more effective use of materials,

equipment, and machinery by standardization of the work going

through the plant. It intensifies competition on articles of greatest

interchangeability and tends to open up new opportunities for small

and specialized manufacturers.
III. THE OFFICE.

The work of the office comprises supervision of the units of the administrative branch;

selection, recommendation, and assignment of oifice personnel; planning and supervision

of the bureau's clerical routine (finance, personnel, property and stores, transportation,

mail and files, purchase, and information) ; supervision of the editorial work of the bureau; and of the technical library.

GENERAL CONDITION IN THE OFFICE.

During the year 208 changes affecting office personnel were made,

including 36 resignations, S2 new appointments, leaving the net

office personnel at the close of the year 141. The work of the office

has increased and has proceeded in a very satisfactory manner. The

simplification of procedure and concentration of work has proceeded

about as far as feasible without decrease of effectiveness. An important piece of work completed during the year was the rivision

of the bureaii's descriptive list of publications bringing the list up

to the close of the fiscal year, with a supplement which will be issued

every few months to keep the main list up to date. The main list

(Circular 24) will carry a comprehensive index to all published

work of the bureau (19()4—1922) , supplying a long-felt need of the

bureau and the general public.

FINANCE.

Funds.

The regular appropriations of the bureau amounted to $1,257,360.

Additional items amounting to $250,000 were carried in the second

deficiency act, making a total of $1,507,360 appropriated by Congress.

In addition, $325,673 was transferred to the bureau during the cur- rent year from other departments for cooperative investigational

work, and $3,418 was received in reimbursements, making the total

funds received this year available for obligation $1,836,451. A large

proportion of the money received from other departments for cooperative work was transferred under the fortifications act of May 21,

1920.

Appropriation Statements.

The following statement shows the amount and object of each

apiDropriation provided for the bureau for the fiscal year 1922, the

disbursements during the year, the amount of unpaid orders at the

close of the year, and the unexpended balance remaining at the close

of business June 30, 1922. The large balances remaining on most of

these funds are due to the amount reserved for the budget savings.

268
EEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 269

Appropriation.

Salaries Equipment

General expenses Grounds

Testing structural materials Testing machines

Metalliirgical research Optical glass Investigation of tevtiles Sugar standardization Gauge standard! ation High-temperature investigation

Testmg railroad scales Investigation of fire-resisting properties

Testing miscellaneou s materials Investigation of public utility standards Kadio research Investigation of public utility standards 1921-22. .

.

Industrial research Sound investigation

Clay products

Color standardisation Standardizing mechanical appliances

Investigation of mine scales and cars Standardization of equipment

Appropriation transferred from other departments:

Gauge standardiiation, War transfer

Total

Total appropriation.

$432, 360. on

9.5, 000. 00

75, 000. 00

10, 000. 00

I 178, 035. 00

30, 000. 00

40, 000. 00

2 28, 000. 00

15, 000. 00

3 31,800.00

40, 000. 00

10, 000. 00

40, 000. 00 25,000 00

30, 000. 00

70, 000. 00

30,000. 00

15, 000. 00

< 437, 757. 00

b, 000. 00 25,000.00

10, 000. 00

15, 000. 00

15, 000. 00

100, 000. 00

3, 000. 00

1, 805, 952. 00

Disburse- ments. Liability.

S399, 56S. 63

59, 230. 26

51, 679. 21

8,317. 32

142, 791. 44

26, 165. 94

34, 341. 49

20, 835. 77

13, 263. 47

27, 153. 81

36, 619. 72

8, 926. 88

34, 487. 86

17, 737. 06

26, 003. 95

63, 902. 28

25, 615. 85

14, 795. 07

177, 303. 45

4,641.48

21, 757. 46

7, 484. 50

10, 716. 73

12, 878. 20

71, 504. 18

2,324.56

321, 792. 99

17, 797. 38

13, 965. 45

1,384. 92

15, 871. 40

1,975.01

3, 338. 67

2, 943. 26

696. 23

2, 888. 32

1, 337. 13

524. 87

2, 600. 49

5, .534. 17 2,416. 45

5, 453. 69

2, .569. 77

1,320,036.57

59, 3S3. 32

187.83

1, 674. 92

1,777. 99

3, 215. 79

1, 142. 52

17,494. 68

484. 38

188, 451. 63

1 Includes reimbursement of 33,035 received from other departments.

- Includes transfer of $3,000, which is available for the incurring of obligations for the fiscal year 1923 and 1924, received from the Navy Department.

8 Includes reimbursement ol $i,800 received from other departments.

< Includes transfer of $286,173,66, a large portion of which is available for the incurring of obligations for the fiscal year 1923 and 1924, and reimbursement of $1,583.34 received from other departments.

The following statement shows the condition of the appropriations

for the two preceding fiscal years at the close of business June 30,

1922:

Appropriation.

FISCAL YEAR 1980. Salaries Equipment

General expenses Grounds

Testing structural materials

Testiiig machines

Metallurgical research Investigation of optical glass Standard materials

Investigation of textiles Sugar standardization. Gauge standardization High-tempei ature investigation

Testing railroad scales Investigation of fire-resisting properties.

.

Investigation of railway materials Testing miscellaneous materials

Investigation of public utility standards. Radio research

Industrial research, 1919-20

Total appropriation.

$486, 760. on

> ins, 033. 00

95, 000. 00

7, 500. 00

2 150,817. 86

3 35, 263. 49

< 30, 1,54. 00

5 63,701. 12 5,000.00

15, 000. 00

6 21, 800. 00

' .56, 276. 90 10,000.00

8 43, 841. 06

25, 000. 00

16, 000. 00

30, 000. 00

5 114, 1.59. 82

'» 31, 555. 94 " 71, 899. 23

Disburse- ments. Liability.

$462, 361. 53

103, 852. 84

80, 926. 80

7, 397. 95

148, 284. 80 34,614.09

29,677. 69

62, 961. 72

4, 818. 75

14, 840. 44

21,063. 34

55, 823, 27

9,930, 92

42, 854, 84 24,320,04

14,649.36

29, 858. 18 113.548.37 31,382.76

71,485.79

$3, 248, 92

3,639, 13

""32i."i7'

12. 21

144. 25

.60

146. 28

29.81 32.52

39. 45 1.70 25.30

' Includes reimbursement of $33 received from other departments.

» Includes reimbursement of $25,817.86 received from other departments.

' Includes reimbursement of $5,263.49 received from other departments.

Includes reimbursement of $5,154 received from other departments.

> Includes reimbursement of $i3,761.12 received from other departments.

* Includes reimbursement of $1,X00 received from other departments.

" Includes reimbursement of $lj, 276.90 received from other departments.

* Includes reimbursement of $;i,841.06 received from other departments.

' Includes reimbursement of $29,159.82 received from other departments.

Includes reimbursement of $1,555.94 received from other departments. " Includes reimbursement of $21,899.23 received f.om otner departments.
270 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Appropriation.

FISCAL YEAR 1920—Continued. Indnstnnl re<^parrh, 1P20

Soiinri invpstifad'on

Investigation of c)av products

Color <!taiidardi7atioii DeterminitKr phvsical constants

Standa-'di'inp mecbanioal appliances

Investigation of mine scales and cars

Indnst''ial safptv standards

Testing Oovernment matcials

Standardization of eoninment

Platinum and rare metals Retainine v ail Equipping laboratory, 1919-20

Total

FISCAL TEAE 1921. Salaries Eanipment

Genera! expenses Grounds

.Testing structural mate'ials Testing structural materials (interior civil) Testine machines

Metallurgical i esearch

Critical t'lass Additional land

Investi''ation of tevtiles Sugar standardization Gauge standardization High-temr e-ati ; r e i n vestigation

Testing rail' oad sca'es Investication of fire-resisting nronerties./ Investigation of 'ail- ay mate-ials Testing miscellaneous inate' ials Investigation of public utility standards Radio research Indust' ial ' esearch Sound investigation

Investigation of clay products

Color standardization StandaMii in'T mechanical appliances

Investigation of mine scales and cars Standardization of equipment

Appronriations transferred from otlier depart- ments: -

Air Service, Army, War transfer Armament and fortification, War transfer Manufacture of arms. War transfer Ordnance stores ammunition. War transfer Expe' iments, Ordnance, Navy transfer Aviation, Navy transfer

Total

Total annropriatlon.

12 52"!

13 7

20,

in,

•S

1* 50,

15 15, 25,

16 ino, " 52,

15, 20,

100,

775. 05

237. 04

oon. 00

001. 00 OV.OO

S20. 26

179. 73

000. 00

300. 66

292. on

000. 00

000. 00

000. 00

Disburse- ments.

2, 129, 427. 16

432,

18 P5,

75,

10, 125,

2, 30.

1' 25,

2" 31, 47,

21 15.

22 31 _ 23 4r,, 10, 40,

25,

15, 30,

2< 95,

2i 30,

26 ,S37,

27 7

25!

in,

2' 35,

15.

1

360. 00

330. 00

000. 00

000. 00

000. 00

250. 00

000. 00

163. 59

000. 00

272. 00

PSn. 00 m\ on

1S3, 54

000. 00

ono. 00

000. 00

000. 00

000. 00

272. 86

096. 00

?56. SS

000. 00

ono. 00

000. 00

000. 00

ono. on

000. 00

450. 00

3,2.50.00

1,625. 00

1,500. on

0, 000. 00

50, 000. 00

2, 209, 089. 87

$287, 40!!. 54

7, 120. 24

19, 817. 60

9,937. 25

4, 096. 00

50,066. 31

15, 0.50. 22 24,468.67

9<!. 8C5. 71 34,447.03

14,9S2.23

17, 674. 27 98,018.26

2, 047, 536. 81

421, 133.60

89, 813. 72

69, 423. 26

9,933. 51 124,321.28

1,882. 64

29. 900. 74

25. 01 S. 57

27, 467. 44

47, 272. 00

15, 5".9. 38

31.360. 85

44, 701. 00

9, 965. 62

39, 655. 31 24, 495. 43

14, 751. 88

29. 918. 33

85, 045. 08

29,711.79

658, 556. 01

0, 914. 52

24, 519. 71

9. 778. 69

34, 089. 28

11,847. 94

9, 675. 50

297. 83

2, 669. 01 1,332.91

1,349. 24

4,147. 38

29, 577. 90

1,960,405.43

Liability.

$602. 37

216. 69 11.99

13. 65

6.00

151. 09

1,086. 94

9, 729. 97

1,.5.51. .56 3,586. 85

"'iig.'si'

2,902.03

42. 55

is.' 76'

4.'90"

33.'84' 201. 42

30,093.11

61. 12

65. 83 .72

531. 93 22.93

14.07

162. 75

127. 10

23. 00

333. 35

5,443. 39

45, 355. 53

12 Includes reimbursement of 841,775.05 received from other depa'tments.

13 Includes reimbursement of .$2,237.04 received from other deoartments. n Includes reim.barsement of $35,820.26 received f'om other departments.

1^ Includes ' eimliiirsement of $179.73 received from other depai tments.

1^ Includes reimbursement of 5300.61'. received from other departments.

1' Includes : eimbursement of $2,292 received from otlier departments.

IS Includes reimbursement of $330 received from other depai tments.

1' Includes reimbursement of $1*3.59 received from other depa' tments.

2» Includes transfer of So,000, wliich is available for the incurring of obligations for the fiscal years 1922 and 1923. recei-\ ed from other departments.

21 Includes reimbursement of .'5 ;-80 received from other departments.

22 Includes reimbursement of $1,800 received from other depaitments.

23 Includes transfer ot $2,420 and reimbursement of $3,703.54 received from other departments.

2-1 Includes reimbursement of $272.^6 received from other departments.

2'' Includes reimbursement of $96 received from otlier depaitments.

2' Includes transfer of $773,877, a large portion of wliich is available for the incurring of obligations for the

fiscal years 1922 and 1923, and reimbursement of $13,979.88 received from other departments.

2' Includes trausfer of S2,000 leccived from other departments.

2s Includes transfer of $20,000 received from other departments.

2' These funds were transferred under the fortifications act dated May 21, 1920, and are available for the

fiscal years 1921, 1922, and 1923.
EEPORT OF DIKECTOR OF BUREAU OF STANDARDS. 271

PERSONNEL.

Bureau Staff.

The staff averaged 342 statutory employees and 546 other employees engaged in connection with researches and investigations

specially authorized by Congress. The average total staff for the

year was 888 regularly appointed employees. There were also en- gaged 40 experts on part-time basis, their services being rendered

for short periods at intervals during the year. The slight increase

is caused by new lines of work authorized by Congress, which includes the division of building and housing and the work of simplified practice, as well as the standardization of specifications, for

which the Director of the Budget established the Federal Specifications Board with the Director of the Bureau of Standards as exofficio chairman.

Changes in Staff.

There were 1,461 personnel changes during the year—262 separations, 317 entrances, 341 promotions, and 541 miscellaneous changes

of status. The total turnover—30 per cent for the entire staff

was 35 per cent for the scientific staff; clerical staff, 26 per cent;

construction force, 10 per cent; and operating staff, 30 per cent.

A summary by divisions shows the staff and average salary for

the year.

-Average Number of Employees and Approximate Salaries by Classes.

Division. Employees. Salaries. Averagesalary per employee.

555 $1,008,831

175, 028

182, 995

52, 317

$1, 818

1,241

1,430

141 128

64 817

Total 888 1,419, 171 1,598

Sources of Personnel.

Employment conditions affecting the bureau are becoming normal

with respect to workers not highly specialized. For higher specialized technical grades eligibles are scarce and not easy to lo- cate. To fill low salaried statutory positions is still a problem,

since experienced workers are unwilling to enter at such salaries.

It is a pleasure to acknowledge cordial, effective cooperation by the

Civil Service Commission and its staff in recruiting candidates for

the scientific staff. Leave of Absence.

The employees on the average took 32.4 days of leave (compared

with a possible maximum of 60 days) , divided 27.3 days annual and

6.1 days sick leave.

Deaths,

During the past fiscal year the bureau has lost nine employees by

death, including two division chiefs and one section chief. The losses

9644—22 19
272 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

include Mr. L. A. Fischer, chief of the weights and measures division

since the establishment of the bureau ; Dr. C. W. Waidner, chief of the

division of temperature and heat for 20 years; and Mr. S. S. Voorhees, chief since 1910 of the section devoted to the investigation and

analysis of cement and bituminous materials. Their invaluable

services in developing specialized branches of the bureau's work will

be an enduring memorial to their memory, although the loss of their

experience and wise counsel will not easily be replaced.

Special Activities.

The personnel section maintains the accident records of the staff as required in administering the employees' compensation act; cooperates with the emergency and first-aid volunteer staff distributed

throughout the bureau; maintains rooming lists to aid employees in

securing accommodations; keeps records of applicants and of those

who have resigned, including their reasons for leaving the service;

and maintains a visible index and directory of all employees.

The complexity and wide range of specialization of the bureau's

work involves a very large number of grades and specialties in technical and other personnel. There are, for example, approximately

126 grades and specialties in the scientific work, 27 in office work, 27

in construction, and 13 in the mechanical plant or operating force,

making a total of approximately 193 grades and classifications in

which it may be necessary to call upon the Civil Service Commission

for eligibles. In the development of such registers the bureau co- operates with the Civil Service Commission by publicity and by direct appeal through the sources of well-trained scientific personnel.

PURCHASE.

Procurement of Equipment and Materials.

The purchase section has placed during the year a total of 6,633

orders, involving the issuance of more than 15,000 proposals to prospective bidders for furnishing the industrial, scientific, and technical

equipment and materials required in the bureau's work. This work

included the preparation of all contracts for large purchases and

enterprises. An efficient follow-up system for securing prompt delivery was maintained, and a dependable system of accessible records

kept for all orders, bids, travel reports, vouchers, and supply sources pertinent to the bureau's work.

The total orders placed included 4,735 orders for industrial, scientific, and technical equipment and materials ; 500 exigency orders cov- ering emergency purchases; 73 orders for miscellaneous office supplies, secured through the division of supplies; and 350 orders for

printing, including forms, results of scientific researches and tests,

and other documents, secured through the division of publications.

Orders were also placed by this section for 975 travel authorizations

applying to the bureau's work.

More than 5,800 vouchers were received by this section and given

all necessary attention up to the time they are ready for final approval for payment.
REPORT OF DIRECTOR OE BUREAU OF STANDARDS. 273

Scientific Catalogue Library.

For the efficient selection and procurement of the latest types of

scientific aj^paratus and grades of technical materials, this section

maintains an up-to-date library of 10,000 scientific and industrial

catalogues, exclusive of price lists and circulars, for the direct use of

the scientific staff. The chief of the section confers with the laboratory men in locating sources of such special supplies and equipment.

The section has an effective system for the prompt procurement of

the late issues of such technical supply literature—catalogues, descriptive ciruclars, and price lists. PROPERTY, STORES, AND TRANSPORTATION.

Stores.

During the year special storerooms for the sujDply of chemicals

and mechanical stores were placed under the general supervision of

the head of this section, and approximately $72,000 worth of scientific

and other supplies were received, checked, and shelved ; and supplies

to the value of $65,000 were dispensed through the technical storerooms of the several laboratories.

Property.

More than 8,000 pieces of apparatus, tools, and other equipment

were received, inspected, and stamped with the bureau's inventory

numbers, and the necessary accountability records were prepared

and filed.

Shipping.

The bureau's freight and express shipments—20 tons per week

included much delicate and valuable apparatus, calling for unusual

care in unpacking, inspection, and distribution. Approximately

seven shipments of apparatus and materials per day were returned to

the owners after being tested by the bureau.

Transportation.

An effective schedule of transportation service by motor trucks

has been maintained: (1) By mail truck between the Department

of Commerce, the post office, and the bureau; and also (2) by heavy

trucks between the bureau, the express offices, and freight depots,

and Government buildings. All hauling has been done with the

bureau's own trucks, and freight has been moved promptly from

the depots, avoiding storage fees. Freight movements have at times

been as high as 20 to 25 tons per day. The bureau has also saved to

the department considerable amounts of hauling by using the bureau

trucks for the purpose. With the cooperation of the automotive

section of the bureau, the truck mileage has been increased 15 per

cent per gallon of gasoline and 30 per cent per quart of lubricating

oil. MAIL AND FILES.

Communications.

A daily average of more than 800 pieces of first-class official mail

are handled by the mail and files section. About one-half of this

mail requires special card indexing. An effectiA'e system provides
274 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

both writer and subject indexes. Telegraphic communication during

the j^ear included the receipt of 1,600 and the dispatch of 1,070 telegrams. The first-class official mail handled during the 3'ear aggregated 263,345 pieces.

Schedules.

The mail and files section operates efficiently on strict time

schedule, each essential step in the complete handling of incoming

and outgoing mail being graphically controlled. Simple graphic

schedules are maintained showing the daily magnitude of the sev- eral classes of mail received and sent and the actual time schedule

of sorting, indexing, and distributing operations.

Availability and Use of Files.

The importance of the contents of the technical correspondence

made it especially desirable to adopt a subject filing system for

letters. Sections of the file may therefore ,be drawn by the ex- perts promptly owing to the efficient classification adopted by the

section. The section is now enabled to locate any correspondence

received by the bureau since its establishment in 1901, since adequate accountability records for withdrawals are filed in place of

the withdrawn correspondence.

Standard Correspondence Practice.

The mail and files section, on the basis of regulations, special

orders, and authoritative sources of data concerning good corre- spondence practice, maintains, under the immediate direction of

the chief of the administrative branch, a " standard office practice " for the entire clerical staff of the bureau. A series of office notes

supplements this practice by adding later orders and regulations and

by pointing out items calling for special care as ascertained from

the daily inspection of the mail by this section. The system has

resulted in uniformity and standard quality in the bureau's outgoing correspondence, including letters, reports, certificates, and

other material.

General Services.

The mails and files section maintains a complete system of collection and delivery of intrabureau communications covering all

sections of the bureau and extending to about 20 separate buildings.

This section also acknoAvledges and refers mail addressed to the bu- reau in error. The communication service of this section includes the

messenger, telephone, telegraph, and elevator ser\'ices.

LIBRARY.

Accessions of Technical Literature.

During the year 2,089 books were accessioned in the scientific

library of the bureau, making the net total at the close of the year

23,350 volumes. The library receives currently 578 scientific and

technical periodicals, more than half of them by exchange. Of

the total number, 230 are American journals, 135 British and other

journals printed in English, 64 in French, 110 in German, and 39

in 9 other languages.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 275

I

Relations with Other Libraries.

The bureau maintains cordial exchange relations with the vari- ous technical libraries in AVashington and elsewhere, including,

especially, the Library of Congress. Books are loaned to such

libraries and their facilities are in turn extended to the bureau.

By mutual understanding this arrangement results in economy,

since rare and expensive books and sets of journals can be obtained by the respective libraries most concerned and be made available for occasional use to all other libraries.

Subject Analysis of Periodicals.

The technical journals are the important means by which the

specialist obtains promptly the new knowledge in his field. Such lit- erature is, therefore, of the utmost importance to the work of a re- search bureau such as the Bureau of Standards. So far as is known,

the technical periodical literature, even of one specialty, is not available at any single library. The limited funds available permit the se- lection of only those found most helpful. Of the 578 periodicals currently received, the bureau takes 18 periodicals in the field of scientific

and technical bibliography and abstracts ; 61 journals on general sci- ence ; 15 in physics, and 38 additional journals very closely related to

physics; 60 journals in general engineering, and 59 in special fields

of engineering; 48 journals in metallurgy; 70 journals in electricity,

telephony, and wireless; 51 in chemistry and chemical technology;

11 in illumination and radiology; 9 in architecture and building; and

the remainder in miscellaneous or general technical subjects.

Library Expenditures.

During the year 1921-22, $3,627.24 was spent for books and periodicals as compared with $4,176.37 for the preceding year, and $5,-

954.17 for the fiscal year 1920. The working value of up-to-date

technical literature is particularly large in a research institution

such as this bureau.

General Services.

The librarian, who is technically trained in physics and mathematics, as well as library science, aids the staff in locating and collating sources of special and recent scientific literature, aids in technical

translation and bibliography, and maintains a close contact with

dealers in this country and abroad in order to complete important

sets and secure rare works which are out of print. The bureau's

library is, as a result, peculiarly well equipped in physics and re- lated subjects.

INFORMATION.

Scope of the Information Work.

The information section collates and disseminates technical information, and arranges for the distribution of bureau publications and

the issuance of reports covering tests of materials. The work is

probably the most important means which the bureau possesses of ren- dering the results of its researches available to the public.
276 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

Special Reports.

Several special reports and articles of a more or less popular character describing various phases of the bureau's work were prepared

during the year. In addition, a number of articles written by per- sons outside the bureau were sent to the information section for correction, the amount of this work being considerably greater than has

been the case heretofore.

A new series of mimeographed pamphlets, known as letter circulars,

each one dealing with some special subject, was .«tarted early in the

year. These circulars arb made up of topical lists of publications

and timely statements on technical topics of particular interest.

Where the importance of the subject Avarrants, such material will

later be included in regular printed publications of the bureau.

The Technical News Bulletin has been issued regularly each month,

as heretofore, for the prompt announcement of the bureau's researches

and new publications to industrial experts, laboratories, and technical libraraies, to facilitate the prompt application of the bureau's

research results in the industries.

Directing Inquiries.

This section routes incoming inquiries by mail and telephone to

members of the staff best qualified to answer the questions. General

inquiries concerning the functions of the bureau are answered directly

by this section. Many letters are received each week from newspaper

information bureaus and the routing of these communications forms

part of the work of the section.

Announcements of New Publications.

The announcement of new publications is now handled very effectively in several ways: (a) Announcements in the monthly list issued

by the Superintendent of Documents, of Avhich a large edition is

circulated; (h) announcements in the monthly list of Department of

Commerce publications; (e) announcements in Commerce Reports,

the weekly publication of the Bureau of Foreign and Domestic Commerce; (d) technical abstracts of all new publications distributed to

the technical press; (e) announcements in the monthly issues of the

bureau's Technical Xews Bulletin; (/') publication of title and

abstract in the descriptive list printed in the Supplement to Circular

24. and later in the circular itself; (r/) an advance copy of each new

publication is sent with a personal letter to the editor of selected

technical journals directly concerned Avith the subject treated; and

(h) in addition to the aboA^e. copies of bureau publications are sent

by the Superintendent of Documents by provision of law to selected

(scA'eral hundred) libraries throughout the counti-y, known as Government depositorj^ libraries, Avhich undertake to keep the publications aA^ailable for consultation by the public.

Publications Issued During the Year.

During the fiscal year just closed the bureau has issued 67 new

publications and 23 reprints—a total of 90 publications. The new

publications comprise 25 scientific papers, giving the I'esults of

scientific researches; 22 technologic papers, giA'ing results of new
REPORT or DIRECTOR OF BUREAU OF STANDARDS. 277

investigations in the field of engineering and the special technologies;

16 circulars, containing important compiled technical information in

the bureau's field useful to the industries, and especially to scientific

and technical laboratories ; and 4 miscellaneous publications.

Tests.

The bureau's work includes, among other things, a large amount

of testing of standards, weights and measures, measuring instruments, and materials. Incident thereto much of the testing involves

primary investigation of the scientific principles underlying such

tests, the study of existing methods, and the development of new

standard tests of determinate precision. A reasonable fee is charged

for each test, except when made for the National or for State Governments. The tests completed during the year, together with their

value, are summarized in the following table

:

Number and Valxje of Tests Completed,^ Fiscal Teak Ended .June .30, 1922.

Kature of test.

For Government. For pubUc. Total.

Number. Value. Number. Value. Number. Value.

Lensth:

199 $499. 45 83 $181.65 282 $681. 10 395 1,060. 20 1,490 1,461.60 1,885 2, 521. 80 Mass:

1,079 .504. 80 2,231 997. 80 3,310 1,502.60

1,088 50,325 50 3 12. .50 1,091 50,338.00 Capacity 4,235 1,702 55 8,954 5, 230. 75 13, 189 6,933.30

306 429 50 281 418.85 587 848.35 Time 15,488 10,833 50 38 61.00 15,526 10, 894. 50

Electrical tests 1,096 4,352 80 690 3, 1.36. 00 1,786 7, 488. 80

2,575 10,226 00 403 887.00 2,978 11,113.00 Radioactivity 57 124 80 2,216 18,455.80 2,273 18,580.60 Temperature:

5,785 474 44 8,652 768.05 14,437 1,242.49 other thermometers and miscellaneous 1,552 1,691 91 1,421 3,802.68 2,973 5,494.59 Optical tests: 1,628 1,628 00 26 91.00 1,654 1,719.00

2,200 1,223 00 200 1, 096. 50 2,400 2,319.50 Chemical analyses: Structural meterials 778 7,780 00 778 7, 780.00 Other materials 7,598 118,667 00 7 70.00 7,605 118,737.00 Standard samples •.

.

584 1,126 15 2,905 5,808.37 3,489 6,934.52 Mechanical instruments and appli- ances 400 1,9.50 GO . 61 377.50 461 2,327.50 Aeronautical instnunent tests 81 2,098 00 10 78.50 91 2, 176. 50 Physical tests of materials: Cement 4, 076 32,086 00 10 27.00 4,086 32, 113.^0

927 2,017 00 89 269. 00 1,016 2,286.00 Miscellaneous materials, includ- ing paper, textUes, rubber,

leather, etc 9,351 44, 774 25 551 1, 946. 50 9,902 46, 720. 75 Metallurcjcal tests 564 2,617 50 9 141. 25 573 2,758.75 Miscellaneous 62 1,014 00 134 475. 40 196 1,489.40

Total 62, 104 299,206.35 30,464 45, 794. 70 92,568 345,001.05

1 The tests reported in this table include only the tests for n'hich all technical procedure was entirely

completed during the year 1921-22.

2 In addition the bureau inspected 1,646,692 incandescent lamps at various factories for other departments

of the Government, the fees for which would amount to $4,297.78.
/

IV. ENGINEERING AND CONSTRUCTION.

This division operates and maintains the power, heating, and refrigerating plants, in- stalls and repairs electrical and plumbing equipment, and cares for buildings and grounds.

GENERAL.

Aims and Recommendations.

The division has with great difficulty met the most urgent re- quirements for j)ower, heating, and lighting, made necessary repairs

and installations of new equipment, and furnished the best service

possible in meeting all special requirements. This has on many oc- casions entailed work on holidays, Sundays, and after hours, to make

repairs, change overs, and new connections which could not be made

during office hours without serious interruption of service. A special

effort has been made and economies effected in the use of electricity,

water, and gas, not only in the plant but throughout the bureau.

The need for a new centralized power plant of greater capacity is

becoming more pressing as additional and heavier power-consuming

equipment is being installed in the laboratories. A larger maintenance force is also needed. The pressure of work frequently necessitates the delay of needed repairs, sometimes causing operating wastes or greater repair expense due to the delay.

OPERATION AND MAINTENANCE OF MECHANICAL PLANT.

The mechanical plant comprises heating, ventilating, air conditioning, and refrigerating equipment; electric generating, converting,

and transforming equipment, and storage batteries; water; air;

vacuum; steam; and gas service.

The plant has been improved during the year by the installation

of an automatic combustion control-system and a venturi feed-water

registering and recording meter. These have made possible a closer

check on boiler operation, which has resulted in material savings.

A new feed-water pump was added and a new and larger vacuum

pump installed to replace worn-out equipment. The absorption re- frigerating plant was thoroughly overhauled and several new sets of coils installed.

The electric-power service during the past year has been better than

before from the standpoint of continuity of service owing to the

addition of an emergency power feeder, from which the bureau is supplied when service is interrupted over the regular line. However,

^the direct-current service is continually becoming more inadequate to

carry the new loads, totaling several hundred horsepower, which

have been added during the past fiscal year. A frequency changer

of 500 kilowatts capacity was installed during the year, which provides an ample supply of 3-phase 60-cycle power.

278
REPOKT OF DIEECTOB OF BUREAU OF STANDARDS. 279

CONSTRUCTION AND REPAIR.

Electrical. "

The installation, extension, and repair of all wiring, switchboards,

motors, and electrical equipment for the various laboratories, as well

as for the mechanical plant, are performed by this section. In addition to necessary repairs to present equipment the section erected a heavy power feed line to supply a 200-horsepower motor for the

new wind tunnel, installed permanent wiring to supply new service or replace temporary wiring in the ceramics laboratory, rubber laboratory, leather laboratory, the optical shop, the annex machine shop,

the dynamometer building, the sound chamber, and made numerous

other small installations of switchboards, motors, ovens, and other

electrical apparatus. Watt-hour meters were installed to meter

the power used by all of the heavier power consumers. Plumbing.

This section installs, maintains, and repairs all plumbing fixture's

and all pipe lines and steam traps used in connection with the heating systems, and for the distribution to the laboratories of water, air,

gas, vacuum, steam, and refrigerating service. In addition to the

necessary maintenance and repair work in connection with the above,

the section has taken an active part in the investigation of plumbing fixtures which has been in progress during the past six months

at the bureau. Plumbing service was extended to the sound chamber

and the large compressor supplying the kiln building furnaces was

taken out of the industrial building to make room for the Emery

testing machine. This, with another compressor to provide for

emergency service, was installed in the kiln building ; the absorption

refrigerating plant was overhauled; and a large number of smaller

installations of apparatus, and supplying or altering of service, were

taken care of by this section.

Miscellaneous.

The most important work under this section during the past year

includes the construction of the sound chamber, laying of a new roof

on the northwest building, removal of a wireless mast with massive

concrete base, construction of cinder concrete roadway between the

north and south buildings, building of an incenerator, pouring re- inforced concrete foundations for the Olsen and Emery testing

machines, and numerous smaller installations of motors and other

apparatus. Necessary internal and external painting was done,

leaky roofs were repaired, cornices and gutters broken by the heavy

snows were repaired.

BUILDINGS AND GROUNDS.

Janitors and Laborers.

The work of this section is largely of a routine nature in cleaning

the buildings, including offices and laboratories, disposing of rubbish and keeping sanitary conditions throughout. This section is

also called upon for moving heavy equipment about the bureau or

assisting in the handling of such equipment from the freight stations

9644—22—20
280 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

to the bureau. The janitor service is entirely inadequate and should

be increased immediately.

Watchmen.

The duties of the watchmen consist in making inspections of the

buildings to prevent fire, theft, and damage by weather to the property of the bureau. They also report to the superintendent's office

all matters pertaining to this division which need attention such as locks out of order, broken windows, leaking valves and faucets,

burned-out lamps, waste of water, gas, or power. They also shut

off or start apparatus at specified times as requested by members of

the scientific staff. Watchmen's clocks make a record of their movements.

Grounds.

Some progress has been made in the improvement of the appearance of the grounds. Grading was done north and east of the south

building, south and west of the chemistry building, around the sound

chamber, and the industrial and kiln buildings. Drainage was improved around several buildings and a material decrease in trouble

from heavy rains effected.

i
V. GENERAL RECOMMENDATIONS.

Salaries.

IP

The question of salaries of the scientific employees in the Government service has been so much before the public of late that it might

be considered unnecessary to refer to it again. However, this problem is of such extreme importance in the case of the Bureau of

Standards and is so closely connected with its satisfactory functioning that I feel compelled once more to call attention to the very

unsatisfactory conditions which exist.

At the time my last annual report was prepared, most of the industries in this country were passing through a period of extreme

depression. At such times the salaries which can be offered by private

corporations are naturally far less attractive than during periods

of commercial activity. Nevertheless, the bureau lost many members

of its scientific staff, who felt obliged to accept the higher pay which

they could obtain in private employ, although by so doing they realized that they were lessening their opportunities for research work.

As a matter of fact, it is this devotion to their work which has enabled

the bureau to keep its staff in a reasonably efficient condition ; without

this loyalty the labor turnover in the more important positions would

be excessive.

During the coming fiscal year, with industrial conditions improving everywhere. Government scientific institutions will be under a greater handicap than ever before, and it will become increasingly

difficult to render efficient service. The staff of a scientific laboratory can not be picked up " overnight " to carry a peak load. New employees in scientific positions, no matter how willing they may be, are an actual drag on the work of the more experienced members of

the staff until they become familiar with the particular problems in

hand. The loss of one man from a laboratory may set back an entire

investigation much more effectively than the destruction of all that

laboratory's equipment.

There should be no need for such financial sacrifice on the part of

scientific men in the Government service. We can and ought to pay

them salaries commensurate with the importance of the work and

more nearly on a plane with what they can earn in the industries and

in educational institutions.

It is, therefore, again earnestly recommended that steps be taken

to remedy this situation. Such action will be found in the end to be

a paying investment for the entire country.

Power Plant.

The need of a new power plant for the Bureau of Standards has

been pointed out in previous annual reports. Entirely aside from

the more reliable service which would be rendered by a plant

specially designed to meet the needs of a research institution, the

matter is of particular importance at the present time owing to the

281
282 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

greatly increased economy which would result from centralization of

the bureau's heating and power-producing equipment. The tendency

in all lines of work is toward centralization of equipment, and it

is well Imown that nowhere does this result in greater economy than

in the operation of a power plant.

The bureau's original plant, designed for two buildings, and now

supplemented by two separate boiler plants for heating purposes

and .numerous pieces of electrical equipment for changing the^

electric power bought from the commercial company into energy

suitable for the needs of the laboratories, forms a glaring example

of decentralization with the unavoidable a,ccompaniment of high

labor charges and low fuel economy. Owing to the small capacity of

the electric generating equipment of the bureau's plant, it has been

found necessary for some years to purchase a large part of the

current from the local power company. Such a source of supply

is necessarily much less reliable than a plant specially designed

for the needs of a research institution.

It is believed that the expenditure necessary to build a modern

central power plant capable of caring for all the probable future

needs of the bureau would be saved in a short time through increased economy in fuel and operation and greater reliability in the

service rendered.

Care of Buildings.

The same conditions as regards the number of janitors, laborers,

and watchmen necessary to properly care for the buildings and

grounds, as mentioned in my report of last year, still apply. The

bureau is made up of a large number of separate buildings, each

of which contains a great deal of valuable apparatus and in which

some processes must necessarily be carried on day and night. Watchmen with more than ordinary intelligence are therefore absolutely

necessary. To curtail services of this character is questionable

economy, and may result in accident and loss of equipment. The

force at present provided is too small and should be increased

immediately.

Buildings and Grounds.

It is again recommended that provision be made by Congress for

the purchase of the land between the present boundary of the bureau's property and Connecticut Avenue on the east. This tract

is needed to round out the site, and as it will without doubt be

purchased eventually it would be better to secure it now before it

it is built upon.

Considerable progress has been made in grading and clearing

up the grounds and in the construction of some permanent road,

but a more adequate fund is needed to properly finish up this

work and to keep the bureau's grounds in proper condition.

Respectfully,

S, W. Stkatton,

Director.

To Hon. Herbert Hoo\^r,

Secreta')'^ of Commerce.

o

I