ANNUAL REPORT

OF THE

DIREGTOR

B UREAU OF STANDARDS

TO THE

SECRETARY OF GOMMERCE

FOR THE

FISCAL YEAR ENDED JUNE 30, 1918

WASHINGTON

GOVERNMENT PRINTING OFFICE

1918

ANNUAL REPORT

OF THE

DIRECTOR

BUREAU OF STANDARDS

TO THE

SECRETARY OF COMMERCE

FOR THE

FISCAL YEAR ENDED JUNE 30, 1918

WASHINGTON

GOVERNMENT PRINTING OFFICE

191S
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.

2
CONTENTS.

Page.

Chart showing functions of Bureau facing. . 13

I. Functions, organization, and location 13

1. Standards of measurement 13

2. Physical constants 14

3. Standards of quality 14

4. Standards of performance 15

5. Standards of practice 16

6. Relation of the Bureau's work to the public 16

7. Relation of the Biu-eau's work to the Government service 18

8. Organization 19

9. Location 20

II. Scientific and technical divisions 21

1. Weights and measures 21

Length. 21

Military work in connection with weights and measures. . . 21

Additional consulting work 22

Length measures 22

Hsemacytometers 23

Expansion of insulating materials 23

New equipment for measuring expansion 23

Length testing 24

Special war problems 24

Mass 24

Weights and balances 24

New material for small weights 25

New method of testing weights 25

Routine weight testing 25

Time. -.. 25

Time-measuring devices 25

Capacity and density 26

Capacity and density 26

Density researches 27

Gas-measuring instnunents 27

Gas measurement 27 Weights and measures laws and administration 27

General weights and measures legislation 27

Cooperation with States and other interests in weights and

measures administration 28

Comriiercial scales . 28

Preliminary mine-scale investigation 28

Continuation of mine-scale investigation 30

Railroad track-scale work 31

Cooperation with railroad administration 31

Testing equipment for track scales 31

Master scale 32

Tests of track scales 32

Consulting work on track scales 33

Capacity rating of track scales 34

Gauges 34

Gauge work 34

Gauges tested 35 - Work of gauge shop 35 Present facilities 36

Publications and information 36

Publications 36

Miscellaneous information furnished 36

3
4 CONTENTS.

II. Scientific and technical divisions—Continued. Page.

2. Electricity 38

Scop? of the electrical work 38

Special military work in electrical subjects 39

Standards of resistance 39

Inductance and capacity 39

Electrical measuring instruments 39

Testing of electrical instruments 39

New deflection potentiometer 39

Instrument transformers 39

Methods of testing the electrical properties of transformer

oils 40

Blasting machines 40

Ignition in gasoline engines 40

Mica for electrical purposes 41

Printing chronograph 41

Velocity of projectiles 41

Magnetic measurements 41

Bismuth spiral for measurement of magnetic fields 41

Determination of magnetic susceptibility 42

Standard magnetic bars 42

Magnetic analysis 42

Magnetic compasses 42

Railway signal relays 43

Photometry and illuminating engineering 43

Trench flares 43

Portable acetylene lights 43

Photometric tests of field searchlights 44

Special problems in illumination 44

Standard specifications for electric incandescent lamps . 44

Inspection and life testing of lamps 44

Gas-filled standards of spherical candlepower 45

Automobile headlight specifications 45

Radio communication 46

New radio building and equipment 46

Circular on radio instruments and measurements 46

Use of closed-coil antennas 46

Insulating materials for radio apparatus 46

Miscellaneous testing, calibration, and designing of radio

instruments 46

Vacuum-tube apparatus 47

Sound ranging 47

Sound ranging 47

Electrochemistry 48

Electric batteries 48

Miscellaneous electrochemical work 49

Radioactivity and X-ray measurements 49

Luminous materials 49

Standard radium solutions 51

Radium emanation work 51

Gamma-ray measurements of radium 51

X-rays ; 52

Public-utility standards 52

Public-utility investigations 52

Relation of the bureau to municipalities and public-service

commissions 53

Gas engineering 54

Gas-service standards 54

Natural-gas service 54

Gas lighting 54

Proposed national gas safety code 55

Economic importance of the national gas safety code 55

Toluol investigations 56

Balloon-gas manual 56

Coke-oven investigations 56
CONTENTS. 5

II. Scientific and technical divisions—Continued.

2. Electricity—Continued. Pag*"- Electrical service standards 57

Standards for electric service 57

Standards for street-lighting service 57

Standards for heating service 58

Electrical safety engineering 58

National electrical safety code : 58

Engineering and experimental work in connection with the

safety code 60

National electrical safety code in practical use 60

Travel and conferences for explanation, application, and

development of the code 60

Scope and application of the electrical safety code 61

Use of the code in educational institutions 61

Electrical protection for householders 61

General industrial safety standards 61

Electrolysis prevention 62

Electrolysis problem among public-utilities » 62

Economic importance of the electrolysis problem 63

Inconvenience and hazard due to electrolysis 63

Current work on electrolysis mitigation and related problems 64

Telephone-service standards 65

Telephone-service standards 65

Standards of telephone transmission 65

Study of local telephone service 66

Battleship fire-control telephone equipment 66

Microphones 67 Standard cell work 67

3. Heat and thermometry : 67 Thernaometry 67

Clinical thermometers 67

Airplane thermometers 68

Copper-constantan thermocouples 68

Low-temperature scale 68

Antifreezing solutions 68

Solidifying point of naphthalene 69

Pyrometry 69

Pyrometer absorption glasses 69

Optical and radiation pyrometry : 69

Optical ammeter 69

Standardization of thermocouples 69

Wehnelt tube discharge 69

Simple method of measuring EMF accurately 70

Pyrheliometers 70

Standard samples for thermometric fixed points 70

Investigations in electronics 70

Thermoelectric power of liquid-solid metals 71

Aeroplane gas-engine explosion 71

Annealing of optical glass 71

Temperature problems in coke ovens 71

Heat measurements 72

Standard heat samples for use in calorimetry 72

Refrigeration constants 72

Thermal constants of ammonia 72

Specific volumes of ammonia and ethyl chloride in the liquid

and vapor phases 72 Special military investigations 73

Low temperature 73

Low-temperature laboratory 73

Fire-resistive properties of structural materials 74

Fire-resisting properties of structural materials 74

Fire tests of building columns 75

Fire tests of reinforced concrete columns 76

Strength of metals at high temperatures 77 Building codes, information, cooperative work 78
6 CONTENTS.

II. Scientific and technical divisions—Continued.

3. Heat and thermometry—Continued. Fage. Airplane power plant , 78

Altitude laboratory 78

Additional equipment 78

Spark plugs 79

Carburetion 79

Radiators 79

Lubricants 79

Special tests 79

Acti\ities in conferences, committees, and scientific societies 80

Heat and thermometer tests ; 80

Information furnished 81

4. Light, optical instruments, and sound 81

Spectroscopy 81

Red and infra-red spectra of chemical elements 81

Red and infra-red spectrum of the sun 82

• Refractive index and dispersion of air 83

Landscape photography with red sensitive plates 83

Spectroscopic analysis 84

Polarimetry 85

Circular on polarimetry 85

Testing of qviartz control plates 85

Natural rotation of quartz at high temperatures 85

Magnetic rotation of quartz at high temperatures 86

Standard samples 86

Pure sugars for miscellaneous purposes 86

Influence of temperature on speed of inversion of sugar 87

Solubility of dextrose 87

Magneto-optical properties of magnetic substances 87

Solubility of sugar and the causes of molasses formation 88

Intense monochromatic light sources 88

Constants of quartz wedge saccharimeter 89

Customs laboratory at Savannah, Ga 89

Utilization of discarded polariscopes 89

Polarimetric testing '. 89

Polarimetric tests of raw sugar 90

Sampling of molasses at Key West 90

Supervision of the customs laboratories of the Treasury

Department 90

Definitions and specifications for refined sugars 90

Standard glassware for customs service 90

Bureau of Standards Baume scale 90

Basis of saccharimeter standardization 91

Testing of imported molasses 91

Colorimetry 91

Colorimetry 91

Color-standards investigation 92

Extension and improvement of spectrophotometric methods. 93

Collection of specimens of measured spectral transmission.. 93

Standardization of nomenclature and forms 93

A precision method for the production of artificial -daylight. . 93

The specification of the color of light from the ordinary light sources and the photometry of lights of different color. . . 94

The color grading of cottonseed oil 94

Determination of the spectral transmission of standard piu'e

dyes and other materials 94

Cooperation with societies and organizations 94

Examination of glasses intended to protect the eyes from

harmful radiation 95

Investigations on color, visibility, and related subjects for the military and naval authorities 95

Colorimetric and related optical tests 95

Information, advice, and assistance on colorimetric and

related optical questions and problems 96
CONTENTS. 7

II. Scientific'and technical division—Continued.

4. Light, optical instruments, and sound—Continued.

Colorimetry—Continued. Vag&. Information, advice, and assistance rendered the Army and

Navy and other war agencies of the Government 96

Information and advice to applicants representing scientific,

commercial, and industrial interests 97

Determination of thermal expansion by interference meth- 97

ods

Gauge calibration by interference methods 97

Index of refraction of gases and saturated vapors • 97

Optical instruments 98

Ail-plane camera 98

Projection lens 98

Instruments for Navy 98

Long-range photography 98

Testing of optical systems and glass 98

Circular on optical instruments 100

Optical glass 100

Glass for photographic lenses 100

Methods for testing optical glass 100

The effect of striae in optical glass 101

Corrosion tests 101

Cu'cular on the testing of optical glass 101

Nonshatterable glass 101

Radiometry 101

Radiometry 101

Life tests of quartz mercury vapor lamps 102

Optical properties of balloon fabrics 102

Photo-electric properties of various substances ].03 Infra-red transmission spectra of various substances 103

Glasses for protecting the eyes from injurious radiations. . . 103

Information furnished on radiometric subjects 103

Publications on radiometry 103

Dispersoids 104

Scope of work on dispersoids 104

Sound 104

Sound investigation 104

5. Chemistry 106

Chemical testing 106

The new chemistry building 106

Chemical publications 106

Physical chemistry 107

Chemical work on refrigeration problems 107

Purification of materials for special purposes 107

Electrochemistry 107

Electrotyping and electroplating investigations 107

Metallurgical chemistry 109

Rapid determination of carbon in steel 109

Determination of gases in steel 109

Gas chemistry 110

Balloon fabrics 110

Balloon-gas investigations Ill

Gas analysis investigations 112

Miscellaneous gas problems 113

Reagents and apparatus 113

Chemical reagents 113

Platinum 113

Asbestos ] 14

Oils, rubber, paper, textiles, ink, and glue 114

Chemical work on rubber 114

Chemical work on leather 114

Chemical work on %vriting and other inks 115

Chenaical work on paste, glue, and mucilage 115

Lubricating oils and greases 115

Chemical work on textiles and dyes 115

Airplane dopes 115
8 CONTENTS.

II. Scientific and technical division—Continued.

5. Chemistry^—Continued. Page.

Metals, cement, and bituminous materials 116

Chemical work on metals and alloys 116

Protective coatings of zinc 116

Cement, concrete, etc 117

Bituminous materials 118

Marine glues 119

Coke-oven process 119

Protective coatings for concrete ships 119

Paint, varnish, and soap 120

Paint and varnish specifications 120

Fire-retarding paints 120

Removing metal fouling from rifie barrels 121 Analytical Methods and standard samples 121

Standard analyzed samples 121

Determination of tungsten and molybdenum in ores 121

6. Engineering research and testing 122

Theory of measuring instruments 122

Routine tests of instruments and devices 122

Miscellaneous military tests of devices and equipment 122

Mechanical appliances 122

Fire-extinguisher investigations and tests 122

Tests of airplane equipment 123

Comparative tests of roof ventilators 123

Thermostatic valves for vacuum heating systems 123

Engineering inst^iunents 124 Water-current meter-rating station 124

Current-meter investigations 124

High-pressure gauges 125

High-pressure oxygen gauges 125

Aeronautic instruments 125

Oxygen control apparatus 126

Statoscope design 126

Barographs 126

Airplane thermometers 126

Testing and investigation of aeronautic instruments 126

Aerodynamics 127

Wind tunnel investigations 127

Free-flight investigations , 128

7. Structural, miscellaneous, and engineering materials 129

Metals 129

Investigation of metal airplane beams 129

Substitutes for spruce in aii'plane construction 129

Investigation of mahogany for ahplane propellers 130

Investigations of the effects of kiln-drying spruce 130

Airplane strut investigation 130

Airplane thrust and torque dynamometers 131

Instrument for measuring tension in airplane cables 131

Shock-absorbing wheels for airplanes 131

Investigation of magneto couplings for airplane use 131

Sea-plane tail booms 131

Metal wheels for motor trucks 131

Tests of palmetto wood for sea-faring purposes 132

Investigation on failure of steel plate 132

Investigation of electrically-welded plates 132

Investigation as to cause of failure of bearing plates and

rollers 132

Investigation of floor stress in the new Arlington Building. 132

Machine-tool investigation 132

Report on extensometers 133

Adaptability of scleroscope for testing rubber 133

Depth-measuring appliance for Brinell hardness machine. . 133

Brinell meter investigation 133

Calibration of testing machines 133

Investigation of galvanized wire to determine loss of ductility .' 134
CONTENTS. 9

II. Scientific and technical diA'isions—Continued.

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

Metals—Continued.

Investigation for changes in design on specification of 'P^.ge. materials submitted by the War Department 134

Equipment 135

Investigation of brick piers 135

Investigation to determine bearing power of soils 136

General summary of testing 136

Calibration of testing machines 137

Xew equipment. 137

General tests of structural materials 138

Tests of tile walls 138

Cement, concrete, stone, gravel, and sand 138

Investigation and testing of cement, concrete, and stone 138

New branch laboratories at Denver and San Francisco 139

Government specification for Portland cement 139

Routine inspection and testing of cement 140

Development of testing methods, standardization of test- ing apparatus, etc 142

Investigation of the -value of fine grinding of Portland

cements 142

Standard cement sieves 143

Standard fineness samples 143

Durability of stucco and plaster 143

Durability of concrete in sea water 144

Durability of concrete in alkali waters 144

Acceleration of the hardening of concrete 144

Moisture and temperature changes on concrete 145

Flat-slab floor design 145

Floor and roof failiu-es 146

Service tests of floors and floor treatments 146

Concrete aggregates 146

Field control of concrete 147

Effect of reversal orf stress on concrete beams 147

Concrete bulkheads for ships 148

Concrete oil-storage tanks 148

Automatic freezing and thawing apparatus 149

Investigation of building stones of the United States 149

Miscellaneous investigations 150

Miscellaneous routine tests 151

The constitution of Portland cement 151

Hydraulic cements other than Portland 152

Tests of concrete ship sections 152

Tests of columns 152

Tests of cement and concrete 153

Miscellaneous materials 153

Lubricants 153

Lubrication of airplane motors 153

Specifications for lubricating oil purchased by Government'

departments 154

Investigation and tests of lubricating oils 154

Testing of lubricants 154

Leather 154

Investigation of leather goods 154

Routine tests of leather 156

Rubber 156

Investigation and testing of rubber 156

Cooperation with technical societies and testing laboratories representing manufacturers and consumers 156

Experimental rubber plants 157

Solid-rubber truck tire tests 157

Pneumatic tires and tubes for automobiles, motorcycles,

and bicycles 158

Airplane materials 159

Gas-mask materials 159

Tests of medical supplies ; 159
10 CONTENTS.

II. Scientific and technical divisions—Continued.

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

Miscellaneous materials—Continued. Page. Tests of hose and packing for the Greneral Engineer Depot

of the Army 159

Tests of fire hose for Government departments 160

Rubber insulated wire 160

Tests of miscellaneous materials 160

Textiles 161

Blanket investigations 161

Uniform fabrics ". 162

Airplane fabrics 162

Attaching of fabrics to planes 163

Inspection of airplane fabrics 16S

Balloon fabrics 163

Balloon seams , 164

Parachute fabrics 16-4 Physics of airplane fabrics 164

Packing of textiles 164

Miscellaneous military materials 164 Test methods 165

Microscopy 165

Industrial laboratory 165

Paper 165

Investigation and testing of paper 165

Utilization of wall and plaster board 166

Development of special papers 167

Paper-testing devices 167

Filter paper for explosives testing 168

Information finished on paper 168

Summary of tests 169

8. Metallurgy 170

Equipment 170

Publications 171

Metallurgical tests 172

Tests of new alloys 174

Military boards and committees 174

Military inventions 174

Information furnished by correspondence 174

Microscopy of metals 175

Corrosion of nonferrous metals 175

Protective metalHc coatings 175

Microstructure of wrought iron 176

Valve steel for airplane engines 176

Ladle test-ingot investigation 176

Heat-treatment and thermal analysis 176

Iron-carbon transformations 176

New furnace for thermal analysis 176

Gun erosion 176

Physical properties of metals and alloys 177

Light aluminum alloys 177

Magnesium-aluminum alloys for mirrors 179

Investigation of railway materials 179

The failure of brass .- 179

Acceleration tests for season cracking and for initial stress. . 180

The eUmination of initial stress by annealing 180

Arc welding 180

Fusible metals and alloys 180

Aluminum solders 181

Tin conservation 181

Cadmium solders 182

Bearing metals 182

Metals at high temperatures 182

Copper plugs for testing cartridge powders 183

Metals for instrument parts 183

Preparation of metal specifications 183

Metalhugical chemistry 183

Electrolytic carbon method 183

Rapid determination of carbon in steel by the barium car- bonate titration method 184
CONTENTS. 11

II. Scientific and technical divisions—Continued.

8. Metallurgy—Continued.

Metallurgical chemistry—Continued. Page.

Nitrogen in steel 184

Goeren's method for determining gases in steels 184

Determination of gases by the Goutal method 184

Critical study of the Ledebur method for determining

oxygen in steel 185

Oxygen content (by the Ledebur method) of steels deoxi-

(fized in various ways 185

EquiUbrium between iron oxide, carbon, and hydrogen 185

Determination of carbon monoxide as obtained from steels. . 185

Special alloy work 185

Pure aluminum 186

Manganese and deoxidation researches 187

Oil-proofing concrete liners 187

Foundry 187

Foundry investigations and tests 187

Sand investigations 187

Experimental and practical casting 188

9. Ceramics 188

Clay products 188

Investigation of building tile 188

Industrial cooperation and dissemination of technical infor- mation concerning ceramic products 188

Design of new equipment 189

Enamels for copper 189 Iron enamels 189

Efficiency studies of ceramic kilns 189

The use of clay in chemical reactions 189

Clay aggregate for concrete 189

Cooperation with the War Industries Board 189 • Cooperation with the United States Fuel Administration.. 189

Cooperation with the United States Potters' Association... 190

Clay survey 190

Pottery saggers .• 190

Refractories for marine boilers 190

Work on refractories 190

Refractory porcelain 190

Spark plugs for airplanes 191

Crucible clays 191

Architectural terra cotta 191

Hard-fire porcelain 191

Glass 192

Examination of raw materials for optical glass manufacture. 192

Casting process 192

Glass pots 192

Optical glass 193

Lime, gypsum, etc 194

The use of hydrated lime in concrete 194

Properties of hydrated limes 195

Plasticity of hydrated limes 195

Sand-lime brick 195

Gypsum products 195

Dolomite as a refractory 196

III. Office 197

Finance 197

Appropriation statements 198

Summary of tests 199

Personnel 201

Personnel changes 20]

Efficiency methods 201

Publication 202

Publication -. 202

Printing 202

Distribution 202

New publications 202
12 CONTENTS.

III. Oflnce—Continued. Page.

Property and stores 203

Equipment records , '204 Progress 204

Purchase 204

Mail and files 204

Library 204 - Important accessions 205

Equipment and space 205

Dispatch 205

Copying 205

Information 205

Progress-of-work records 205

Distribution of military information , 206

NATIONAL BUREAU OF STANDARDS

Washington, D. C.

1918

FUNCTIONS

Development, construction, custody, and maintenance

of reference and working

STANDARDS

and their intercomparison, improvement, and application

in science, engineering, industry, and commerce.

80'J«(i 18. (To face pa gi 18.)
REPORT

OF THE

DIRECTOR, BUREAU OF STANDARDS.

Department of Commerce,

Bureau of Standards,

WashingtoJi, July 1, 1918.

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

Bureau of Standards for the fiscal year ended June 30, 1918.

I. FUNCTIONS, ORGANIZATIONS, 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 the 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.

I. 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. The fundamental standard must be subdivided

and working standards prepared of these parts, and for the measure- ment of greater lengths standards must be prepared which are multiples of the fundamental standard. 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 whole set of standard weights must be prepared before the standard weight of the Government can become

available to the public. When the standard of length or weight has

been found with as many desirable qualities as possible, and before

the working standards of the subdivisions or multiples can be prepared, the question as to the method of comparison arises, which

again involves 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 capable of measuring a load of thousands of tons. The complete range must be covered, which involves

13
NATIONAL BUREAU OF STANDARDS

Washington, D. C. 1918

FUNCTIONS

Development, construction, custody, and maintenance

of reference and working

STANDARDS

and their intercomparison, improvement, and application

in science, engineering, industry, and commerce.

STANDARDS

1 STANDARDS OF MEASUREMENT

Reference 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 or

quantities which underlie scientific research and industrial processes when scientifically organized. Mechanical equivalent of heat, light, and electricity and of gravitation; specific densities; viscosities; melting and boiling points; heat capacity; heats of combustion; velocity

of propagation of light; conductivities of materials to heat and light; electrochemical and atomic weights and many similar magnitudes determined experimentally with maxi- mum precision and referred to fundamental standards of measure.

STANDARDS OF QUALITY---

Specifications for material (by description, sample, or both), known as STANDARDS OF QUALITY, fixing in measurable terms a property or group

of properties which determine the quality.

.Z^t "'^'f

°f each constituent property pertinent to the quality involved

PURPOSE

To aid ACCURACY IN INDUSTRY through uniform and correct TM

To ASSIST COMMERCE IN SIZE STANDARDIZATION , products; ' "Containers and To PROMOTE JUSTICE IN DAILY TRADE through svstem.f • and regulation; systematic inspection To facilitate PRECISION IN SCIENCE and TECHNOLOGIC RE,t.i,» through calibration of units, measures, and instruments involved

To FURNISH an EFFICIENT CONTROL for industrial processes in • reproducible and uniformly high quality in output- "cunng To SECURE UNIFORMITY OF PRACTICE in 'graduating measuring ins.TM ments, compiling tab es, in standards of quality and performance, and where,« uniformity is desirable; wnerever To AID LABORATORY RESEARCH BY REDUCING ERRORS and tainty caused by use of data of doubtful accuracy.

To secure HIGH UTILITY in the PRODUCTS of industry by setting an attainable 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

Specification of operative efficiency or action fnr „„.i.- j ,

susceptible STANDARDS

of OF PERFORMANCE,^ specif;r;he"Lr rolvT/ in^r; measurement. terms

Numerical statement of speed uniformitir Which together define the n'e. tif:::^^:'^^:::':^^^^-^"^'-

STANDARDS OF PRACTICE

Codes and regulations impartially analyzed and w„ i . j , experiment into STANDARDS OF PRrCTICF f ^'"^y and

struction, installation, operation and h..",

regulation of conquality, and performa;ce. ^ ^'^"'^"'^^ measurement.

Collation of standard data, numerical marrnV ^ defining quality, safety, economy, convenience a d^^fficie'licy °t "1= pertinent factors

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

To FURNISH for each utility a single IMPERSONAL STANDARD of practice 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 main- tenance and OPERATION of such utilities; To SECURE UNIFORMITY OF PRACTICE where such is practicable, and EFFECTIVE ALTERNATES in other cases.

14 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

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.

2. PHYSICAL CONSTANTS.

There are many fixed relations between physical quantities, the

values of which it is extremely important to know. These values

are usually termed " physical constants," and are used in every branch

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

change a pound of water into steam under normal conditions and the

relation between heat and mechanical energy are two important physical constants; their values are used in practically every computation in connection with 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 value of the

relation between electrical and mechanical energy is involved in

many important commercial transactions concerned in electricity.

Accurate and authoritative values of these constants are just as

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

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 work in all

branches of physics and chemistry—a fact not generally known by

those not engaged in the scientific or technical work where these

constants are used.

3. STANDARDS OF QUALITY.

A standard of quality for a given material may sometimes take the

form of a sample of that material with 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 properties by means of the usual standards

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

then arise, Wliy is it good or poor; What are the physical or chemical properties or the particular combination of elements which 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 answer and involve physical and chemical investigations of the

most difficult sort.
REPOKT OF DIEECTOR OF BUREAU OF STANDARDS. 15

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 m'list be suitable for the purpose intended, and

the Bureau's investigations in connection with the properties 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.

The actual testing of materials by the Bureau of Standards to

ascertain whether or not they comply with specifications is confined

almost exclusively to Government purchases, but in making these

tests (in which the Bureau has had the hearty cooperation of practically all the departments of the Government service) it is compelled to make many investigations concerning the properties of

materials, their specification and measurement. "While this work

is of great value in placing Government purchases on a correct busi- ness basis, the results of the investigations as to the properties of

materials and the information gained in testing Government supplies

are even more important to the general public and are distributed in

the form of suitable publications.

The Bureau does not compete with private testing laboratories,

but endeavors to assist them by the development of standard specifications, methods of measurement, and other matters where uniformity is desirable, much of which information, as stated above, is se- cured in connection with the testing of materials purchased by the

Government and a close observation of their use. The time is not far distant when it will be required that all materials bought or sold shall be as represented, but it should be kept

in mind that this is impossible except in the case of those materials

where proper standards of quality and methods of measurement have

been developed. It must not be assumed that the purchaser or user

is the party principally benefited in the development of such standards ; on the contrary, the manufacturer, first of all, is interested in

the quality of all things which affect the quality of his product, and

while the Bureau's efforts in this field are devoted principally to the

pointing out and measurement of those properties upon which the

quality of the materials depends, it is to be regretted that its force

and equipment are insufficient to render more assistance to manufacturers with a view to a direct improvement of those parts of the

process upon which the quality of the output depends.

4. 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 measurement. 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 specifications or guaranties have been complied with.
16 REPOET OF DIBECTOR OF BUREAU OF STANDARDS.

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 method used

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

do this properly involves the use of standards of measurement,

standards values of constants, and standards of quality. The Bureau

of Standards does not attempt to cover this field completely, but

only those cases where there is a lack of definite information upon

which to base specification^ and only to the more important classes

of apparatus. To secure this information 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.

The Bureau's activities in this field have only been developed to a slight extent and almost entirely in connection with Government

purchases. It has had in this, as well as in the field of the properties

of materials, the most hearty cooperation of the various Government

expei'ts, manufacturers, engineers, and technical societies.

5. STANDARDS OF PRACTICE.

Standards of practice are generally involved in the enactment of

laws when technical and scientific matters are concerned, in the ordi- nances 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 touch only upon the more important aspects

of the work, where national uniformity is desired—fields which can

not be covered efficiently in private laboratories.

6. RELATION OF THE BUREAU'S WORK TO THE PUBLIC.

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

that the maintenance on the part of the Government of correct standards 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 or measviring instruments of States, cities, scientific laboratories, educational institutions, manufacturers, Government bureaus, or the public, for which a nominal fee is charged, except in

the case of the National and State Government institutions. It gives

advice concerning these standards or their use, whether it be in con- nection with the enactment of laws, regulations, or ordinances con- cerning the weights and measures of everyday trade or in connection

with precision standards used in scientific Avork and the industries.

It gives advice upon request to State and city officials, public-service

commissions, and public-utility corporations regarding the standards

of measurement, or quality, or performance involved in legislation or regulation pertaining to the public utilities. Many questions of
EEPORT OF DIBECTOE OF BUBBAU OF STANDARDS. 17

disagreement between the public and utility companies as to these

matters are referred to the Bureau for advice or adjustment, often

avoiding unfair or inconsistent regulations, as well as long-drawnout and expensive litigation. 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.

It must not be inferred from the above that the Bureau's activities are devoted principa.lly to the interests of the user or consumer. The

fundamental facts regarding standards of measurement, quality, or performance are the very things which most deeply 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 are just beginning to realize

the importance of precise methods of measurement and scientific investigation, which, in i^ractically every case, involve some kind of

measurement.

It is upon quality 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 unknown 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 institiitions 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 inspection service of the trade weights and measures; also the National

Physical Laboratory, whose functions include matters pertaining to

scientific and technical standards, physical constants, and to some

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

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

with similar duties. Germany maintains three such institutions—the

Normal-Eichungs Kommission, equipped with the buildings, personnel, and apparatus necessary in standardizing and controlling the

weights and measures of trade; the Physikalisch-Technische Eeichsanstalt, covering testing and investigations in connection with

scientific and technical standards other than weights and measures;

and the Prussian Government maintains the Materialpriifungsamt,

a large institution devoted to the investigating and testing of structural, engineering, and other materials.

86986—18 2
18 KEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

It is generally recognized that these institutions have been exceedingly important factors in the industrial progress of these countries.

7. RELATION OF THE BUREAU'S WORK TO THE GOVERNMENT

SERVICE.

The bureaus of the Government engaged in scientific and technical

work are necessarily dependent upon standards of measurement of

every variety. In addition, many of them are engaged in the design,

construction, and specification of a great variety of special apparatus, in which the principles of mechanics, heat, optics, electricity, and

chemistry are involved and are vital to their efficiency and successful

operation. In such matters the Bureau has been consulted most

freely by the War and Navy Departments, and various other military departments of the Government, including the Eailroad Adrtiinistration, Shipping Board, Fuel Administration, Food Administration, and National Advisory Committee for Aeronautics; also the

Post Office Department, the Department of Agriculture, the Public

Health Service, and others.

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 testing and investigating the properties of

structural materials 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 as necessary to

the public in construction work, and every effort is made by the

bureau to make its findings in a form available to the public generally.

The demands for information of this sort have come from practically

all Government bureaus and establishments, but especially so 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.

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 plac§ 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, when delivered, to ascertain whether or not they comply

with the specifications. This is especially important, since such materials are purchased b}^ means of competitive 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. Furtherm6re, most purchasing officers are realizing the great importance of having such testins: done by a disinterested institution equipped with the scientific and other facilities for

performing the service in a manner that is fair to both parties con- cerned in the purchases.
BEPOET OF DIRECTOB OF BUEEAU OF STANDAEDS. 19

Among the many Government bureaus and establishments which

have utilized the Bureau of Standards as a testing institution in

connection Avith 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 Avith the purchase of paper, twine, textiles, etc, A wide

range of materials has been tested for the Quartermaster's Department of the Army, the Paymaster's Department 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.

Many bureaus of the Government service are charged with the administration of laws and the establishment of regulations in Avhich

scientific data are vital. This is true to a much greater extent than

is generally supposed. The Bureau of Standards has cooperated

freely with such branches of the Government and the service ren- dered 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 sou.rce of misunderstanding and litigation between the Government service and the public. Conspicuous

examples of bureaus to which such assistance has been given are the

Customs and Internal Revenue Services; the Steamboat-Inspection

and Coast Guard Services, in the promulgation of safety regulations

and the Bureau of Navigation of the Department of Commerce, in

the administration of laws regulating the use and inspection of

radiotelegraphy.

8. 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, Avhether 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 measure- ments form the fundamental and most important factor would be

referred to this division.

The division of heat and thermometry has to do with heat standards, the testing of heat-measuring apparatiis, the determination of

heat constants, of which there are many, and all investigations pertaining to quality or performance where heat measurement is the es- sential 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 equipmeiit.
20 EEPOET OF DIRECTOR OF BUEEAU OF STANDAEDS.

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

extent than has been snpj^osed; 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.

. Practicalh' 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 imiDortant

classes of materials, but many of the purely scientific questions involved would be handled by one of the above-mentioned scientific

divisions or jointly with it. The work of the technical divisions is

just as scientific in character, but deals more specificallj'^ 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, the clay products, paints, oils, paper,

textiles, rubber, and other miscellaneous materials.

The division of engineering research makes investigations and

tests regarding the performance and efficiency of such instruments,

devices, or machinery as the Bureau may take up that do not fall

directly under one of the scientific divisions. The division is a small one and its work is devoted almost exclusively to assistance given

other departments of the Government and the General Supply Committee in designing, specifying, or testing equipment. It should in

time form one of the more important branches of the Bureau's work.

The questions pertaining to the manufacture, specifications, test- ing, and use of the metals and their alloys have become so important

that a division known as the metallurgical division has been formed

of the experts engaged in these problems.

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

accounting, and library are known as the olRce division, while those

employed in the operation of the mechanical plant, the various shops,

and the care of the buildings and grounds form the engineering and

construction division.

9. LOCATION.

The laboratories of the Bureau of Standards are located in the

northwest section of Washington, on Pierce Mill Road, near Connecticut Avenue, and are reached by the Chevy Chase car line. They

were located 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 populated sections of the

city. Furthermore, the area of ground necessary precluded a site near the city. It has been found by experience that the efficiency of

the employees, especially those engaged in testing and scientific investigation, has been greatly increased by the location of the laboratories in a section free from the ordinary disturbances of city life.
II. SCIENTIFIC AND TECHNICAL DIVISIONS.

I. WEIGHTS AND MEASURES.

[Length, area, volume, mass, density, pressure, and time, including researches on units and

standards, measuring methods and instruments, specifications and tolerances, and the standardization incident thereto for inspectors of weights and measures, manufacturers of measuring appliances, scientific and technical laboratories. Government bureaus, engineers, and

the general public]

LENGTH.

(The design, improvement, and investigation ojf length-measuring apparatus, calibra- tion and test of yard bars, meter bars, geodetic tapes, level rods, haemacytometer apparatus, cement sieves, expansivity of solids.)

Military Work in Connection with Weights and Measures.

Other work having a military bearing, yet proper to be mentioned

here, includes the following

In connection with the test of coke ovens the Division of Weights

and Measures tested and adjusted the railroad ti*ack scales used for

weighing the coal, etc., used in the test. Parts of a new ordnance

design were weighed and the position of the center of gravity determined for the Ordnance Department. Considerable consulting work

has been done in relation to tolerances on screw threads, investigation of systems for sci'ew-thread tolerances, and improvements in

design of measuring machines.

Cooperation has been afforded in the design of precision micrometers of two types, one for measuring outside dimensions and one for

measuring inside dimensions, manufactured for the bureau by the

Mount Wilson Solar Observatory. An arrangement of projection

lantern has been devised for the determination of the angles of screw

threads, which is a great improvement over the apparatus previously

employed in this work.

A contact indicating device has been designed and constructed

which is found to be very sensitive and gives promise of many useful

applications; a torque measuring instrument for use in connection

with precision micrometers has been constructed, and the specifications and general features of design for an end standard measuring

machine were worked out in conference. A new method for determining the paths of artillery projectiles in flight has been proposed

and turned over to the military authorities. This division is also

cooperating in the development of a device for synchronizing machine guns to shoot between the aeroplane propeller blades and an

investigation of a machine for gauging rifle barrels is now beingconducted.

This division has also conducted a research to determine the elastic

indentation which takes place when spherical surfaces are employed,

as they are in much of the gauge-standardization work, and the cor- rection resulting from the indentation has been determined.

Many computations have been made covering such subjects as the

springs used in machine gun adjustments, tables for use in measuring

21
22 EEPOET OF DIEECTOE OF BUEEAU OF STANDAEDS.

screw threads, table for constants for the three-wire method of screw measurement, and a table of metric equivalents, which now has been

published as a supplement to Circular No. 47.

A few communications have been issued in connection with military work, among which may be mentioned one which calls attention

to some fundamental misconceptions regarding use of screw-thread

gaviges, two on the j)recision test of micrometers, and one on symbols

for screw-thread notation. This last has been adopted by the Committee on Screw-Thread Tolerances of the American Society of

Mechanical Engineers.

Additional Consulting Work.

In addition to the consulting work on track scales and testing

equipment and on specific military problems, the Bureau has done

work of similar character in reference to the use of spring scales

for investigating quarry stone under the Office of Public Eoads;

depot and wagon scales for the Engineer Corps of the Army ; platform scales and parcel-post scales for the Post Office Department;

specifications for freight-house scales for the Southern Railway;

specifications for hopper scales for the Pennsylvania Railroad and

for the American Railway Association; specifications for hopper

scales for manufacturers; an invention for obtaining an automatic

compensation for automatic grain scales for the inventor and manufacturer ; prescription scales for the Medical Supply Depot of the

Armj^ ; investigation of a new design of flexure plate scale for parcelpost work; design of 5,000-pound weights for the New York Central

Railroad ; autotruck scales, wagon scales, paper weighing scales,, platform scales, and specifications for 500-pound standard weights,

these requests coming from various sources. A series of charts for computing scales were examined and report

rendered to a manufacturer of computing scales. A careful study of

a mechanical device for measuring cloth was made for the manufacturer, special attention being paid to its acceptability for use in trade.

Length Measures.

During the fiscal year 2,071 tests for accuracy of linear measure- ments were made upon the following articles

Line standards and measuring scales (tested or ruled) 27

Tapes 695

Level rods 29

Sieves 51

Samples of sieve cloth 14

Polariscope tubes 46

Hfemacytometer chambers 228

Micrometer calipers, vernier calipers, end standards, disk gauges, etc., for

the equipment of the gauge section 919

Miscellaneous articles 62

Observations were completed on six State standards of length, a complete calibration of a bar for the electrical division of the Bureau

was made, and 24 intervals on a Pratt & Whitney bar were determined.

Among the miscellaneous articles to which length tests were applied were slotted drums for an oscillograph timer, a master chart

for compass dials, Johansson gauge blocks, steel balls, and viscosimeters. Besides the routine testing and the investigations noted,
BEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 23

mention should be made of a considerable number of informal tests and investigations for the gauge section, for other divisions of the

bureau, and for the Army,

A thorough investigation and test was made of an end comparator

at the Washington Navy Yard with a view to ascertaining whether

the apparatus was suitable and sufficiently accurate for the work

being done upon it. The results showed that a more accurate comparator was needed, and one is being purchased for this work to con- form to recommendations made by the bureau. A careful calibration

was also made of a Gaertner comj)arator for the gauge section of the

bu-reau.

Special investigations were made also of the accuracy of the large

dividing engine and of the special end comparator in use in the

Bureau.

Haemacytometers.

During the previous fiscal year the test of hsemacytometer chambers and pipettes was taken up and specifications were prepared for

the test of this apparatus. These are important instruments widely

used by physicians and bacteriologists in counting the number of

corpuscles in a given quantity of blood. Close cooperation has been

had with the manufacturers, and during the past year two prominent

manufacturers of haemacytometers visited the bureau for consultation.

As a result of the bureau's work, there has been a gratifying improvement in the instruments submitted for test. These instruments are

extensively used by the medical departments of the Army and ^avj,

and in one lot of instruments submitted for Government use excessive errors were found in the chambers. A special device is being designed to facilitate the test of these instruments.

Expansion of Insulating Materials.

Numerous synthetic insulating materials such as " bakelite,'' " condensite," " formica," etc., have been tested and heat treated to

obtain necessary information in connection with the Bureau's spark

plug investigations. It has been shown that, without exception, the

colloidal substances mentioned above are not suitable for use in delicate apparatus which may be subjected to temperatures above 60° C.

The thermal expansion soon vanishes and continued treatment shows

marked contraction and loss of weight of the specimen. A paper

on this subject will soon be prepared. Specimens of tile and porcelain were also investigated for their thermal expansion properties.

New Equipment for Measuring Expansion.

A new furnace having a limiting temperature of 1,000° C. has been

installed, and tests were made above 900° C. in connection with investigations on steel for machine guns. This new furnace has been

equipped with an improved thermocouple. With this thermocouple,

which is incorporated in a single tube, it is possible to determine temperatures at the center of either end of the furnace, also to make

differential determinations for any combination of the three points.

The set-up, in general, is a decided improvement over earlier arrangements for the work. The shape of specimens used in expansion

measurements has been modified to eliminate all possibilities of errors
24 KEPOET OP DIEECTOR OP BUEEAU OF STANDAEDS.

due to rust or blisters forming between the specimen and the drop

wires at high temperatures.

Length Testing.

The following table gives a summary of the thermal expansion

tests made during the year

Number of Materials. Samples.

Aluminum-copper magnesium alloys ' 2

Zinc-aluminum alloy 2

Bakelite, continental 1 Bakelite, dilecto 5

Bakelite, micarta ~ 2

Condensite . 3

Formica 4

Copper alloys 61

Molybdenum 1 Nickel steel 4

Tile 1

Verilite , 2

Porcelain 17

Marble 3

Silicon steel 1 Steel - 41 Steel (machine gun) 2

Total 115

Six aluminum alloys tested in cooperation with the Metallurgical

Division were under consideration as possible materials for airplane

construction. The copper alloy work has progressed far enough to

show a definite mathematical relation between the coefficient of ex- pansion and percentage of alloying metals.

Special War Problems.

{a) Assistance was given the Signal Corps in correcting certain

defects in the range-finding mil scale used in officers' field glasses.

The Bureau also cooperated with the Navy Department in improving

the quality and quantitj^ of mil scale production at the optical shop

annex. Master plates used in making the above scales have been constructed giving the ranges in meters and yards on each scale.

(6) A new type of direct reading micrometer gauge was designed

and constructed for special requirements of the Surgeon General's

Office. Values correct to one-thousandth inch are shown automatically.

(<?) Errors in Brinell microscope scales used in testing the hardness of iron have been located.

{d) Computation and introduction of metric range values for mil

scales.

MASS.

(The preparation of specifications and tolerances for weights and balances, improvement in design of balances, solution of fundamental problems arising in connection with

weighing; examination and test of precision weights and balances and design of weights.)

Weights and Balances.

A new classification of weights, together Math new_ specifications,

and new regulations and fees for testing standard weights were put

into force in December. Because of unavoidable delays in complet-
REPOET OF DIEECTOE OF BTJEEAU OF STANDARDS. 25

ing the new edition of Circular No. 3, this new classification and the

regulations were issued in abbreviated form in a mimeographed

pamphlet.

New Material for Small Weights.

In view of the present scarcity of platinum and its urgent need

for TDther technologic work in which no satisfactory substitutes are

available, this Bureau early approved the use of gold for weights

of 500 milligrams and less. Since then, " rhotanium A " and " palau " have also been approved for use in sets of high-grade analytical

weights, such as are included in class S of this Bureau's classification.

A brief announcement in regard to these facts was sent to all makers

and dealers who could be reached. The War Industries Board now

refuses to release platinum for use in making such weights.

New Method of Testing Weights.

In continuation of the plans for shortening the time required in

the testing of ordinary analytical weights there was purchased a high-grade assay balance equipped with a device by which a special

set of weights can be applied from without the case. On account

of certain defects which developed in this balance, the method was

not at first wholly satisfactory. The difficulties in details have now

been largely overcome. It appears that the method will ultimately

succeed in saving a considerable amount of time.

Routine Weight Testing.

Testing of this character carried out during the year was somewhat less in amount than during the preceding year. Standards

were tested for six States and for a number of ditferent offices of the

Federal Government. The latter include the Ordnance Department

and the office of the Surgeon General of the Army, the Director of the

Mint, the Bureau of Mines, the Bureau of Ordnance and the Office of

Inspector of Hull Material of the Navy Department, and several

others. An increasing amoimt of work has also been done for other

divisions of the Bureau.

TIME.

(Origin and improvement of methods of test, and tlie testing of watches, clocks, and

chronometers, and preparation of specifications therefor.)

Time-Measuring Devices.

The work of the Time Section has increased very greatly over that

of the previous year. The increase has been primarily due to the

requirements of the United States Shipping Board for ship watches, or high grade watches of proved quality to be used on ships of the

Emergency Fleet in place of marine chronometers, which are unobtainable in the numbers required, and for ship clocks, and to a demand by the Ordnance Department, United States Army, for accurate stop watches.

On account of this urgent war work the regular class A tests scheduled for August, 1917, and each succeeding three months were

canceled, only one test for this class of watches being held during

the fiscal year. This was begun on April 25, with 26 watches submitted.
26 EEPOKT OP DIRECTOS OF BUEEAU OF STANDAEDS.

A summary of the year's work follows

Number tested. Class A -vratches 25

Eesearclies for Government Bureaus 52

Researches for Time Section 7

Ship watches 553

Ship clocks 745

Airplane clocks 71

Stopwatches (precision test) 4

Stop watches (ordinary test) 3,743

Miscellaneous tests 2

Total 5,202

Of the 25 watches submitted to the class A test, certificates were

granted in the case of 9, all of which were of American make ; certificates wei'e refused in the case of 15 watches, of which 3 were of

European and 12 of American make.

Continuous assistance in an advisory capacity was rendered the

United States Shipping Board throughout the first part of the year

in the purchase of navigation instruments. This included the preparation of the major poi'tion of the specifications for ship watches.

The Bureau also assisted in preparing specifications for certain airplane watches.

During the year a number of Government Bureaus submitted

specifications for timepieces for test, and asked for rejoorts on their

performance, with a view to drawing up suitable specifications. Eecently the Bureau has been asked to prepare specifications for factory tests of timepieces and to do " calibration testing " as a key to

the performance in special phases which are not included in factory

tests. The outlook is very encouraging for a wider application of the

Bureau's specifications and a greatly increased use of its facilities

for testing timepieces.

CAPACITY AND DENSITY.

(Deslarn and improvement of apoaratus and methods of test, preparation of specifica- tions for. and testing of glass volumetric apparatus, capacity measures and hydrometers,

measurement of density and thermal expansion of liquids, density of solids.) Capacity and Density.

The following is a summary of the volumetric apparatus tested

during the year

Number

submitted.

Number

rejected on

preliminary examina-"

tion.

Metal capacity measures

Burettes

Cylindrical graduates

Dilution pipettes Flasks Transfer pipettes

Measuring pipettes

140

27569 438 560

643

94

20

511 216

114

4

Of the volumetric apparatus submitted for test 60 per cent passed

the test, while of that actually tested 72 per cent passed.

One thousand three hundred and nineteen hydrometers were

tested, an increase of 35 per cent over last year. Sixty-seven per cent
REPOET OF DIKECTOK OF BUREAU OF STANDARDS. 27

of the hydrometers submitted passed the test, while of those actually

tested 71 per cent passed. In addition 1,100 sugar flasks were tested,

100 miscellaneous tests were made, and the work of inspecting and

testing a lot of 216 cylindrical graduates is well under way.

Two hundred and twenty-four density determinations were made

on A'arious substances, representing an increase of 45 per cent for

the year.

Density Researches.

Density determinations were made on several samples of sea water

and other sodium chloride solutions in cooperation with another sec- tion of the Bureau. The data obtained in this work will be useful

in problems of oceanography. Several samples of sodium chloride

solutions of various concentrations have been prepared for the completion of an investigation on the density-concentration relation and

for the purpose of establishing a percentage scale for salt solutions

for use in the manufacture of hydrometers to be used in the pickling

industry.

During the year several firms interested in the manufacture of dilution pipettes sent representatives to the Bureau for conference and

information on oar method of testing such pipettes. The dilution

pipettes recently submitted show an improvement over those submitted in the early part of the year, indicating that the manufacturers are producing a better grade of pipettes.

Several of the manufacturers of other glass volumetric apparatus

have visited the Bureau and spent some time in studying our methods

of testing volumetric glassware.

GAS-MEASURING INSTRUMENTS.

(Design and improvement of apparatus, and the Investigation and improvement of methods of tests of gas meters and meter-proving apparatus and other instruments used in connection with the flow of gases; testing of meters and meter-pi-oving apparatus.)

Gas Measurement.

The gas-measuring section has made tests of six dry gas meters for use in war work by difl'erent branches of the Government and furnished information and advice from time to time regarding the meas- urement of gas in small and large quantities. The iinproved type of

portable cubic-foot apparatus for calibration work, developed by this

section, has been used in the investigational work of the Gas Warfare Division of the Army, and a considerable number of these instruments have been constructed for this purpose.

This section has cooperated with different branches of the naval

and military service with considerable success, a part of this work

being of a confidential nature.

WEIGHTS AND MEASURES LAWS AND ADMINISTRATION.

(Cooperation with States in the administration of weights and measures laws; promulgation of specifications and tolerances for apparatus, and of rules and regulations ; en- forcement of standard barrel laws ; conducting weights and measures investigations ; an- nual conferences of State and local oflBcials on weights and measures.)

General Weights and Measures Legislation.

Several States have enacted amendments strengthening their code

of weights and measures laws during the past year. No national

weights and measures legislation has been passed, but there is now
28 BEPOKT OF DIRECTOB OF BUREAU OF STANDARDS.

before Congress a bill designed to standardize packages of flour,

which has the hearty support of this Bureau and also of the milling

trade in general. By the terms of this bill the 100-pound package is

made the standard, and all other packages are required to be a multiple of 100 pounds, or one of the following fractional parts thereof,

viz. 50, 20, 10, 6, 4, 2, or 1 pound. This bill eliminates the present

odd-size barrel of 196 pounds and its subdivisions, 98, 49 or 48, 24 or

24^, 12 or 12^ pounds, etc. It therefore simplifies the package units

vei'y much and provides for uniform packages thi-oughout the country, a condition which does not exist at the present time on account

of conflicts in State laws and of the customs of trade.

Cooperation with States and Other Interests in Weights and Measures Administration.

This feature of the work, which has proved to be of the greatest

utility in obtaining the proper and uniform enforcement of weights

and measures laws in the past, has been continued in so far as possible during the present year. While it was deemed advisable again

to postpone the session of the annual conference on weights and

measures on account of congested conditions on the railroads and in

Washington and on account of the greatly increased work devolving

upon the bureau staff and upon State and local officials on account

of the war, assistance has been rendered in other ways whenever practicable. Eepresentatives of the bureau have attended State conferences in Indiana, Maine, Massachusetts, New Jersey, New York, West

Virginia, and Wisconsin and have given instruction on subjects of

current interest and importance, particular attention being paid to

the standard barrel law, which will be enforced largely through the

aid of State and local officials. Assistance in solving special problems, such as installation of State weights and measures laboratories

and difficulties arising in connection with obtaining and maintaining accuracy in oil pumps and gas, water, and electric meters, has

been furnished both at the bureau and in the field and by corre- spondence. A publication entitled " Manual of Inspection and Information for Weights and Measures Officials" has been completed

. and is now in page proof. This should do much toward improving

and unifying practices among the various departments throughout

the country. Many requests for copies have already been received.

In its work of cooperating with other interests representatives of

this Bureau have contributed to other conferences and meetings,

among which may be mentioned, in addition to those referred to

above, the National Scale Men's Association, the American Society

of Mechanical Engineers, where war problems were particularly

presented and discussed, and a meeting in Cleveland to discuss the

matter of specifications for structural steel for the bridge construction of railroad track scales.

COMMERCIAL SCALES.

(The testing of railroad track scales, elevator scales, mine scales, other commercial

scales and weighing and measuring apparatus ; specifications for and capacity rating of

scales.) Preliminary Mine-Scale Investigation.

In August, 1917, it was brought to the attention of the Bureau

that a serious condition of affairs existed in the coal fields of Alle-
BEPORT OF DmECTOE OF BUREAU OF STANDARDS. 29

gany County, Md., as a result of disputes continually occurring between the miners and operators in regard to the condition of the

scales and methods used in weighing the coal mined by the workers,

upon which their wages depended. The miners distrusted the weighings obtained from the scales in use and believed that they were not

receiving the full amount of pay to which they were entitled. No

method of remedying the situation had been found and it had become so acute that a general strike was impending and would cer- tainly have occurred had not the Bureau promptly intervened and

obtained a postponement of this action while an investigation was

conducted. This matter was considered to be of the greatest importance on account of the special necessity for continued production of

coal at this time, when it is so vitally needed.

No attempt was made to test all the scales in the region, those

being selected for test at mines whei'e the friction between operators

and employees was most pronounced. As a corollary to the test of

scales an investigation was conducted into the matter of average

tare weights and others matters closely related to the accuracy of the

weights obtained.

It was demonstrated that the grievances of the miners were in

many cases well founded. The scales had in many instances been

improperly installed, and, again, no proper attention to their maintenance had been given throughout long periods of service. Again,

in at least one instance fraud in weighing was very strongly indicated. The result of all these condition^ was that very serious errors of use were common—not a single scafe examined being within the

tolerance allowable in such work; moreover, important errors were

in every case in favor of the operator. One scale used to weigh loads

of less than 2 tons was out of balance by the extraordinary eri'or of

616 pounds, and one of the counterpoise weights used thereon was in error by 111 pounds on a nominal weight of 1,120 pounds, both er- rors, of course, resulting in underpayment of the miners for the coal

dug b}^ them. In another case two counterpoise weights were found

which had been plugged with lead in such a way that errors of 103

pounds and 41 pounds were introduced, the total error on the scale,

including other causes, being 166 pounds, this discrepancy again re- sulting in short weight. Other errors were consequent upon faulty

methods of operation, such as the incorrect determination of tare

weights of cars. The representatives of the bureau were called before the Allegany

County grand jury and gave testimony regarding the results of the

inspections and tests, and later, indictments having been found, testimony was given in court. In the cases of three scales fines of $300

and costs were imposed in each case, while in a fourth case sentence

was suspended upon the company's action in paying to their workers more than $2,200, which had been wrongfully withheld on ac- count of the inaccuracy of the weights.

As a result of the above-described circumstances an urgent deficiency appropriation of $16,000 was granted by Congress for the

continuation and broadening of the scope of the work. Also certain

changes recommended in the State mining law by the bureau were

incorporated in a bill introduced in the State legislature. While this

bill failed of passage, it is understood that many of the proposed
30 REPORT OF DIRECTOR OF BUREAU OF STAOTARDS.

changes were adopted by mutual agreement of the operators and

miners. Assurances were given by the companies to the court that

attention would be directed to the immediate repair of all scales

owned by them in this region and that such scales would thereafter

be properly maintained to guard against the recurrence of errors.

Continuation of Mine-Scale Investigation.

When the appropriation for the continuation of the investigation

became available steps were taken to build up an inspection force

and equip them for efficiently carrying on the work. Two motor

trucks of the light aviation type built in accordance with Signal

Corps specifications have been procured through the cooperation

of that branch of the service for transporting the personnel and

equipment required.

During the last month of the fiscal year the investigation has been

renewed, the same region being chosen for its inauguration, and the

same method of selection of scales being adopted as in the preliminary

work.

It has already been demonstrated bej'ond all doubt that the investigation has been productive of beneficial results, since the conditions

here are on the whole enonnously better than those which obtained

at the time of the preliminary investigation. A general awakening

to the necessity of maintaining accurate weighing equipment and

properly using the same is evidenced throughout the whole region.

Less dissatisfaction appears «imong the miners than formerly, and

they show entire willingness to abide by the decisions of the Bureau.

During the later phase of the investigation it developed that about

45 per cent of the scales tested were installed or repaired in the time

intervening between the two visits of the Bureau inspectors. This

is a great contrast to former conditions, since at that time nearly all

of the scales had been in use for years practically without attention.

Thirtj^-seven per cent of the scales thus far tested have been found

to be within the tolerance allowed and the average error and the

average shortage on those found incorrect are only about one-third

and one-fifteenth respectively of the former figure^ Moreover, only

about one-half of the incorrect scales are now in favor of the operator, while in 1917 two-thirds were in this condition, and, as stated,

the average magnitude of the errors has been materially decreased.

The following shows in brief tabular form the conditions found in

this region in the investigations of 1917 and 1918, respective^

1917 1918

33 53

67 47

0.4 3.0

do.... 9.3 1.7 do.... 7.0 • 2.4 do.... 7.4 0.5

While conditions have greatly improved, the fact can not be over- looked that some of the companies are still maintaining grossly inaccurate scales (one was found which had an error of 350 pounds on

a ton in favor of the operator) ; inaccurate average tare weights are
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 31

in use in some cases, and faulty methods of weighing (such as weighing cars in motion, coupled cars, etc.) are occasionally en- countered. The county authorities plan to prosecute in all those

cases where errors are such as to warrant that xDroceeding.

"Wlaile it is probably true that improvements thus far caused are limited to the one district investigated, it may be said that the bettering of conditions here is distinctly encouraging, and it appears that,

in general, conditions can be materially improved in this manner

and the production of coal thereby definitely stimulated throughout

the country.

Railroad Track-Scale Work.

The investigation of railroad track scales and railroad weighing

throughout the country has been carried on by the Bureau since 1913.

In this work the Bureau now has, generally speaking, the hearty co- operation of the State departments of weights and measures, rail- • road companies, industrial concerns, manufactui-ers and shippers,

and weighing inspection bureaus, and is constantly receiving requests

for tests from all of these sources. The Bureau's scale-testing equipments are generally recognized as far superior to any other scaletesting equipments in the country and the tests made by the Bureau

are considered authoritative. As a result the Bureau in many instances is called upon to settle disputes between railroads and

shippers.

The war has had a marked effect upon the railroad track-scaletesting work during the last fiscal year. This has been due to two

things: First, a considerable portion of the energies of the staff has

been applied to direct war problems (the nucleus of the pi-esent

gauge-testing force of this Bureau was obtained from the railroad

track-scale-testing staff) ; second, the war has altered the status and

increased the importance of this work since the Government has

taken over the railroads and guaranteed their revenues. Cooperation with Railroad Administration.

When the operation of the railroads of the country was placed in . the hands of the Director General of Railroads, it was immediately

apparent that the track-scale work of the Bureau would be greatly

enhanced in importance, since the larger part of the revenue of the

roads is derived from freight charges levied as a direct result of the

indications of these scales. It was the desire of this Bureau to cooperate to the fullest extent with the Railroad Administration in order

that the work might be made of the maximum benefit, and accordingly an offer of cooperation was promptly made. This offer was

accepted by the Railroad Administration, and Circular No. 13 has

been issued by that service, under the terms of which the Bureau

is authorized to make tests of any railroad scales or test cars for the

purpose of obtaining necessary data and information relative to

specifications and tolerances and methods of test of scales. Reports

of tests are to be furnished to the railroads and the regional directors concerned.

Testing Equipments for Track Scales.

During the past year the Bureau had in operation 2 track-scaletesting equipments—test cars Nos. 1 and 2—each comprising 100,000
32 KEPOET OP DIRECTOR. OF BUREAU OF STANDARDS.

pounds of accurate standardized weights carried in a freight car of

special construction equipped with an electric generator for the purpose of developing power for operating the machinery employed in

handling the weights and in moving the cars during the test. In April, 1918, a new scale-testing equipment, consisting of 2

weight units of 40,000 pounds and 80,000 pounds traveling upon

their own wheels, was completed and put into operation. These 2 cars are designed to be operated together as one testing unit, and

will be satisfactory for testing all commercial track scales when used

in a region accessible to a master scale, permitting the checking of

the accuracy of the weights at appropriate intervals. The acquisition of these cars makes it possible to employ the other testing equipments largely in the testing of master track scales, for which work

they are particularly suited on account of their special design.

Master Scale.

Since the inauguration of the track scale work it has been realized

that it would be necessarj? to provide a master scale to serve as a primary standard for standardizing railroad track scale test cars that would be used in turn as standards for testing railroad track

scales on the various lines. Therefore some time ago a master scale

was ordered ; this is now complete. In connection with this and as a part of the installation of this scale a building will be provided for

housing the scale and an auxiliary laboratory equipped for the calibration of test weights used in connection with the test car work,

such as the 10,000-pound weights forming a part of testing equipments Nos. 1 and 2, and the 50-pound test weights supplementing the

equipments, and for the standardization of test cars Nos. 3 and 4. In

addition a shop will be equipped for the general overhauling of the

cars which becomes necessary from time to time and to furnish a storage depot for cars and other equipment. This has become especially necessary now, since the two new test cars mentioned are standard weights traveling on their own wheels, and require frequent

verification to maintain accuracy consistent with the work of this

Bureau. This can only be accomplished on a master track scale.

Tests of Track Scales.

During the fiscal year tests were made in 35 States and in the

District of Columbia, as follows: Alabama, Arkansas, Connecticut,

California, Colorado, District of Columbia, Georgia, Indiana, Illinois, Iowa, Kansas, Louisiana, Michigan, Massachusetts, Missouri,

Minnesota, Montana, Mississippi, North Dakota, North Carolina,

New Jersey, New York, Nebraska, Nevada, Ohio, Oregon, Oklahoma,

Pennsylvania, South Carolina, South Dakota, Tennessee, Texas,

Utah, Virginia, West Virginia, and Washington.

The scales tested belonged to the Federal Government, State governments, railroads, and industrial concerns.

Master track scales '. 16

Scales owned by railroads 291

Scales owned by industries 276

Total number of scales tested ! 583

Forty-two per cent of the track scales owned by railroads and 36

per cent of the track scales owned by industries passed the Bureau
EEPOKT OF DIKECTOE OF BUBEAU OF STANDAEDS. 33

tolerance. This tolerance is based on a maximum allowable error of

200 pounds in weighing a car of 100,000 pounds gross weight. Only

2.5 per cent of the railroad master scales tested were found to be

within the tolerance adopted by the Bureau for scales of that type.

In addition to the tests of railroad track scales and master scales

the Bureau's testing equipments were used in the test and calibration

of 31 scale test cars owned by railroads.

Detailed reports of the tests were rendered to the owners of the

scales. Copies of these reports were frequently sent to other interested parties, as, for example, officials of those States which have or- ganized departments of weights and measures, officers of weighing

and inspection bureaus haA'ing jurisdiction over scales, chambers of

commerce, and the American Eailway Association. Most of these

reports were rendered directly by the field statf. These reports represent a very important phase of track scale work. They give the

results of the test in detail, show the conditions found by careful inspection, and make definite recommendations looking to the correc- tion of such faulty conditions as are present. It was necessary to

discontinue the practice of preparing reports in the office on account

of the pressure of extra war work.

The owners of the scales have been afforded every opportunity

to witness and become conversant with the methods of the tests, and

the recommendations included in the reports have, perhaps in the

majority of cases, been carried out. In many cases new scale installations have been made, when necessary, as a result of the test and

recommendations of the Bureau.

The principal deficiency in reference to the railroad track scale

situation has been the great lack of master scales for calibrating the

test cars necessary for the proper maintenance of railroad track

scales on the part of the railroads. It is believed that when the

necessary facilities have been provided for all the roads there will

be a marked improvement in the design of scales installed and in

the accuracy Avith which they are maintained. The Bureau purposes

giving this matter the fullest possible consideration during the next

year. At the present time there are important sections of the country in which no facilities exist for the proper test of railroad track

scales, particularly those which are the property of private owners. Consulting Work on Track Scales.

With reference to track scale specifications the Bureau has been

consulted in the matter of drawing up requirements or considering

bids by a number of Government agencies, railroads, and industries,

among which may be specifically mentioned the Bureau of Yards and

Docks of the Navy Department, the Nitrate Division of the Ordnance

Department. St. Elizabeth's Hospital (a Government institution), the

Virginia Shipbuilding Corporation, and the Eailroad and Warehouse

Commission of the State of Minnesota. With regard to the last named,

specifications were prepared under the direction of the supervisor

of scales governing the design and installation of railroad track

scales in the State of Minnesota coming under the jurisdiction of the

Railroad and Warehouse Commission, as a result of the conference

between the representatives of that State and the Bureau.

86986—18 3
34 BEPOKT OP DIEECTOR OF BUREAU OF STANDARDS.

Capacity Rating of Track Scales.

In connection with the conservation of engineering effort and material and at the same time to avoid deterioration in the product, the

bureau plans to make a study of the capacity rating of railroad track

scales to aid the manufacturers and railroads in the procurement

of weighing equipment which will be adequate for modern needs,

and at the same time will eliminate unnecessary variety in the number and character of scales constructed. This work will be pushed

as rapidly as the competent technical assistance can be secured.

GAUGES.

(Improvement in the design and use of munition and other gauges, origin and development of methods of test, manufacture and salvage of gauges, examination and test of gauges.

Gauge Work.

The Division of Weights and Measures has for several years tested

and standardized precision length standards and various forms of

gauges and measuring instruments for the several branches of the

Federal Government and for industrial concerns. In keeping with

the program for the rapid production of munitions, this work has

been expanded to a large degree in order to provide for the many

demands made by the War and Navy Departments and by manufacturers having contracts for war material.

On June 15, 1917, a special war appropriation of $150,000 for the

gauge work of the Bureau of Standards was granted by Congress,

and on July 8. 1917, apparatus and equipment were transferred to a

special temporary building for the testing of munitions gauges. Apparatus and personnel for testing gauges were assembled at an early

date to enable this Bureau to test without delay such gauges as might

be submitted. The first lot of munitions gauges was submitted on July 16, 1917.

Practically all of the various lots of gauges have been completed

and shipped within three or four days from the time of receipt. In

many instances the gauges were received, tested, and shipped on the

same day.

The main demands which have been made on the gauge section

have been the test and certification of master gauges for artillery

ammunition, trench warfare material, and cannon components

being produced in large quantities for the Ordnance Department of

the Army. A considerable number of gauges have also been tested

and certified for the Motor Transport Division of the Army, these

being employed in the production of motor trucks. The Signal

Corps of the United States Army also submitted during the latter

part of the calendar year 1917 a considerable number of master

gauges which were for use in connection with the production of

aeroplanes and aeronautic instruments. In addition to the work of

testing and certifying master gauges for the War Department the

Bureau has received a large number of inspection gauges which were

submitted by various manufacturers having Government contracts.

The organization of the gauge section includes a shop which

was formed primarily for the construction of special apparatus re- quired in the rapid and accurate testing of the more complicated

forms of gauges, e. g., thread gauges and profile gauges. The per-
BEPOET OF DIEECTOE OP BUEEAU OF STANDAEDS. 35

sonnel of this shop being mainly toolmakers and gauge makers, it has been of service in the salvage and building of gauges for exigent needs.

The gauge section has also prepared and distributed technical

information pertaining to the methods of test, tolerances, tables for

computation, and other essential data for use of gauge makers and

gauge inspectors. Blueprints and specifications of special machines

designed by this Bureau for measuring gauges have been distributed

to manufacturers.

Gauges Tested,

An idea of the amount of work which has been submitted is given

in the following table, which indicates the number of gauges that

have been received, tested, and certified or rejected during the past

year:

1917—July '-- 244

August 473

September 456

October- 737

November ; 1, 735

December 1, 142

1918—January 2, 519

February 1, 813

March 3, 582

April 4, 688

May 4, 91T

June ^ 5, 559

Total 27, 865

In the above table about 60 per cent may be classed as plain gauges

(plain plug, snap, and ring gauges) ; about 20 per cent as profile

gauges (complicated templets, chamber gauges, and fixture gauges) ; and about 20 per cent thread gauges. Attention should be called to

the fact that of the 27,865 gauges mentioned about 60 per cent were

examined for the Ordnance Department, United States Army; 15

per cent were examined for the Motor Transport Division, United

States Army ; about 10 per cent were on account of the Signal Corps,

United States Army; and the remaining 15 per cent were examined

for other branches of the Federal Government and industrial con- cerns having Government contracts.

In addition to the foregoing tests the bureau has been called upon

to inspect at various points in the field numerous gauges used in the

production of cannon. In this connection over 300 master gauges

were inspected at Rochester, N. Y., for the 75-millimeter field guns,

and about 500 master gauges for the 3-inch antiaircraft gun at Philadelphia. About 1,500 gauges have been inspected at the New York

City branch of the gauge section of this bureau since that branch

Avas opened on May 15, 1918.

Work of Gauge Shop.

There have been produced in the gauge shop about 50 machines for

measuring screw threads and profile gauges, and various other instruments and accessories for use in connection with measuring instruments. The work of salvaging and manufacturing gauges re- quired for immediate use was stai'ted at the request of 'the inspection

division of the Ordnance Department about May 15,, 1918. Since'
36 EEPOBT OF DIRECTOR OF BUREAU OF STANDARDS.

that time about 400' gauges have been salvaged and in the neighborhood of 50 new gauges have been made.

Present Facilities.

At the gauge section of the Bureau of Standards in Washington

there is available an organization of about 100 men for the test and

certification of all kinds of munitions gauges. There, are available

also a shop force of about 40 men and shop equipments for gauge

manufacture and salvage to the extent of over 60 machine tools.

This tool-room equipment with stock accessories represents an outlay

of about $100,000.

In the Branch Gauge Section at New York City there has been

duplicated practically all of the various types of equipment available

at the bureau in Washington for the test of munitions gauges. This

branch is conveniently located in the Engineers Building at 29 West

Thirty-ninth Street. At the present time about 16 men are assigned

to the New York branch ; this number will be increased whenever the

requirements of the work make it necessary. Preparations have

been made for the organization of a branch laboratory in Cleveland

and one in Bridgeport. The laboratory in Cleveland became available for the test of gauges on July 1, 1918, and the laboratory at

Bridgeport will be opened about August 15, 1918.

Suitable increase of facilities at Washington and at the branch

laboratories will take place as fast as the needs of the War and

Navy Departments and manufacturers are presented.

PUBLICATIONS AND INFORMATION.

(Publications issued on mass, length, capacity, expansivity, and cooperation with

States on weights and measures ; and mention of miscellaneous information on humidity,

nickel steels, tonnage space, and weights and measures apparatus.)

Publications.

The following publications have either been prepared or entirely

revised during the year: Circular No. S, The Design and Test of

Standards of Mass; Circular No. 10, Legal Weights (in pounds)

per Bushel of Various Commodities ; Circular No. 67, Wire Gauges

Circular No. 71, Rules and Regulations Promulgated under Authority of the Federal Standard-Barrel Law ; Circular No. 77, Tables of

Unit Discplacement of Commodities; Miscellaneous Publications

No. 1, A Manual of Inspection and Information for Weights and

Measures Officials; a paper on The Thermal Expansion of Molybdenum, and Technologic Paper No. 114, Portable Cubic-Foot Standard

for Gas.

Miscellaneous Information Furnished.

Some information has been given regarding the measurement of

humiditj^ in the temperature range 50°-160° C, and a chart giving

approximate computations has been prepared.

A number of letters have been answered giving data on expansion

of materials, especially the nickel steels, concerning which there seems to be a considerable demand for information.

An investigation was made for the Post Office Department of the

claims concerning a tide motor as set forth in advertising matter

transmitted through the mails by a certain corporation, the object

of the investigation being to give the Post Office Department a basis

on which to determine whether it was permissible to send such ad-
BEPORT or DIRECTOE OF BrREAU OF STAIsDAEDS. 37

vertising matter through the mails, under the postal laws. The

bureau found that the claims made were gross exaggerations and

that the motor is entirely impracticable.

During the early part of the fiscal year the bureau cooperated

with the Food Administration by furnishing lists of weights and

measures officials in the various States, about 1,.500 in all. so that the

Food Administration could enlist the services of these officials in

the conservation of food, as it was believed that this body of men,

in view of their acquaintance with the methods used and the channels employed in the production of food supplies and their distribution from the producer to the consumer, could render valuable

service. The bureau prepared a circular letter to these officials ex- plaining that cooperation with the Food Administration wotild be

of great benefit and urging their assistance. The replies to these

letters indicated that the fullest measure of cooperation and assist- ance would be given the Food Administration.

In view of the necessity of making efficient use of the full toimage

capacity of ships, the Biu'eau has been compiling information on the

volume displacement of various commodities as packed for overseas shipment, to ascertain the number of pottnds per cubic foot, the number of cubic feet of space required for a short ton and a long ton.

and the manner in which the material is packed for shipment, so that

the data might be compiled in a form readily usable. Information

along this line has been furnished from time to time to various

branches of the Govermnent, as well as to private concerns. A short

circular has already been prepared presenting much of this information and a more extensive publication is now nearly ready.

At the request of a representative of the inspection office of the

Quartermaster's Department of the Army data were made available for the comparison of the accuracies in field service of two

types of liquid-measuring pumps under consideration for ptirchase

by the Depot Quartermaster Corps. The data furnished were derived from the extensive field inspection made about a year ago.

which was recorded by the use of index cards in a manner making

it possible easily to determine statistically the comparative merits in

operation and the relative permanence and accuracy of the various

makes concerned. This information when considered with results

subsequently obtained in a test of efficacy of the filter with which

the ptunps are equipped for separation of water from gasoline provided adecjuate information on which to decide the purchase.

In connection with the purchase of a large munber of prescription

balances and apothecaries" weights for the medical supply depot of

the Army at Xew York City, the Bureau was enabled, in view of the

thorough study that it had given to tolerances and specifications for

balances during the past several years, to render valuable assistance

in the preparation of specifications with which the apparatus should

comply and the tolerances that should be allowed. A considerable

saving in time, which is always so important a factor in war work,

was also undoitbtedly effected.

Assistance was rendered the weights and measures department

of the State of Massachusetts in preparing plans for rearranging and

enlarging their laboratory to take care of expanding work, a representative of the Bureau being sent to Boston to inspect personally

the available space and to confer with the State officials in the matter.
38 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

2. ELECTRICITY. .

lElectromotive force, resistance, current, inductance, capacity, conductivity, insulation,

magnetic permeability and hysteresis, radioactivity and radiocommunication, including researches on electrical units and standards, measuring instruments, and methods of measurement, and cooperation with standardizing committees of technical societies, with testing laboratories, the electrical industries, public-service companies, and publicutility commissions, municipalities, and engineers upon problems of electrical standardization, including standards of adequacy, and safety of electric service.]

Scope of the Electrical Work.

One of the most important functions of the Bureau with respect to

electricity and allied subjects is the establishment and maintenance

of the fundamental standards upon which all measurements in these

fields are based, including cooperation with similar institutions in

other, countries so as to secure international uniformity. This includes the intercomparison of standards and 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 immediately 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.

The testing of electrical instruments and apparatus is of two main

classes. First, there is 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 types. The

greater portion of this testing is done for the Government services,

and serves the double purpose of providing information to be used

in formulating specifications, and of determining the quality of deliveries of materials purchased 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 jDlays an important role. Electrical, radio, and

illuminating engineering interests are all served by these investigations. The Bureau also renders important service, both directly and

indirectly, to manufacturing and other industries. Some of this investigational work is on the more fundamental aspects of the

principles involved, 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 in measurement of lights of different colors, and correlations of magnetic and mechanical properties of

iron and steel, and study of galvanometers are examples.

The research work in radiocommunication, 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 measurement are being improved, and
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 39

important special problems of significance to the industries and in a number of cases of particular importance to the Government, are being investigated. Specific examples of the projects in hand during

the past year are given in the sections below.

Special Military Work in Electrical Subjects.

During the past fiscal year opportunities for service to military

departments have been so numerous both in testing and in research

that the resources of the electrical division, like those of other parts

of the Bureau, have been very largely devoted to such service. This

has involved a greatly increased amount of work similar to that

performed in ordinary times, including consultation with other departments on a large number of technical problems; opportunity

has also been found to undertake somewhat extensive investigations

of a few important military problems. This military work has been

made possible in part by the use of special funds provided by Congress and by the military departments and in part by cutting down

so far as practicable the time devoted to ordinary work which has

less bearing on the war. STANDARDS OF RESISTANCE.

(Maintenance of fundamental standards of electrical resistance, calibration and devel- opment of practical resistance standards and apparatus, testing of conductors and of con- ductivity of materials, galvanometer design.)

INDUCTANCE AND CAPACITY.

(Methods of measuring inductance and capacity, preservation and calibration of stand-- ards of inductance and capacity, design of apparatus involving inductance and capacity

phenomena, development of formulas for computing inductance and capacity, measurement

of shoi't time intervals.)

With the exception of necessary work in routine testing, these

two sections have devoted practically all their time during this

year to urgent military problems of a confidential nature.

ELECTRICAL MEASURING INSTRUMENTS.

(Design and calibration of electrical instruments and appliances.)

Testing of Electrical Instruments.

This work has necessarily been considerably curtailed during the

year. Pi*eference has been given to tests for the military authorities,

but the needs of others have been met so far as possible. Work of

this kind is made more difficult, but at the same time more necessary

by the fact that mechanical defects and errors of calibration are more

frequent now than in normal times. Even the best makers of instruments have had difficulty in keeping their output up to the usual

standards of accuracy.

Nev/ Deflection Potentiometer.

Some improvements in the design of deflection potentiometers

have been made, and the latest type of this kind of instrument incorporating these improvements was received from the makers early

in the year. The design has been simplified as compared with former

instruments. This latest potentiometer has a fundamental range of

to 150 millivolts readable by estimation to 10 microvolts.

Instrument Transformers.

The accurate testing of instrument transformers is of increasing

importance on account of their use in measuring electrical energy,
40 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

especially where it is sold in large quantities or at high voltages.

Some of the State public utility commissions now require the periodic

testing of instrument transformers used in the sale of electrical

energy. A very considerable amount of assistance has been given

to some of the State commissions and the larger central stations

in designing special equipment for their laboratories for the testing

of instrument transformers. Two sets of such equipment have been

constructed and submitted to the Bureau for test. Methods of Testing the Electrical Properties of Transformer Oils.

In cooperation with a committee of the American Society for

Testing Materials, a comparative study is being made of disk and

sphere spark gaps for testing the dielectric strength of transformer

oils. A carefully prepared schedule of tests on different gaps and

different spacings is being carried out in four different laboratories.

This investigation has been delayed by the pressure of war work.

Some progress has been made in correlating the data obtained in the

Bureau's tests and those of the Vacuum Oil Company. The Westinghouse Company has made the tests but their results have not been

received by the bureau. The General Electric Company is also to

make measurements for comparison with the others. It is expected

that data will be obtained which will permit results obtained on one form of gap to be interpreted in terms of other forms of gaps, or

possibly a uniform method of testing may be agreed upon.

Blasting Machines.

At the request of the General Engineer Depot and of the Army

Ordnance Department, tests have been made of the electrical blasting

machines used in firing trench mortars, mines, etc. There seems to

be room for much improvement in the design of apparatus for this

purpose and several experimental models have been constructed

which show promise of reduction in weight and cost, and increase

in reliability. Improvements have also been suggested for the indicators used to show that such machines are in working order just

before firing.

Ignition in Gasoline Engines.

Investigation of problems connected with spark plugs, magnetos

and other ignition devices, has been carried on by the Electrical Division in cooperation with other parts of the Bureau. Statistical

records are now being kept of' the plugs used in various aviation

engines at the Bureau to determine their average service.. These

records indicate that fouling from carbon deposits is by far the most

frequent trouble.

Improved porcelains, developed by the Ceramic Laboratory of

the Bureau, have been put into production by at least one manufactui^er and are now being tested in Liberty motors.

At the request of the Bureau of Aircraft Production oscillograms

have been taken showing the performance of various types of magneto and battery ignition systems. The information contained on

these oscillograph films is gradually being digested and will be incorporated in a series of reports covering various features of the

operation of magnetos.

An investigation has been begurn on the use of subsidiary spark

gaps and condensers in various connections with ignition systems.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 41

The phenomena appearing in such circuits are exceedingly complex

but there is definite evidence that such arrangements will cause a heavily sooted plug to fire under certain conditions. There is promise of developing on this basis a practical system of great value.

Mica for Electrical Purposes.

At the request of the War Industries Board, tests have been made

on a number of samples of mica to determine their suitability for

use in magneto condensers. A number of magneto factories were visited in connection with this work, and the methods of testing used

in the factory were studied in order to duplicate as far as possible

the requirements of commercial practice. The best utilization of our mica supply is of great importance because difficulty is experienced

in obtaining shipments from India, which has previously been the

chief source of supply.

Printing Chronograph.

For the Bureau of Ordnance of the War Department, a printing

chronograph was rebuilt so that four printed records may be made

simultaneously by as many observers. This instrument. is for use in

securing experimental data for improved range tables, and in the

timing of shrapnel fuses which are tested at the Aberdeen Proving

Ground.

Velocity of Projectiles.

For several months the Bureau cooperated with the Sandy Hook

and Aberdeen Proving Grounds on the problem of the rapid and ac- curate determination of the velocity of projectiles. A representative

of the proving grounds was stationed at the Bureau, and membersof the Bureau cooperated with him in the preliminary laboratory

study of various methods for the measurement of velocities, accompanying him on trips to the proving ground for field trials.

The method finally decided upon is now in regular use in the test- ing of ammunition in this country and in France. Arrangements

of the electrical circuits for the recording part of the method were

worked out at the Bureau. A master direct-reading scale for this

work was made at the Bureau, and in use was found to make it possible to obtain final results in 10 seconds.

MAGNETIC MEASUREMENTS.

(Measurement of magnetic properties of materials ; design and calibration of magnetic

instruments and appliances, including compasses; magnetic analysis.)

Bismuth Spiral for Measurement of Magnetic Fields.

In many kinds of investigational work bismuth spirals are very

useful, but suitable methods of calibrating the spirals have been

lacking. The development of a method and of apparatus for the

calibration of these spirals, has been completed during the year and

a paper on the subject has been submitted for publication. The

method provides a means for placing the spiral under test in a magnetic field which is measured by means of a standard test coil

and ballistic galvanometer. Suitable temperature control is also

provided. Numerous precautions which must be observed both in

the calibration and the use of bismuth spirals are pointed out in

the paper.
42 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Determination of Magnetic Susceptibility.

Considerable experimental work has been done on the development of a rapid method for the determination of magnetic susceptibility in routine testing. Two methods have been investigated, one

using a sensitive balance for weighing the attraction of a magnetic

solenoid for a sample under test, and the other a ballistic method.

This work is not completed but has been laid aside for more important Avork arising from military needs.

Standard Magnetic Bars.

A set of bars has been prepared to serve as magnetic standards.

Their magnetic homogeneity has been carefully examined and com-

• plete magnetic data determined. The magnetic properties will be

redetermined from time to time as a check on their constancy.

Magnetic Analysis.

For a number of years work has been under way at the Bureau

in the development of methods and apparatus for using the magnetic

properties of materials as an indication of their quality and mechanical properties. During this year a paper entitled " Magnetic

Analysis as a Criterion of the Quality of Steel and Steel Products " has been submitted for publication. The magnetic properties which

might serve as criteria for the estimation of the mechanical fitness

of steel are considered in detail and some methods of testing are

described. The correlation between heat treatment and magnetic

properties of high carbon steel is given, as well as many other valuable data.

The general method of " magnetic analysis " has been applied

during the year to the three special problems of rifle-barrel steel,

ball-bearing races, and steel cable. The plant of one of the large

manufactui'ers of small arms was visited in connection with the study

of the process of manufacture of I'ifle barrels and special work was

imdertaken with a view to the development of suitable methods of

magnetic testing for this steel. Promising preliminary results have

already been obtained and apparatus is now in process of construction

for the testing of the steel bars used, as received from the mill.

The application of magnetic testing of ball-bearing races was

undertaken in cooperation with one of the larger manufacturers of

ball bearings, and in this connection efforts are being made to develop a design of testing apparatus which will be suitable for use in

the factory. Some preliminary experiments in the work on steel

cables have been carried out, but, as in the case of the last-mentioned

investigation, have suffered serious interruption on account of the

transference of men into the military service.

Magnetic Compasses.

The formulation of specifications and the development of methods

of testing of compasses have received little attention in the past.

During this year specifications for performance of airplane compasses and of lensatic compasses have been drawn up and submitted

to the military authorities. The proposed specifications for the lensatic compasses were adopted by the Engineering Bureau of the Army

Ordnance Department.

Methods of testing were developed in cooperation with the Inspection Department, Equipment Division of the Signal Corps, and
BEPORT OF DIRECTOR OP BUREAU OF STANDARDS. 43

cooperation with this Department is being continued. Apparatus,

has been constructed for compass testing at the Bureau and is still in

process of development.

Investigations have been carried out on damping liquids for airplane compasses which have led to the adoption of kerosene instead

of the alcohol and water mixture formerly used. Specifications were

prepared for kerosene for such use. Experiments were also made on

the methods of heat treatment and aging of magnets for compass

needles and compensators.

Railway Signal Relays.

At the request of the Committee on Direct Current Relays of the

Railway Signal Association, an investigation of railway signal relays

has been undertaken. This is to include the development of a suitable aging process by means of which deterioration of a relay will be

produced comparable with that which occurs in a long period of service. This process is to form part of a test procedure to be used in

tests under the auspices of the Signal Association.

PHOTOMETRY AND ILLUMINATING ENGINEERING.

(Maintenance of photometric standards, calibration of standard lamps, development of methods of photometry, inspection and life-test of electric lamps, problems in the utiliza- tion of light.)

Trench Flares.

The exigencies of trench warfare call for the use of many special

illuminants. Many of these are quick-burning flares of very high

candlepower. Immense quantities of these materials are being purchased by the War Department, and no quantitative information

about their performance was available. In cooperation with the Ordnance Department, measurements of candlepower, time of burning

and smoke produced were made on samples obtained from different sources to find out what might reasonably be expected of each type

of light. Similar measurements were made on many samples in order

to improve the performance by modifying the composition and construction. The developmental work on these illuminants is largely

chemical and has been handled by the Ordnance Department. The

Bureau has developed methods of making the photometric tests re- quired and has assisted the ordnance officers in initiating the work of

routinp. inspection and testing.

Portable Acetylene Lights.

Several months were spent in a test of numerous types of portable

acetylene lights with particular reference to their suitability for

military use at the front. These tests were made primarily to obtain information which should serve as a basis for choice between the

different types of light. It developed, however, that nearly all of

them had certain defects for such use. The defects of various types

were discussed with the makers and a number of modifications suggested by the bureau were made.

At the request of the Signal Corps, comparisons were also made

between two types of acetylene generators for use in traveling photographic woi'krooms. After tests were made in the Bureau laboratories, the development of improved apparatus was taken up with

the mannfactnrers and as a j-esnlt a satisfactory outfit much simpler

than that now in use is nearly ready for production.
44 REPORT OF DIRECTOR OF BUREAU OF STANDAEDS.

Photometric Tests of Field Searchlights.

This work has included field measurements and laboratory tests. The field work has been largely the measurement of illumination in

the beam at various distances up to 4 miles, with particular refer- ence to the distribution of the light from different types of searchlights and to the effect of front glasses, louvers, various reflectors,

and various types of carbons. The laboratory measurements have

included determinations of the intensity and distribution of the

light from the arcs (without reflectors) under various conditions.

Special Problems in Illumination.

Numerous conferences on illumination problems have been held

and many minor tests made for various departments of the Government. A great deal of this consultational work has been done

for different sections of the Science and Research Division of the

Signal Corps, for whom at various times more than thirty lamps

have been standardized or measured under special conditions. Besides these a number of tests of lamps at excessive overvoltages have

been made in order to determine the best condition of operation for

tracing by photographic methods the course of falling bombs.

For the Field Medical Supply Depot of the Army, a collection

of flashlights were tested to determine the candlepower of the lamps

and the distribution of light in the beams. A comparative life test of flashlight lamps was also carried out. This included the comparison of lamps of American manufacture with a number of samples submitted by importing firms. It was found that the American

lamps in general were far superior to the imported ones. In connection with the choice of lighting fixtures for various

buildings under construction for the Government, a considerable

number of samples were obtained at various times, and measure- ments of the distribution of the light from them were made. Several

sets of samples of window fabrics for use in the war zone were

measured to determine their transmission.

Standard Specifications for Electric Incandescent Lamps.

Unsettled manufacturing conditions arising from the war have

made necessary considerable changes in the standard efficiencies of

incandescent lamps. A new (eighth) edition of Circular 13, "Standard Specifications for Electrical Incandescent Lamps," has been

prepared and issued. The most important changes are (1) a small

reduction in the efficiency of vacuum tungsten lamps, necessitated

by unfavorable manufacturing conditions, (2) the addition of

specifications for gas-filled tungsten lamps, and (3) a provision for

small readjustments of efficiencies downward as well as upward at

the request of the manufacturers. Previous specifications have allowed increases of efficiencies but not decreases.

Inspection and Life Testing of Lamps,

As a result of war activities, the Government's purchases of electric

lamps have miiltiplied several fold. Orders placed during this year

call for about 8.500,000 (5,350,000 large tungsten, 1,450,000 large

carbon, and 1,700,000 miniature lamps), and inspection by the Bureau was requested on about 5,800,000 of these. Production has

lagged behind this great increase in orders and about 2,800,000 of the

above lamps were undelivered on July 1, 1918. Actual inspections
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 45

during the year, including lamps delivered on orders placed last year,

approximate 3,700,000 lamps, of which about 1,100,000 were carbon

and 2,600,000 tungsten. Life tests were completed on 2,015 tungsten

and 659 carbon lamps. A new detail in the method of keeping

records and reporting results is that samples have been marked to

indicate the month of manufacture, and separate records of the

product of each month at each factory have been compiled. This en- ables the Bureau to judge more fairly the average quality of the

yearly output and also gives data which are useful as checks on

current factory life-test results.

While gas-filled lamps have not been covered by the specifications

in force during the year, a considerable number of them have been

subjected to life tests for our information. In general they have

shown a satisfactory performance.

With regard to the value of the routine inspection of lamps, it

may be said that while the percentage of lamps rejected on inspection at the best factories is low (about 3 to 6 per cent), there is incontrovertible evidence that orders which are to be inspected receive

special attention and that lamps which fail on inspection are applied

on orders which are not to be inspected. Moreover, it is generally

granted by factory men that the inspection is a continu.al stimulus

to them to exercise all possible vigilance to keep the product up in

quality.

Gas-Filled Standards of Spherical Candlepower.

Experience during the past j^ear has shown that gas-filled lamps

of special construction give very good service as standards of spherical candlepower. Following the Bureau's investigation of methods

of comparing these lamps of high efficiency and large candlepower

with the older standards, several groups of the newer lamps have

been very carefully calibrated to serve as reference standards at the

Bureau, and a large number of these lamps have been calibrated for

various other laboratories during the year.

Automobile Headlight Specifications.

On accovmt of the Avidely different regulations adopted by various

States and cities for the control of automobile headlights, it has appeared desirable for the Bureau to make a study of this subject in

the hope that it might assist in obtaining the adoption of more uniform regulations. Accordingly complete information regarding regulations which have been adopted has been collected, and samples of

many devices which are intended to fulfil the requirements of the

various regulations have been obtained. Measurements of the distribution of the light from many of these devices have been made.

A special committee of the Illuminating Engineering Society having been appointed to formulate specifications for head lamp devices,

it appeared best for the Bureau to cooperate with this committee.

Representatives were accordingly sent to assist in several road tests of such devices. As a result of these tests, general specifications cov- ering the allowable and required intensities of head lamps have been

formulated by the committee, with particular reference to a recently

enacted law of New York State, and these specifications have been

adopted by the Secretary of State of New York as a basis for the

approval or disapproval of devices submitted to him. In case of dis-
46 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

pute as to the results of tests made under these specifications, provision is made for appeal to the Bureau.

RADIO COMMUNICATION.

(Methods of measurement at radio frequencies : design and calibration of radio instru- ments.)

New Radio Building and Equipment.

A ne^v annex to the Electrical Building, which v.'ill be used by the

radio section of the Bureau and also afford quarters for laboratories

for the Army and Navy, has been nearly completed. A large amount

of new equipment has been desig-ned and ordered, and it is hoped that

greatly improved facilities for the radio work will be available early

in the coming year.

Circular on Radio Instruments and Measurements.

The theory and practice of radio communication have advanced so rapidly in the past few years that satisfactory text books are not

available. The need of such text books for use in the Signal Corps

trainmg courses has been very urgent. To meet this need the Bureau

has prepared a cu'cidar (No. 74:7 entitled "Radio Instruments and

Measurements,"' which has met with a very favorable recognition and

is now in use in the training courses mentioned. About 4,000 copies

have been distributed.

Use of Closed-Coil Antennas.

For several months considerable experimental work was carried on

in the field, in cooperation with officers of the Signal Corps, with

closed-coil antennas or loops for transmission, reception, and direction finding. With the results of this work as a basis further study

is being made of the apparatus by the Signal Corps, with a view to its

practical application. In connection with this investigation of

closed-coil antennas several interesting characteristics of such coils

have been developed, and further studies of the theory and practical

application of this type of antenna are planned.

Insulating Materials for Radio Apparatus.

An important investigation was undertaken early in the year

mvolving the study of various kinds of insulating materials used in

the construction of radio apparatus. Various properties of these

materials were measured in other laboratories of the Bureau; the

principal measurements made in the radio laboratory were those of

phase difference and voltage properties. Preluninary results have

been furnished to the War and Navy Departments and should have

an important bearing on the production of radio instruments.

Miscellaneous Testing, Calibration, and Designing of Radio Instruments.

A great deal of testing and calibration work has been done during

the year for various branches of the War Department, and in several

instances designs of apparatus have been turned over for the use of

the Signal Corps. For example, the standard variable condensers

developed by the section have been adopted for use in the Signal

Corps laboratories. Standard high-frequency resistance imits have

been constructed and supplied to the Signal Corps, and a standard

inductance constructed in accordance with the design developed at
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 47

the Bureau has recently been requested for the Little Silver laboratories. It has been necessary also to supply full calibration data

for all of this equipment, some of which required considerable experimental work. Many wavemeters. decremeters, condensers, resistance

units, grid-leaks, vacuum tubes, and other miscellaneous pieces of

equipment have been calibrated for various branches of the War

Department.

A small portable decremeter for field use was designed, and several

instruments of this type were calibrated for the Signal Corps after

construction. A study was made of precision resistance measure- ments including the development of a direct reading phasemeter and

decremeter. Extensive experiments were made upon the shielding

effects of wire cages. Equipment was developed and constructed for

producing high voltages, long and short waves, and for other special

requirements of measurement work. An investigation of crystal

detectors was undertaken and is still in progress.

Vacuum-tube Apparatus.

Vacuum-tube apparatus is finding a rapidly increasing application, and considerable attention has been given to the study of such

tubes at the Bureau dui-ing the past year. Methods for measuring

the characteristics of tubes have been developed and other experimental work is under way.

A compilation of published information regarding the theory and

operation of these tubes as used in radiotelegraphy, radiotelephony,

transcontinental telephony, and in laboratory measurements, was prepared by a member of the Bureau and published in book form by

the Signal Corps, under the title Vacuiun Tubes—Theory and

Use." It includes the general theory and description of the tubes,

the mathematical theory of their operation, results of experimental

research with the tubes, their use in radio reception, miscellaneous

tubes and uses, and a bibliography. This book has been widely

distributed among officers of the Army and Navy, and among radio

engineers and others directly interested in the use of these instruments.

SOUND RANGING.

(In normal times Section 7 is devoted to a study of electrolysis and related problems. During the past year nearly all of the staff of the section have been working on various

military problems, especially sound ranging.)

Sound Ranging.

A large amount of time has been given to the study of means of

locating batteries and the development of new equipment for this

purpose. Two members of the Bureau were commissioned during

the year and sent abroad to put into use at the froiit the equipment

developed at the Bureau. One of them, Capt. Ernest Weibel, was

killed during the German offensive of March, 1918. Capt. Weibel's

death interfered seriously with the plans which had been made for

field trials of the equipment, but the work has been vigorously prosecuted at the Bureau, and field tests have been made at the proving

ground at Winthrop, Md. The apparatus which has been developed

has some features in which it excels any other equipment in use, and

it is expected that sets will soon be put into use in France.
48 EEPORT OF DIEBCTOR OF BUEEAU OF STANDARDS.

ELECTROCHEMISTRY.

(Electrochemical problems, particularly those involved in electrical batteries and elec- trical measurements.)

Electric Batteries.

The need of the development of specifications and methods of

testing for electric batteries has long been recognized; but facilities

have not been available to undertake this work. The needs cff the

military departments have recently beconpie so urgent that the study

of batteries has been undertaken.

Attention was given first to dry cells, and all the available information on the subject was abstracted and classified. Letters were

sent to the leading manufacturers asking for information, and their

replies were also abstracted and classified. Laboratory measurements

on various types of dry cells were made under various conditions,

and an examination of the structure of the cells was also made. In

order to become familiar with the process of manufactui-ing cells,

members of the staff visited a considerable number of factories.

As a result of this work, a circular has been prepared for publication. This includes information regarding the various sizes and

kinds of dry cells, the general electrochemical principles involved,

and the electrical performance of such cells. A set of proposed

specifications for dry cells intended for Government use is also

included. This circular has been sent to the leading manufacturers

for criticism, and after discussion with manufacturers and users of

the cells, will be published. , A large amount of chemical work has been done on dry cells, including the development of methods of determining the available

oxygen, the total sal ammoniac, moisture, and chlorine, and also analytical methods of finding certain impurities which are frequently

present and reduce the life of the cell. No chemical process for determining the difference between a good cell and a poor one has been

discovered; but the chemical results run parallel to the electrical

tests in that cells which are deficient in available oxygen or sal ammoniac, show comparatively poor electrical performance. It has been

found that cells of the same make often differ greatly in composition,

tind in some cases where such variations of composition occur, the

cells deteriorate very rapidly on open circuit.

On storage batteries, work is just being begun. A few plates have

been analyzed, and attention is being given to the development of

special analytical methods which are required for the electrolyte, be- cause minute quantities of certain impurities in the electrolyte seriously affect the performance of the cells. Experiments have also

been made on containers, particularly the celluloid used in some

military batteries. Celluloid containing a strong solution of sulphuric acid has been found to liberate nitric acid which is detrimental to the storage battery. A considerable number of storage

batteries are being received for test and electrical equipment for more

extensive tests of these batteries is being assembled.

Two special reports have been prepared. One of these dealt with

the question of obtaining American cells to replace the Hellesen cells

which the British Government was purchasing from Scandinavia.

This problem involved fitting a battery which would meet certain
KEPORT OF DIBECTOE OF BUEEAU OP STANDARDS. 49

voltage and current requirements into a limited space, provided for

it in submarine mines. The second report was submitted to the

Food Administration on the use of wheat flour in batteries. Wheat

flour has long been used by manufacturers in the paste which is con- tained in the bag-type cells, and it was believed that an appreciable

saving of wheat might be made by substituting other kinds of flour.

Attention has also been given to the construction of special cells

to give long shelf life. A small number of cells were constructed at

the Bureau for the Signal Corps for this purpose, and were found to

give an unusually long life. The Signal Corps is taking steps to

patent the process used in order that the Government may have free use of it for military purposes.

At the request of the military authorities, the development of a galvanic pile which would give comparatively high voltage and small

capacity in a limited space has been undertaken. Three types of piles

have been under development, one using lead peroxide, another manganese dioxide, and a third a simple pile of zinc and copper.

Among the batteries which have been tested, are the following

kinds: Paper-lined dry cells, bag-type cells, silver-chloride cells, re- serve cells, special batteries for the Ordnance Department of the Navy,

special batteries for radio work, carbon-steel cells, flash-light batteries,

alkali track batteries, alkali signal batteries, acid storage batteries,

alkali storage batteries, and dry storage batteries. Tests have been

made for the Panama Canal, the Bureau of Ordnance of the Navy

Department, Naval Torpedo Station, Signal Corps, Engineer Corps,

Medical Corps of the Army, the Depot Quartermaster and the Ordnance Bureau of the War Department. The total number of batteries

which have been tested during the year at the Bureau is 450, while

•3,000 have been tested at the military storehouses.

Miscellaneous Electrochemical Work.

Minor problems in electrochemistry have included the platinizing

of electrodes for work in conductivity of electrolytes, the plating of

radio detector crystals, the preparation of impregnated paper for

spark recorders, testing the continuity of the enamel of large iron

kettles used by the chemists of the Gas Defense Service, and assist- ance given to the Chemical Division in developing a new process for

cleaning gun barrels.

RADIOACTIVITY AND X-RAY MEASUREMENTS.

(Methods of measurement of radio-active materials and phenomena, standardization of radium, radium preparations,' and similar materials; development of X-ray equipment.)

Luminous Materials.

Both the apparatus for and the technique of the measurement of

the brightness of self-luminous materials .have been much improved

during the year. The fifty preparations under study in June, 1917,

and a few others obtained since then have been measured at intervals.

The conclusions drawn from these measurements have been made

available to the military authorities interested in such materials.

These materials are largely used for airplane instrument dials.

Since little information regarding the brightness needed for satisfactory legibility of dials was available, the Bureau arranged to have

86986—18—--4
50 BEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

a number of dials of various known brightnesses examined under

service conditions of illumination by members of the air service of

the United States and allied nations. A better idea of the brightness desired under different conditions was thus obtained. The variation of the legibility with the size and brightness of the characters has also been studied.

The conclusions thus reached have been used, and passed on to

those interested, as rapidly as obtained and are now being collated

in a series of recommended specifications for luminous articles.

Regarding the permanence of luminous material under service

conditions little was known. It was believed that in general, an

exposure to direct sunlight markedly decreased the brilliance of

applied material. Observations made during the past winter have,

however, shown no very marked decrease in brightness, due to an ex- posure either to the sun or to a mercury arc. The dials used in this

test were of low brightness. Similar tests upon other dials will be

begun at once. Specifications for luminous markings upon airplane dials have

been recommended to the Signal Corps, United States Army, the

Bureau of Steam Engineering, United States Navy, and informally

to other departments of the Government. These specifications have

been in the main adopted by the Signal Corps.

Since September, 1917, the brightness of a large number of dials

has been measured for the Science and Research Division of the Signal Corps, United States Army), (recently transferred to the Bureau

of Aircraft Production), as a basis for the awarding of contracts

for the illumination of airplane instruments.

At the request of the Inspection Department of the Signal Corps,

the Bureau has prepared and standardized equipment for factory

inspection of dials, and has instructed inspectors in the details of

factory testing. Since this equipment has been in use, brighter dials

have been secured.

Since the first of January, 1918, a percentage of the luminous dials

accepted by the Inspection Department has regularly been sent to the

Bureau for careful measurement of brightness. Certain of the dials

have been submitted to a life test, and a number of compass cards

have been measured both dry and submerged in kerosene. The effect

of continued immersion in kerosene also has been studied. The cause

of some of the changes observed on immersion is still not clear; the

study is being continued.

An investigation of methods for applying luminous materials to

dials and other objects was undertaken late in November. Luminous materials were obtained from the different manufacturers and

were applied to dials by means of various adhesives and methods.

The various characteristics of the different adhesives and methods

were noted and the brightness of the finished product was measured.

The problem was studied from many angles and a method of application that is more efficient than any now in use was developed.

The following reports have been issued : " Self-Luminous Materials Containing Radioactive Excitants," " Notes and Suggestions

Concerning Luminous Instruments," " Self-Luminous Materials

Brief Notes Covering a Few Points of Practical Importance." All

of these were typewritten reports issued in editions of a few copies
KEPOKT OF DIRECTOB OF BUREAU OF STANDARDS. 51

each and have been distributed to those Government departments

that have appeared to be most interested.

Throughout this work the cooperation of the manufacturers and

users of these materials has been most gratifying and of great assist- ance to the Bureau.

Standard Radium Solutions.

Incidental observations indicate that the standard radium so- lutions made up in the summer of 1914 have not changed by as much

as 1 per cent since they were prepared.

During the year, 100 cubic centimeters of the dilute solution (10-'

gram of radium per cubic centimeter of solution) were furnished

to McMaster University, Canada.

Radium Emanation Work.

The work involving radium emanation measurements is mainly

the examination of materials suspected of radioactivity, of waters

(natural and artificial), and of therapeutic preparations. No steps

have been taken to encourage the development of this branch of the

work, because all the facilities available could be used to advantage

in more urgent lines.

During the year 1 activator has been tested, the study of 4 others

has been completed, and 5 radium determinations have been made ; 2

of the latter were for the Department of Agriculture.

Gamma-Ray Measurements of Radium.

In July, 1917, the Bureau of Mines donated to the Bureau the tube

containing about 49 milligrams of radium which was loaned to the

Bureau of December, 1916, and also a second tube containing about

91 milligrams. Further than this, no change has been made in the

equipment for this work.

Early in 1918 the rate of receipt of specimens for gamma-ray

measurement decreased markedly and has remained low. The

amount of material for certification to physicians is now very small

on account of war conditions.

During the year 177 specimens, containing a total of 5,376 milligrams, have been measured. Of these, 50 specimens containing a

total of 1,009 milligrams were certified for foreign shipment. These

were distributed as follows:

Most of the radium certified for expoi-t to France is said to be for

the use of the French Government in the manufacture of self-lumi- nous material for war purposes. Two tubes (74.1 milligrams) were

certified to the American Eed Cross Society ; it was understood that

these were intended for the Russian Government.

Country. Number. Millisram radium.

France

Japan.,

Spain..

India..

24

1112

3

851.55

207. 19 129.55 20.38
52 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

X-Rays.

The X-ray equipment purchased in the spring of 1917 was installed in July. The apjDaratus has been studied in some detail, subsidiary equipment has been constructed and purchased, the routine

testing of protectiAX materials has been established, and miscella- neous radiographs have been taken for the purpose of obtaining information regarding the internal structure of materials and articles.

In its endeavor to secure the domestic manufacture of improved

protective materials, the Bureau met with splendid cooperation on

the part of the manufacturers. As a result, one can now obtain

commercial material which gives nearly twice as much protection

per unit thiclmess as was given by material obtainable a year ago.

(Improvement in glass reaches 80 per cent, in rubber 100 per cent.)

A note on this work has been published in the American Journal of

Roentgenology, and a more detailed joaper has been prepared for the

same journal.

A study of the technique for the radiographic detection of flaws in

aluminum and in steel is still in progress.

PUBLIC-UTILITY STANDARDS.

Public-Utility Investigations.

A large and important field of work, including more of engineering and field work than most of the electrical work so far described,

is concerned with the various public utilities, particularly electric

light and power, gas, street railway, and telephone companies. The

work includes (i) scientific and engineering research, (2) the study

of public-relations questions, (3) the preparation of specifications

regarding the quality of public-utility service, (4) methods of test- ing and inspection employed by municipalities and commissions, (5)

safet,y rules for use by the utility companies to safeguard their employees and the public, and (6) the collection and distribution of information by published papers and through correspondence.

This work is a natural outgrowth of the research and testing work

done by the Bureau of Standards for the public-utility companies

for several years. The testing of electrical instruments and meters,

of gas lamps and the standards employed in measuring the candlepower and heating value of 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

the public utilities have all involved to a greater or less degree questions of standards of service in the various public utilities. The

bureau has gradually accumulated a considerable amount of information on these questions and has been able to contribute materially

to the establishment of standards of quality of service 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 an enviable position as an impartial medi-

?.tor in such questions. Consequenth^, during the past j^ear, when

abnormal conditions have given rise to many cases in which readjustment of service standards or of rates has been called for, the

public-utility statf of the bureau has been called upon for an im-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 5S

possible amoTint of work. The opportunities for serving the public

have been great and good service has been rendered. The provision

by Congress of additional funds for this work b}' a special appropriation has made possible considerable additions to the staff toward

the close of the 3'ear, and it is hoped that even more may be accomplished during the year. The work of the following sections is largely in connection with public-utility problems.

Relation of the Bureau to Municipalities and Public-Service Commissions.

In many States the public-service cormnissions have set standards

of service, and the Bureau has cooperated with most of those that

have done so. In other States the railroad or public-service commissions have taken no action in the matter, although having authority

to do so. Again, in some States there are no public-service commissions to issue regulations or to inspect the quality and safety of the

service rendered b}" the various utilities. In any case the cities and

towns must look after their own interests, in whole or in part, and

frequently have taken up such matters very siiccessfully. Even

where there are well-equipped and active State commissions, which

have adopted rules and are ready to hear complaints regarding rates or service, a very large responsibility rests upon the municipalities.

Few State commissions will ever be likely to have a force of engi- neers and inspectors large enough to enable them to take the initiative in every case and relieve the municipalities of all the responsibility. On the contrary, if the municipalities are active and enterprising in their own behalf, and if the larger ones have well-equipped

public-utility dei^artments which can prepare the city's complaints

or requests and take them up to the State commissions for hearing

and adjudication, the State commissions will be better able to serve

all the municipalities of the State, and the municipalities will enjoy

in large measure the advantages as well as the resiDonsibilities of

home ride without its greatest disadvantages.

But for most cities and manj- commissions it is a difficult matter to

judge the quality of service rendered by its utilities. The studies

made by the Bureau are a great help in this connection, but much

remains to be done. It will conduce to fairness luid a good imderstanding 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.

Obviousl}'. it will never be practicable for any State 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 be settled onh^ b}^

reference 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 although it has not been able to do as much as it would have liked to do. it has

done enough to demonstrate the practicability and acceptability of

the method. The success and approval which the work has met so

far fully justify its greater development.
54 REPOET OF DIEECTOE OF BUEEAU OF STANDAEDS.

GAS ENGINEERING.

(Standards of gas service; efficiency and economy of manufacture and distribution of gas ; studies of gas utilization ; by-product fuel processes and related tests.) Gas-Service Standards.

During this year the bureau has participated in important cases involving adjustment of standards for gas service before the New

Jersey Board of Public-Utility Commissioners and before the First

District Public- Service Commission of New York. A report was

also made to the Indiana Public- Service Commission on the revision of standards for gas service contemplated for that State, and

comments have been given to the Oregon Public- Service Commission on a petition relating to a change of standards in Portland, Greg.

In the city of Cleveland assistance was given in establishing a

testing laboratory, in calibrating equipment for it, and in instructing the chemists who were to carry on the routine testing. This

work also included a very brief consideration of the adequacy of

the natural-gas supply. At the request of the Railroad Commission

of Georgia a study of gas-service conditions in Atlanta was made.

It developed that the principal cause of dissatisfaction with the service was a shortage of oil for the manufacture of water gas. The

bureau's report was accepted by the State commission as the basis

for its decision in this case. The shortage of supplies of oil has led to the suggestion that

changes should be made in standards for gas quality, and it has been

suggested to the Fuel Administration that all existing standards of

heating value be abrogated and.a uniform requirement of 528 British

thermal units per cubic foot should be adopted. The bureau, in

common with most State and city authorities, has felt that this radical change is of doubtful wisdom and has given considerable attention to alternative methods of meeting the situation without such a general reduction in the quality of all manufactured gas.

This and numerous other cases in which readjustments of standards

of quality have arisen during the year have given rise to opportunity

for a very extensive application of the results of the experimental

work carried out last year upon the relative usefiilness of different

qualities of gas.

Natural-Gas Service.

As mentioned above, some attention was given to natural-gas service in the city of Cleveland. The same question was raised with

regard to the supply of natural gas for the city of Louisville, and

this has led to an extensive field investigation on the supply of natviral gas available for this territorj'. Data for a preliminary report

on this subject have been gathered and the cooperation of various

agencies is assured in continuing this work.

Gas Lighting.

As partial reports upon the investigation of relative usefulness of

different qualities of gas, Technologic Paper No. 99, entitled " Gas

Mantle Lighting Conditions in Ten Large Cities in the United

States," has been issued and Technologic Paper No. 110, entitled " The Influence of Quality of Gas and Other Factors Upon the Efficiency of Gas Mantle Lamps," is in press. The work reported in the

latter paper gave results not in accord with the general opinion that
EEPOKT OF DIEECTOB, OF BUREAU OF STANDARDS. 55

gases of lower heating value are much more efficiently used. The

margin of advantage in utilization of such " leaner " gases is small

in mantle lamps, and consequently the heating value is an excellent

measure of the usefulness of the gas for lighting.

Proposed National Gas Safety Code.

The Gas Safety Code has been advanced very little during this

year, but a first draft of part 2 of the code has been prepared in

manuscript form. A preliminary report of tests of flexible tubing has

been prepared and sent out for comment. The results obtained in

these tests enabled the Bureau to render assistance to the city of New

York in connection with a proposed ordinance fixing standards

for the construction of flexible gas tubing. As a result the city

avoided the adoption of a very drastic and undesirable form of

ordinance.

Economic Importance o£ the National Gas Safety Code.

The Bureau of Standards in carrying out this investigation desires

to serve as a national coordinating agency to the end that the resulting code will be acceptable and adequate, not only from the standpoint of the user of gas but also of the casualty and fire-insurance interests, the gas companies and their employees, and the gas-appliance

manuacturing and selling interests.

The need and value of such a code is so great that the various

national organizations dealing with subjects covered by the code have

appointed special committees and expert representatives to assist in

the investigation. The following organizations have cooperated in

this work: The American Gas Institute, the National Commercial

Gas Association, the Natural Gas Association of America, the National Fire Protection Association, the American Institute of Architects, the National Safety Council, and the National Association of

Master Plumbers. In order that the Bureau may have the fullest information on every detail of the subjects discussed, the American

Gas Institute has appointed 12 committees, four in each of the three

principal sections of the country—East, Middle West, and Far West.

One committee in each district is intrusted with the work bearing

upon one of the principal phases of the investigation.

It has been estimated that avoidable accidents, due to ignorance,

carelessness, or faulty installation result in the loss each year of

hundreds of lives and the destruction of property of large aggregate

value. It may reasonably be expected that many of these losses will

be eliminated when the code has been completed and adopted

throughout the country, both because of the official enforcement of

the code and because of its educational value to gas fitters, appliance

manufacturers, utility operators, and the general public.

The code will also serve to unify practice in gas installations and

gas-company operation throughout the country, and it is anticipated

that much-needed reforms will result. This uniformity of practice

will not only tend to greater safety, but will also contribute to higher

efficiency. In many cases differences between the insurance and gascompany officials can be settled by reference to the code, and thus

more harmonious cooperation of the two parties can be expected.

Already several important instances have been referred to the Bureau

for consideration with a view to the settlement of differences in in-
56 BEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

surance-inspection practices or questions as to the magnitude of the

fire hazard in certain types of gas installations. In this field the

services of a recognized national authority are essential in order to

standardize the practices and to make generally available the benefit

of experience obtained in individual localities. The effort of the

Bureau has therefore been directed not only to the preparation of the

code but to the collection of such information as will enable it to serve as a national coordinating agency in this field.

Toluol Investigations.

Toluol has been required in large quantities for military use, and

manufactured gas is one of the most readily available sources. The

necessity of removing the toluol and benzol from gas has raised many

questions with regard to the readjustment of standards and of the

financial arrangements for carrying on this operation. Early in the

year a conference to consider these problems was held at the Bureau

and a committee representing State, city, and gas-company interests

was organized. This committee met on two occasions for conference

at the Bureau.

A report entitled " Recovery of Light Oils and the Eefining of

Toluol " was prepared, and after submission to the committee mentioned was circulated in mimeographed form and later reprinted in

several journals. Another article on " Toluol Eecovery and Standards for Gas Service " has also been published in various gas journals. There has been a very large demand for both of these papers,

and a report to include both of them is being prepared.

Representatives of the Bureau have given a great deal of time in

conference with the Ordnance Department with regard to contracts

for the construction and operation of toluol plants in connection

with city gas works.

Balloon-Gas Manual.

At the request of the Bureau of Steam Engineering of the Navy

Department, a manual including a description of methods for the

generation, handling, storage, and use of hydrogen for balloons and

dirigibles was prepared. This manual is used for instructing the

aviation personnel and as a guide in the operation and care of the

balloon equipment.

Coke-Oven Investigations.

The seriousness of the fuel situation has lent particular importance

to several investigations of fuel possibilities. It has been generally

considered that only a small proportion of the coal deposits of the

country could be used for coking, and consequently- this coking coal

has been hauled long distances to sections where large supplies of

" noncolring " coals are available. New processes of coking have

been proposed which would remedy this difficult}^ by utilizing the

so-called " noncoking " coals. A comprehensive investigation of

one of these processes was ordered by the President and carried

out at the plant in Dover, Ohio, by the Bureau with the cooperation of the Bureau of Mines and the Geological Survey. The test was the most extensive ever conducted on a coke-oven process. More

than 40 Government and company representatives participated in

the work, which continued 24 hours a day for a period of 17 days.

The results obtained in general supported the claims of the pro-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 57

meters of the process, but final conclusions must await further tests

to be made with more complete equipment in operation.

As an outgrowth of this investigation the Bureau has also had

opportunity to make measurements on ovens of other types and has

been asked to make a test of a different type plant to cover approximately the same ground, but more briefly than yyas done in the very

elaborate tests first mentioned.

ELECTRICAL SERVICE STANDARDS.

( standards of electric service ; eflBciency and economy of operation of power plants in the generation and distribution of electricity ; street-lighting systems ; central steam and

hot-water heating problems.)

Standards for Electric Service.

For several j^ears the Bureau has been studying the questions of

specifications for electric light and power service, and the requirements that should be made by municipalities or by State publicservice commissions of the public-utility corporations engaged in

furnishing such service. This study was published last year as Circular No. 56, Standards for Electric Service.

In addition to proposed State rules and specifications for accept- ance of types of meters, the circular contains three regulatory ordinances, suggested for cities of various sizes, descriptions of commissions standardizing laboratories, and a complete and exhaustive

digest of State rules and of ordinances in force in various cities.

The. demand for this circular has been large, and it is gratifying to

note that the rules, specifications, and ordinances proposed have been

made the basis for State rules and city ordinances in many instances.

Even before the circular was published a few states had revised

their electric service rules, and an appendix was added to include the

new material. Since its publication, several new commissions have

been established, the functions of old commissions changed and service rules have been revised in three States. The new laws and re- vised rules have been collected and are ready for inclusion in a new

edition of the circular, for which the material is about half completed.

In all this work the Bureau has profited by the cordial cooperation

of public-service commissions, municipalities, and public-service cor- porations, the National Electric Light Association, and the Association of Edison Illuminating Companies.

Standards for Street- Lighting Service.

For a year or more the Bureavi was engaged in a study of street

lighting in its technical and engineering aspects, with particular

reference to the requirements that should be put into contracts between municii^alities and public-service corporations for furnishing

gas and electric street lighting. A number of municipal and private

plants were inspected, photometric measurements made, and conferences held with managers and illuminating engineers.

The Bureau was receiving the heartj'' cooperation of municipalities

and lighting companies, but the war has necessitated a discontinuance

of much of the work on the part of the Bureau, and public-utility

companies also find themselves unable to cooperate as fully as they

would like to do. A special committee of the Edison Association of

Illuminating Companies on street lighting will resume its cooperation with the Bureau at a later date.
58 BEPORT OF DIEECTOE OF BUEEAU OF STANDAEDS.

The manuscript of a circular on " Standards for Street-Lighting

Service" is partly completed. The scope and completeness of this

study of street lighting are indicated by the following proposed table

of contents : The purpose and problem of street lighting ; the meas- urement and distribution of light and illumination in street lighting;

lamps and accessories used in street lighting ; general principles governing the design of a street-lighting system ; description of typical

street-lighting systems ; the economics of street-lighting systems ; discussion of contracts for street-lighting service; suggested street- lighting contracts ; statistical appendixes.

No very active work has been done on the circular during the

past fiscal year, but the digest of the literature has been kept up, new

contracts obtained and additional data accumulated. Early in the

year measurements were made on two types of street arc lamps to

determine the distribution of the light and the variation of th^

candlepower and efficiency with current. This is part of an ex- tensive program of such measurements which have been planned in

order that first-hand information may be available for use in the

circular.

As in the case of standards for electric service the Bureau seeks,

while representing the public interest, to get the utilities' point of

view also, and the study of street lighting will not be published until

full discussion and cooperation can be had from public-utility cor- porations, technical societies, municipalities, and other interested

parties.

Standards for Heating Service.

At the request of the Public Service Commission of Indiana, a study of hot-water heating service was begun and a representative

of the Bureau spent about three weeks during February in Ohio,

Indiana, and Illinois, visiting hot-water heating plants and con- ferring with their engineers. A proposed set of rules for heating

service was formulated by the Bureau, and after public hearing on

the matter these rules were adopted by the Indiana commission substantially as recommended. The manuscript of a .circular on heating service is in preparation, and the National District Heating Association has appointed a special committee to cooperate in its completion.

ELECTRICAL SAFETY ENGINEERING.

(Study of means of reducing hazard to life and property arising from the use of electricity, in particular the development and application of the National Electrical Safety

Code, and other safety codes.)

National Electrical Safety Code.

The Bureau has been engaged for 5 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

Avhom are connected with the electrical operating and manufacturing

companies, others being engineers and inspectors of State commissions, municipalities, and insurance underwritei-s. 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 realized to be quite as great

for accident-prevention rules as for fire-prevention rules, and the

advantage of having such a code prepared and presented by a na-
EEPOET OF DIEECTOE OF BUBEAU OF STANDARDS. 59

tional agency that can study the subject thoroughly and consult all

the interests affected is obvious.

The Safety Code consists of four principal parts, as follows:

1. Eules for the installation and maintenance of machinery, switchboards, and wire in central stations and substations.

2. Eules for the construction and maintenance of overhead and

underground lines for the transmission and distribution of electrical

energy and intelligence.

3. Eules for the installation and maintenance of electrical apparatus and wiring in factories, residences, and wherever electricity is

utilized for light, heat, or power.

4. Eules to be observed by operators in working on or near electrical machines or lines.

This code does not include the matter covered by the Underwriters'

Electrical Code, but it is parallel to the latter and consistent with it. The code is intended to be adopted by State industrial and publicservice commissions and municipalities and to be complied with by

public-service and industrial corporations. It is also intended to be

adopted voluntarilj^ by electrical interests when the code has not

been adopted by any administrative body having jurisdiction in their

district.

The Bureau's thorough studv of the diverse conditions under which

electricity is generated, distributed, and utilized, and of the effect

of the rules on operating and construction costs, has secured a code

which involves no unreasonable expense, but in general assures an

adequate measure of safety and a useful standardization of practice. The large number of conferences held in all parts of the country for discussion of preliminary drafts of the code aided largely in

its development to the point where it was possible to recommend it for general use throughout the country. 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 examination and criticism ; the operating rules were published in August,

1914, and revised in May, 1915 ; the construction rules were published

in April, 1915. Both operating and construction rules, again re- vised 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.

It has been the intent of the Bureavi, as well as the desire of all

branches of the industry, that the rules should be revised and ex- tended, as experience in their use and the progress of the electrical

industry shows revision and amplification to be to the public advantage. The present edition of Circular No. 54 has been exhausted and

a revision is now under way which will be completed before reprinting the circular. In this revision only minor changes in subject matter have been made, but there will be considerable changes in form

with a view to making the code more concise and more convenient for

reference. For this purpose the rules will be separated and published

in one volume supplemented by separate volumes, one giving ex- planations of the rules and examples of their application and an- other engineering data which have been worked out in connection

with the development of the code.
60 REPORT OF DIRECTOR OP BUREAU OF STANDARDS.

Engineering and Experimental Work in Connection with the Safety

Code.

Considerable work has been done on engineering data for the construction of outdoor electrical lines, especially with reference to sags

of overhead conductors. Sags have been computed for temperatures other than those used in the original i^ublished tables, and steel

wires and cables have also been considered. An article on the latter

subject has been prepared for publication in the Electrical World.

Experiments for determining the wind pressure upon overhead

wires and the shielding effect of wires upon others where they are

closely grouped have been carried out. Measurements of the pres- sure upon models set up in the, wind tunnel have been made and will

be supplemented by experiments in the open air, for which apparatus has been constructed and mounted upon the roof of the Electrical Building. The results already obtained show that there is a

definite shielding effect when two or more wires lie very nearly in

the plane parallel to the wind velocit3^ With regard to the magnitude of this shielding effect it is desired to obtain the measurements

in the open air before reaching final conclusions, since it is possible

that the limitations of the wind ttmnel may have an effect upon the

pressure.

National Electrical Safety Code in Practical Use.

The code has now been adopted in one form or another, in part or

in whole, by some 20 administrative bodies, and many others have

taken favorable action upon it, such as the issuance of bulletins rec- ommending the application of the code. In a few States its application has been made mandatory, notably in Pennsylvania, Wisconsin, and Montana. The code is also being used by the inspection departments of many cities and boards of tmderwriters. It is being

used as a basis for a merit-rating schedule by casualty interests just as the Underwriters' Electrical Code has been used by the fire underwriters for som.e years. Such schedule ratings should result in emphasizing both the merits and demerits of particular installations

from the safety standpoint, and tend to reduce accidents by proper

financial recognition of each improvement made.

The code is also being voluntarily applied by a large number of

utilities and industrial concerns in their own practice. It is receiving the general approval of all these interests as rapidly as its useful- ness is becoming recognized, and its advantges are seen to be greater

than any minor present inconvenience which its introduction may

cause, it is becoming generally understood that the stabilitj^ in electrical practice provided by such a national standard also conduces

greatly toward the general economy, the necessity for which is becoming emphasized during this period of national stress. Travel and Conferences for Explanation, Application, and Development of the Code.

Since some 80 State administrative bodies and many cities have

electrical departments, it is desirable to send engineers frequently

to different parts of the country to assist and cooperate with officials

who are considering the adoption of the Safety Code, or, as sometimes

occurs, are considering the adoption of other electrical safety rules

prepared locally. During the past year a considerable part of the
REPOET OP DIEECTOK OF BUEEAU OF STANDAEDS. 61

time of the most competent engineers engaged in the safety work

has been devoted to travel and consultation with State and city

authorities and others concerned. Thirty-nine State commissions

have been visited and in some cases considerable time has been spent

in assisting these commissions to reconcile the views of opposing

interests. The code as already formulated has met with gratifying

success as serving as a basis for agreement in such cases. Scope and Application of the Electrical Safety Code.

To aid in presenting the Safety Code in cases where conference

is not possible with the limited staff of the Bureau, and to assist

in explaining the intended application of the code, a publication has

been issued entitled " The Scope and Application of the National

Electrical Safety Code." In this are included brief summaries of

the different parts of the code, reasons for the character of treatment employed, some discussion of the measures taken to secure adequacy and reasonableness, and some recommendations for the

method of conducting inspections of installations to secure compliance with the Safety Code provisions. The publication also contains descriptions of a number of typical accidents, repetition of

which would largely be prevented by observation of the National

Safety Code rules for construction and operation.

An index to the code has also been published.

Use of the Code in Educational Institutions.

A special effort has been made during the year to bring the code

to the attention of technical schools, and as a result, a number of

engineering colleges have decided to make use of the code in their courses during the next college year. Twenty-five schools will use the code as a part of the required work in electrical engineering, and

a number of others will use it as a reference. It is believed that this

application of the code will have an important effect in the future

development of electrical practice through its influence in inculcating

safety ideas among the new generation of engineers.

Electrical Protection for Householders.

The Bureau has conducted a study of electrical hazards in the

household and the means of reducing them to a minimum. The re- sults have been incorporated in an illustrated electrical chapter of a

circular on Safety for the Household (Circular No. 75), which has

been issued during the year. In this study the cooperation and criticisms of lighting utilities and underwriters haA-e been received, and

the publication is in popular language, calculated to appeal to the

understanding and interest of school children as well as to the intelligent householder.

General Industrial Safety Standards.

As a result of the work of the Electrical Safety Code and the

numerous points of contact thus established with State and other

authorities interested in safety work, the Bureau has been called

upon to serve as a coordinating agencj'^ in promoting the adoption

of uniform safety requirements in other than electrical lines.

Early in the year the United States Employees' Compensation

Commission undertook a general inspection of Federal establishments from the safety standpoint. The National Electrical Safety
62 EEPOET OF DIKECTOB OF BUREAU OF STANDAEDS.

Code was utilized as a standard of reference in this work. Later

safety engineers were appointed in the several navy yards and arsenals, and conferences of these safety engineers were held for the

purpose of formulating definite safety standards for application in

the Federal establishments. Representatives of the Bureau were invited to attend these conferences and the Bureau was later asked to

undertake the revision and codification of the tentative rules covering

mechanical safety. The National Electrical Safety. Code was

adopted as a standard for electrical construction and installation.

The Bureau has revised the standards for mechanical safety, and

the work has been largely completed, except with respect to goggles

and eye protection.

The need for carrying out work of this kind upon a larger scale

became at once evident, and the Bureau has now undertaken a study

of all available rules covering mechanical safety, with the idea of

preparing a set of codes, similar to the Electrical Safety Code,

which will be available for the use of State commissions and other

administrative bodies concerned with the application of such rules.

Steps have been taken to cooperate with State industrial commissions, insurance interests, and technical societies in this work, as well as with other Government bureaus, such as the Working Conditions Service of the Department of Labor. A large field is opened

up by this work.

ELECTROLYSIS PREVENTION.

(Study of the effects of stray electric currents and development and application of methods of reducing damage resulting from them.)

Electrolysis Problem Among Public-Utilities.

The majorit}' of the street railways of the country are operated

on the single overhead-trolley plan, with the electric current flowing

into the rails through the car wheels, after it has passed through the

car motors. The current then flows back to the generating station or substation by way of the tracks and earth, some of it, however,

often flowing through underground gas and water pipes and the

lead sheaths of underground telephone and electric-light cables, and

sometimes through reinforced concrete structures. The earth con- ducts electricity b}' virtue of its moisture and the salts dissolved in it, which render it an electrolyte. Hence, when the electric current

flows away from iron pipes or lead-cable sheaths, it carries away

iron or lead by electrolytic action, and this in time corrodes the pipes

and shortens their useful life and sometimes completelj' destroys

them in a relatively short time. The property damage caused by

these earth currents when they are considerable, affects to a greater or less degree all the public utilities.

The trouble is the more serious in places where the soil has a

greater conductivity^ than usual, and where the conductance of the

tracks is small in proportion to the current, and the distance the

current travels back to the stations is relatively great. Many remedies have been proposed and tried, but no standard practice for

the handling of the return current has ever been agreed upon in this

country. As the electric railways have been extended and traffic has

become heavier, the volume of current handled has increased very

greatly, and the resulting destructive effects, which are cumulative

with time, have become increasingly evident. In some cases litiga-
BEPOKT OF DIKECTOE OF BUBEATJ OF STANDARDS. 63

tion has resulted between the pipe-owning companies suffering damage and the railway companies whose cun-ent causes the trouble. But

although the courts have considered the question of legal responsibility, these cases did very little to pi'event the trouble in an effective

and economical manner.

Economic Importance of the Electrolysis Problem.

The subject of electrolysis of underground pipes, cables, and other

metal structures is one which has been given more attention in re- cent years than formerly, but it still does not receive the attention

in many quarters that its importance deserves. When one considers

the enormous value of the pipe and cable properties buried in the

streets of cities and forming in many cases transmission networks

between cities throughout the country, and considering further that

there are very few water, gas, or lead-cable systems which are not

more or less subject at some points,to electrolytic damage from stray

currents, it is possible to form a better judgment of the practical

importance of this subject. The water and gas pipe systems of this

country alone have an aggregate value at the present time in excess of a billion of dollars, and in addition to this there is a vast extent

of underground lead-cable systems belonging to telephone and electric power, companies and to municipalities. In addition to these

vast properties in the earth, a considerable part of which may be

more or less subject to electrolytic damage, there are possibilities of

trouble in the case of bridge structures, portions of steel frame buildings, and piers, which are occasionally exposed to damage from this source. While the total losses due to shortening of the life of underground

pipes and cables must be considerable, such loss does not by any

means represent the total annual damage due directly to electrolysis.

It is well known that the annual loss due to leakage of water and

gas from distribution systems is very great. It is true that only a part and probably a small part of the total leakage is due solely to

electrolysis, but it is only necessary to assume that a few per cent of

the total is due to the more rapid developments of leaks caused by

electrolysis in order to make the total loss resulting from this cause run well into the millions annually.

In making a valuation of underground pipe systems, as, for ex- ample, in the case of a valuation to be used as the basis for a transfer

of property or for rate revision, it is necessary to consider possible

deterioration of the pipes due to electrolysis, since in those localities

in which the pipes have suffered from electrolysis the actual physical

value of the system will be materially reduced.

Inconvenience and Hazard Due to Electrolysis.

It is not alone the property loss, however, that makes the electrolysis problem one of importance. An important fact is the inconvenience to consumers of water, gas, and telephone service due to

the interruption of the service when repairs are made necessary by

electrolytic damage. Possible interruption of the service of police

and fire-alarm systems is also one of considerable importance to almost every municipality.

Wherever currents are permitted to flow on the underground pipe

systems there is the possibility of electric arcs being formed when
64 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

pipes are disconnected, or when different pipe systems make momentary contact. Accidents of this kind are rare, but they have sometimes occurred, resulting in the loss of life and a considerable damage

to property. Cases have occurred also in which leakage of gas re- sulting from electrolytic corrosion of the pipe has given rise to ex- plosion with disastrous results. Many gas explosions in basements

and manholes have occurred, and although it is difficult to determine

what proportion is due to electrolysis, undoubtedly some of them are due to this cause. A water-pipe line weakened by electrolytic corrosion may even

present a fire hazard much greater than would result from interruption of water supply at normal times. In many cities it is quite common practice during bad fires to increase temporarily the water

pressure in the district adjacent to the fire. It is very obvious that

a badly corroded water main might be capable of withstanding the

normal pressure on the system and thus give no warning of the weakened condition of the pipe, but at the critical juncture during a bad

fire when the pressure is suddenly increased the pipe may burst, and

thus seriously hamper the work of fire fighting. It will readily be

appreciated that in any region in which electrolysis damage is known

to be in progress to a greater or less extent the mains are far more

likely to break at these critical times than at any other period, and

thus a real, though indirect, fire and life hazard due to electrolysis

must be recognized.

Current Work on Electrolysis Mitigation and Related Problems.

In the field of electrolysis mitigation the work has been greatly

cu:rtailed during the year since practically all the men formerly en- gaged in it have been diverted to military problems. The work done

has been largely accomplished by a single member of the staff. Electrolysis Surveys.—Electrolysis surA^eys were supervised in St.

Paul and Duluth during the summer of 1917. In December and

January a similar investigation was made in New Orleans. The

recommendations of the Bureau are being carried out in St. Paul and

Duluth; but no action has been taken as yet in New Orleans. The

Bureau has recommended a three-wire system for this city, which, if

installed, will be the most complete and extensive system of its kind

in this country.

The electrolysis conditions in a number of cities were investigated

by conferences with the different companies concerned. In Los Angeles it was found that the three-wire system is being extended to

three or four additional substations, and the engineers of the railway

company reported complete satisfaction with this type of power

distribution. Rather careful study was made of the cause of cor- rosion of gas mains, and surveys were made in Aberdeen and

Hoquiam, Wash.

The- Bureau has been asked to supervise electrolysis surveys in

Milwaukee, and in Marion, Ohio, and it is expected that this work

will be taken up immediately.

Results of Previous Work.—As "a result of the Bureau's investigation of conditions in Springfield, Mass., the Springfield Railway

Company is preparing to operate their cars on a three-wire system.

It is believed that this installation will be completed during the summer of 1918. In the city of Omaha, after a trial of the three-wire
REPOKT OF DIBECTOR OF BUREAU OF STANDAKDS. 65

system in the Lake Street district, the main-station district was also

converted for tliree-wire operation, and is now giving excellent re- sults with regard to electrolysis. The Omaha electrolysis committee

has just completed a survey, and the results show excellent conditions prevailing over the entire city. The recommendations of the

Bureau have been carried out in XDractically every detail, and the

work of the permanent committee has been very satisfactory. It is believed that, as a result of this work, no further important electrolysis trouble wdll occur in that city.

Revision of Paper on ^'•Electrolysis and its Mitigation.''''—Technologic Paper No. 52, entitled " Electrolysis and Its Mitigation,"

has had a wide distribution. Since the original edition has been

exhausted, a revision has been made, and a second edition is ready

for printing. In this new edition the three-wire method of power

distribution has been discussed at some length, and a new discussion

of the subject of pipe drainage has been included.

Field tests on lead pipes haA'e been begun to determine the extent

of natural corrosion resulting from various kinds of earth encountered in city streets. Specimens have been buried on the Bureau

grounds in the following different soils : Compost consisting of

leaves and street sweepings, hydrated lime, cinders, Portland cement,

fi'esh street sweepings, vegetable mold. This investigation was instituted as a result of numerous reports of corrosion of pipes and

cables from causes other than electrolysis. It wilh require at least

two or three years to secure definite results from these experiments.

Electrical Resistance of Street Raihoay Roadbeds.—For the past

3 years field work both on city streets and on the Bureau grounds has

been under way to determine the electric resistance of different kinds

of street railway roadbeds. Some tests are also being made in Madison, Wis., by the Forest Products Laboratory in collaboration with

this Bureau. A technologic paper covering this work has been practically completed.

TELEPHONE-SERVICE STANDARDS.

(Systems of telephony; standards of telephone service. This section has also dealt with standard electric cells and has done much of the work on vacuum tubes.)

Telephone-Service Standards.

The investigation of telephone-service standards is of great importance, not only to public utility commissions, but to the telephoneusing public at large. Nearly every branch of telephone engineering is involved. Standards of transmission, traffic conditions and

the methods of handling traffic, the equipment used in the various

systems, including subscribers' instruments, apparatus used in central office and private branch exchanges, and the wire plant necessary

for subscribers' lines and trunks all have a very direct bearing on

the quality and the cost of service rendered the public. The staff

for handling the work has been increased during the year, and it is hoped that a more substantial increase will be possible in the near

future so that the work may be more actively prosecuted.

Standards of Telephone Transmission.

Progress has been made in the measurement of the efficiency of

telephone transmission, and in the development of standards upon

86986—18 5
66 EEPOBT OF mKECTOB OF BUREAU OF STANDABDS.

which this and much allied work must be based. Some of the work

done for the military establishments has contributed indirectly to

this development. A large number of comparisons of the efficiency

of transmitters has been made. A study has been undertaken of

problems which are involved in the highly complicated subject of

telephone transmission, and a knowledge of which is essential to

the interpretation of the results of transmission measurements. On

account of the complexity of modern telephone circuits, this is a

laborious undertaking, involving not only the development of suitable methods, and the making of measureraents under the manifold

conditions met in practice, but also the determination of the constants

of representative types of telephone apparatus under service conditions. Such work is of great general value, and has also a direct application in question of telephone service with which jDublic utility

commissions have to deal, such for example as the feasibility of

physical connection between different telephone systems.

Study of Local Telephone Service.

During the latter part of the year nearly the whole time of the

Telephone Section has been devoted to a study of the local telephone

situation in Washington, in connection with the rate case pending

before the Public Utilities Commission of the District of Columbia.

This is an unusually important case, involving the problem of deciding on proper measures to meet the unprecedentedly high operating expenses encountered by the local company under war conditions,

and also the question of the introduction of automatic switching

equipment to reduce the operating expenses, which the commission

wished to have investigated. Throughout the case the engineers

of the Bureau have acted as technical advisers to the commission. At

the request of the Postmaster General a report of the whole matter

was prepared and rendered to him. It contained a digest of the

hearings held by the commission, analysis of the local telephone situation as brought out in those hearings, and a discussion of the relative advantages and limitations of the manual, semiautomatic, and the

fully automatic systems of telephony, with particular reference to

their possible use in meeting the emergency in this case. The report

was submitted by the Postmaster General to the House of Kepresentatives' Committee of the District of Columbia, and was published

as a supplement to the House of Representatives' Report, second

session. Arrangements have been made for the engineers of the

Bureau to testify in further public hearings to be held by the commission.

Battleship Fire-Control Telephone Equipment.

An important test of battleship fire-control telephone equipment

was made for the Bureau of Steam Engineering of the Navy Department. Equipment submitted by 2 makers was so assembled as to

facilitate tests in accordance with suggested Navy Department specifications. One of the sets which was tested represented the equipment installed on the U. S. S. South Carolina. Equipment submitted by another maker represented two types of circuits and allied

apparatus, one being that designed for installation on the U. S. S.

Florida and the other that already installed on the U. S. S.

Utah.
EEPOET OP DIRECTOB OE BUREAU OF STANDARDS. 67

The observations made included tests for volume of transmission

for intelligibility and for naturalness of the sound transmitted.

Tests were also made for mechanical defects and to determine electrical properties of the transmitters.

The Navy Department having made a formal request that the Bureau of Standards assist in drafting new specifications for battleship fire-control telephone equipment, an inspection trip was made

to one of the naval bases, where both types of equipment were thoroughly inspected under service conditions and additional syllabic

tests were made. These confirmed our laboratory tests. The matter of new specifications will be taken up as soon as opportunity offers.

Microphones.

A considerable portion of the last half of 1917 was devoted to

experimental work in connection with sound detecting devices. Special microphones were designed and numerous experiments were

made. Tests were made using various sources of sound and with

and without the use of amplifiers.

Considerable experimental work was also done with various forms

of microphones for the detection of subterranean sounds. These

included the electrostatic and electromagnetic types as well as the

usual microphone. Several types were produced which gave fairly

satisfactory results. Some of this work is being carried on as time

permits with the hope that an acceptable instrument may be produced.

In connection with the microphone work, studies have been made

of the theory of the electrical and mechanical characteristics of

various telephone transmitters, of diaphragms and membranes, and

of vacuum tubes not only as amplifiers, but also as oscillators and

detectors.

Standard Cell Work.

The investigation of the cause of the cracking of Clark cells and

the best method of preventing it has been continued. Nearly two

years ago 18 cells of this type were set up, blanks being employed in

which the platinum terminals of the zinc limbs were subjected to

the action of zinc amalgam before being sealed into the cell wall.

Until this time none have cracked and they have remained remarkably constant.

3. HEAT AND THERMOMETRY.

[Establishment of the standard scales of temperature throughout the range of measurable temperatures ; testing and standardization of thermometers, pyrometers, and other temperaturemeasuring 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 measurements are the principal requirement ; standardization of calo- rimeters ; production and distribution 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 struc- tural materials; investigations relating to airplane and other internal combustion engines

and their auxiliaries.] THERMOMETRY. . (Researches on standard temperature scales and thermometric fixed points ; standardlza-

.

tion of instruments and methods foi- measuring temperatures up to about r)00° C.) Clinical Thermometers,

During the year, the new clinical thermometer certificates described in the last annual report have been issued and appear to be
68 REPOET OF DIKECTOE OF BUEEAU OF STANDAEDS.

giving satisfaction. The new edition of Circular No. 5 on the Testing

of Clinical Thermometers has been widely distributed during the

year. Specifications for clinical thermometers were prepared for the use of and were adopted by the Medical Supply Depot, United States

Army.

Some manufacturers of clinical thermometers had been issuing

certificates which were misleading, as on any but the most careful inspection it would appear that such certificates had been issued by the

Bureau of Standards. The Bureau informed the manufacturers of

its desire to have the practice discontinued. The manufacturers,

through their association, agreed to discontinue the use of certificates objectionable to the Bureau. It is believed that the use of misleading certificates will be practically eliminated.

Airplane Thermometers.

In July, 1917, an investigation of airplane thermometers was begun. Tests Avere made of instruments offered by American manufacturers and of such foreign instruments as were available. Investigations as to the nature of tests required and of methods of carrying

out such tests were also made. In cooperation with the Signal Corps,

specifications for several types of airplane thermometers were prepared. These were among the first specifications for airplane instruments to be issued by the Signal Corps, and served as a type for

others. The Bureau was also of service in finding sources of material required in the manufacture of the thermometers. Several inspectors for the Signal Corps received instruction in testing methods

in the thermometric laboratory. The Bureau has tested a certain

proportion of all thermometers purchased and has made several

minor investigations in connection with these tests. Copper-Constantan Thermocouples.

The Bureau has a small stock of selected constantan wire from

which a number of very homogeneous thermocouples have been constructed. A convenient flexible mounting has been designed and several couples have been calibrated at low and high temperatures. It

has not, however, been possible to obtain wire of sufficient homogeneity to permit construction of precision couples without considerable care in selection and matching of wires.

Low-Temperature Scale.

A number of vapor pressure thermometers, consisting of a barometric column connected to a tube containing a condensible gas

(oxygen, carbon dioxide) were prepared and used in the calibration

of several platinum resistance thermometers. The temperature scale so established will serve as a working scale for testing and as a

tentative basis for certain low-temperature researches of a military

character.

Antifreezing Solutions.

In collaboration with the chemical division, a circular letter on

antifreezing solutions for use in automobile radiators was prepared

and issued. The freezing points of various glycerin-water, alcoholwater, and glycerin-alcohol-water solutions were determined in the

laboratory. The freezing points of a number of proprietary antifreezing compounds containing principally calcium chloride were

determined.
EEPOKT OF DIRECTOE OF BUREAU OF STANDAEDS. 69

Solidifying Point of Naphthalene.

A standard method for determining the solidifying point of naphthalene was required by the Treasury Department for use in the

Customs Service. On December 7, 1917, representatives of the various customs laboratories met at the Bureau for a conference which

was also attended by several members of the Bureau's staff. A report

of preliminary investigations by the Bureau was presented. A

method for determining the solidifying point was agreed upon.

The Bureau was requested to prepare the detailed specifications for

the method and for the thermometers to be used. This has been

done, and the thermometers were purchased and tested at the Bureau.

It was also agreed that the Bureau should distribute a number of

samples of naphthalene to the various laboratories for comparative

tests. The samples have been distributed and results should be available shortly.

PYROMETRY.

(Researches relating to temperature scales, melting points, specific heats, latent heats,

thermal conductivities, and other properties of materials at high temperatures ; heat treat- ment of materials ; investigation and testing of high-temperature measuring instruments ; the application of pyrometric methods to industrial problems.)

Pyrometer Absorption Glasses.

A paper on the proper type of absorption glass for an optical

pyrometer appeared in Journal of Washington Academy of Sciences.

This paper described the specifications for absorption glasses applicable for precision work in extrapolating the high temperature scale.

The specifications were adopted by the American manufactui"er of

optical pyrometers. . . Optical and Radiation Pyrometry.

A general outline of the theoretical principles of optical and radiation pyrometry and methods of determining the fundamental constants of pyrometry were described in a paper published in the

Transactions of the London Faraday Society.

Optical Ammeter.

A paper was published in the Journal of Washington Academy of

Sciences describing a hot-wire alternating-current or direct-current

ammeter in which the hot wire is operated at a visible heat. Measurements are capable of high precision.

Standardization of Thermocouples.

Methods suitable for calibration of base metal and rare metal

thermocouples and precautions necessary in the measurement of temperatures by means of thermocouples were described in two papers

appearing in Metallurgical and Chemical Engineering. This subject

is of timely importance and the methods outlined have been followed

by many technical industries engaged in the production and heat

treatment of shell, guns, and various metallurgical products.

Wehnelt Tube Discharge.

In connection with the determination of certain physical constants,

especially latent heat of vaporization, an investigation of the

Wehnelt discharge tube was necessary. Two papers upon this subject

appeared in Journal of Washington Academy of Sciences showing
70 REPORT or DIRECTOR OF BUREAU OF STANDARDS.

that a film of high resistance forms at the surface of a probe wire

placed in the anode glow of a Wehnelt discharge. It was found that

a potentiometer or electrometer should be employed for measuring

the anode fall, or if a voltmeter is used, correction must be made for

the resistance of the film. The laws of shunt and series resistance

hold for these polarization films.

Simple Method of Measuring EMF Accurately.

Two new methods applicable to determining temperatures with a thermocouple, measuring potential drop across resistance standards,

were developed.

Pyrheliometers.

In Bureau of Standards Scientific Paper Xo. 323 are described

methods of calibration and the behavior of the type of pyrheliometer

used by the United States Weather Bureau for the measurement of

solar radiation. "Within the errors of observation, the solar radiation

scale defined by this investigation agreed with the standard pyrheliometer scale of the Smithsonian Institution.

Standard Samples for Thermometric Fixed Points.

The standard scale of high temperatures is most conveniently re- produced by the use of certain pure metals, the melting or freezing

points of which have been carefully determined. A large number

of such standard melting point samples of very pure tin. zinc,

alimiinum. and copper were prepared during the previous year.

One hundred and twenty-one of these samples were supplied to

various metallurgical industries for use in standardizing the master

tiiermocouples used to check the numerous pyrometers throughout the

works. That these standard samples have proved of great service to

the industries is attested by the fact that the demand for them from

arsenals, navy yards, and other industries engaged on military work

greatly exceeds the stock which this division has been able to prepare

with the personnel and funds available for this work.

Investigations in Electronics.

A series of investigations have been completed on the determination

of resonance and ionization potentials for electrons in vapors of

boiling metals. AYlien electrons are accelerated in a metallic vapor,

two types of inelastic impact between an electron and an atom occur. The first of these results in an orbital shift of the electrons

bound in the atom and the second in the complete removal of an electron or ionization of the atom. The potential differences through

which an electron must fall to give sufficient velocity for these two

types of collision are known as the resonance and ionization potentials for the particular metal in question. Work of this character,

which is of great interest from the standpoint of theoretical physics,

has also many important practical applications. Thus the data so far obtained laave resulted in the determination of one of the important physical constants of optical pyrometry. The work has a direct

bearing on problems in illumination by the electrical excitation of

gases, on the possible nature of gaseous explosions, on methods of

modifying and detecting electrical oscillations, etc. That the possible

practical "applications are many is evidenced by the fact that several

of our largest industrial laboratories are undertaking work of this
BEPOET OF DIRECTOE OP BUREAU OP STANDARDS. 71

character. Papers describing these researches have been published

and others are in press.

Thermoelectric Power of Liquid-Solid Metals.

The determination of the thermoelectric power of liquid-solid

metal thermocouples is of considerable interest from the standpoint

of electronic theory, and of importance in adding to our knowledge

of physical constants. The work with tin has been completed, and

the investigation will be extended to other metals.

Airplane Gas-Engine Explosion.

This problem has arisen as a by-product of the work on ionization.

In the further improved design of spark plug and sparking device

for gas engines it is essential to understand the physical mechanism

of an explosion. The first step under way in the problem is the determination of whether or not an explosion can be produced by

ionization due to photoelectrons liberated by excitation of a metal

with Rontgen rays.

Annealing of Optical Glass.

The manufacture of optical glass must be followed by a thorough

heat-treating process in order to remove the mechanical strains in

the glass. This new problem has 'arisen with the necessary and

rapid development in the American manufacture of optical glasses

required in the production of military instruments. For each type

of glass it is necessary to determine the temperature at which the

glass becomes sufficiently mobile to allow the internal stress to dissipate in a reasonable time. The annealing temperatures of the optical glasses made by the Bureau have been determined by different

methods, and investigation is being conducted to establish the relationship existing between the various physical properties of the

glasses and the process of annealing. These properties include viscosity, thermal expansion, electrical conductivity, thermal characteristics and transformation points, birefringence, etc. Briefly stated,

the object of the present investigation is (1) to determine the temperature at which the strain existing in a sample of glass of specified dimensions is dissipated in a specified lengih of time, usually 10

hours; (2) to determine the maximum rate at which the glass can be

cooled without danger of introducing permanent strain, and (3) to

determine the maximum temperature at which the annealed glass can be removed from the furnace without danger of fracture. The

above characteristics depend upon the size and kind of glass, but

fortunately these may be in general reduced to standard practice,

thus greatly diminishing the number of variables affecting the process of annealing. The work has been developed to such an extent that

routine tests are being conducted for various American manufacturers, and a complete report will be published later this year.

Temperature Problems in Coke Ovens.

The investigation of the coke ovens ordered by the President in

order to determine the relative merits of these two ovens for coking

certain grades of coal for use in the iron industry of Illinois and

vicinity was made by representatives of the high-temperature laboratories in connection with the study of the temperature conditions

under which these ovens are operated. Measurements were made of
72 KEPOET OF DIRECTOR OP BUREAU OF STANDARDS.

temperatures of the coal during coking, of the heating walls, of the ovens while empty, in the regenerators, in the waste-heat flues, in the

hot-vapor mains, etc. A considerable amount of valuable information has been accumulated. The work will be extended and a complete report submitted later.

HEAT MEASUREMENTS.

(Thermal constants and tUermal properties of materials at low and ordinary temperatures ; heats of reaction; investigation and tests of methods and instruments.

Standard Heat Samples for Use in Calorimetry.

Large fuel contracts are now quite generally based on heatingvalue tests made with calorimeters. The Bureau has furnished during the year 153 standard heat samples of sugar and naphthalene,

which have served the important purpose of enabling users of calorimeters to conveniently check the accuracy of their fuel tests. Refrigeration Constants.

This extensive series of investigations, undertaken at the request of

American refrigeration engineers, expressed through their national

associations, includes the determination of the fundamental constants of refrigeration engineering. The work is being carried out

with the cooperation of committees of the American Association of

Refrigeration and the American Society of Refrigerating Engineers,

the members of which have kept in close touch with the work by

visits to the Bureau and by means of the reports presented before the

annual meetings of these societies by members of the Bureau's

staff. The complete series of investigations contemplated under this

topic was outlined in the annual report for 1916. Most of the staff

engaged on these investigations have been diverted to another investigation of somewhat similar character but of immediate military importance. The work done during the year is briefly summarized in the following sections.

Thermal Constants of Ammonia.

The specific heat of anhydrous ammonia in its liquid and vaipor

phases and its latent heat are among the most important constants

of refrigeration engineering. The experimental work involved in

the determination of these constants was completed during the previous year, and a brief statement of the methods employed and the

results found was given in the annual report for 1916-17. During

the early months of the present year the results of these investigations were finally worked up and have since been published as follows : Bxireau of Standards Scientific Paper No. 301, An Aneroid

Calorimenter for Specific and Latent Heats; Bureau of Standards

Scientific , Paper No. 313, Specific Heat of Liquid Ammonia; Bureau of Standards Scientific Paper No. 314, The Latent Heat of Pressure Variation of Liquid Ammonia ; Bureau of Standards Scientific

Paper No. 315, Latent Heat of Vaporization of Ammonia. Projected

work on the specific heat of superheated ammonia vapor was deferred

for the future.

Specific Volumes of Ammonia and Ethyl Chloride in the Liquid and

Vapor Phases.

^ The experimental work incident to the determination of the specific volumes of these refrigerants in the interval —50° to +50° C.
REPORT OE DIRECTOR OF BUREAU OF STANDARDS. 73

has been nearly completed. One method used was an application of

the well laiown mass-volume method. An optical interformeter

method has also been applied to the determination of the specific

volume of the vapor phase, making use of the relation between re- fractive index and specific volume. When opportunity affords, the

large amount of experimental data that has been obtained will be

worked up and put into form for publication.

Special Military Investigations.

Several special military researches have been under way in this

division during the latter part of the year and have occupied the

greater part of the time of a number of the senior men of the division.

LOW TEMPERATURE.

(Production of low temperature down to those of liquid 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 ; special tests requiring the facilities of the low-temperature plant.)

Lov/-Temperature Laboratory.

This laboratory has continued to furnish during the year to the

several laboratories of the Bureau, as well as to other Government

laboratories, special facilities for tests and investigations requiring

low temperatures and gases at high pressures. Liquid air runs were

made on 36 occasions, the total aggregating some hundreds of liters.

Seven compressed air runs were made for the low-temperature comparators in the thermal expansion laboratory. The air compressor

was frequently operated for work on noxious gases, for development

work on air inductors, tests of silencers, oxygen valves, high-pressure

metal hose, etc. Electrolytic oxygen was furnished continuously in

large amounts to the chemical laboratories, and for welding purposes. Air and hydrogen, highly compressed in cylinders, were furnished to the various laboratories of the Bureau and to the Signal

Corps for special investigations.

The carbon-dioxide cycle was operated almost continuously to provide cooling for the refrigeration constants work; for the thermometer comparators of the heat division, and for development

work, by the Aeronautical Instruments Section, in connection with

aviators' oxygen regulators. It was also used for tests by other divisions of the Bureau and for low-temperature tests of aeroplane

watches, lens systems, electric batteries, rubber samples, and aviators'

masks.

The acetylene generator was kept in operation to supply acetylene

gas as needed.

A new air liquefier involving a rather unique automatic float valve

for discharging the liquid air without waste of cold air was built

and installed. While this addition increased the output of the plant

to the full capacity of the compressor, it was built chiefly for the

sake of providing duplicate equipment as insurance against accident.

The liquefier which had previously been depended upon for the supply of liquid air was overhauled and provided with the automatic

outlet.

The separate parts of an improved hydrogen liquefier were tested

and assembled. This will be put into operation in the near future.
74 EEPOET OP DIKECTOR OP BUEEAU OP STANDAEDS.

A liquid air and charcoal purifier for hydrogen was built for use on the liquid hydrogen cycle.

Two rotary vacuum pumps were installed for use in series with

mercury condensation pumps to give vacua of the order of 0.00001

millimeter of mercury. This assembly of pumps for high vacuum

work, while primarily designed for study of rare gases, has proved

very useful for the exhaustion of Dewar flasks, mercury arc lamps,

special manometers, barometers, and electrical devices.

Preparations have been made to install early in the coming year a new hydrogen compressor and two 90-foot gas holders, deliveries of

which are expected within a few weeks. The latter are of the annular type and arranged for variable water loading.

A second electrolytic oxyhydrogen gas generator was installed,

thus balancing the load across the three-wire electric circuit.

A gasoline bath, suitable for cooling large specimens to as low as —50° C. by means of the carbon-dioxide cycle, was constructed and

has been used frequently for special military tests. This laboratory has also cooperated in the calibration of a set of

orifice air meters for the War Department ; the production of liquid

oxygen for standard temperature bath; tests of special pressure

gauges, and tests of airplane unit sights for fogging with moisture

imder conditions occurring in aviation.

The Bureau was enabled, with the facilities alforded by the lowtemperature laboratory, to prepare a quantity of pure neon from

a mixture of helium and neon submitted by an industrial research

laboratory. The mixture, from which half a liter of neon was separated, was the volatile inert residue derived from atmospheric air.

The neon was condensed in coconut charcoal surrounded by liquid

hydrogen and later removed at liquid air temperatures. Members of

the optics division kindly assisted in the spectroscopic control.

There is still needed for the completion of the liquid hydrogen

plant a compound rotary vacuum pump of considerable capacity for

evaporating the precooling air under reduced pressure. Tlais equipment should be provided as soon as possible.

The next stage in the development of the low-temperature laboratory will include provision for the production of liijuid helium, thus

extending the facilities of the laboratory to the lowest attainable

temperatures. It is hoped that funds may be available to provide

this equipment in the near future.

FIRE-RESISTIVE PROPERTIES OF STRUCTURAL MATERIALS.

(Standardization of fire tests ; fire tests of structural materials and structures ; investi- gation to develop engineering data relative to the fire-resistive features of building con- struction ; investigation and testing of fire-retarding devices ; investigation of building codes and fire codes; cooperative work on fire prevention.)

Fire-Resisting Properties of Structural Materials.

The object of the investigations on the fire-resisting properties of

structural materials is to furnish architects, construction engineers,

builders, State and city building bureaus, insurance interests, and

others with fundamental engineering data relating to the behavior

and safety of various types of building material and construction

when exposed to different conditions met with in fires. •
EEPOKT OF DIRECTOR OF BUREAU OP STANDARDS. 75

Fire Tests of Building Columns.

Many millions of dollars are spent annually on the construction

of buildings, the integritj^ of -which, in the event of fire, is dependent on the behavior of the steel columns supporting the structures.

Very little engineering data are available which would permit of

any certain conclusions as to the thickness and kind of fireproof

covering required to render these columns safe under various conditions of fire hazard. The requirements of city building codes on

these questions are so different that it is evident that either some

codes are requiring unnecessarily thick fireproof coverings, with

undue increase in construction costs, or else other codes are requiring

too thin coverings, with undue increase in danger to the stability of

the structure under the existing fire hazards.

The fire tests on building columns are being conducted jointly by

The National Board of Fire Underwriters, the Associated Factory

Mutual Fire Insurance Companies, and the Bureau of Standards.

The present program of tests was formulated after consultation with

riiany engineers and architects interested in fire-resisting building

construction.

Types of columns.—The types of columns being tested include

rolled steel sections, built-up steel sections, round cast-iron sections,

steel pipe filled with concrete, vertically reinforced and hooped concrete columns, and wooden columns. At least one of each of the sec- tions is unprotected, others are partially protected by filling the re- entrant portions with concrete, and others are completely protected

by various thicknesses of concrete, clay tile, filled and unfilled gypsimi blocks, plaster on metal lath, and common brick, in accordance

with the methods commonly employed in practice.

Materials.—The materials used in the construction of the test columns and protective coatings have been obtained from various sec- tions of the country, and have been selected with a view to obtaining

those representative of their respective classes.

The column coverings have been applied by experienced men in

accordance with plans and specifications drawn to secure average re- sults obtainable under ordinary commercial conditions.

Methods of test.—In the fire tests the column, mounted within a

gas-fired furnace and kept luider nonnal working load applied by a hydraulic ram of special construction, is exposed to a predetermined

furnace temperature rise until the column fails. A record of the

temperature at different points within the furnace and at various

points within the test sample is obtained by means of suitable thermocouples. The deformation of the colimm from time to time is

determined by means of pairs of nichrome wires inserted into the

column at a known distance apart and extending horizontally outward through the walls of the furnace, the wires being run coaxially

through fire-clay protecting tubes.

In the fire and water tests, the tolumn is exposed to a furnace

temperature built up at the same rate—i. e.. in accordance with the

standard time-temperature curve that has been adopted for these

tests—until the desired temperature rise in the furnace is attained,

when two opposite walls of the furnace are rolled out of position

by means of trolleys provided for this purpose and the hose stream

applied.
76 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

T&sts completed.—A total of 75 columns have been tested during

the year. These comprise 10 tests of unprotected steel and cast iron

columns, 11 tests where the metal was partly protected by filling the

reentrant portions or interior with concrete, 24 were protected by 2-

inch and i-inch concrete coverings, 17 by 2-inch and 4:-inch hollow

clay tile, 2 by common brick, 5 by single and double layer of Portland cement plaster on metal lath, and 6 were vertically and laterally

reinforced concrete columns. The coverings and columns were designed according to standard methods of current practice applied

in a manner best adapted to secure quality of workmanship obtaining on ordinary construction work. Under the conditions of the

tests the columns so far tested stood up for periods varying from 11

to 35 minutes, for the unprotected steel and cast iron columns, to over eight hours for the heavier types of full protection, which

demonstrates the danger incident with the use of unprotected columns even under conditions of moderate fire hazard and also the

practicability of obtaining adequate protection with the use of moderate amounts of covering materials properly selected and applied.

The effectiveness of the protection was found to vary greatly within

any given class of protecting materials depending for example upon

the aggregate used in the concrete, the type of clay in hollow tile,

etc., while duplicate tests with a given material showed only relatively small differences in the protection afforded.

Several hundred tests to determine physical, chemical, and thermal

properties of the materials used have been made by this Bureau, as

also calibrations of the loading ram of the column furnace and ac- cessory testing machine.

A relatively small number of tests are required to complete the

program, after which the results will be prepared for publication.

A brief prospectus of the proposed tests was issued early in the

year.

Fire Tests of Reinforced Concrete Columns.

Fire tests of reinforced concrete columns now being carried out at

the Pittsburgh laboratory are intended to supplement the column

tests being made at Chicago, as the latter relate mainly to structural

steel columns. The equipment installed for these tests was briefly

described in the last annual report.

Types of columns.—Fifty-four columns have been cast. The columns include square sections 16 by 16 inches with 2 per cent vertical

reinforcement, and circular sections 18 inches in diameter, some with

2 per cent vertical reinforcement, others with 2 per cent vertical and

1 per cent of spiral reinforcement, and a few without reinforcement.

In all cases the covering outside of the reinforcement was 1^ inches

of concrete. All columns were 8 feet 9 inches long. Two types of

aggregate, washed river gravel and a high calcium limestone, both

from the Pittsburgh district, were used. Preliminary tests of 4 aggregates showed the ones selected gave concrete of very poor and

very good fire-resisting properties, respectively.

Methods of fes^.—Three columns of each type were made. One of

these was tested to failure when cold. In the fire tests the column,

mounted within a gas-fired furnace and kept under normal working

load applied by a hydraulic ram. is exposed to a predetermined fur- nace temperature rise until the column fails, or until the end of 4
KEPOET OF DIEECTOR OP BUEEAU OP STANDAEDS. 77

hours. If failure does not occur in the 4-hour period, the load is

increased to 600,000 pounds, the limit of the testing equipment; if

this does not cause failure, the column is allowed to cool and is subsequently^ tested to failure in a large testing machine. During the

fire test a record of the temperature at various points within the

furnace and within the column is obtained by means of suitable

thermocouples.

Tests completed.—Forty of the columns have been tested. The

most notable result of these tests is the earlier failure of the gravel

concrete columns, due principally to the spalling off of the outer

perfecting layer of concrete, thus exposing the steel and load bearing concrete to the fire. For example, a square limestone-concrete

column, with 2 per cent vertical reinforcement, had lost about 55 per

cent of its strength at the end of the fire test, while a similar gravel

concrete column had lost about 80 per cent of its strength.

Of the cylindrical columns with 2 per cent vertical reinforcement,

the limestone concrete columns showecl about the same loss of strength

in the fire test as the corresponding square columns, while the gravel

concrete columns showed less loss of strength than did the cor- responding square columns.

Of the cylindrical cohunns with 2 per cent vertical and 1 per

cent spiral reinforcement, the limestone concrete columns showed

the smallest loss of strength and the gravel concrete columns the

greatest loss of strength of any of the cohunns tested.

Supplementary tests.—In order to determine the effectiveness of

an aclclitional outer layer of fireproofing material to prevent spalling

of the concrete, additional tests were made of gravel concrete columns. One of the square gravel-concrete columns, which was protected with one inch of gypsum plaster with very light expanded

metal reinforcement, lost only about 40 per cent of its strength in

the fire test. The cylindrical vertically and spirally reinforced gravel

concrete columns, with a similar additional protection, withstood the

600,000 pounds load at the end of the fire test, and one column tested

subsequently when cold had lost only about 10 per cent of its strength.

It is clearly indicated that aggregates high in quartz introduce a

serious hazard in fire-resistive concrete, but that this hazard can be

practically eliminated by the use of suitable protective material.

These experiments have a bearing on the use of protective coatings to take care of the fire hazard, together with a possible reduction in the high factors of safety at present considered necessary in

concrete construction. The experiments with protective plasters of

various types will be continued.

A more detailed progress report describing the fire test on reinforced concrete columns has been published in- the Proceedings of the

American Concrete Institute.

Strength of Metals at High Temperatures.

An apparatus for determining the compressive strength and elastic

properties of materials as affected by heat has been completed during

the year. This has a maximum load capacity of 100,000 kilograms

and will take specimens up to 12^ centimeters diameter and 25 centimeters long and subject them to temperatures up to 800° C. The

load is applied by hydraulic pressure within a horizontal restraining

frame of structural steel, the heat being supplied by a circular elec-
78 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

trie furnace with concentric end coils to compensate for conduction

losses. The deformation is measured over a 15-centimeter gauge

length using microscope settings on wires attached to the specimen

and extending to the outside of the furnace. A series of 60 tests on

specimens of structural steel, cast iron, and concrete is under way

which it is expected will give much needed information on the properties of these materials at high temperatures.

Building Codes, Information, Cooperative Work.

Considerable correspondence has been carried on with engineers,

State fire marshals, and others interested in fire-protection work,

and the bureau has cooperated with committees on the standardization of fire tests and on safety to life.

Cooperative work has been done by participation in committee

work and in the preparation of reports for the Office of the Quartermaster General on the following subjects: Handling of petroleum

and coal-tar products, spontaneous combustion of cotton in bales, the

fire hazards in connection with wet and dry processes of cleaning and

sterilizing Army uniforms, plaster wall boards, paper safety matches.

Some work has been done in collecting, for the Tariff Commission,

information regarding the hazards of the various kinds of imported

safety matches.

Further work has been done on an index for collating information

relating to fire-resisting features of building construction.

Comparisons have been made of 15 city building codes in reference

to the following features of building construction : Height of buildings ; wall thickness ; fireproofing of building columns, etc. The section on "The fire hazard in the home " for the Bureau of

Standards Circular 75, on Safety for the Household, was completed

and the circular published.

AIRPLANE POWER PLANT.

(Investigations and tests relating to airplane engines, fuels, carburetion^ cooling sys- tems, ignition systems, and other auxiliaries, with special reference to conditions of temperature and pressure obtaining in actual use; special problems in lubrication.)

Altitude Laboratory.

There has been constructed an altitude laboratory, in which aero- nautic engines can be tested under all conditions of temperature and

pressure met with in flight. This apparatus is housed in a temporary building of 24 by 50 feet floor area. This laboratory was completed in January, and investigations have been under way continuously since that time. A total of about 120 sets of observations

have been made covering 500 or 600 hours actual engine operation.

Results of utmost importance have been secured on various features of engine performance at different altitudes. Confidential

reports of about 12 in number are in the course of preparation cover- ing part of the results obtained in these results.

Additional Equipment.

A second 24 by 50 foot building has been constructed in which is

housed a 400-horsepower dynamometer with necessary testing equipment and a torque stand on which engines can be run with propeller

load. These two units have been in use since their completion for

spark-plug and lubrication tests and other special tests described

below.
BEPORT OF DIRECTOR OE' BUREAU OP STANDARDS. 79

Spark Plugs.

An investigation of the design and characteristics of spark plugs

and ignition appliances was undertaken in 1917 and has been continued throughout the year. Methods of testing spark-plugs have

been developed and, on recommendation of this Bureau, adopted hy

the Bureau of Aircraft Production. A systematic study has been

made of the electrical and mechanical characteristics of some 50

different porcelain compositions for the purpose of selecting the best

material for spark-plug insulators. This investigation has led to the

adoption of a porcelain having a marked superiority to any porcelain

previously used for the purpose.

The Bureau has taken charge of the routine testing of spark-plugs

for the Signal Corps and the Bureau of Aircraft Production, for

which purpose aeronautic engines have been in operation a considerable part of the time on the dynamometer laboratory torque stand.

A study of the characteristics of a number of different types of

magnetos has been completed and has yielded results of value. The

results of the ignition investigation are included in some 15 confidential reports, some of which have been compiled and distributed.

Carburetion.

A study of the problems of carburetion for aeronautic engines has

been under way partly in connection with the tests in the altitude

laboratory. Results of utmost importance have been obtained indicating serious faults with 'all existing carbureting systems at high

altitudes and furnishing data from which it is hoped radical improvements may be developed.

Radiators.

A fundamental study of the problem of radiator construction for

high-speed airplanes undertaken in 1917 has been continued throughout the year. Careful analyses have been made of the performance

of something over 100 radiator designs under various conditions of

air speed and air temperature. The results of this investigation are being compiled into a series of confidential reports now nearly completed. The work done so far represents substantially a completion

of the program as adopted a year ago. There remain several important features of this problem to be undertaken. Additional information is needed on the performance of radiators in flight; on

the characteristics which are desirable for radiators placed in vari- ous positions on fusilage ; on the effect of radiator design and location

on head resistance of the plane; and on the effect of surface and

length of radiator cells. Lubricants.

Investigations of the behavior of a number of typical airplane

engine oils have been carried out and engines running on the test stand. Analyses have been made of the used oils from engines which

have been running in the altitude chamber from which valuable

information has been secured. Recently a more fundamental laboratory investigation of the characteristics of different oils has been

undertaken and has already yielded results of considerable interest.

Special Tests.

Special tests have been made on the performance of two new

models of the Hispana Suiza engine in the altitude chamber with
80 REPORT OF DIRECTOR OF BTJEEATJ OF STANDARDS.

special reference to pi'oper carburation; of Liberty engines on the

dynamometer stand and torque stand, "witli special reference to characteristics of performance, durability, and lubrication. In addition

to this, tests of several experimental engines have been undertaken,

in j)articular, one engine, designed under the direction of the National Advisory Committee for Aeronautics, was subjected to an

extended series of tests. A brief series of investigations was undertaken with an experimental 1-cylmder Liberty engine. This engine

has recently been mounted on a special test stand for the purpose of

studying temperature and pressure distribution in the cylinder and

in the various moving parts with a view to solving some difficult

questions as to ignition and lubrication.

Activities in Conferences, Committees, and Scientific Societies.

Members of the Bureau have participated in numerous conferences

with representatives of the military and other departments of the

Government and with technical men visiting the laboratories. The

committee work has frequently involved long and continuous service

on committees considering important new military developments.

Ten papers bearing upon pyrometry and related subjects were presented before various scientific societies, such as Washington Philosophical Society. American Physical Societv, and Optical Society

of America. Abstracts of these papers have appeared in Journal of

Washington Academy of Sciences, Physical Eeview, and Proceedings

of National Academy of Sciences.

Heat and Thermometer Tests.

The tests completed in the heat division during the year are summarized briefly, as follows

The number of mercurial thermometers of various lands, exclusive

of clinical thermometers, submitted for test, was 4.9.51, of which

4.464 received certificates or reports. Among those submitted were

341 Parr calorimeter thermometers, 19 high-precision calorimeteric

thermometers, 146 Beckmann thermometers, -56 clinical standards,

2.330 industrial thermometers for the United States Shipping Board,

Emergency Fleet Corporation, and the remainder laboratory and

special thermometers of various types ranging from below 0^ to 500''

C. Two hundred and forty-eight indicating airplane thermometers

of the vapor pressure and liquid expansion types were tested for the

United States Signal Corps, the Navy Department, and various

manufacturers. Of the 15,039 clinical thermometers submitted, 13,151

received certificates or reports giving results of test. In addition to

the above there were tested 9 platinum resistance thermometers, 4

thermocouples, and freezing point determinations were made on 25

samples of materials (naphthalene, toluene, and fixe-extinguisher

liquids).

In the high temperature laboratories the following tests were

made: One hundred and fifty-four thermocouples; 13 indicating instruments for thermocouples ; 23 homogeneity tests of thermocouples

18 optical pyrometers; 5 absorption glasses; emissivities of 3 metals;

heat resisting properties of 22 materials; heat treatment of 54 materials; melting point of 52 refractories; and 19 special tests. One

hundred and twenty-one samples of metals with certified melting

points were furnished to the technical industries. Among the special tests made in these laboratories the following may be mentioned
KEPOET OF DIRECTOK. OF BUREAU OF STANDARDS, 81

Preparation of 400 standard melting point samples; life test of

thermocouples; melting point of pyrometer porcelains; annealing

of 5 samples of optical glass, 3 of which were 8-inch cubes for periscope heads; annealing temperature of 16 samples of optical glass;

maximum safe temperature for removing A^arious optical glasses

from annealing furnace; specific heat of 2 samples of fire brick and

1 sample of gun metal; test of several thermocouples installed at

the Washington Navy Yard ; melting points of 2 aluminum soldering

fluxes; temperature of 3 illuminating bombs for the Signal Corps;

cooperation with the American Univei'sity Station, Bureau of Mines,

in the manufacture of arsene and other poisonous gases (50 furnace

heats made) ; temperature measiirements in Roberts' and Koppers'

coke ovens. The tests made in the heat measurements laboratories were : Standardization of 1 gas calorimeter; heat of combustion of 1 sample of

fuel oil and of a number of samples of airplane engine fuels; the

thermal conductivities of 32 samples of insulating materials; the

thermal leakage of 7 food containers. One hundred and fifty-three

standard combustion samples were furnished for the standardization

of calorimeters.

The tests made in the Ioav -temperature laboratory, either by its

staff or in cooperation with others using the facilities of this laboratory, have been referred to under the section of this report relating

to the low-temperature laboratory.

The total work of testing accomplished during the year greatly

exceeds that of any previous year, and its increase is very considerably greater than the increase in the personnel engaged in this worlc.

At least 75 per cent of the total testing was done directly for the

various military and civil bureaus of the Government, and most of

the remainder for industrial establishments engaged on Government

work.

Information Furnished.

SeA^eral hundred letters and reports relating to the work of the

heat division were prepared in reply to reqiiests for information on

testing of temperature measuring instruments, methods of temperature measurements, calorimetry, thermal conductivity, thermal constants, etc. Many engineers and technical men have visited the laboratories for consultation on special problems. A considerable number

of devices were submitted for examination and criticism.

4. LIGHT, OPTICAL INSTRUMENTS, AND SOUND.

[Development of photographic plates sensitive to red and infra-red light; use of these color- sensitive plates in spectral investigation and for landscape photography; standards and test- ing of sugar and other materials by optical means; investigation of magnetite and optical

properties of magnetic substances; color measurements and specification of color standards;

artificial daylight; spectral transmission of dyes and other materials; interferometry ; design

of optical instruments; testing of optical systems; production and testing of optical glass;

radiometry; transmissive and reflective properties of various substances; dispersoids; investi- gations in sound.]

SPECTROSCOPY.

(Measurempnt of standard wave lengths of light; application of suoh standards to the measurement of wave lengths of the spectra in chemical elements ; development of data

for the spectroscopic analysis of chemical compounds, alloys, minerals, etc. : development

of photographic methods for investigating the red and infra-red spectral regions.)

Red and Infra-Red Spectra of Chemical Elements.

Researches in the red and infra-red spectra of chemical elements

were continued during the past year with the aid of specially sensi86986—18 6
82 EEPOET OF DIKECTOfi OF BUREAU OF STANDARDS.

tized photographic j)lates. Ordinary plates stained with photographic dyes sucla as ]Dinacyanol and dicyanin were used for this

pui'pose and a large amount of spectroscopic data has resulted.

The arc spectra of iron, cobalt, nickel, chromium, manganese,

silicon, gold, silver, zinc, lead, aluminum, tungsten, and molybdenum

were photogi'aphed in the region of long wave lengths. In order to

determine to what extent photogi'aphic methods with a large diffraction gloating are applicable to the infra-red spectral regions, the

spectra of iron, cobalt, and nickel were photographed to the extreme

limit which it is practicable to reach with our apparatus and photographic method. A large concave grating was used, and exposures

up to 10 hours' duration registered many lines with wave lengths

greater than 10,000A, or 1 micron. In the arc spectrum of iron, 298

lines were measured between the wave-length limits 6.750A and

10,689A; 606 lines were measured between 6,503A and 11,623A in

the arc spectrum of cobalt ; and 290 lines between 5,504A and 10,843A

in the arc spectrum of nickel. These results (Scientific Paper No.

324) demonstrated that an invisible long-wave interval as large as the entire visible spectrum is accessible to photography with dicyanin

stained plates. The incompleteness of spectroscopic data for these

longer light waves invites extensive application of this method of

spectrum photography.

A scientific paper entitled " Measurements of Wave Lengths in the

Spectrum of Neon '' has been completed and presented for publication. This paper contains the wave lengths of 55 strong lines in the

red and violet portions of the neon spectrum. Interferometers were

used to measure the wave lengths in terms of that of the red radiation from cadmium, which is the fundamental standard. The probable error of these wave lengths is about one part in seven millions,

and the^e values will therefore be of importance as spectroscopic

standards. Differences of vibration frequencies corresponding to

these wave lengths are found to be exactly constant within the limits

set by the accuracy of the wave lengths.

In addition to the strong lines mentioned above, the wave lengths

of 189 less intense lines in the red and infra-red spectrum of neon

were determined with the aid of a large concave grating and are included in this publication.

Other spectroscopic researches described in the last annual report

were published during the past year, as Scientific Paper No. 312,

" Wave-Length Measurements in Spectra from 5600A to 9600A." and

Scientific Paper No. 318. "Application of Dicyanin to the Photography of Stellar Spectra."

Red and Infra-Red Spectrum of the Sun.

A map of the solar spectrum from 6800A to 9600A was made from

spectrograms obtained at the Johns Hopkins University last year,

and this map was reproduced in the January number of the Astrophysical Journal. ]\Ieasurements of the original photographs reveal

nearly 2,000 Fraunhofer lines in this part of the solar spectrum.

Thus far about 400 of these solar wave lengths have been identified

with those of emission lines in the red and infra-red spectra of 19 of

the chemical elements which have been studied in our laboratories.

Through the courtesy of Director Frank Schlesinger, the Porter

spectrograph at Allegheny Observatory was used during the past
EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 83

year for tlie continuation of work on the solar spectrum and data

were collected to permit the absorption lines in the solar spectrum to

be classified as solar or terrestrial. This spectrograph was designed

for work on the rotation of the sun and served to separate the solar

from the telluric lines by means of the displacement suffered by

solar lines in consequence of the solar rotation. Excellent spectrograms were obtained between 5600A and 9400A, but instrumental

difficulties made it impossible to photograph the spectrum beyond

9i00A in sharp focus. Between these limits over 3,000 absorption

lines were recorded, of which number about two-thirds were shown

to be due to absorption of oxygen and water vapor in the earth's at- mosphere. More extensive application of stained-plate photography

to astronomical subjects promises to yield further important results

in astrophysics.

Refractive Index and Dispersion of Air.

In connection with spectroscopic work it is necessary to know some

of the optical properties of air. For example, the difference in the

index of refraction of the air for different wave lengths must be

taken into account in the measurement of standards of wave lengths,

and for the proper discussion of numerical relations among spectral

lines it is necessary to reduce wave lengths which have been measured

in air to their value in a vacuum. This requires a knowledge of the

index of refraction of air of various densities for a large range of

wave lengths. Over 1,200 observations on the index of refraction of

air of various densities were made for wave lengths from 2200A to

9000A, which is the entire spectrum range easily recorded by direct

photograph}'. Tables were prepared to enable the proper correc- tions to be made to standard wave lengths measured in air whose

density is not normal and also make possible the conversion of wave

lengths or frequencies measured in air to their values in a vacuum.

The computations were completed during the past year and the re- sults prepared for publication in Scientific Paper No. 327.

Landscape Photography With Red-Sensitive Plates.

The success in spectrum photography with plates sensitized to red

and infra-red light with photographic dyes has led to their application to landscape photogi'aphy. Their greatest importance arises

from the fact that ordinary plates are sensitive only to shorter waves

in the blue portion of the spectrum and these waves are largely

scattered in the atmosphere. The intensity of this scattered light

in the sky varies inversely as the fourth power of the wave length,

so that red light of twice the wave length of blue would be scattered

only one-sixteenth as much. The great value of red-sensitive photographic plates in penetrating the haze due to light scattered in the

atmosphere has been fully demonstrated. Another important characteristic of these red-sensitive plates is their power to detect camouflage designed to defeat the eye. It has also been shown that in cer- tain cases where contrast is especially important it is brought out

much better by making use of red-sensitive plates.

Comparisons of numerous types of American and European commercial color-sensitive plates have been made. These plates have

been compared among themselves and with plates sensitized by staining with dyes in our laboratories. This investigation has shown
84 EEPOBT OF DIRECTOR OF BUREAU OF SIAXDAEDS.

that when certain dyes are applied to the proper photographic emulsions, the plates are superior to any others which have been available

for this comparison, and these include the most recent commercial

orthochromatic and panchromatic plates.

Ap^Dreciation of the importance of photographic dyes has created

an interest in their production in this country. Heretofore the best

photographic sensitizers were manufactured only in foreign countries, but now a number of chemists in this country are engaged in

the problem and have already succeeded in making some of the most

important ch'es. The sensitizing power of a number of domestic

dyes has been tested at this bureau, and the outlook for American

photographic dyes is very hopeful.

In coimection with these color-sensitive photographic plates the

question of color filters has received considerable attention. Screens

showing the greatest possible transmission of light in certain spectral

regions are required and the production of such filters for use in

special photographic work is of great importance. In the same con- nection some work has been done in designing photographic lenses

which are corrected for the longer waves.

Spectroscopic Analysis.

Considerable time has been given to analyses by the spectroscopic

method. The spectroscopic method is extremely sensitive and often

detects impurities which escape the chemical method. In some cases the quantity of a sample is too small for a successful analysis by

chemical means. The presence of all the constituents of a compound

in a single small sample can generally be tested quite easily by a spectrum examination, while the chemical method often requires sev- eral portions of the material, each one of which is separately ex- amined for a certain element or group of elements. Coordination of

the results of spectroscopic and chemical analyses of standard samples in certain cases makes possible the substitution of a rapid and

accurate spectroscopic method of quantitative analysis for a cumbersome chemical method. In cases where the chemical quantitative

analysis can not be replaced by the spectroscopic method a rapid preliminary qualitative analysis by the spectrum often saves the chemist

much time.

During the past year spectroscopic tests were made on a large variety of materials of which the following may be cited as typical.

The constituents of samples of optical glass and of colored glasses

were found spectroscopically. and some of the materials used in the

manufacture of optical glass were examined for impurities which

might color the glass.

At the reqtiest of the zinc-refining industry, a considerable ntunber

of ores, electrolytes, anodes, etc.. were examined to detect impurities

which gave trouble in electrochemical processes.

A variety of cored and impregnated carbons used in electric arc searchlights were analyzed.

The spectra of various poisonous gases were examined, but it was

found that their instability under the conditions required to i^roduce

a spectrtim makes it difficult to detect them spectroscopically.

Various alloys such as "" hardened " copper. " tempered aluminum,

nickel-tungsten and alloy steels were analyzed qualitatively from

their spectra.
EEPORT OF DIRECTOE OF BUREAU OF STANDARDS. 85

SeA'eral hundred samples of tin from steam boiler safety plugs were

anah^zed quantitatively for copper, lead, zinc, and iron by means of

spark spectra. This is a case in which routine and wearisome chemical analysis can be replaced by easy and accurate spectroscopic work.

Cooperation of sjDectroscopists and analytical chemists will make

spectrum analysis more powerful and practicable in quantitative

work.

POLARIMETRY.

(Standardization of materials, including sugars, sirups, and otber compounds, by polar- imetric methods ; precision polarlnietrj-, including tlie determination of polarlmetric con- stants ; development of standard definitions, methods, and Instruments ; calibration of polarlmetric apparatus ; standardization of the technology of sugars and related materials ; research in all factors affecting the efficient organization of sugar manufacture and test- ing ; sugar standards for precision calibration purposes ; laws and principles of magneto

optics and their practical application.)

Circular on Polarimetry.

Since the completion of Circular M, on Polarimetrj', referred

to in the last annual report, it has been necessary to print

two editions, and the third is now under way. The last edition of

1,500 copies was exhausted in three weeks, nearly the entire edition

being purchased by the public. The demand has proved to be a confirmation of the Bureau's recognition of the possibilities of polarimetry in both science and industry.

Testing of Quartz Control Plates.

Quartz control plates are indispensable for the accurate daily

checking of saccharimeters. Eight of these plates were tested and

certified. Two of them, which were improperly mounted in wax,

were removed from their original mounts and placed in loose metal

holders in such a way as to comply with the Bureau's specifications.

Owing to the fact that all quartz control plates are imported from

Europe it has been impossible to secure any for some time. With

the object of being of the greatest possible assistance to the sugar

industr}^ in this emergency, the Bureau has abandoned its previous

practice and whenever feasible is remounting and testing discarded

plates in a manner to make them serviceable.

Natural Rotation of Quartz at High Temperatures.

The iuA'estigation of the natural and magnetic rotation of light

by crystalline quartz at high temperatures has been continued. Additional knowledge of the properties of quartz is of special importance from the theoretical standj^oint because of its extensive use

in polariscopes and other optical instruments and because of its relation to the problems involved in the study of the history and formation of the earth.

Crystalline quartz has a transition point at about 574° C. At

this temperature the crystal changes over into another crystal form

with an absorption of heat when passing through the inversion point

from a lower to a higher temperature, and an evolution of heat when

going down through the point.

At this so-called " inversion point " it has been found that there

is an abrupt jump in the natural rotation, its magnitude depending

upon the wave length or color of the light used. Also, there is an

abrupt change in the direction of the rotation curve below the point,

a small temperature change causing a very large change in the rotation, while above even a large change in temperature has very little
86 REPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

effect on the rotation. The curve showing the rotation plotted

against temperature was found to be a straight line almost parallel

to the temperature axis from the inversion point at 573°3 C. to

1,500° C.

The Bureau's polarimetric measurements are the first precision

measurements ever made at high temperatures, and a new line of

attack for many unsolved problems is therefore opened. It is a matter of great theoretical importance that a mere regrouping of

the atoms in a crystal can result in such profound changes in its

physical properties.

Magnetic Rotation of Quartz at High Temperatures.

When a plate of crystalline quartz is placed between the poles of

a magnet it rotates the light passing through it, the rotation due to

the magnetic, field being superimposed on the natural rotation. The

magnetic rotation at high temperature has been successfully investigated by placing the furnace containing the quartz plate iDetween

the poles of a large magnet. In contrast to the remarkable changes

in the natural rotation of the quartz as the temperature rises, the

magnetic rotation is found to be practically independent of the temperature, increasing very slightly as the temperature rises and showing not the slightest effect due to the regrouping of the atoms which

occurs at 573° C. The establishing of this fact is of much importance in modern electrical theory.

Standard Samples.

During the past yea,r 64 standard samples of sucrose and 11 samples of dextrose were disti-ibuted. These materials are used principally for industrial and scientific purposes, such as the standardization of saccharimeters, for the determination of the heat value of

coal and as standards in sugar analysis.

Pure Sugars for Miscellaneous Purposes.

Sucrose has been issued by the Bureau as a standard sample for

several years. Being pure carbon, it is widely used as a calorimetric

standard in the analysis of coal on account of its high purity and its

accurately known fuel value. It is also used as a saccharimetric

standard, as a source of pure invert sugar for standardizing sugar

analysis, and for other miscellaneous purposes. Similarly dextrose

(or glucose) in highly purified form has been issued as a " reducing " sugar standard for use in sugar analysis.

In response to a request from the Army Medical Supply Depot, we

have supj)liecl a quantity of our purified dextrose for use in differentiating bacteria of the colon group. This material is not at present

obtainable to a satisfactory degree of purity on the general market

and we are preparing either to supply it in the necessary quantities or to assist outside manufacturers to prepare it. One manufacturer has submitted a sample of his purest dextrose

for test. While his product still contains considerable impurities, it

is hoped that slight improvement in his process will yield a product

of sufficient purity for this and other purposes.

It is very desirable that other members of the sugar group be

added to the list. They are useful in chemical work and in the

differentiation of bacteria. Considerable progress has been made in

the production of levulose, a sugar occurring in honey and fruits;
EEPOET OF DIEECTOE OF BUEEAU OF STAISTDAEDS. 87

but none of the others have been prepared in pure form by the

Bui-eau.

Influence of Temperature on Speed of Inversion of Sugar.

This investigation begam in the previous fiscal year has shown the

exact time required for complete inversion of sugar at each temperature. By •• inversion " is meant the transformation of sugar by

means of acid into a mixture of dextrose and levulose which has

a definite rotation in the polariscope in a direction opposite to that

of sucrose. These measurements have shown that the time used in

practice is veiy greatly in excess of that required. During this excessive time the inverted sugar suffers a serious decomposition in the

presence of the acid. This preludes the possibility of accurate

analysis. As a result of these experiments a new procedure is being

developed and an accurate measurement is being made of the rotation

of inverted sugar. In these measurements the decomposition of invert sugar is avoided as far as possible.

A determination of the rotation of invert sugar is being made not

only at 20" C. the standard temperature, but also at the higlier temperatures 28-31° C. which prevail in climates where cane sugar is

produced. The importance of this investigation arises from the fact

that upon it are based the data for devising the method of analysis

of the sugar mixtures which occur in sugar manufacture.

Solubility of Dextrose.

The Bureau has assisted manufacturers in the preparation of pure

dextrose by suggestion and by examination of their jDroduct. In view

of the importance of encouraging the production of the pure sugar,

solubility in water has been investigated, since a water solution is

always the starting point from which the substance is purified.

From these experiments it appears that the solubility increases rapidly with increasing temperature up to about 35°. at which point

there is an abrupt change in the crystalline form and a resulting

change in the relation of solubility to temperature. These measure- ments will be carried out at still higher temperatures and complete

data on the solubility obtained.

Magneto-Optical Properties of Magnetic Substances.

Eesearch has been continued on the magnetic rotation of metallic

films, namely, iron, iron oxides (hematite, magnetite, etc.). and

nickel, fi'om room temperature to tem^Deratures as high as 1.000° C.

in some cases. Tlois work is the first study of magneto-optical phenomena ever made at high temperatures. The behavior in this region

of the stibstances mentioned is of great theoretical importance, existing theories having been based on the experimental facts observed

at ordinary temperatures. The experimental difficitlties which had

to be overcome were described in the last annual report.

The results obtained now show that the magneto-optical effect (rotation of the plane of polarization of polarized light) for all the

magnetic compounds so far studied, becomes zero at temperatures at which their ordinarv magnetic properties are lost. This effect is

especially clear in the case of nickel, the rotation falling abruptly

to zero at about 360° C, the temperature at which nickel loses its

magnetism.
88 EEPORT OF DIRECTOR OP BUREAU OF STANDARDS.

In the case of iron the phenomena are much more complex. As

soon as the temperature rises above room temperature, the magnetic

rotation begins to decrease rapidly. It rises again somewhat at about

300° C, indicating that some change or transformation in the material is taking place, then falls olf again gradually to practically zero

at about 780° C, the transformation of iron.

In the case of hematite, the phenomena are even moi^e complex and

at present unexplainable. The rotation for some wave lengths is

negative and for others positive. In some cases the i-otation is

negative at room temperature, becomes zero at about 400° C, and

diminishes to practically zero again at 700° C. It remains zero up to

800° C., which was as high as these observations were carried.

Another peculiarity discovered in hematite is that it acquires a

"set " in the magnetic field—i. e., after the field is removed the hematite film still shows a rotation, whereas it did not before putting it in the field. The direction of this " set " is changed with the change

of direction of the field. It would appear at first sight as if an optically inactive substance were transformed into a naturally active

one by placing it for a moment in a magnetic field. This phenomenon

is undoubtedly connected up with the residual magnetism of the film

as the "set" disappears at about the same temperature (about 400°

C.) that the hysterisis of hematite disappears. The field required to reverse the set is about 5,000 Gauss.

Solubility of Sugar and the Causes of Molasses Formation.

Nearly 15 per cent of sugar obtained from beets and cane is lost to

the production of granulated sugar in the form of " exhausted

molasses. Exhausted molasses is a solution of sugar, and the nonsugars occurring in the juices from which no further sugar can be

obtained by crystallization. It is therefore of practical as well as

scientific importance to ascertain the causes of molasses formation.

This investigation, which was begun in the previous fiscal j^ear, is proceeding along two principal lines.

First, experiments are being conducted upon the molasses themselves. We are endeavoring to ascertain whether all molasses act

in a similar fashion in inhibiting the crystallization of sugar and

in what respects the molasses from different locations differ. The

behaviors of the two great classes, namely beet and cane molasses, are being compared.

Secondly, the effects of single pure constituents of molasses are being studied from the standpoint of pure physical chemistry, for

the purpose of ascertaining what occurs within a solution containing

pure sugar and a pure salt in a very concentrated solution.

Some of the theories which have been proposed to account for the

formation of molasses already appear to require modification. From

what has been already accomplished it now seems probable that the

most promising line of attack of the problem of the prevention of

excessive molasses formation is an exhaustive study of the complicated chemical reactions involved.

Intense Monochromatic Light Sources.

In connection with the work in polarimetry it has been necessary

to secure sources of intense monochromatic light for colors which

have heretofore not been available. To this end considerable effort
REPOET OF DIRECTOR OF BUREAU OF STANDARDS. 89

has been expended iipon the production of cadmium amalgam lamps

and after much experimenting a lamp using a new alloy has been

produced, which promises to open up a new field of investigation.

Constants of the Quartz Wedge Saccharimeter.

The quartz wedge saccharimeter is used almost universally in the

analysis of sugar. In Scientific Paper No. 268 the Bureau has described its standardization of pure sugar at the 100 per cent point

on the scale. In order to place this standardization bej^ond question

it is proposed to corroborate it with many further measurements.

For this purpose pure sugar has been prepared from very varied

sources of supply and analyses made to prove the purity of the

samples. Sugar from Cuba, Java, Peru, beet sugar from Colorado,

and maple sugar from Vermont have all been brought to the highest

attainable purity. Such measurements as have been made show that

the substance is identical regardless of its source. Besides those on the 100 per cent point on the sugar scale, some

measurements have been made on the lower points in order to correct

for changes in rotation due to the altered concentration of the

solution.

In addition to sucrose, many other sugars are analyzed on the

saccharimeter. In Scientific Paper No. 293 the weight of dextrose

(i. e., the normal weight) required to give the same reading as 26

grams of sucrose was determined experimentally. Similarly measure- ments are in progress on the rotation of levulose. It is desirable that

all the common sugars be purified and their normal weights be determined to correspond to the true constants of the saccharimeter.

Customs Laboratory at Savannah, Ga.

The installation of a customs laboratory at Savannah, which was

started under Bureau supervision last 3'ear, has been completed and

the laboratorj^ has been in operation for several months. A Bureau

type precision saccharimeter was secured hj transfer of the instrument from the New York service. The new laboratory has been of

the greatest assistance in collecting the revenue on <:he abnormally

heavy southern shijjments of sugar from Cuba.

Utilization of Discarded Polariscopes.

In view of the inability of sugar manufacturers and refiners to

obtain polariscopes for use in the chemical control of their factories,

it has been necessary for them to use old types of instruments. In

many cases the 'basis of calibration of these polariscopes is different

from the newer and recognized types. The Bureau has been consulted in regard to the use of these instruments and has been able

to render considerable aid in this respect. The Bureau is continuing

to repair and adjust discarded polariscopes for sugar manufacturers

in an effort to remedy the existing shortage.

Polarimetric Testing.

During the year 644 cover glasses for polariscope tubes were tested

for optical homogeneity. The abundant supply of cover glasses now

available is due to the Bureau's efforts in assisting American manufacturers to produce a satisfactory product. It was most fortunate

that the Bureau's efforts culminated in the first American-made cover

glass just before the war started.
90 EEPOBT OF DIBECTOE OF BTJBEAU OF STANDAEDS.

Polarimetric Tests of Raw Sugar.

In connection with the Bureau's supervision of the sugar testing

in the Customs Service, Treasury Department, 1,533 exchange samples of raw sugar were tested. Approximately 50 per cent were

direct polariscope determinations of the quantity of sucrose present

and the remainder were tested for the per cent moisture in addition

to the sucrose content.

Sampling of Molasses at Key West.

The changes in the method of sampling molasses in tank cars inaugurated by the Bureau a year ago have given improved results.

The samples are now taken at Key West in transit to interior points

and shipped to New Orleans for testing. This method was recom- mended to avoid the expense of installing and maintaining a laboratory at Key West.

Supervision of the Customs Laboratories of the Treasury Department.

During the past year the work incidental to the supervision of the

customs sugar laboratories has been greatly increased. This may be

attributed to two causes

1. The heavy importations of sugar from the West Indies, due to

the necessity for refining before shipping to Europe.

2. The abnormal routing of shipments due to scarcity of ocean

tonnage.

The latter cause results in the unavoidable collection of considerable revenue at interior points of destination where poor facilities or, at best, only inadequate facilities are available for sampling and

testing. Nevertheless, the work has been done with accuracy and

reasonable dispatch. No protests have been carried into the courts

by the importers. The work of assisting the Treasury Department

in improving the equipment, personnel, and efficiency of its general

customs laboratories has been continued.

Definitions and Specifications for Refined Sugars.

The work of preparing definitions and specifications for the commercial sugars has been continued. However, the progress made has

not been as great as had been hoped. This is attributable to the fact

that the problem is a far more difficult one than had been anticipated.

In order to accurately separate and define the various grades, it will

be necessary to resort to every assistance which science can jDroduce.

All antagonism on the part of the industry has been eliminated and

it is hoped to haA-e preliminary results within the year.

Standard Glassware for Customs Service.

The work of interesting American manufacturers in the production of suitable chemical glassware for the Customs Service has been

continued. Good results have been secured on some articles, but in

the case of others the results have not been satisfactory. It is now

believed that in normal times the service will be able to entirely

discard European-made chemical ware for this work.

Bureau of Standards Baume Scale.

The new Bureau of Standards Baume scale has already resulted

in the elimination of much of the confusion and misunderstanding

which has been prevalent relative to density determinations in in-
REPOBT OP DIRECTOR OF BUREAU OF STANDARDS, 91

diistrial work. It is based on the specific gravity A-alues of Plate,

on a Avorking temperature of 20° C. and on the moduhis 145. It is

therefore adapted to the most convenient range of Laboratory working conditions and the best avaihxble scientific data. Its immediate

adoption in industrial sugar work and hy scientific investigations

has been gratifying. The Bureau has received a number of communications commending its action in this matter.

Basis of Saccharimeter Standardization.

In the last annual report attention was directed to the Bureau's

work on the 100° sugar point of the saccharimeter, shoAving that the

better grades of sugar tested over one-tenth of a per cent loAver than

theA^ should. Since under present conditions it seemed hopeless to secure a correction of this error by international agreement, the

Bureau has begun the standardization of saccharimeter and quartz

control plates for the industry' on the corrected basis. A report of

the Bureau's work was submitted to the Secretary of the Treasury, who then requested the Bureau to restandardize all the

quartz control plates in the Customs Service. This has been done,

with the result that the GoA'ernment's revenues from imported sugar

have been increased by $60,000 a year. It is now planned to issue a circular letter to all owners of saccharimeters and control plates

who have had their apparatus tested by the Bureau on the old international basis, apprising them of the error and of the necessity of

correcting it. Testing of Imported Molasses,

The importation of molasses, principally from the West Indies,

has continued to increase and the value of the product per gallon

has been enhanced from 100 to 300 per cent. The average polariscopic test shows less than 40 per cent sugar is present.

When the molasses schedule in the tariff act of 1913, in force at

present, was drawn, the product was nearly worthless and an ad

valorem rate of 15 per cent was fixed. Molasses testing over 40 was

assessed cents per gallon.

The recent rapid increase in value has therefore brought about

a very anomalous situation, in that the low-grade product testing

under 40 must pay a higher rate of duty than the more valuable

product testing over 40,

There has resulted considerable difficulty in the customs laboratories in satisfactorily testing the low grades. The methods in force do

not give the precision necessary to meet the situation. The bureau

has begun preliminary work on this important problem and is co- operating with the customs laboratories to find a satisfactory

solution,

COLORIMETRY.

(Measurement of the factors determining color; standardization of units, methods, and

Instruments used in colorimetry ; development of primary and secondary standards of

color, and their applications to the special industries ; determination of color composition of light sources, relative color transmission, and reflection of constituent colors ; the

practical definition of color by formula ; and the development of instruments for color measurement.)

Colorimetry.

Colorimetry is the measurement of the factors which determine

or serve to specify color. Color is strictly and properly defined as a

sensation; but the color of a light source may, nevertheless, be logi-
92 REPORT OP DIRECTOR OF BUREAU OP STANDARDS.

cally defined as the sensation produced by tlie liglit from that source,

and likewise tlie color of an object as the sensation produced by the

light transmitted or reflected by it. The fundamental physical basis of

colorimetry is spectrophotometry, the measurement of relative emission, transmission and reflection for light of different wave lengths.

Color may also be empirically specified by reference to arbitrary colored standards. The work comprised in this section deals generally

with light sources, the transparenc}^ of materials, and the transmission,

reflection, and diffusion of light and other radiant energy by materials. In some problems where color itself is not the prime consideration, still the measurements required and instruments and methods

used are identical or similar. Such problems are therefore dealt

with in this section. This work is closely related to and interlocks

with other sections of the bureau's work, viz, photography, photometry, and radiometry. Its methods find practical application in

chemistry, ceramics, pyrometr}', and the testing of textiles, paper,

paints, dyes, oils, and other materials, and in specifications and regulations concerning railway and other signals and eye-protective

glasses.

Color-Standards Investigation.

The color-standards investigation mentioned in last year's report

(p. 86) has been continued, although greatly impeded by the neces- sary diversion of effort to urgent military work.

The demand for color standardization mentioned in previous re- ports continues to be insistent. While the fundamental principles

of the subject are fairly well understood by a few experts who have

given particular attention to it, the practice of color specification is in a very unsatisfactory and indeed chaotic state. This condition

is due to the following circumstances

Lack of agreement as to standards, definitions, nomenclature, and

methods, even among those experts who are competent to deal with

the subject.

The failure of those most vitally interested in the subject from a

practical and commercial point of view to comprehend at all the

fundamental principles involved, i. e., a lack of clear concepts by

those most interested.

The widespread current use, without standardization, of pseudo

standards and empiric methods having no definition or even description other than their maker's or originator's name.

The lack of reliable quantitative data on the fundamental physical, physiological and psychological constants and factors involved.

The lack of well made precision instruments suitable to make the

measurements requisite for color specifications.

The purpose of color standards investigation is to provide for the

correction of these conditions. The work which the Bureau can do

and has already begun can be considered as follows:

1. Experimental loork.—A. Development of instruments and methods for general fundamental work; B. Determination of fundamental data and establishment of working standards ; C. Application

of spectrophotometric and colorimetric methods to specific technical

purposes; D. Routine tests.

2. Organizing and educational work.—A. Cooperation and discussion Avith experts outside the Bureau for the purpose of develop-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 93

ing and establishing uniform nomenclature and standards; B.

Compilation and coordination of previous data, preparation of

tables, graphs, etc. ; C. The giving of information by correspondence, conference, and circulars.

Extension and Improvement of Spectrophotometric Methods.

The fundamental physical requirement for placing color standardization on a secure and reliable basis is the permanent installation at the Bureau of apparatus for convenient, accurate, and rapid

spectrophotometric work by intercompared methods of testing of

known precision and reliability. Visual spectrophotometric work

has been in progress for several years. Its shortcomings were

pointed out in the report for 1916 and plans for improvement and

extension mentioned. These improvements and extensions have now

been largely accomplished in that the apparatus for determination of

spectral transmission by photo-electric and also by photographic

means has now been installed and is in actual use. Both of these

provide for accurate determinations of transmission for blue, violet,

and ultra-violet light ; and the photo-electric has been used throughout the greater part of the visible spectrum to wave lengths as great

as 600 millimicrons. The photo-electric apparatus has also been

used to measure reflection and plans are being made to adapt the

photographic to the same purjDose. An improved illumination apparatus for transmission and reflection has been designed for use with

the Konig-Martens visual spectrophotometer. Its construction in

the Bureau instrument shop was nearly completed at the close of the

year. The three methods now in use supplement each other admirably and give gratif3dng check results. It is intended, however, to

study much more carefully the comparison of results and the, accu- racy of each of these methods. This will involve a great deal more

detailed work.

Collection of Specimens of Measured Spectral Transmission.

The systematic classified collection of marked and identified specimens of colored glass has been greatly increased and numerous determinations of the spectral transmission made by different methods.

Standardization of Nomenclature and Forms.

Considerable time and attention has been given to the careful se- lection and definition of numerous technical terms for our own use and to the standardization of forms and symbols for expressing results. This is preliminary to a hoped-for more general agreement

on such matters of form and convention. After further consideration and discussion with others it is expected to incorporate such material in a Bureau circular. This matter has already been brought

to the attention of the Illumination Engineering Society.

A Precision Method for the Production of Artificial Daylight.-

One of the primary requirements for the establishment of color

standards is the experimental realization of artificial light of the

same spectral energy distribution as average daylight. For commercial purposes this has been more or less satisfactorily accomplished

by others heretofore by screening artificial light sources with blue

glass. While these glasses find an important and wide use commercially they do not give a perfect reproduction of daylight and are not
94 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

suitable for all purposes of precise specification. As mentioned in

the report for last year, the Bureau has developed a novel method of

reproducing daylight by means of the rotatory dispersion of quartz.

A description of this method with explicit specifications for producing

the desired results has now been published. This method will be of

basic importance in the establishment of color standards, but it is

intended solely for precision work with instruments, and is not a commercial competitor with the blue-glass method. Its scientific

advantages oA^er the latter are: (1) A much more accurate reproduction of the desired spectral energy distribution; (2) certain and

convenient reproducibility and definiteness of specifications; (3)

convenient adjustability.

The Specification of the Color of Light from the Ordinary Light

Sources and the Photometry of Lights of Different Color.

The development of methods and apparatus for this purpose was

mentioned in the last annual report. Since then another paper

further explaining and substantiating these methods has been published. By request of the Cooper Hewitt Electric Co., preliminary

experiments on adapting this method to the photometry of mercury

vapor lamps have been made; but it has been necessary to temporarily discontinue this on account of the urgency of military tests and investigations.

The Color Grading of Cottonseed Oil.

This investigation which lias been in progress for several years has

been almost entirely dropped for the present to give place to military work. Otherwise it could have been brought to a satisfactory

conclusion. This necessity is greatly regretted, and it is hoped to

take up this work again at the earliest opportunity.

Determination of the Spectral Transmission of Standard Pure Dyes

and Other Materials.

This work is of immediate importance in order to put dye standards on a secure and reliable basis for the purposes of trade and the

assessment of customs by the Government. There is now little or no reliable quantitative data available on this subject. Our own

work on it is only beginning, and its proper and satisfactory early

completion will require considerable increase in space and personnel.

The commercial importance of this work Avould seem to warrant the

additional expenditure required. The Bureau is now in possession

of a large collection of important prewar German dye samples. Arrangements are being made to secure other pure standard samples

and commercial samples of American manufacture. The necessary

elaborate and expensive apparatus for making the determinations is already provided and installed at the Bureau, and the extensive

series of determinations required will be undertaken during the coming year. It could be greatly expedited by an additional appropriation of about $5,000.

Cooperation with Societies and Organizations.

It is the Bureau's policy to cooperate and maintain close relations

with technical organizations, interested in the work in progress at the

Bureau. By invitation, the Bureau's expert in charge of colorimetry

has contributed a paper describing its work on color standardization

to the Transactions of the Illuminating Engineering Society. This
REPORT OP DIRECTOR OF BUREAU OP STANDARDS. 95

section of the Bureau was represented at the New York Dyestuff

Convention, January 22-23, 1918, and has been represented on committees of the Illuminating Engineering Society, the National Research Council, and the Society of Cotton Products Analysts.

Examination of Glasses Intended to Protect the Eyes from Harmful

Radiation.

This investigation mentioned as in progress in the last annual re- port has been completed and a Bureau of Standards technical paper

on it is now in course of publication.

Investigations on Color, Visibility, and Related Subjects for the

Military and Naval Authorities.

By far the greater part of the time and effort of this section during the year has been given to work of a military nature. This

Avork has continually increased until at the close of the year it re- quired attention to the almost complete exclusion of other matters.

Eoutine military tests are reported in another paragraph. Besides

these, several reports on extensive confidential investigations have

been made.

Investigations of the following kinds were in course at the close

of the year, but no extensive reports had been issued : Color of searchlights ; chromatic camouflage ; color specifications for signal flares.

Colorimetric and Related Optical Tests.

Formal reports have been made on the color, spectral transmission,

reflection, or transparency of 95 separate specimens or samples submitted for test. These include various colored glasses, eye-protective

glasses, colored signal glasses, camouflage material, tracing cloth,

binoculars, photographic paper, etc. By far the greater number of such tests during this year have been

of a military nature. There has been a notable falling off in the

number of civil and commercial tests. This has been due in part to

fewer applications and in part to the military necessity of declining

to undertake some commercial tests applied for. Of special note

among the military tests, because of its somewhat exceptional nature

and the urgency with which the results were demanded by the Signal Corps, was a test of the spectral transmission of binoculars. The

bureau was informed by the Signal Corps that the acceptance of

several thousand urgently needed binoculars would result from the

report on this test. The following table shows the number of submitted specimens

tested for various applicants:

Military Tests. War Department

General Engineer Depot

Office of Chief Signal Officer. Chief of Ordnance

16

12

9

Total, War Department. 37

Navy Department and United States Navy

Bureau of Steam Engineering

Washington Navy Yard

United States Naval Hospital

First Naval Disti'ict Bureau of Construction and Repair

8

6

5

8

2

Total, Navy Department. 24
96 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

National Research Council (military work) 9

Total of military nature 70

Civil Testa.

Civil departments of the United States Government 22

Railway 2

Manufacturer 1

Total of civil nature 25

Information, Advice, and Assistance on Colorimetric and Related

Optical Questions and Problems.

Besides the preparation of definite reports on tests and investigations mentioned above, a great deal of time and effort has been given

to complying with requests for information, assistance, and loans of

materials or apparatus. This service is rendered partly by the preparation of letters in reply to inquiries and partly by personal conference. During the past year these questions have been largel}' of a military nature.

Information, Advice, and Assistance Rendered the Army and Navy

and Other War Agencies of the Government.

Assistance has been rendered the war agencies of the Government

by furnishing desired information, supplying or loaning materials,

and affording laboratorj' facilities for cooperative experimental

work. These services may be briefly enumerated in part as follows:

For the office of the Chief Signal Officer, War Department:

Information concerning the ultra-violet transmission of several

glasses has been furnished to the Balloon Section. Information con- cerning camouflage material and color screens (ray filters) has been

given to the Science and Research Division. Some of the personnel

of the same division have been afforded laboratory facilities and

various color screens, mirrors, crystals, etc.. have been provided for

their use elsewhere. For the General Engineer Depot, United States

Army : Laboratory facilities have been provided for cooperative

work on the spectral distribution of the light from searchlight arcs. For the Quartermaster's Corps. United States Army: Information

in regard to chromatic camouflage. For a company of Engineers,

United States Army: Officers and men of this company have

been given information and advice on color measurements, chromatic

camouflage, color screens, etc. For the American University Experiment Station : Advice in regard to color measurements and specifications. For the National Research Council: Information in regard

to ultra-violet photograph_y. For the National Advisory Committee

for Aeronautics : Information in regard to chromatic camouflage.

For the Navy Department: Information in regard to chromatic

camouflage, signaling, searchlights, visibility under water, and transmission and diffusion of light by certain glasses has been given.

Special anticamouflage screens have been made and provided. Apparatus and instruments requiring weeks of work have been designed and constructed for certain confidential investigations. For

the United States Shipping Board: Information and advice on

chromatic camouflage and color specifications.
KEPOET OF DIRECTOE OF BUREAU OF STANDAEDS. 97

Information and Advice to Applicants Representing Scientific, Commercial, and Industrial Interests.

The following list summarizes in a general although incomplete

way the kinds of information given, together with representative

names of the applicants who requested it

1. Concerning eolorimetric and photometric apparatus and methods of measurement and their application to specific problems:

Bureau of Plant Industry, Department of Agriculture; United

States Tariff Commission; Johns Hopkins University; American

Writing Paper Co.; Williams, Brown & Earle; New York Butter

Packing Co.; Max Levy; Cooper Hewitt Electric Co.; American

Lithographic Co.; Forbes Lithographic Co.; Eimer & Amend; E.

I. Du Pont De Nemours Co.

2. Concerning eolorimetric definitions, standards, charts, etc.: Artificial Daylighting Co.; Supreme Council Thirty-third Degree

Masonry, Southern Jurisdiction; Hon. Clifford Ireland, et ah

3. Concerning colored signal glasses: Navy Department; Bureau

of Lighthouses; Pennsylvania Eailroad.

4. Concerning methods and standards for color-blindness testing:

Sante Fe Railway.

5. Concerning eye-protective glasses: United States Patent Office;

F. A. Hard}' Co. ; safety experts and commissions.

6. Concerning , the ultra-violet transmission of certain glasses

Pennsylvania Wire Glass Co. ; Corning Glass Works ; Vernon M.

Dorsey.

7. Concei-ning colored glass for use in illuminating of telescopic

micrometer: United States Naval Observatory.

Determination of Thermal Expansion by Interference Methods.

The thermal expansion of small samjDles from 1 to 20 millimeters

long is determined by methods using the interference of light waves. All the necessary apparatus has been completed for making thermal

expansion determinations from liquid air temperature to 1.000° C.

During the year tests have been made upon glass for searchlight reflectors, standard gauges, fused quartz, optical glass in connection

with the optical glass investigation, and aeronautical instrument

alloy.

Gauge Calibration by Interference Methods.

Interference methods for determining the planeness, parallelism,

and length of standard gauges have been devised and used. Two

sets of gauges ranging in length from 0.05 meter to 4 inches have

been calibrated in terms of standard light waves. Further investigation in connection with manufacturers of standard gauges is in

progi'ess.

Index of Refraction of Gases and Saturated Vapors.

The work started last year on the index of refraction and dispersion of air has been completed. In order to make the necessary cor- rections for the humidity of the atmosphere, the index of refraction

of saturated water vapors was measured for the temperature range

-10° to 103° C.

A special fused quartz interferometer and pyrex glass container

were built for this work. Using the same apparatus the index of re- 86986—18 7
98 BEPOKT OF DIKEOTOE, OF BTJEEAU OF STANDARDS.

fraction and dispersion of the saturated vapors, ammonia for the

temperature range —50° to +27° C. and ethyl chloride for the temperature range —50° to +50° C. were measured. One of the objects

of this work is to find an accurate and rapid method for determining

the density of saturated vapors.

OPTICAL INSTRUMENTS.

(Design of optical Instruments ; testing and research on optical systems, optical Instru- ments, and appliances such as telescopes, binoculars, cameras, gun sights, and the like, and optical parts such as lenses, prisms, mirrors, parallel plates, etc.) Airplane Camera.

The design of a new airplane camera using film was begun last

year. This camera uses a lens 37-inch focus and takes pictures on

film 8 inches square. The capacity of this camera is 75 to 100 pictures

at one loading. An additional feature in this camera is the simultaneous photography of several auxiliary instruments on a corner of

the film, furnishing desirable information- in connection with identification and interpretation of the picture.

Projection Lens.

Due to the great demand for instruments for military purposes,

all available manufacturing facilities were impressed into war work.

Such industries as use projection lenses found themselves unable to

obtain any, and were forced to make plans for manufacturing these

lenses. One lens was measured and the construction data supplied to

a company, enabling them to make their own lenses.

Instruments for Navy.

. A small telescope for use with stadimeters was designed for the

Navy and is now being turned out in quantity.

The constants of a gunsight telescope, Avhich will eventually become the standard for the Navy, were measured and work begun to

adapt the design to available glass. Further work of this kind will

be carried on with other telescopes as the needs arise.

Long-Range Photography.

For purposes of photographing at great distances and obtaining a

visible picture, lenses of rather long focal length should be used.

Three types of lenses were tried for this work, and experiments _are being carried on to determine the best type for the purpose.

Testing of Optical Systems and Glass.

Several hundred optical instruments, comprising binoculars, gun

telescopes, periscopes, range finders, camera lenses, etc., were tested

for the Army, Navy, Emergency Fleet Corporation, and various

manufacturers. Practically all of the instruments were made in

America, Avith optical parts of American-made optical glass, and it is gratifying to observe the high standard of perfection wTiich these

products have now attained.

Binoculars.—Auxiliary to the acceptance tests of field glasses,

more searching tests have been made of the optical constants of many

binoculars. For this work it has been necessary to develop testing

methods which enable the tests to be made accurately and quickly.

Some of the tests may be made by relatively unskilled persons after a short period of training, but one or two of the tests are difficult to
EEPOKT OF DIEECTOK OF BUEEAr OF STANDAEDS, 99

simplify to this extent. The methods devised are being applied to

acceptance tests. Camera lemes.—A number of camera lenses have been given thorough tests, "n-ith special reference to their use for specific military

purposes. A large number have been measured for equivalent and

back focal lengths. The change in focal length with temperature

"was investigated to temperatures as low as —35° C. and found to be

small.

Military Telescofes.—A number of military telescopes of various

types have "been examined and the constants of the instruments determined for both the Army and the Navy Ordnance Bureaus. In

general, information as to light transmission, definition, field of view,

and magnification is desired.

Miscellaneous Tests.—Other tests than the. ones referred to above

have been made of the constants and quality of lenses, lens systems,

and instruments. These tests have mostly been for military bureaus.

Optical Glass Constants.—^The index of refraction, dispersive constant, and transmission of many samples of optical glass have been

measured. These data have been mosth- for Bureau of Standards

glass, but a number of determinations for other glass have been made.

In addition to these routine tests a number of determinations of

indices for special purposes have been made.

A list of the tests referred to above follows

OPTICAL GLASS AXD IXSTEtTMENT TESTS.

Binoculars.

For Signal Corps 31-5 For Naval Ordnance Bureau 35

For General En^neering Depot 14

For Shipping Board (acceptance tests) 729

Special tests 120

1. 213

Militury Telescopes.

Gun sight telescopes 14

Range finders 3

17

Lens Systems.

Photographic lenses

Complete tests 17

Focal lengths : 50

Radii 4

Temperature change of focal length 5 Special tests 1

Other lenses : Focal lengths . ^ 20

Radii and constants.^ 1 Condenser lenses

For striae 152

250

Optical Glass.

Indices of refraction and dispersive constants 278

Transmission 183

461
100 REPORT OF DIRECTOK, OF BUREAU OF STANDARDS.

Miscellaneous.

Lens test plates, pairs for radii of curvature 16

Refractometer 1

Goggle lens frames 60

77

2, 018

Circular on Optical Instruments.

In response to numerous requests for general information on optical instruments a new circular on The Properties and Testing of

Optical Instruments has been prepared. In this circular the important characteristics of different types of optical instruments are

discussed in an elementary way and methods of testing the performance of such instruments are described.

Optical Glass.

Production..—The experiments in optical glass manufacture have

progressed very favorably during the past year. The Bureau of

Standards is shipping glass in quantities for the manufacture of

optical instruments and the glass is of a very good grade.

Quality.—Some large lenses of a high relative aperture, made

entirely out of some of the earlier melts of Bureau of Standards

glass, performed excellently. The absorption of the glass is small,

being regularly less than 1 per cent per centimeter in the case of the

prism flint glasses, and, with the exception of the heavy barium

crown glass, seldom running over 2 per cent.

Types of Glass.—The Bureau of Standards is producing glass of

the following types

Kind of glass. Bp. V.

i.518

1.574

1.580 1.55

1.621 1.655

1. 610

1. 517

60.0 57.5

42.0

.50.5 36.5

34.4

57.0

64.0

3. Liu'ht aint

Glass for Photographic Lenses.

The bureau has been successful in producing dense barium crown

glass of a usable quality. The light absorption of this glass is still

greater than is desirable and there are also more bubbles than could

be wished, but the color is good and the glass is free from stones.

The index of refraction of different melts varies somewhat, but

an imjDrovement in this direction is looked for.

Methods for Testing Optical Glass.

Successive improvements in methods of examining optical glass

for bubbles, stones, and stria? have been made during the year.

Optical glass is usually molded in flat slabs, polished on the edges,

and is then examined between these two polished faces for bubbles

(seed), stones, and striae. The same examination may be made without polishing, by grinding the edges and then placing cover glasses
REPORT OF DIRECTOR OF BUREAU OP STANDARDS. 101

against the ground faces, using a few drops of oil between the cover

glass and the ground surface. Somewhat more conveniently the piece

of glass may be placed in a tank containing a mixture of carbon

bisulphide and gasoline of the same index of refraction as the glass.

In this method of examination monochromatic light may be used to

advantage, and this method is now in use at the Bureau of Standards

glass factoi-y. This method has been used with success in testing

manj' small unworked pieces which would otherwise have been discarded for lack of such examination.

The Effect of Striae in Optical Glass.

An investigation of the effect of striae upon the performance of

lenses and prisms has been undertaken and some progress has been

made. The investigation has proceeded far enough to show that the

presence of light striae in moderate amounts does little harm to the.

image formed by an optical system. This has been demonstrated by

tests on many binoculars and on a number of lenses and prisms

containing striae, some of them in amounts great enough to badly impair the image.

Corrosion Tests.

Methods of investigating the weathering and hygroscopic properties of optical glass have been developed and a great many tests liave

been made to compare the permanency or resistance to corrosion of

different types of optical glass from various sources. Gratifying

success has been attained in producing optical glass whose surfaces

will not disintegrate.

Circular on the Testing of Optical Glass.

For the general use of manufacturers and consumers of optical

glass a circular entitled "Testing of Optical Glass" was prepared

and distributed. An effort was made to define and explain methods

of measuring the desirable properties as well as to describe tests for

the detection of common defects in optical glass in such a simple

form as to be of assistance in the production of better glass for optical

use. The revision and extension of this circular is contemplated.

Nonshatterable Glass.

At the request of the National Advisory Committee for Aeronautics, an investigation was made of the so-called nonshatterable glasses

intended to protect the eyes from splinters when accidents occur which fracture the glass used in spectacles, aviator goggles, face

masks, wind shields, etc. It was found that the relatively increased

nonshatterability of laminated glass and its comparatively good

transparency and rigidity even after puncture, give it great importance in devices for protecting the eyes and face.

RADIOMETRY.

(Development of standard instruments and methods of measuring thermal radiation,

commonly designated ultra-violet, visible, and infra-red rays ; determination of the reflective, absorptive, and emissive properties of materials for thermal radiation ; development of standards of thermal radiations ; determination of radiation constants ; and the measurement of thermal radiation in absolute value.)

Radiometry.

In the general subject of radiometry, investigations have been

continued in connection with the improvement of instruments for
102 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

measuring weak radiations, using selective radiometers. Considerable time was spent on military work involving radiometry. For this reason the investigation of the radiation constants have been in abeyance. One of the subsidiary problems undertaken was the adaptation of

the Callendar sunshine receiver and the sliding mechanism of the

recorder to the diaphragm opening of a camera, which is to be used

in obtaining a series of exposures at frequent intervals throughout

the day. By connecting the diaphragm with the sliding arm of the

recording mechanism the to-and-fro motion of the latter regulates

the diaphragm opening of the camera and hence the amount of light

reaching the photographic plate.

The incandescent lamps, used as standards of radiation in absolute

value were intercompared, and a set of two lamps were standardized

for a well known research laboratory. These lamps give the radiant

flux per square millimeter area, in absolute value, at a distance of

2 meters from the lamp. They were prepared some years ago by

direct comparison with a black body on the basis that the coefficient

of total radiation is ff=5.70. which is close to the value (t=5.72X10~^^

watt cm~^ cleg"*, recently determined by this Bureau.

Among the subsidiary investigations was a determination of the

spectral reflecting power of a series of magnalium allqj'^s.

Life Tests of Quartz Mercury Vapor Lamps.

The ultra-violet, as distinguished from the infra-red rays, appear

to have a marked effect in accelerating chemical action, as for

example, in the fading of dyes. There has arisen among manufacturei's of paper, dyes, cloth, rubber goods, paints, etc., a need of

information concerning sources, and their constancy of emission, of

ultra-violet radiations, for use in testing the lasting quality of their

products.

It is well known that the intensity of the radiation (especially

the ultra-violet component) from quartz mercury vapor lamps,

decreases greatly with usage.

In response to the demand for exact data, during the past jear

methods were dcAdsed for determining quantitatively the decrease

in intensity of emission with usage, and measurements were made

on radiant-power life tests of a number of quartz mercury vapor

lamps.

The data obtained indicate a marked decrease in the total radiation, as well as the ultra-violet component, emitted in the course of

1.000 hours' usage of the quartz mercury vapor lamps now obtainable on the market.

Optical Properties of Balloon Fabrics.

In connection with the general investigation (chemical, mechanical, etc.) of this subject, the transmissive and reflective properties

of numerous samples of balloon fabrics was determined, using a hemispherical mirror and thermopile, mentioned in previous reports.

Measurements were made also of the rise in temperature when the

fabrics were exposed to solar radiation, using a modification of the

fine thermocouples mentioned in the report of 1916. The investigation is being continued on a small-sized model balloon.
EEPOET OF DIEECTOB OF BUREAU OF STANDARDS. 103

Photo-electric Properties of Various Substances.

This- is a continuation of the investigation mentioned in last year's

report. The photo-electric sensitivity of several substances is being

determined, for equal energy values, in different parts of the

spectrum.

Extensive data have been obtained on the spectral photo-electric

sensitivity of molybdenite as affected by temperature, intensity of

the stimulus, humidity, etc. For certain radiometric investigations,

samples of molybdenite, which are photo-electrically sensitive, may

be used instead of a selenium cell. Infra-Red Transmission Spectra of Various Substances.

The spectral transmission of various substances, including special

glasses, colored fluorite, etc., was determined, and the data are now

in press.

Some of the glasses examined have narrow sp)ectral bands of high

transmission, which renders them useful as transmission screens for

infra-red photography and for producing bands of fairly homogeneous radiations Avithout employing a spectroscope.

Glasses for Protecting the Eyes from Injurious Radiations.

In last year's report attention was called to the importance of

this subject and that radiometric measurements are the logical basis

upon which to specify what constitutes ample protection from ultraA^olet and infra-red radiations.

During the past year considerable new data Avere obtained on the

ultra-violet and infra-red radiations transmitted by A^arious glasses

used for spectacles. The sources of radiation used Avere typical of

those to which one is exposed in occupational pursuits. For examj)le,

the quartz mercury A apor lamp and the magnetite arc, used in these

tests, were repi-esentatiA^e of sources of extremely intense ultra-AdoIet

radiation, while the gas-filled tungsten lamp and the sun represented

high intensities in the A'isible and infra-red spectrum. These new

data were published in a revised and enlarged edition of Technologic Paper No. 93, Glasses for Protecting the Eyes from Injurious

Radiations.

Information Furnished on Radiometric Subjects.

In reply to specific requests therefor information was giA'en on

A^ariotis radiometric matters, such as, for example, the reflectiA-e properties of metals useful in searchlights, etc.; thermal-radiodynamic

signaling devices; photo-electric substances; eye-protectiA'e glasses;

the constancy and methods of standardization of sources of ultraviolet radiations of high intensity ; emissivity of paints to be used for

preA'enting the heating of certain kinds of electrical machinery ; construction of iron-clad Thomson galvanometers; standard blackening

of radiometer receivers; and various radiometric questions having a military application.

Publications on Radiometry.

During the past year the following papers on radiometry were published : Technologic Paper No. 93 (second edition, revised and en- larged). Glasses for Protecting the Eyes from Injurious Eadiations;

Scientific Paper No. 319. Instruments and Methods Used in Radiometry, III—The Photo-Electric Cell and Other Selective Radiometers
104 KEPORT OF DIBECTOR OF BUREAU OF STANDARDS.

Scientific Paper No. 322, Photo-Electric Sensitivity of Bismuthinite

and Various Other Substances.

DISPERSOIDS.

(InvestiRation of the physical properties of dispersoids, such as smol^es, water supplies,

biological fluids, optical glass, etc. ; preparation and specification of standard dispersoids

development and standardization of dispersoid constants, instruments, and methods of measurement ; cooperation in the technical application of dispersoid information in other branches of Government, in science, and in the industries.)

Scope of Work on Dispersoids.

There is a large class of substances of technologic importance

which possess in common the characteristic of containing in sus- pension another substance in a dispersed or finely divided state. All such media are called turbid or heterogeneous, and have been

named dispersoids. A dispersoid is more complicated than a homogeneous material because it is always composed of two substances,

the suspended particles and the medium in which they are dispersed.

Smoke, fog, condensation nuclei, dust, and powders are examples

of turbid gases; water supplies, muddy rivers, lakes, and harbors, ocean turbidity, technical colloidal suspensions and emulsions, and

biological fluids are important fluid dispersoids; optical glass, crystals for optical instruments, such as calcite, quartz, and fluorite, and

opal or milk glass are solids in which turbidity is an important

factor.

The measurement and standardization of the physical properties

of dispersoids presents extremely difficult and technical problems.

In studying dispersoids the optical properties have been most useful.

For several years the Bureau has been developing instruments and

methods in order to standardize measurements in this field. For a quantitative measure of the light scattered by a dispersoid a turbidimeter has been designed and constructed; to measure the size

of particle the microscope, ultramicroscope, and corona methods

have been used, and to count the number of particles in gases con- densation methods have been employed. The problems of evaporation, condensation, convection, diffusion, coagulation, settling, filtration, and the production of standard dispersoids have also been

attacked.

This work is of wide application. A satisfactory standard of turbidity in water analysis is much needed in determining the efficiency

of the filtration of municipal water supplies. Industrial processes

such as tanning, dyeing, and the manufacture of paper involve dispersoids, the quantitative measurement of whose properties would

make possible control and improvement. Biological fluids such as

sera are already a commercial product of great importance for which

a standard of turbidity is needed. Smoke and dust are produced in

many industries, and man^^ cities regulate the extent to which they

may be discharged into the atmosphere. A more precise specification

of such gaseous dispersoids would facilitate the administration of

such laws.

SOUND.

(Research and testing upon sound sources, sound-analyzing instruments and appliances ; Investigation of the theory and methods of sound measurement.)

Sound Investigations.

The Section of Sound Investigation was started in the Bureau in

August, 1917. An important part of the work of the year, therefore,
BEPOBT OF DIRECTOE OF BUREAU OF STANDARDS. 105

was the establishment of the section and the assembling of equipment for the work to be done. While the demands of military work

necessarily took precedence at this time, the apparatus acquired is

practically all of it such as has permanent value and usefulness for

investigations of a general nature in the subject of sound.

A Koenig clock fork, the most refined instrument yet constructed

for the exact measurement of vibration frequencies of tuning forks,

has been secured and put into good running order in our shops. The

most refined instrument for the measui-ement of sound intensity is

Prof. Webster's phonometer. Prof. Webster has had one of these

made for us in his own shop at Clark University, embodying all the

improvements he has been able to work out for it. One of the most promising inventions of recent years in its relation to sound, in addition to its great usefulness in wireless telegraphy, IS the " audion " or " pliotron." It is especially interesting

and useful b,y reason of the fact that it serves either as a maintainer

or as an amplifier of oscillations. One of these tubes has been se- cured, and, together with the proper auxiliaries in the way of condensers, inductance coils, etc., forms an oscillator which promises,

with suitable acoustic fittings, to furnish a more flexible, dependable,

and exact source of sound than any hitherto available.

A good beginning has been made on a collection of tuning forks.

Among these is a unique and valuable set of 37 forks covering the

range from 523 to 4,186 vibrations per second (that is, three octaves)

by semitones, made expressly for the Bureau at a nominal price by

a Chicago manufacturer.

Besides these apparatus that have been secured from outside

makers two forms of apparatus for soimd analysis have been developed. The first of these is a set of " Eeed phonometers " similar

in principal to Webster's phonometer, but very much simplified, and

used in considerable numbers, so as to give data for a mimber of

pitches at once instead of only one. This forms a somewhat elaborate installation, so that for an easy and rapid, though less accurate,

indication of the quality of a given sound, a form, again much simplified, of the " phonodeik " was devised and is being used with

success. The section therefore is now equipped with the best type of instruments for determining the three distinguishing features of sounds,

namely, pitch, intensity, and quality or composition. It also has a good assortment of sources of sound and standards of comparison.

The work of the year, besides the acquiring and development of

these apparatus, included cooperation in certain phases of the work

done by members of the engineers of the Army on sound-ranging

and advice and help in various problems arising in other sections of

the Bureau or other departments of the Government involving the

application of acoustical principles of apparatus.

.A series of tests was made, in cooperation with the National Advisory Committtee for Aeronautics, of the effectiveness of seA^eral

types of mufflers offered for gasoline engines. In these tests, which

are still proceeding, both the Eeed phonometer and the phonodeik

are being used to find the effect of the muffler on the noise of the

engine.
106 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

5. CHEMISTRY.

[Chemical composition and purity of material, chemical properties and constants, including re- searches upon methods of analysis, specifications for technical materials, and preparation of pure materials for standardization work for the Government and for industrial and scientific laboratories.] Chemical Testing.

The number (18,365) of tests made in the chemical laboratories

during the year is double that of the preceding year. Distributed by

types of materials they were as follows: Ferrous metals (irons and

steels), 2,309; nonferrous metals, alloys, and coated metals, 1,638;

cements and cement materials. 5,870; coal tars, asphalts, saturated

felts, burlaps, and building papers, 1,056; linseed oils, turpentine,

driers, varnishes, and shellacs, 1,052; red lead, white lead, putties,

graphite paints, and miscellaneous paint materials, 888; lubricating

oils and greases, 649; soaps, nondrying oils, and metal polishes, 630 ; inks and ink materials, typewriter ribbons, sealing waxes, etc., 406;

balloon fabrics, 895; rubber, 676; leather, 1,030; miscellaneous, including flax packing, asbestos, textile materials, etc., 1,266.

The above tests were made for very many Government bureaus and

establishments and for States, municipalities, foreign and allied commissions, and private parties, as follows : Agriculture, 64 ; Commerce,

6,956; Interior, 95; Labor, 6; Navy, 564; Post OlRce, 294; Treasury,

1,666; War, 6,485; Panama Canal, 1,539; General Supply Committee

of the District of Columbia, 406 ; other Federal institutions, commissions, and committees, 178; State, municipal, and other institutions

and committees, 25; foreign and allied commissions, 44; private

parties, 43.

By far the major part of these tests were made for the military

branches of the Government. Much of the increase over the preceding 3'ear occurred in the last four months of the fiscal year 1917-

18. If this increase is maintained over the year 1918-19, the number

of samples to be tested may reach 30,000.

The New Chemistry Building.

The transfer of the chemical statf to the new chemistry building

was completed in August of 1917, although the building still lacked

certain important parts of its equipment. These have for the greater

part since been installed, but th? permanent electrical wiring re- mains to be done, as also the installation of the vacuum cleaning

apparatus.

In consequence of the rapidly growing requirements of the military branches of the Government, the capacity of the building is already largely overburdened and the need for additional space elsewhere is imperative. Designed to accommodate a maximum of 120

workers of all classes, the building now housed on July 30, 1918,

about 150. This crowding does not make for efficiency.

Chemical Publications.

The following papers emanating from the Chemistry Division

were published during the year, or are nearly ready for publication

Scientific Paper No. 316, Gas Interferometer Calibration; Technologic Paper No. 98, Effects of Heat on Celluloid and Similar Materials ; Technologic Paper No. 105, Comparative Tests of Porcelain

Laboratory Ware; Technologic Paper No. 107, Comparative Tests of
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 107

Chemical Glassware; Technologic Paper No. 113, Determination of

Permeability of Balloon Fabrics; Technologic Paper No. 118, Critical Study of the Ledebur Method for Determining Carbon in Steel

and Iron; " Eapid Determination of Carbon in Steel by the Barium

Carbonate Titration Method," Journal of Industrial & Engineering

Chemistr}', volume 10, page 520, 1918 ; " Investigation of Ladle Test

Ingots, II,'' to appear in the Year Book for 1918 of the American Society for Testing Materials ; " Causes and Eemedy for Gas Formation

in Ammonia Absorption Systems," Journal of the American Society

of Refrigeration Engineers ; " Toluol Recovery and Standards for

Gas Quality," Journal of Industrial & Engineering Chemistry, volume 10, page 251, 1918; "Notes on the Color Designation of Oil

Varnishes." Journal of Industrial & Engineering Chemistry, volume

10, page 475, 1918; " Investigation of Balloon Fabrics by the Bureau

of Standards,"' Third Annual Report of the National Advisory Committee for Aeronautics.

PHYSICAL CHEMISTRY.

(Preparation and purification of materials required in investigation of physical constants, for example, refrigeration of materials, calorimetric samples, etc.) Chemical Work on Refrigeration Problems.

A number of samples of pure ammonia and ethyl chloride were

purified for the Heat Division of the Bui'eau for use in the determination of important physical constants. Methods of purification and

testing previously used Avere perfected and tried out. The apparatus employed was also used in preparing pure gases for other purposes.

A method was devised for eliminating the formation of noncondensing gas in refrigeration systems using ammonia absorption,

whereby corrosion is avoided and the saving of considerable ammonia is made possible. This work has been given considerable publicity by the Food Administration in its circulars to operators and

owners of refrigeration plants in part of its campaign to conserve ammonia.

Purification of Materials for Special Purposes.

Samples of pure carbon dioxide and oxygen were prepared by

fractional distillation (sublimation in the case of carbon dioxide).

The boiling points of these two substances are to serve as fixed points

in the reproduction of the low temperature scale, which is necessary

for contemplated work on methane.

The purification of mercury has been placed upon a routine basis

and it is estimated that nearly a thousand pounds of the metal was

purified for the use of the Bureau.

A considerable quantity of pure methane was prepared for use in

the determination of its physical constants by the Heat Division.

ELECTROCHEMISTRY.

(Electrodepositlon, including electrotyping. electroplating, the latter including investi- gation of zinc, lead, nickel, copper, silver plating, etc.)

Electrotyping and Electroplating Investigations.

Owing to the increased demands for information on electroplating of military supplies, and to delays in the installation of equip-
108 EEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

ment, not much progress was made upon the study of electrotyplng, even though the International Association of Electrotypers had en- gaged a chemist to assist in this work. Upon his resignation from

this position in January the electrotypers were advised not to at- tempt to replace him at that time, owing to the demand for chemists

for military work. Arrangements were then made for a bureau

chemist to continue the experiments upon substitutes fbr Austrian

ozokerite, as the product made from American ozokerite was apparently not satisfactor3^ Since then, however, the compan}^ controlling the domestic deposits has improved its product, which is now

extensively used. There is therefore no pressing need for investigation of this subject, although cheaper substitutes might be devised

through such an investigation.

The study of electroplating has been principally directed toward

the formulation of specifications and definition of methods of operation and testing of military supplies. In general, this work forms

a part of the general investigation of protection against corrosion,

and is closely associated with the other phases of that investigation.

Since it has been found that zinc coatings exert far better protectioii

to iron and steel than do copper or nickel plating, or other forms of

protective coating, special stress has been laid on the study of zinc

plating. Owing to the extensive use of black nickel plating to produce a black finish upon military supplies constructed of brass or

steel (preA'iously plated with copper, or preferably zinc) the methods

of black nickel plating are also being studied. The application of

lead plating, especially on gas shells, is also being studied.

In view of the fact that there were almost no specifications or

satisfactory tests to form a basis for the inspection of plating on

military supplies, a conference upon this subject was held at the Bureau of Standards on March 27, 1918. Eepresentative platers and

manufacturers of plating supplies were present, as well as officials of

the War and Navy Departments and of the Bureau of Standards.

Definite recommendations were made, the most important of which

were

1. For protection of iron and steel against corrosion, only zinc

coatings should be employed.

2. Where a black finish is required, the black nickel finish should

be recommended.

A plating adviser was engaged on May 15, 1918. Since then he

has made numerous visits to plants manufacturing military supplies,

and has conferred with officials of the War and Navy Departments

upon improvements in existing methods. In general, the cooperation

and assistance of the Bureau of Standards in this work lias been

appreciated by the military officials, who have referred numerous

plating problems to this Bureau. Among the classes of military supplies to Avhich plating is or may be applied are, a^ircraft fittings for

both land and sea planes, material used in the construction and equipment of vessels by the Navy Department and the Shipping Board,

hardware and equipment used by the Ordnance, Quartermaster's,

and Marine Corps (e. g., buttons, belt fittings, harness fittings, hardware for tents, ammunition boxes, etc.), fuses and other parts of

artillery ammunition, magazines, and cartridge clips for rifles and

machine guns, siirgical instruments, tableware, and in general, almost
REPOKT'OF mRECTOR OF BUREAU OF STANDARDS. 109

any supplies constructed of metal. So far as possible it is important

to have the specifications and methods of testing such products

uniform or at least consistent, since oftfen a great variety of work is

made or plated in the same plant.

The present equipment at the Bureau for sernicommercial electroplating has proven useful not only for research work, but also for

occasional plating of articles made in the Bureau shop. If, however,

much of such work should be required, a separate small job plating

plant should be installed, which might be operated under the supervision of this section. In either case it is desirable to install equipment for the grinding, polishing, and buffing incidental to plating.

Since at present there is no suitable equipment at the Bureau for

this work, such machinery should be selected with a view to meeting

not only the research requirements, but also the probable needs of

the Bureau in this line.

METALLURGICAL CHEMISTRY.

(Preparation of metals and alloys required in connection with metallurgical investi- gations and special methods of analysis for such products.)

Rapid Determination of Carbon in Steel.

The electrolytic method reported upon last j^ear has been still

further improved and simplified so that an accurate determination

of carbon can be made in 4-J minutes.

Means have been devised for increasing by 50 per cent, with only

slight decrease in accuracj^, the output of work when using the barium carbonate titration method for carbon in steel.

Determination of Gases in Steel.

Several experimental forms of apparatus were constructed and

tried out for determining the nitrogen content of steel by the method

of absorption by metallic calcium that was referred to in last year's

report. One especially of these pi'omises to give excellent service.

Further progress was made in the development of Goeren's method

for determining gases in steel. Several practical applications of this

method are indicated by recent metallurgical problems that have

been brought to the Bureau by military branches of the Government

and by commercial firms.

Further work on the Goutal method of determining gases in steel

has confirmed the conclusions reported last year, but before publishing results some additional work will be done.

Supplementary work was done upon the Ledebur method for determining oxygen in steel and a paper on the subject is about ready

for publication.

The work referred to a year ago on the oxygen content of steels

deoxidized in various ways was continued. The various methods of

deoxidation used, namelj', by ferromanganese, ferrosilicon, aluminum

and titanium, have yielded steels with nearlj^ identical oxygen contents as determined by the Ledebur method.

The work on the Ledebur method made necessary an investigation

of certain questions connected with the equilibrium between iron

oxide, carbon, and hydrogen. It was found that carbon alone (as

iron carbide in this case) reduces ferrous oxide at 800° to 900° C.,

with formation of carbon monoxide and dioxide ; as soon as hydrogen
110 EEPOBT OP DIRECTOR OF BUREAU OF STANDARDS.

is introduced there is a jjartition of the reducing action between the

hydrogen and the carbide and the proportions of the reduction products (carbon monoxide, carbon dioxide, and water vapor) formed

vary with the rate of passage of the hydrogen. With very low

rates not more than 20 per cent of the iron oxide is reduced by that

gas ; a rate of not less than four liters an hours is necessary to effect a 90 per cent reduction by hydrogen alone. This investigation showed

also that the rate of hydrogen passage in the Ledebur method should

not be less than 4 liters per hour.

Carbon monoxide is an important constituent of the gases extracted

from steel when this alloy is melted in vacuo. Certain hydrocarbons,

produced by secondary reactions, are also present in the gases. Consequently, in order to determine carbon monoxide in such mixtures,

it is desirable to find a combustion method which will burn the carbon

monoxide without affecting the hydrocarbons. By the use of copper

oxide at 250° C. as an oxidizing agent it was shown that fractional

combustion of carbon monoxide is successfully effected provided unsaturated hydrocarbons are absent. It is believed that suitable absorbents for these have been found. A special form of electric

furnace for heating several copper-oxide reaction tubes in series was

designed and used for this work.

GAS CHEMISTRY.

(Methods of preparation, purification, analysis, and testing of gases, including fuel and

illuminating gas,, and special gases such as hydrogen, oxygen, nitrogen, argon, etc.

Balloon Fabrics.

The work on balloon fabrics has made very satisfactory progress

during the past year. After a complete survey of the field a program

of work was outlined. This was carried out under the auspices of

the Balloon Fabric Committee ; the result has been a uniform development of the field. The results accomplished during the past

year may be briefly summarized as follows

The methods of examination and testing of fabrics have been investigated and standardized. A method for the determination of

the permeability of balloon fabrics to hydrogen by use of the gas

interferometer has been developed and adopted as our standard

method. Other methods have been tested and found inferior. Two

new methods are now being developed and will be used in con- junction with our standard method 'as the circumstances dictate.

One method depends on the measurement of hydrogen by virtue of

its high thermal conductivity. The other method determines the

hj'drogen volumetrically by an ingenious system.

In connection with this line of work a study of the permeability

of rubber to different gases is being made. There is very little information available on this subject, and we have frequent calls for

such information in connection with the employment of rubber for

holding different gases.

The determination of the durability of fabrics has been studied in

detail, with the result that it has probably become one of the most

important parts of the Bureau's work. An investigation of the

fabrics being used in Navy dirigibles enabled us to show the Navy

that the fabrics in at least 9 of their 16 dirigibles then under construction were very poor from the standpoint of their lasting qualities. Only 2 or 3 of these dirigibles were accepted before our results
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. Ill

were reported and service tests confirmed our laboratory tests. We

not only effected a considerable saving to the Navy in time and

money hut stimulated the research activities of the companies re- sponsible for the fabrics to such an extent that a wonderful improvement in quality was obtained in a few months.

In the search for a rapid, reproducible exposure test, a thorough

study has been made of the use of ultra-violet light, heating in ovens,

exposure to light from tungsten lamps, etc., but no satisfactory

substitute for exposure to the weather has been found.

During the winter an extensive series of exposure tests was con- ducted at Pensacola, Fla., with the cooperation of the Navy Department. The Goodyear Tire & Rubber Co. rendered valuable assistance

in these tests by preparing without cost to the Bureau a great number

of experimental fabrics at a cost of several thousand dollars. The

United States Rubber Co. also prepared a series of fabrics for these

tests. The results obtained were very useful to the Army and Navy.

The effect of exposure under tension is now being studied in order

to throw light, if possible, on the deterioration of fabrics in dirigibles.

The effect of radiation on balloon fabrics is important from two

standpoints: First, the rapid changes in balloon temperature produced by sunshine, and, second, its effect on the lasting qualities of

the fabric. A study of these points is rapidly nearing completion.

The effect of various coatings and pigments in protecting the rubber

is a part of this problem.

The effect of impurities in the hydrogen upon the fabric and the

balloon fittings has been reported in a preliminary memorandum.

Further work on the subject is still in progress.

A new method of study which is being developed may be mentioned ; this is the microscopic examination of thin sections of fabric.

It is hoped that the cause of failure of certain fabrics may be determined visually in this manner.

During the year over 1,500 permeability determinations were made.

Exposure tests were completed on over 175 fabrics. Sixty new

fabrics are now undergoing exposure at Washington.

Much work was done on balloon fabrics, both in analyzing them

and in studying the changes undergone in storage and when exposed

to weather conditions at Washington and Pensacola.

Balloon-Gas Investigations.

The question of the best methods of preparing hydrogen from ferrosilicon and sodium hydroxide in solution was referred to this laboratory by the National Research Council and made the subject of an

extended laboratory investigation, as a result of which we were able

to explain all the phenomena connected with the reaction and to

determine with certainty the effect of each possible variation in

methods of generating the gas. Our report of November 5 covering

the laboratory work also included recommendations in the form of

specific directions for the purchase of material and the operation

of the gas generators. These recommendations are the basis of the

present practice of both the Army and Navy. The most important

single result of our work was to demonstrate the possibility of greatly

reducing the amount of sodium hydroxide used in the process with

attendant advantages in plant operation as well as economy. The
112 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

saving to the Navy alone from these changes was at one time computed to be $700 per day.

An investigation was made upon the effect of sodium carbonate

in the sodium hydroxide used in generating hydrogen and the results

were employed in preparing specifications for the purchase of

sodium hydroxide for military and naval use. Experiments were also made to determine the feasibility of re- covering sodium hydroxide from the sludge from the hydrogen generator by precipitating out calcium silicate with lime. Other ex- periments were made to determine whether sodium carbonate and

lime could be used economically in place of sodium hydroxide in

the ferrosilicon method. Both these modified processes were shown

to be impracticable.

A study of the literature relating to balloon gases was made at the request of the Navy Department and an extensive bibliography on

one phase of the subject prepared for their use. Methods have been developed and apparatus constructed for the

experimental study of the inflammable limits and the propagation

of flames in mixtures of balloon gases and air.

A gas density apparatus for determining the purity of hydrogen

for aeronautical pui'poses has been designed for the use of the Navy.

The bureau has had constructed and supplied to the Navy 25 of these

apparatus and 10 to the Army.

A short report on the effect of moisture on the lifting power of

balloons was also prepared at the request of the Navy Department.

Gas Analysis Investigations.

During the year the work upon combustible gas detectors was

completed. One form of detector was adopted by the Navy Department for use in submarines in competition with the instruments submitted by a number of other laboratories. After some months of

service, trouble developed with some of the instruments, partly on

account of excessive vibration of the submarines, which had not

been anticipated, and partly because the recommendations of this

laboratory were not followed in jjractice. The wiring, adjustment,

and calibration of the instruments was then taken over by this

laboratory, and means for testing and eliminating the effects of

vibration were devised. More than 100 instruments, 60 of which

were wired and calibrated in this laboratory, are now in use, and we

have just been requested to prepare 500 more. These instruments

probably do not cost more than $30 apiece and replace an instrument

costing $500 which had been tentatively accepted by the Navy

Department.

A preliminary study has been made of a number of methods for

the quantitative determination of the composition of 3-component

gas mixtures which do not permit easy chemical separation. This

work was requested by the Navy Department; but some of the results may have wide application in other fields.

A laboratory study of. one type of balloon leak detector of foreign

manufacture was made at the request of the Signal Corps and recom- mendations were given for the construction of similar instruments in

this country. We have also examined, tested, and reported upon

not less than 9 other types of gas analysis apparatus for various

purposes.
BEPOKT OF DIRECTOR OP BUREAU OP STANDARDS. 113

After several unsuccessful efforts along different lines a satisfactory continuous indicator for the percentage of oxygen in the air

has been devised and constructed in a crude form. The completion

of a compact assembled apparatus to be used as a model is a task for

the immediate future.

. Routine analyses of the exhaust gases from the aeroplane engines

under test at the bureau have been made regularly for the past two

months. An apparatus for securing instantaneous readings of the

combustible gases in the exhaust is under construction.

Several improvements in apparatus and methods for volumetric

gas analysis have been made and are in constant use. A new form of analytical apparatus depending upon the heat conductivity of gases has been devised and tried out in a preliminary

way with gratifying results.

The problem of the continuous anialysis of the gases in one of the

nitrate plants has been considered and a tentative method for complete analytical control of the plant has been worked out. The

experimental work on this problem is just beginning. The heat

conductivity method mentioned in the preceding paragraph is to be

used for much of this work and it is believed that there will be many

other important applications for this method.

Miscellaneous Gas Problems.

A great variety of minor problems and questions are constantly

coming to the gas laboratory, principally from the War ,and Navy

Departments. The two most important of these miscellaneous problems were the writing of a large part of the Hydrogen Manual for

the Navy and the testing of an oxygen supply apparatus for aviators

to detei-mine its suitability, for supplying more than one person. The

latter problem consumed considerable time only because it was neces- sary to devise entirely new methods for the study.

REAGENTS AND APPARATUS.

(Study of methods of testing reagents and apparatus to be used in chemical analysis,

including study of chemical glassware, porcelain, platinum, and platinum substitutes.)

Chemical Reagents.

AVork was taken up in cooperation Avith the American Chemical

Society and manufacturers with a view to improving the quality

of so-called "analyzed reagents" by a systematic study of the methodp of analysis in general use. Owing to the limited force and the

present abnormal conditions, not much progress has been made. A

representative of the Bureau visited and conferred with a number

of manufacturers, and reagents received for the Bureau laboratories

have been tested and the makers advised of the discrepancies between

the statements on the printed labels and the actual findings. A re- port has been submitted to the chairman of the committee of the

American Chemical Society. This work is of dii-ect interest to all

Government departments and to all other users of reagents, and indirectly affects all users of the products of the industries.

Platinum.

The research upon the chemical and physical properties of the

platinum metals has been started, the work of the past year consisting mainly of a study of the literature and of the analytical methods.

86986—18 8
114 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

From the cooperation of the United States Assay Office at New York

the Bureau has obtained loans of platinum, iridium, and palladium

for this work. It is purposed to undertake the preparation of pure

metals and their alloys for a study of their chemical and physical

properties. A large part of the work has thus far consisted in the

analysis of platinum gauzes for use as catalysts in the oxidation ol

ammonia by the Nitrate Division of the Ordnance Bureau of the War

Department.

Analyses and tests have been made of samples of platinum foil

and sponge for the New York Assay Office.

The New York Assay Office, continuing its cooperation of the past

year, has made for the Bureau about 60 crucibles, 22 dishes, and several miscellaneous articles with varying iridium content. These have

been tested, and, except for minor mechanical defects in some of the

dishes, have proved satisfactory.

Asbestos.

A large number of samples of asbestos from various American

localities have been tested as to suitability for the preparation of

filters for analytical operations, A supply is now on the market

equal in quality to that formerly imported.

OILS, RUBBER, PAPER, TEXTILES, INK, AND GLUE.

(Chemical analysis and investigation of oils, rubber, paper, textiles, ink, and gkie, with

special reference to meet particular requirements.)

Chemical Work on Rubber.

The Bureau has cooperated with representatives of the Army and

with manufacturers in drawing up specifications for rubber tires and

for certain types of packings for military purposes. A very large

amount of analytical work was done on these materials.

The method for the direct determination of rubber that was re- ferred to in last year's report proved very useful in the analytical

work on balloon fabrics.

Following a conference at the Bureau, specifications for two types

of gasoline hose were prepared. Rubber is preferable to metal tubing for use on airplanes because it does not break when subjected to

long-continued vibrations.

Two types of foreign tanks, designed to be tight to gasoline even when punctured by bullets, were tested. A report covering these

tests as well as outlining a method for making such tanks, was submitted to the Signal Corps in 1917. Further work iri cooperation

with representatives of the Signal Corps was done later.

Chemical Work on Leather.

The chemical testing of leather is a new line of work for the

Bureau, but one which it was essential to establish in order to get the

most out of certain investigations relating to the physical testing.

Three chemists are now necessary to carry on the work for the Army

and a fourth is engaged in cooperative work with the National Tanners' Association, as well as in studying waterproofing and preservative compounds. Practical tests of shoes made of leather tanned and

finished in different ways are in progress at one of the Army camps.

Owing to the cooperation of a Philadelphia tanner, it became

possible to obtain specially tanned and finished bends for a com-
EEPORT OF DIRECTOR OF BUREAU OF STANDARDS. 115

parative study of the effect of different methods of treatment upon

the durability of leather. This work is still in progress.

Chemical Work on Writing and Other Inks.

During the jeav an unusually large number of inks of all kinds

were tested. Some confidential work was done for the Navy Department, while more and more testing is being done for the War Department. An ink made at this Bureau for self-recording instruments

used by the Weather Bureau proved to be as satisfactory as the

French ink that was used previously.

Chemical Work on Paste, Glue, and Mucilage.

In addition to the routine testing of paste, some assistance was

given to the United States Food Administration in its attempt to conserve wheat flour. To this end several lots of paste made from

potatoes, potato flour, corn flour and starch, etc., were prepared and

found to be satisfactory for different purposes. Since receiving

suggestions from this Bureau the Food Administration has been

able to eliminate the use of wheat flour for making paste. Further,

by adopting suggestions made by the Metallurgical Division, all the

wheat flour that would otherwise have been used in making" foundry

cores has been saved for food. The Chemical and Electrical Divisions are cooperating in a study of substitutes for wheat flour in

making dry batteries. The total saving from all of the above will

amount to thousands of barrels of flour in a year.

It is but fair to say that in all its correspondence with paste manufacturers there was observed a willingness to help. From some there

were, received valuable suggestions or samples which showed what

could be done without the use of wheat flour. This occasion is taken

to thank those who have given assistance to this Bureau in its efforts

to help the Food Administration.

Some work was done on glue with reference to its use in airplane

construction, but most of the samples of glue and mucilage tested

were not for military use. Lubricating Oils and Greases.

• The Bureau cooperated with the Navy and the Signal Corps in

an extensive series of tests of airplane lubricating oils which were

made at the Washington Navy Yard.

Much testing of lubricating oils and greases was done for different

branches of the Government.

Chemical Work on Textiles and Dyes.

The chemical testing of textiles is a new field of work at the

Bureau. A great amount of this was done for the Army. The work

included not only the analysis of fabrics, but also tests of the fast- ness of dyes and on the fireproofing and waterproofing of textiles.

A collection of dj-es, chiefly those used for dyeing Army textiles,

is being made for an investigation into the best methods for obtaining materials of fast colors.

For the prosecution of certain military work undertaken by the

Optical Division of the Bureau a series of pure dyes is being

prepax^ed.

Airplane Dopes.

' Dope is a name given to certain preparations that are applied to

the fabric of airplane wings in order to impart to them certain
116 REPOET OF DIEBCTOR OF BUREAU OF STANDARDS,

essential qualities. The importance of an investigation of these materials was recognized at the Bureau and begun before our entry

into the present war. As a result it was possible 7 months ago to

draw up very satisfactory, specifications, while even 10 months ago

the Signal Corps of the Army officially approved 4 dopes which had

been tested at the Bureau. As far as possible all phases of the subject

were gone into, including not only the testing of dopes under

laboratory;' and weather conditions, but also the production of cellulose acetate and nitrate and their solvents, the use of plastics, fireproofing materials, etc. The military applications of these matters

are obvious.

METALS, CEMENT, AND BITUMINOUS MATERIALS.

(Chemical analysis of metals, including iron, steel, nonferrous metals, alloys such as

brass, type metal, solders, etc., coated metals such as tin plate, galvanized metals, etc., lime, plaster, cement, concrete, bituminous materials, including tars, asphalt, roofing papers, roofing feit, etc.) Chemical V\^ork on Metals and Alloys.

In addition to a large amount of routine testing of ferrous metals

and alloj^s some attention has been paid to improving methods of

chemical testing of these materials, and much effort put upon systematizing and expediting work.

Protective Coatings of Zinc.

Much attention has been given to the subject of protecting, iron

and steel by protective coatings, particularly of zinc.

Investigation of the methods of stripping the zinc coating indicates that the method of treatment with hydrochloric acid and antimony chloride is preferable to that with lead acetate, since the

metallic lead precipitated is difficult to remove, especially from irregular surfaces. The antimony chloride method requires longer

immersion for .sherardized products than was originally specified

by its author. It was also found that the thickness of practically

all of the coatings is variable, and that microscopic measurements

do not give reliable figures for the average thickness.

Certain limitations of the salt-spray test have been discovered

which affect the usefulness of this test; for instance, the position of

the specimen affects the rate of solution of the zinc coating.

It has also been found that a protecting deposit of a basic salt of

zinc is frequently formed on corroded plates which prevents rusting

of the exposed base.

The coatings on certain specimens of sherardized materials were

found to be so brittle as to be readily removable by sharply bending

the specimens. The powder removed by this treatment showed a

relatively higher zinc and a lower iron content than the solution

obtained by stripping with hydrochloric acid and antimony chloride,

which shows that this reagent attacks the underlying iron. The

time of action of the reagent is different for materials coated in

different ways ; an electrically-plated specimen was stripped in from

5 to 15 seconds, dipped specimens are usually stripped in less than

30 seconds, while sherardized coatings require usually more than 60

seconds.

An effort is being made to determine the specific gravity of the

zinc coating produced by .the various processes so as to permit of
RBPOKI Oi" DIEECTOE OF BUEEAU OF STANDAKDS. 117

calculating the thickness from the weight obtained by the stripping

method.

In order to obtain more definite information regarding the character of the coating produced by the various methods a number of

specimens of sheet steel, made from low carbon Bessemer steel, were

coated by a number of firms using different processes. These were

afterwards exposed to the salt-spray and stripping tests and ex- amined metallogTaphically. Very little relation was found to exist

between the thickness of 'coating as determined by stripping and

resistance to the salt-spray test. Hence, an effort has been made to

devise a test which can be applied to relatively large samples and

which will detect thin spots. The most promising method depends

on the use of a solution of sulphuric acid (15 to 20 per cent strength)

containing sodium bichromate, which will be further tried out.

Cement, Concrete, etc. The routine chemical testing of cements, limes, and plasters shows

an increase from 1.200 samples for 1916-17 to 5,600 samples for

1917-18.

Special tests and reports of most diverse character were made,

some of which are enumerated below.

The Panama Canal Commission was advised regarding the preparation of better specifications for silica sand for steel castings, after a visit had been made to the Washington Navy Yard to observe the

practice there followed in the use of that material.

A large number of tests were made in cooperation with Division

VII-2 on soils, waters, and concretes, with the object of shedding

light on the causes of disintegration of reinforced concrete.

Analyses were made of water, soils, and sands for the Reclamation

Service to determine the presence of substances which might be re- sponsible for the slow type of disintegration occurring in constructions of the Crow irrigation projects. The results indicated that

the materials used in construction were not the cause of the trouble.

Seven samples of soil from Camp Earitan, N. J., were examined

for the presence of any constituents likely to stimulate corrosion

of galvanized banding used in the construction of wooden piping.

Analyses of concrete and laitance from a dry dock at Norfolk,

Va., showed that the cause of the formation of laitance when conciete

is poured was due primarily to the use of an excess of water, with

clay in the gravel and the use of waterproofing compounds as con- tributing factors.

For the Bureau of Mines tests were made of different mixtures of

cement, lime, kieselguhr, etc., to be used in gas masks.

For the Department of Concrete Ship Construction analyses and

tests were made of samples of sands, slags, diatomaceous earths,

prepared clay aggregates, and shales, with the object of producing a

light, strong concrete. For the same department tests are being

made to determine the value of fluosilicate coatings.

A considerable number of floor hardeners have been analyzed and

classified, with the idea in view of carrjdng out test on the wearing

qualities and values of these materials.

At the request of the Constructing Quartermaster General an inspection was made of a car of cement to determine the cause of injury to the eyes and hands of those who handled the sacks of cement

in this car. Final results have not yet been obtained.
118 EEPOET OF DIRECTOR OP BUREAU OF STANDARDS.

Bituminous Materials.

The work on bituiiuROus materials has increased very materially

during the past year, in spite of the fact that samples from the

Supervising Architect have been fewer than in the past. This is

due to the military needs resulting from the war. A number of improvements in methods of test have been made, and

this laborator,y has collaborated with the American Society for

Testing Materials in a series of comparg.tive tests of solubility o'f asphalts in various petroleum distillates and different grades of

ethyl ether. This was necessar}' as ver}^ little work of an accurate

nature has been done on this type of materials, and until the last

few years virtually no work of standardization of methods has been

accomplished. The work on bituminous materials in many of its

phases is more or less intangible and many questions remain to be

decided. Considering the kind of work and its status of even 5

years ngo, it is believed the Bureau is making its influence felt in

this field.

In the report for the year ending June 30. 1917. it was noted that

the Quartermaster General's Office had requested certain cooperation

in passing on prepared roofing purchased for cantonments. A

working agreeracnt between the Quartemaster Corps and the manufacturers through the Prepared Eoofing and Shingle Manufacturers Association had been arranged, and much of this roofing

was furnished under this agreement without test. This arrangement was ineffective and at the present time the Bureau is cooperating closely with the Cantonment Division on prepared roofing.

This division still has great need for roofing on new buildings being put up under its supervision, and in the maintenance and repair

of roofs laid in the past. The Bureau is consulted almost daily

relative to some matters connected with these problems.

It may be mentioned in this connection that representatives of • the Bureau and of the Maintenance and Eepair Division of the Cantonment Division made an inspection of the roofs at Camp Meade.

Requisitions for new roofs to replace the old had been requested

from most of the Army camps which aggregated hundreds of

thousands of dollars. It was found that the trouble was not due to

the quality of the roofing in the case of Camp Meade and that a few hundred dollars for materials and repairs would accomplish

the results desired. Investigation is showing the same condition to

be true for most of the other cam];)s. The Government has thus been

saved many hundred thousands of dollars.

It was suggested in last year's report that this enormous use of

prepared roofing on cantonments offered a wonderful opportunity

for study of this material in service, and it was further suggested

that in a year or so a representative of this Bureau be sent on a tour

of inspection to these camps. The time is not yet come, but it is hoped that this opportunity will not be lost when the roofs shall have

weathered sufficiently to make it worth while.

The Bureau has been frequently requested to prepare or review

specifications for prepared roofing for the Engineer Depot and has

tested samples representing hiuidreds of thousands of squares of material now shipped abroad. Much more of this remains to be purchased and tested.
REPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 119

At the present time the Bureau is working with several branches

of the Army and other Government branches on the one hand, and

the prepared roofing manufacturers on the other, in the development

of uniform specifications for 1, 2, and 3 ply prepared roofings. This

work is made more difficult by the present market conditions and the

difficulty of obtaining certain raw products, but progress is being

made.

In the fall of 1917 the Shipping Board asked the Bureau for specifications for bituminous enamels for the protection of certain inaccessible parts of the inside of steel ships. A provisional specification

was hurriedly drawn up from data then on hand, and a more thorough study of these materials was undertaken in order to permit of

drawing up better specifications for them. This v'ork had scarcely

started when the Philadelphia Navy Yard learned of it, and one of

their men visited the Bureau. Arrangements were made for cooperation, and a representative of the Navy Yard Avas sent to the Bureau

to study the problem there for a short time. This work was completed and specifications were sent to the Shipping Board and the

Philadelphia Navy Yard.

The Ordnance Department of the Army has asked for aid in the

development of bituminous paints for the interior of shrapnel shells.

Some paints were made for i^rnetical test and specifications suggested.

In cooperation with the American Society for Testing Materials,

the chemistry division is studying the penetration needle used for

the hardness test on asphalts. A new needle of standard dimensions

has been devised and several laboratories are to make comparisons of

these with the old needles on a wide range of materials.

Marine Glues.

The Bureau of Construction and Repair of the Navy Yard and the

Naval Aircraft Factor}^ at Philadelphia requested of the Bureau information relative to marine glues for use in pontoon construction

for hydroaeroplanes, and advised that the marine glue used most by

them Avas an article of foreign source and could not noAV be had. It

may be said that marine glues are not glue, but waterproof cements.

An extended study of materials on the market was made and a re- port rendered to the above-named branches of the military service.

Work is continuing on these materials, as new ones are continually

being submitted to the Bureau for test. Coke-Oven Process.

The Chemistry Division detailed members of its staff to assist in a

test of a new type of coke oven at Canal Dover, Ohio, and is con- tinuing to check the scrubber efficiency, to test the by-products obtained from this oven, and to make numerous other chemical determinations that were found to be necessary. Plans are being made

for investigational work on the light oil and its derivatives—benzol,

toluol, and solvent naphtha—that accrue from the operation of this oven. Protective Coatings for Concrete Ships.

The Concrete Division of the United States Shipping Board

placed before the Bureau the problem of developing satisfactory

coatings for inside and outside surfaces of concrete ships, both cargo

ships of the usual type and oil tankers. This means the development
120 KEPOET OF DIKECTOE OP BUEEAU OF STAIfDAEDS.

of oil and waterproof materials of such a nature that they are procurable in sufficient quantities. A representative of the Sliipping

Board is cooi^erating at the Bureau in this work.

PAINT, VARNISH, AND SOAP.

'

(Chemical analysis, testing, and exposure tests of paint and varnish ; chemical analysis

and specifications for soap.)

Paint and Varnish Specifications.

The Chemistry Division has done a great deal of work in preparing

and assisting in preparing specifications for a wide variety of paints

and varnishes for various purposes, as follows

For the United States Slupping Board: Inside white paint, outside slate-color paint, boot topping paint, copper bottom paint and

varnish for wooden ships, anticorrosive bottom paint, antifouling

bottom paint, hand-mixed red lead paint, ready-mixed red lead paint,

bituminous solutions and bituminous enamels.

For the Xavy Department : Enamels for airplanes.

For the "War Department : " Paint specifications " (this in cooperation -with the "War Service Connnittee of the Paint Industry), airdrying and baking enamels for airplanes, shellac-rosin varnish for

coating the interior of shells, shellac or garnet lac. and helmet paint.

A specification for airplane spar varnish prepared by the Bureau

a year or more ago for the Signal Service of the War Department

has been tested by both laboratory and exposure tests. The original

specification has met with very general approval by practically every

other consuming agency of the Government—International Aircraft

Board. Bureau of Construction and Repair of the Xavy. ITnited

States Shipping Board, several branches of the TTar Department, and

the United States Railroad Admmistration. The specifications will secure satisfactory material at a low cost, and many manufacturers

are now making varnish to comply with it. Reports to the United States Railroad Administration gave summaries of the Bureau's work on linseed oil substitutes, for some of

which extravagant claims are made. Most of them are thin-bodied

varnishes with from 60 to 75 per cent of volatile matter. They may

be successfully used in certain kinds of paint, but in considering their

value as compared with linseed oil. it should be remembered that the

non-volatile portion (25 to 50 per cent) should cost no more than raw

linseed oil. Fire-Retarding Paints.

Following a request from the Bureau of Yards and Docks, Navy

Department, the subject of fire-retarding paints was taken under

study and reported upon in Xovember. Subsequent work tends only

to confirm the conclusions of that report, which, briefly sunmiarized,

are as follows

Wliile practically all paint coatings have some fire-retarding action, none of the materials examined aiford very great protection.

All the samples tested were materially damaged by application of

a flame for a few seconds. Both sodium silicate and whitewash rank

relatively high. These have the advantage of cheapness and can

both be used on the same surface. It is believed that, for interior

wood surfaces, the application of sodium silicate solution followed

by whitewash may be more efficacious than either one used alone.
KEPORT OP DIRECTOR OP BUREAU OF STANDARDS. 121

However, no treatment of wood after erection can be expected to serve as an effective fire prevention, and the use of such materials

should not be taken as an excuse for omitting any precautions tending to avert danger of fire starting or for providing ample facilities

for stopping any fire as soon as it starts. Wood construction, no

matter how the wood is treated, either before or after erection, involves serious fire risk. It is recommended that claims as to fireretarding properties of paints be disregarded entirely, since practically all paints have some slight value in this respect and the difference between the best and the poorest is practically negligible.

Removing Metal Fouling from Rifle Barrels.

At the request of the Chief of Ordnance, War Department, a

rather extended investigation was made of methods of removing

cupro-nickel fouling from rifle barrels. What is believed to be a

satisfactory preparation for ready use in the field was finally

recommended.

ANALYTICAL METHODS AND STANDARD SAMPLES.

(General metbods of chemical analysis, with special reference to methods of standardization ; preparation and analysis of standard samples of iron and steel alloys, ores, chemicals, etc.) Standard Analyzed Samples.

Another very great increase is shown in the demand fOr the Bureau's standarcl samples. A good part of this increase was occasioned

by the general use of the samples by the Government and by private

industries engaged in the manufacture of war material. The number of samples called for during the fiscal year 1918 was 4,836, as against 3,536 in 1917, 2,697 in 1916, and 1,826 in 1915. The distribution was as follows: Iron and steels, 3,674; brass, 80; ores, 357; so- dium oxalate, 256; naphthalene, 85; benzoic acid, 44; sucrose, 69;

dextrose, 13; metals for melting points, 221; cement for testing

sieves, 37.

Three irons, 9 steels, and 2 ores are in process of preparation to

replace exhausted stock. A considerable addition to the list of

standard samples is now contemplated.

The granting by the present Congress of an appropriation of

$4,000 has served to place vipon a more stable basis our work on

standard samples, but the needs of the situation call for its increase

to $10,000.

It is of interest to know that private enterprise in England has

made a beginning of providing standard samples for Great Britain.

The preparation of the samples and the form of certificate issued

are modeled with due recognition after the practice of this Bureau.

Determination of Tungsten and Molybdenum in Ores.

In cooperation with prominent analytical chemists in works, analytical firms and universities, the Bureau has carried on an investigation dealing with the methods of analysis for tungsten and molybdenum ores. As a result of this investigation tentative methods of

analysis have been proposed and limited analyzed samples of several

ores ai"e available for special use. This work has now been extended

to include metallurgical products of tungsten and molybdenum all of

which are of much importance for military as well as nonmilitary

uses.
122 REPORT OF DIRECTOR OF BUREAU OP STANDARDS.

6. ENGINEERING RESEARCH AND TESTING.

[Operative efficiency of mechanical appliances, accuracy of engineering instruments, conditions affecting their effective use, e. g., structure and design as related to durability

and efficiency; methods of standardization and tests, standards of performance and

fundamental researches on the scientific principles involved in speedometers, pressure

gauges, water-current meters, anemometers, tachometers, gasoline and other motors, propellers, and other airplane parts and materials, etc.] Theory of Measuring Instruments.

An exhaustive study has been made of the causes which produce

variations apart from the so-called errors of calibration, in the readings of engineering and scientific instruments. The differences from

exact reading, commonly known as calibration errors, are not seriously detrimental in the use of instruments, since they can be cor- rected by simple calculation; another class of errors which may be

termed " variance " is disclosed in inconsistencies or deviations of

the instrument reading when successive, identical values of the quantity being measured are applied. Such variations from constancy

of reading at a given repeated value of the quantity undergoing

measurement are not normally allowed for in the calibration of an

instrument, and means were not hitherto available for general correc- tion of observations for such errors. A detailed discussion of the

causes and results of the variance type of errors has been developed

by a member of the staff and a paper is in press covering the subject,

which is one of great interest to designers and technical users of

measuring instruments of many and diverse sorts. The results obtained promise to be of such importance and of such direct application to many of the types of instruments employed in military uses that the continuation of the work will be provided for as actively

as the requirements of other projects permit.

Routine Tests of Instruments and Devices.

Calibrations were made of 218 current meters, 60 high-pressure

gauges, 66 other pressure gauges, 23 paper testers, 3 anemometers,

and 6 water meters. Miscellaneous tests of instruments and devices,

including safety valves, condenser tubes, speedometers, gauge glasses,

indicator springs, etc., numbered 84.

Tests were made also of powder containers, samples of cast-iron

shells, high-pressure flexible metallic tubing, tachometer shafts,

odometers, and the like for the various divisions of the Army.

MISCELLANEOUS MILITARY TESTS OF DEVICES AND EQUIPMENT.

Numerous tests of this character were made, including tests of

powder containers, samples of cast-iron shells, high-pressure flexible

metallic tubing, tachometer shafts, odometers, and the like, for the

various divisions of the Army.

MECHANICAL APPLIANCES.

(Investigation and calibration of special mechanical appliances; development of methoas and apparatus for standardizing the performance of such appliances; investigation of the operative efficiency of mechanical appliances, such as fire extinguishers, radiator traps, vacuum cleaners, and the like.) Fire-Extinguisher Investigations and Tests.

The investigation of hand chemical fire extinguishers for the

Steamboat Inspection Service has been continued. Tests are being
BEPOET OF DIEECTOR OF BUREAU OF STANDARDS. 123

made and reports submitted to the Board of Supervising Inspections

of Steam Vessels of such extinguishers as are being submitted to that

board for inclusion in its list of extinguishers approved for use in

vessels under its jurisdiction. The number of extinguishers tested

during the year was 41, including those submitted for the first time

and those previously rejected and again submitted after redesign.

As a result of these investigations a great mass of test data has

been accumulated which proved to be of the most vital value to the

Government in the present emergency. When it was found necessary

to purchase several hundred thousand extinguishers of the carbon

tetrachloride type for airplane, motor truck, and similar service, test data were already available relative to most of the machines of this

character on the market and these data have been supplied to the

fullest extent for the information of the various offices of the Army

and Navy interested in the purchase of these deAdces.

At the request of the Bureau of Construction and Repair, a compaRitive test of a number of designs of tetrachloride extinguishers

selected by that bureau has been undertaken to establish an approved list for the purchase of such devices.

A series of fire tests was made of extinguishers of the so-called

dry-powder type, which demonstrated their comparative inefficiency as a first aid fire appliance.

Tests of Airplane Equipment.

To assist the Signal Corps in securing suitable equipment numerous tests were made for the Army of hig-h-pressure oxygen tanks and

.valves.

Comparative Test of Roof Ventilators.

At the request of the Construction Division of the Army tests were undertaken at the end of the present fiscal year to determine the

relative efficiency of a large number of roof ventilators to be purchased by that division for use on Army cantonment and hospital

buildings. A report of the results of this work will shortly be made.

Thermostatic Valves for Vacuum Heating Systems.

The investigation of thermostatic radiator valves for vacuum heating systems for the office of the Supervising Architect of the Treasury

Department has been continued, to include the new devices of this

character submitted to that office in connection with buildings under

its control. The efficient and economical operation of a vacuum system is principally dependent on the successful operation of these

valves, one, of which is connected to each radiator outlet. Tests are made under working conditions to determine if these devices are suc- cessful in keeping the radiator up to the temperature of the steam

supplied, by the continuous removal of air and water, without permitting the wasting of uncondensed steam to the return line.

Performance and economy test data have been obtained on all the

leading brands of such valves. The data obtained have been furnished the Construction Division of the Army for use in the selection

of the best type of equipment for the new cantonment, hospital, and

office buildings which have been and are being constructed.
124 EEPOKT OF DIEECTOR OF BUREAU OF STANDAEDS.

ENGINEERING INSTRUMENTS.

(Investigation and calibration of engineering instruments : testing of water-current

meters, water meters, high and low pressure gauges, speedometers, anemometers, and

tachometers ; researches on problems affecting the precision of operation of such instru- ments, including standards of performance.)

Water-Current Meter-Rating Station.

One of the most important engineering services rendered by the

Bureau is the furnishing of accurate calibration of current meters.

These instruments are used by civil hydraulic engineers in the meas- urement of the velocity of flowing water in rivers, irrigation canals,

and other open channels, to secure data for the computation of the

quantity of water discharged through such channels in a given time,

such data being essential in the development of the water resources

of the country in power projects, irrigation, flood prevention, and

similar projects. To secure accuracy in these measurements, the

instruments must be carefully calibrated from time to time. A body

of still water must be available for this purpose, together with equipment for towing the instrument through the water at different uniform speeds and for accurately recording the observations.

Adequate installations of this character are costly and are necessarily confined almost entirely to Government stations and large university laboratories, and the latter are not always available for this

purpose. In the new rating station designed and constructed by the

Bureau especially for this work, exceptional facilities are afforded for

the calibration and study of these instruments. The entire flume is

housed over aiad the station is in continuous operation throughout

the year. Wliile a majority of the ratings made are for the different

engineering bureaus of the Government, this service is also performed

for engineers in private practice, a rating curve and table being furnished for a nominal fee.

During the fiscal year 218 current-meter calibrations were made.

A series of tests were made to determine the characteristics of a new

type of screw-operated current-meter recently developed hj an instrument manufacturer. Two current meter ratings were made for

the Colonial Department of the Government of the Netherlands.

Current-Meter Investigations.

While the routine calibration of current meters has been continued

without interruption, the investigations having for their object the

study of problems relating to their characteristics and use have necessarily been suspended during the period of the war in favor of

work of a military nature. One investigation, however, made during

the previous fiscal year for the United States Geological Survey to

determine the variation from the normal meter rating caused by the

use of various arrangement's of standard weights suspended with the

meter on a cable was extended to include certain new equipment re- cently adopted. When velocity measurements in deep stream are made, such accessories are employed to maintain an approximately

vertical alignment of the cable. The series of conversion factors has

now been completed, permitting conversion of the standard rating

table and application to all arrangements of meter and weights ordinarily used in the field. This renders unnecessary a separate calibration of the meter in each case. A circular has been issued by the Geological Survey to its field

engineers tabulating these data for their use.
REPORT OF DIRECTOR OP BUREAU OF STANDARDS. 125

High-Pressure Gauges.

During the past fiscal year calibrations were made of 60 gauges

intended for the measurement of pressures ranging from 1,000 to

30,000 pounds per square inch. Included in this number are the

instruments tested for the Government inspectors of the Ordnance

Department for use in the testing of munitions, and for the manufacture of munitions and of gauges. On several occasions calibrated

instruments have been furnished to oflfices in the War Department

for the purpose of special tests. High-Pressure Oxygen Gauges.

For a branch of the Army tests were made on different makes of

small gauges for use on high-pressure oxygen apparatus. This work

included a study of instruments developed to meet the peculiar conditions encountered in this service, for the purpose of formulating

specifications as well as acceptance tests of production samples.

AERONAUTIC INSTRUMENTS.

(Investigation and testing of all types of aircraft Instruments, including altitude- measuring instruments, engine speed and air speed indicators, airplane pressure gauges,

inclinometers, gasoline depth gauges, mercurial barometers, weather and surveying aneroids, sphyg-momanometers, oxygen control apparatus, bomb sights, and rate of climb indicatoi's ; development of methods of testing. Improvement of design of such instruments,

fundamental researches on underlying priiiciples of such instruments, study of the operation in actual service, provision of the numerical data required in their use.) After the war began, the general scope of the Bureau's work on

airplane instruments was expanded to include practically all types

of aviation instruments. Investigations were begun in this and

other sections of the Bureau of practically every type under simulated service conditions, and with accelerated tests under exaggerated conditons. Such instruments as used in the modern airplane

include the altimeter for indicating height above ground, compassfor indicating north, inclinometer for indicating the angle of the

plane with respect to the horizon, airspeed indicators for relative

speed of plane and the air, tachometers for showing revolutions of

engine shaft, special nonfluid thermometers, pressure gauges fqr the

engine, gasoline level indicators, timepieces, oxygen control apparatus, statiscope to show whether the aircraft is rising or descending,

range finders, angle-of-attack indicators, and the like. The prompt,

reliable readings of these instruments are vital to successful aircraft

control upon which depends the accurate control of gunfire, the

mapping of enemy positions and movements, as well as the efficiency

of action, of bombing and fighting planes.

The Bureau has collected examples of the typical French, English,

and American aviation instruments, as well as of German instruments captured by the French. All available data regarding the

construction and use of the various instruments has been placed at

the disposal of manufacturers and interested officers of the War and

Navy Departments.

_ An important part of the work of the Aeronautic Instrument Section has been the instruction of inspectors in the Bureau of Aircraft

Production in the testing of the instruments which they are to inspect at the factories for Army and Navy use. A series of technical circulars has been prepared discussing the

principles involved in the various aeronautic instruments and the

methods of testing employed at this Bureau. These circulars are for

the instruction of the experts engaged in aviation work. Large num-
126 REPOET OF DIRECTOR OF BUREAU OF STANDARDS.

bers of these circulars are called for by the technical divisions of the

Army and the jSTavy.

A series of lectures was conducted for a group of naval aviation

officers on the principles of operation and methods of testing the different aeronautic instruments. Plans are under way to complete' this

course, with extensions to other groups of naval and Army officers.

Oxygen Control Apparatus.

The oxygen control apparatus is of special interest in view of its

vital relation to the phj^sical condition of the aviator at high altitudes. At higher levels the aviator must have artificial sources of

oxygen, and these must be of known and assured reliability. The

apparatus delivers oxygen in amounts which are regulated by an

aneroid control valve, so that the amount of oxygen delivered is cor- rect for each altitude. The performance of the entire device is being

investigated in the aviation instrument laboratories of the Bureau.

The Bureau has studied the effect of the variations in temperature

upon the accurac}^ of the action of these instrimaents, and has also

made suggestions looking to the removal of defects and improvement

of operation.

Statoscope Design.

A serious defect in the existing design of the statoscope was discovered. The statoscope is used to indicate with extreme sensitive- ness whether a balloon or aircraft is ascending or descending. The

Bureau's knowledge of the technical points inA'olved in airspeed indicator design enabled it greatly to assist the American manufacturers in improving the quality and quantity production of such instruments.

Barographs.

An interesting and important development devised at the Bureau ex- tends the range of barographs so that they will operate at higher altitudes than the instruments were constructed to encounter. The Bureau

has also devised an electrical spark method of recording graphically

the changes in pressure which indicate the altitude of aircraft.

The Bureau has computed new pressure altitude tables covering all

heights up to 35,000 feet. These have been duplicated and furnished

to the military officials concerned. The Bureau has also computed

tables of temperature corrections to these tables to correct the variations in readings of barometric devices caused by temperature fluctuations. Tables of data such as those mentioned will greatly aid

in the accurate location of position in the air with a view to due allow- ance for altitude in bomb dropping and for other purposes.

Airplane Thermometers.

The Bureau suggested sometime ago to the manufacturers of thermometers the making up of airplane thermometers of the pointer-anddial type, operated by vapor pressure. Some of these were made

up in the factories and submitted to the Bureau of Standards for

complete test. The results were gratifying and it was shown that

the new instruments possessed marked advantages over those previously'^ manufactured. For high altitudes, the ordinary thermometers

would not be usable on account of the freezing of the mercury.

Testing and Investigation of Aeronautic Instruments.

An important aspect of the Bureau's researches on aeronautic instruments has been the provision of laboratory facilities whereby the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS, 127

conditions at high altitudes could be simulated—for example, the

pressure, temperature, and the vibration peculiar to airplanes, in

order that the behavior of measuring instx'uments might be accurately

studied under conditions found at any and all altitudes and conditions likely to be encountered in flight.

In testing the aeronautic instruments a special temperature chamber was constructed provided with cooling coil, fan. and heater for

controlling the temperature Avithin the inclosure. Aviation instruments are placed in the chamber to determine the error resulting from

temperatiire changes experienced in airplant flight. The apparatus

was found perfectly adapted to test thermographs—-self-recording

thermometers for recording changes in the air temperature during

airplane flights. While the data provided by the Bureau cover

altitudes beyond those ordinarily used in military operations—in

some cases altitudes of 40,000 feet—the rapid progress in aviation

makes it desirable to anticipate the possible developments of the near

future.

Aeronautic instruments, including a newly designed pressure gauge

and valves for high-pressure cylinders, have been tested at very low

temperatures. A low temperature comparator was built for tests of

()xygen cylinders at low temperatures, high pressures, and with mechanical vibration—to get conditions encountered in high altitude

airplane flights.

AERODYNAMICS.

(Measurement of the resistance of the air to the motion of bodies relative to it. in- cluding the determination of the magnitude, direction and point of application of the re- sultant force, and its relation to the relative speed ; study of the aerodynamical properties

of airplane wing models, stability of model airplanes, efficiency of propellers and wind

motors, characteristics of air bombs, and testing of airplane equipment and other apparatus functioning in an airstream.)

Wind Tunnel Investigations.

The construction of the Bureau's new wind tunnel building was

undertaken in September, 1917, and completed, including the installation and operation of the wind tunnel, in January, 1918. The

room housing the tunnel is 70 feet long, 29 feet wide, and 18 feet

high, with a self-supporting roof. The building contains in addition

a small shop, a computing room, and a drafting room on the mezzanine floor above these..

The wind tunnel is of the open' type, octagonal in cross section,

the distance between opposite faces of the octagon being 54 inches.

The straight portion of the tunnel is of wood, supported by a

structural-iron framework. The entrance and exit cones are constructed of the cotton cloth used for covering airplanes, doped and

varnished, and supported on an open steel and wood framework.

The wind stream is maintained by a tractor propeller 9 feet in diameter, mounted directly upon the shaft of a 100-horsepower directcurrent motor. An air speed of 90 miles per hour is attained with

an expenditure of about 85 electrical horsepower.

The tunnel is equipped with two weighing balances, so arranged

(hat either can be used independently of the other, but not. of course,

simultaneously. One balance is of very heavy construction, designed,

to carry heavy models, such as air bombs and engine radiator sec- tions, and is adapted for lift and drift measurements only. The

other balance, which is a modification of the National Physical Laboratory type, is designed primarilj^ for the investigation of the

characteristics of airfoils and airplane models. The measurement

of the moment from which is determined the center of pressure of
128 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the airfoil is made by means of an auxiliary balance connected with

the moving member of the main balance in such a manner that it is possible to measure lift, drift, and moment simultaneously.

The wind tunnel, since its completion, has been devoted almost

entirely to work of a military nature, including tests of airfoils,

models of airplanes and dirigibles ; tests and calibration of air-speed

indicators of the Pitot, Venturi, and combination Pitot-Venturi

types; investigation of propellers for driving the generators used

in aeronautic radio signaling, to the end of developing a constant

speed propeller; testing bomb-dropping devices and determining the

characteristics of aerial bombs in the wind stream ; investigating the

head resistance of a large number of radiator sections; and other

work of a similar character for both the Army and the Navy. In

addition, cooperation has been afforded another division of the

Bureau in making an extensive investigation for the Quartermaster's

Department of the efficiency of various types of ventilators.

The tunnel has also been used in an investigation of wind stresses

on power lines and telephone and telegraph wires under conditions

in which the wind resistance is increased by a coating of ice on

the wire.

Free-Flight Investigations.

The purpose of the work has been to develop the instrviments and

methods which will make it possible to secure continuous autographic

records of the performance of an airplane and its power plant during a free flight of the airplane under the normal operating conditions. The quantities which it is most important to record autographically are : The torque and revolutions per minute of the engine,

the thrust of the propeller, the speed of the airplane with reference

to the air, and the angle of incidence of the wings and their inclination referred to the true horizon. The measurement of these quantities on a full-sized airplane in free flight would furnish the ultimate

test of the theories on which airplanes are designed. It would add

greatly to the value of all the laboratory studies of airplanes and

their engines which are now being made, by showing what correc- tions must be made to the direct conclusions from such studies to

fit them to the actual conditions under which full-sized airplanes

operate.

During the year all 6 of the new autographic instruments desired

have been designed. The construction of the torque meter, of the

thrust meter, and of the angle of incidence meter have been completed and these instruments are now awaiting laboratory tests and

calibration. The airspeed meter is nearly completed.

The instrument for determining the inclination of the wing chord,

known as the Bureau of Standards stable zenith, has been subjected

to extensive tests, whicli have demonstrated that it will serve its

purpose in the air with a much higher degree of accuracy than any

other Imown instrument. This instrument combines two gyroscopes

in a novel manner which secures a great gain in accuracy and in

adaptability to various conditions. It is believed that out of the

instrument there will be developed in due time a group of new gyroscope instruments adapted to various uses. All of the above work described in this section has been done

in close cooperation with the National Advisory Committee for

Aeronautics.
REPOilT OF DIRECTOR OF BUREAU OF STANDARDS. 129

7. STRUCTURAL, MISCELLANEOUS, AND ENGINEERING

MATERIALS.

[Investigation of properties, use, fabrication, and design of structural, miscellaneous, and en- gineering materials; development of specifications covering the use of such materials; im- provement of processes of manufacture ; improving present and developing new methods of

testing; development of testing apparatus.]

METALS.

(Development of airplane design, including structures, and appurteuaiu-fs and dis- covery of suitable materials for construction parp<jses, especially metal construction ; investigation of processes for kiln-dryiny ot timber ; design and calibration of airplane

flight recording instruments ; welding research for ship construction ; calibration of testing machines and extensometers ; standardization of hardness testing with various

machines; determination of the physical properties of metals, woods, molded materials,

and rope.)

Investigation of Metal Airplane Beams.

Extensive experiments have been made this year on sheet steel -and

aluminium alloy as a possible substitute for spruce in airplane structure. The resisting moment of the present spruce spar was computed, and possible sections formed of sheet steel and alminum sdloy

were compared for resisting moments and weights per linear foot.

Specimen metal beams were also tested to failure. In these tests alummum was found to offer the best prospects.

Extensive experimental work Avas carried on in cooperation with

a metal company at College Point. N. Y., who made metal parts

from designs furnished by a member of the Bureau staff. This member of the staff spent several months at College Point supervising

the work in person. Steel and aluminum alloy were used and it

was found that cold-rolled steel beams had only about one-half the

strength of wood. Aluminum gave more promising results, and was

used for the beams of two sets of Curtiss JN-4B wings, whose ribs,

ailerons, and other parts \Aere of steel. Flights totaling about 60

hours were made in an airplane equipped with these wings at

McCook Field. Dayton, Ohio, and no deterioration in their structure

was found. Sand-loading tests of the flown wings, and of duplicate

new wings gave a factor nearly the same as that obtained with a set of Curtiss wood wings.

Heat-treated steel beams were tested under combined bending and

axial load to determine their strength. A rough test on beams heattreated in this manner showed a high modulus of rupture. Judging

from these tests the heat-treated .steel beams have the same strength

as the wood beams.

Other aluminum alloys, one of which contained silver and copper,

were tested in tension and bending to determine their suitability as a material for airplane construction. Tests showed that these materials were not as favorable as other materials procurable. All of the

data obtained from these experiments have been embodied in the

" Report on Steel Construction " for the Advisory Committee for

Aeronautics.

Substitutes for Spruce in Airplane Construction.

In an endeavor to find suitable substitutes for spruce in airplane

•construction, numerous tests were made on the following woods

Cypress, fir, juniper, gum, redwood, tanwood, cuban wood, oak, ash,

mahogany, pine, balsa, majagua. tupelo, Spanish cedar. Brazilian

8698f>—18——
130 EJEPORI OF DIEECTOE OF BUREAU OF SIANDABDS.

walnut, and California spruce. In general, the tests showed that

cypress and Douglas fir offered the best possibilities. Balsa wood

proved to be very light, soft, and elastic, but of a lower specific

strength than woods now used for airplane construction. Spanish

cedar was also found to be satisfactory from the point of weight and

uniformity of structure, but low in strength compared with other

available woods. On the other hand, tupelo wood was found to be

excessive in weight as well as deficient in strength, while Brazilian

walnut proved to be rather heavy but of correspondingly high

strength. Short-leaf pine from Arkansas was found favorable,

while majagua wood proved, under tests, to be unreliable and inconsistent, due apparently to the irregularity of the sap and heartwood.

As a rule specimens showing a large percentage of sapwood proved

to be the stronger.

Investigation of Mahogany for Airplane Propellers.

Several kinds of mahogany were subjected to expansion tests, after

their moisture content had been reduced to zero by oven-drying, to

obtain information as to probable distortion or warping of airplane

propellers, the present construction of which is largely of that

wood. After first reducing the moisture contents of these specimens

to zero by oven-drj^ing, they were exposed to air for different lengths

of time and the expansion measured. Further tests were made by

exposing the specimens to an atmosphere of high humidity. All the

species tested were afi'ected about equally by given changes in the

moisture content, but the true mahogany absorbed moisture much

more slowly than the other varieties.

Investigations of the Effects of Kiln-Drying Spruce.

The investigation started last year to discover the efi^ect of kilndrying on spruce to be used for airplane manufacture has been

continued this year. A member of the department visited several

places where kiln or other methods of drying were used. The methods studied involved the drying of cypress and Port Orford cedar

as well as Eastern and Western spruce. While all the methods were

not equally satisfactory, and it was necessary to compare the cypress

and cedar with data collected from air-dried spruce, due to lack of

data on air-dried cypress and cedar, the general conclusion was that,

with improvements of the process, artificially dried wood would

prove just as satisfactory as air-dried.

Airplane Strut Investigation.

This investigation, inaugurated some time ago for the determination of proper strut formulae for airplane design, was progressed to

the completion of tests on struts ranging from 24 to 255 L/R with

both square and round ends. The results of the investigation have

been prepared for formal publication as one of the contributions of

the Bureau of Standards to the work of the National Advisory Committee for Aeronautics. A number of typewritten copies have been

made to supply any demands that may be received before the publication is completed.

Aluminum latticed and veneer spruce struts have also been tested

and a report made on the former. One of the 30-foot aluminum
REPOBT OF DIKECTOE OF BUREAU OF STANDABDS. 131

girders was tested with a uniform transverse loading and direct axial

compression. This girder was also tested supported at one-thjrd

points to duplicate service conditions and the ultimate compression

load recorded.

Airplane Thrust and Torque Dynamometers.

Much of the time of one member of the division was spent on the

detailing of thrust and torque meters for determining engine performance under flight condition. Detail dra,wings of the torque

dj'namometer were prepared under the supervision of this division.

The completed drawings were sent to the shop and the instrument

has been completed, except for minor details.

A thrust dynamometer was calibrated under static and dynamic

conditions for the Bureau of Steam Engineering of the Navy Department.

Instrument for Measuring Tension in Airplane Cables,

The " tensiometer," an instrument for measuring of the loads on

airplane cables, was designed by a member of this division and made

in the division shop. This instrument, after being successfully tried

out and calibrated, was submitted to the Navy I)epartment for inspection and was reported on favorably by them.

Shock-Absorbing Wheels for Airplanes.

Tests were made in radial compression and side thrust on two

wheels designed to substitute spring rods for radial spokes, and also

to put sheet-metal cases in place of pneumatic tires in obtaining the

required resiliency. These tests revealed certain defects in design

which were corrected by the manufacturer, and tests on the corrected

wheels shoAved them to be about 30 per cent stronger in resisting side

thrust. These proved stronger in side thrust and weaker in radial

compression, but did not prove as stiff as the wheels with the original

hub construction.

Investigation of Magneto Couplings for Airplane Use.

Three magneto couplings were investigated for the Signal Corps

to determine their suitability for airplane use. They were tested

for mechanical strength and for durability of the flexible rubber connections, and were found to be satisfactory.

Sea-Plane Tail Booms.

Tests were made on 4 hollow spruce tail booms of two different sec- tions and weights but of the same length. The larger sectioned boom

was only 20 per cent heavier, but 60 per cent stronger.

Metal Wheels for Motor Trucks.

An investigation as to the suitability of metal wheels for motor

trucks was undertaken for the Quartermaster's Department of the

Army. These Avheels were tested to destruction in radial compression and side thrust. A Govemment design of composite wheel, also

tested, was found to be superior in some respects. Tests were made

on two composite cast steel wheels and two pressed steel wheels which

differed from the wheels previously tested by having web spokes

and a brake drum cast as an integral part of the wheel. Reports on
132 EEPORT OF DIBECTOE OF BUREAU OF STANDARDS.

those tests were sent to the Quartermaster's Department, Ordnance

Department, and the Signal Corps.

Tests of Palmetto Wood for Sea- Faring Purposes.

A sample of palmetto wood was tested for water-excluding purposes at the request of the Bureau of Construction and Kepair of the

Navy Department. Oven-dried specimens were tested for the per

cent of water absorbed in a given time, and compression tests were

also made. Compressive and shear tests were made on specimens

which had not been previously dried. The results obtained showed

this wood to be exceedingly weak both in compression and shear.

Investigation on Failure of Steel Plate.

Tests on the steel plate which broke last June, under crane manipulation, at the Homestead Steel Works, have been completed. This

investigation was attacked from the standpoint of internal stresses. Besides tensile tests, microscopic and chemical analyses were made,

and the whole embodied in a report which was sent to the Bureau of

Construction and Eepair of the Navy Department.

Investigation of Electrically-Welded Plates.

Arc-welded sheets were tested for the Steamboat-Inspection Service to determine their availability for lifeboat construction. Tension

tests showed the arc welds to be 100 per cent efficient. Alternating

stress tests showed that the welded section was not injured appreciably during the process of welding.

An investigation of spot-welded top joints proposed for airplane

construction was inaugurated to determine the efficiency of the welds.

Certain drilled and rectangular tubular sections were also tested in

cross bend and tension to determine their relative efficiency for this

purpose.

Investigation as to Cause of Failure of Bearing Plates and Rollers.

Two bearing plates and 5 rollers from the thrust bearing of the

turbo-generator units of the Gatun hydroelectric station, submitted

by the Panama Canal, were investigated for cause of failure. The

failure of one of the bearing plates was found to be due to quenching

cracks, while the second one failed from abrasion of the surface; the

rollers in this instance being harder than the plates. The heat treatment required to produce the necessary hardness and still not develop quenching cracks was ascertained.

Investigation of Floor Stress in the New Arlington Building.

Strain gauge measurements on the reinforced concrete floor slabs

of this building were taken for the Treasury Department. AH the

field work has been completed and the data and conclusions are being

prepared for a complete report.

Machine-Tool Investigation.

The investigation inaugurated last year in cooperation with the

Research Committee of the American Society of Mechanical Engineers on the cutting action of machine tools was continued this

year. A cutting tool of the De Leeuw type was designed and drawn
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 133

in detail and the library searched for literature of valne in this connection.

Report on Extensometers.

Two vrell-known types of extensometer were attached to the same

specimens in tandem and data for stress strain diagrams were obtained. (^om]iarison of this data showed that the one instrument,

although more convenient to use. has not the precision of the other.

It can Ijo useel to ud^•antage in obtaining the elastic limit and the

yield point, but not for precise determinations of the modulus of

elasticity where set measurements are necessary.

Adaptability of Scleroscope for Testing Rubber.

An investigation was made as to the adaptability of the scleroscope numeral as an index in determining the i^hysical properties of

solid rubber tires. A certain degi'ee of proportionality was found to

exist in using this numeral in predicting physical properties. The

similarity of this test with the Whiteney rebound test, already established in rubber testing, was pointed out in the report made.

Depth-Measuring Appliance for Brinell Hardness Machine.

An instrument company supplied the Bureau with a depthmeasuring attachment to be used with the Brinell hardness testing

machine. This instrument is being tried and the relation between

depth and diameter measurements for hardness will be worked on

Avith the object of determining a conversion factor.

Brinell Meter Investigation.

An investigation was made of a Brinell meter submitted by the

Boston Xavy Yard foi' the purpose of obtaining the Bureau's opinion

as to its value. This was accomplished by tests made on standard

bars and specimens with the Brinell meter and the regular Brinell

machine. The object of the investigation was to determine the relative precision of these instruments, standardize the practice, and to

facilitate the tests for hardness in munition plants. Considerable

data were gathered as to the comparison of hardness numerals obtained with the Brinell meter and with the Universal Brinell machine. The report on the investigation recommends the Brinell

meter, if a vai'iation in Brinell hardness numerals to plus or minus

5 per cent is permissible,

CaHbration of Testing Machines.

A number of calibrations (both direct and by comparison) have

been made this j^ear by the department. Besides calibrations of the

Bui'eau machines. 9 machines with capacities ranging from 60.000 to

800.000 ])ounds have been tested hy means of the Emery-rating levers.

A great jnany more have been calibrated by means of calibration bars.

Considerable work was done in connection with a comparison test of the 800,000-pound chain tester at the Boston Navy Yard with the

large Emerj^' machine at the Bureau. This necessitated the designing

of an outfit to obtain a comparison of the tension and compression

supports of the large Emery. Certain changes in the design of this

apparatus have also been made as to capacity and recording device.
134 RETOKT OF DIRECTOR OF BUREAU QF STANDARDS.

such that the ^vork of calibrating commercial testing machines may

be accomplished with it. The machine work for this is under way

in our shops. The original design of a hydraulic capsule has been

revised to adopt it to calibration of testing machines up to 500.000

poniids capacit,y. The revision consists mainly of a multii^ljang system of diaphragms and suitable scale beams for weighing the applied

load.

Investigation of Galvanized Wire to Determine Loss of Ductility.

The investigation undertaken last year for a steel and wire mill to

determine the reason for loss of ductility in wire due to galvanizing

was completed this year. Four types of coated rods—" rust-resisting" black finish. Lohmann lead-coated. Meaker electroplated, and

Parker rustproof—were tested for another firm, and 6—copper cyanide, sherardized zinc, cyanide, pickled, shot-blasted, and zino

sulphate—for another. These specimens were heat-treated and then

given tension tests.

Investigation for Changes in Design on Specification of Materials

Submitted by the War Department.

A number of tests have been made for the Ordnance and Quartermaster Departments and the Signal Corps, with the object of recom- mending changes in design or for determining specifications. Among

these the following tests were the most important

Electric butt-welds were investigated from a metallurgical, chemical, and physical standpoint and were found to be of a superior

character.

Retard and safet}'^ springs employed in French detonating fuses

and steel and bronze springs from French motor fuses were tested

in accordance with. French specifications, to determine the specifications for our departments.

An extract of existing specifications on manila rope was compiled

to form a basis for new specifications to be submitted to the cordage

manufacturers.

A fairly exhaustive report on the physical properties of bakelite,

silicon-steel, Swedish iron, phosi)hor-bronze, German silvei'. spring

steel, and woods was furnished the Electrical Engineering Section

of the office of the Chief Signal Officer. The information was re- quested in connection w'ith construction of insulators, magnet cores, armatures, yokes, contact and tension springs, as well as boxes

and cases for field-signaling equipment. Reference to additional

literature and recommended practice were also included.

To obtain information upon which to base specifications, many

miscellaneous tests were made on bolts and nuts, turnbuckles. steel

wire and cables, and. sheet steel for gasoline tanks. The last two

items coniprised over 400 individual tests, which were made in our

laboratories, in greater part, by members of the Signal Corps.

Three sets of piston rods for a 12-inch barbette carriage were

tested in the large Emery testing machine. In no instance was the

proof load sufficient to reach the yield point of the rods.

In addition to the usual tests made every year, a great variety of

special tests have been made this year, for different' branches of the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 135

War Department. This work comprised tests on steel for naval guns,

shovels and hoes, oak keel blocks for ships, transverse girders, a 150-ton floating crane, chrome-vanadium steel, magneto couplings,

trench jacks, French airplane material, aluminuni girders, veneer

struts, piston rods, electric-welded wrought-iron bars, welding refrigeration pipe. Army knives, armor plate, wire cable clamps, loading

of shells, wall boards, celluloid, wire rope, lock nuts, brazed joints,

gas mask parts, electric-welded steel mesh for concrete reinforcL--

ment, mess spoons and forks, fuse parts, copper-covered wire cables,

bakelite control pulleys for airplanes, copper-coated wood for airplane propellers, powder containers, vulcanized fiber, eye splices,

strap ring bolts, coupons of boiler plate steel, belt fasteners, halter

chains, welded steel rings, steam pipe insulators, insidated copper

wire, axes, machetes, manganese-steel bars, cutter blades, nickel-steel

tubing, specimens of verilite, elastic safety belt, leggings, belt buckles,

Duff jacks, Siniplex jacks, meter oxygen tanks, sash chain, zinc for

battery tinning, ash and hickory trench spade handles, compression

grease cups of sheet metal, bakelite insulations, powder containers,

buttons for unifoi-ms, etc. Equipment.

During the year the following equipment has been added : Small

Olsen transverse bending machine, capacity 10,000 pounds: constanttemperature electrical oven for determining the moisture content of

woods ; Erichsen machine for finding drawing properties of different

sheet metals; Riehle extensometer ; Brinell meter; Olsen impact machine, capacity 400 foot-pounds ; Izod impact machine, capacity 120

foot-pounds; Charpy impact machine, capacity 60 kilogrammeters

Olsen testing machine, capacitj' 50,000 pounds; cross-bend testingmachine for testing veneer boards and wall boards; improved Riehle

extensometer; Olsen tension and compression machine, capacity

20,000 pounds ; wire-testing machine, capacity 2,000 pounds ; UptonLewis repeated stress machine; 6-rotary repeated stress machines

for testing aluminum alloys and wood; Berry strain gauge for tests of concrete buildings; apparatus for calibrating extensometers and

strain gauges ; speed-reducing mechanism for the recording drum of

the Upton-Lewis repeated stress machine; 2 new lathes; 4 cabinets

for small instruments and tools.

Investigation of Brick Piers.

The investigation upon brick piers was completed during the past

year and the report of results is now in press. This investigation

was taken up in cooperation with the National Brick Manufacturers'

Association. It includes compression tests of over 50 piers 2| by 2^

feet in cross-section and 10 feet high, which were constructed of

various grades of brick and mortar and with different types of bonding. The bricks were selected from 4 of the representative districts

east of the Mississippi, so as to be typical of different manufacturing

outputs. The brick were graded as to hardness according to the

t-entative specifications of the American Society for Testing Materials.
136 BEPOBT OF DIRECTOR OF BUREAU OF STASTDARDS.

The following are the conclusions drawn from the results of tests

The strength of brick piers depends primarily on the quality of brick

and kind of mortar used. Of the mortars used, the cement mortar

develops about twice the strength of the lime mortars, or 2,700 and

1,400 pounds per square inch, respectivelj^, for the highest grade of

brick. The cement mortar is harder to work, however, and a combination lime and cement mortar which does not appreciably affect the

strength of the piers is cheaper, and has much better working qualities. The combination used in the present investigation was 1 part

of cement and lime (by volume 65 per cent and 35 per cent respectivety) to .3 parts sand. The strength of piers laid in the combination cement and lime mortar was practically the same as those laid

in a 1:3 cement mortar, giving twice the strength of those laid in

1 : 6 lime mortar and about four times the strength of those laid in

1:3 lime mortar. The type of bond as concerns the number of

header courses used has little, if any, effect upon the ultimate compressive strength of the piers. The introduction of wire mesh in the

horizontal joints adds strength if used in all the joints. This does

not appl}'', however, if used in every third or fourth course only, and

may even decrease the strength of the pier. The transverse, rather

than compressive strength of the individual brick, is believed to bear

the closer relation to the ultimate strength of brick masonry.

Investigation to Determine Bearing Power of Soils.

This investigatioii was taken up in cooperation with the American

Society of Civil Engineers' committees on soils, and has been con- tinued during the past year. The physical properties of different

types of earths are determined by laboratory tests and the results

compared with measurements made in the field. The field tests have

shown that there is in many cases a considerable range of variation

in the observed data, even when the tests are conducted under

identical conditions, upon soils having the same structures, but at different observation points. These variations have been found to

depend upon the relative densities of the earth, the character of the

aggregate and binder, moisture content, and other variables. The

laboratory tests have been conducted for the purpose of ascertaining

the relative influence of the more important factors which control

the bearing values of soils in relation to foundations and other en- gineering structures.

General Summary of Testing.

The following is a summary of the testing done in this division,

and represents an increase of 50 per cent over the number of specimens tested during the previous year

Tests for the. yarn Department.

1. Bureau of Const luction and Kei)air

2. Bureau of Yards and Docks

3. Other branches

175

24

4f)
REPORT OF DIRECTOR OF BUREAU OF STANDABDS. 137

Test-t for the War Department.

1. Ordnance Department

2. Quartermaster's Department—.

3: Bureau of Aircraft Production

4. Engineering Department

5. Surgeon General's Office

.•!44 113

fi70 145

10

Tests for the Panama Canal

Tests for the Department of Interior

Tests for Treasui'y Department

147

12

6

TestK for Depa rtiiirut of Coinmerce.

1. Bureau of Standards

2. Other branches

3.SS6

Tents for United States Sliipplng Board.

1. Shipping Board

2. Emergency Fleet Corporation

19

36

Tests for the Post Office Department

Tests for National Advisory Committee for Aeronautics

Tests for private firms and individuals

Total 2, 990

Calibration of Testing Machines.

It evidently comes within the work of this section to calibrate test- ing machines. Recently the materials-testing laboratories at both

Worcester Polytechnic Institute and the Massachusetts Institute of

Technology have requested very earnestly that some at least of their

machines be calibrated by this Bureau.

They find this necessary because they are testing materials for

acceptance under Government contracts.

It appears feasible to construct a machine for applying dead

weights possibly up to 200,000 pounds. This could then be used to

calibrate a tension bar or other apparatus for use in determining the error in any given testing machine.

The design of this machine is now being considered. Apparently

its cost would be high, due to the present price of cast iron, which

would be used for the weights.

New Equipment.

A large capacity testing machine for transverse tests upon beams

and other engineering structures should be provided for the new

laboratories in the Engineering Building.

A torsion machine of larger capacity and greater accuracy would

also be desirable. It is evident that the equipment at present available for making transverse and torsion tests is much inferior to that

Considerable work has been done upon calibration of hardness

apparatus of the Brinell type. It would be advantageous if a deadAveight machine of this type was provided by mejins of which the

hardness of standard bars could be determined. If this work could

be done rapidly and accurately at this Bureau, many manufacturers

would submit samples of the metals they are using, for standardization.
138 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Two special devices for calibrating extensometers were designed

and built. One of these handles all types of extensometers that will

go on a standard 0.505 inch diameter round specimen. The other

device is for calibration of extensometers of the Berry strain gauge

type. Both devices take instruments with any gauge length from

2 to 10 inches. A number of strain gauges and extensometers have

been calibrated with these devices.

General Tests df Structural Materials.

A number of tests not classified in the reports of research have also

been made for different departments of the Government and various

manufacturers. These include 30 tests of manila rope in sizes up to

3 inches diameter, 52-wire rope in sizes up to If inches diameter, 4

concrete columns of diameters 12 to 20 inches, 12 bridge rollers, 6

porcelain insulators 12 inches diameter for wireless towers, 7 tests of

large chain links, 46 compression and modulus tests of porcelain,

and a number of special tests of brick, tile, and steel bars. A number of special tests were made upon projectiles according to Government specifications.

The following tests Avere conducted for different departments of

the Bureau of Standards: Compression tests on approximately 1,200

concrete cylinders 6 inches diameter, 640 tests on 2-inch cubes of

cement, 360 tests of 2-inch cylinders of lime composition, 600 cylinders 2 inches diameter of floor cement, and 600 transverse tests of

bars of floor cement.

Tests of Tile Walls.

A number of tests have been conducted on walls of tile varying in

thickness from 6 inches up to 12 inches, in widths 3 to 6 feet, and

10 and 12 foot heights. The strength of the wall when tested in this

manner varies from 200,000 up to 600,000 pounds or more, depending

on the thickness of the walls, and the geographical district from

which the tile was selected, some clays being superior to others for

developing strengths. The tile are laid in some cases with the flues

running vertically, which develops the greatest strength. Comparative tests are also being made with tlie flues laid horizontal. This

does not give as great compressive strength, but the walls laid in

this manner possess greater lateral stability.

These tests have been continued the present year. A great deal of

interest has been manifested in the tests by manufacturers. Building

Code Commission, and architects. It is believecl the data will ultimately be of great value in devising equitable specifications covering

this important material.

CEMENT, CONCRETE, STONE, GRAVEL, AND SAND.

(Investigation and testing of materials for construction purposes; development of nevp methods of testing ; improvement of apparatus for testing ; preparation of specifi- cations covering structural materials ; development of new uses for cement products : distribution of knowledge as to use of materials ; design and fabrication.)

Investigation and Testing of Cement, Concrete, and Stone.

The work of the section during the year has been radically affected

by war conditions. Several of the normal continuing investigations

have been largely or wholly set aside by the continually increasing

amount of emergency and special work, and the end of the year discloses a program almost entii"ely devoted to war service. Thus no
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 139

work has been done in connection with the investigation of the vahie

of integral waterproofing compounds, the durability of concrete

in alkali waters, nor upon the further development of the granulametric analyzer and air separator for cement, which were described

in the last annual report. On the other hand, the routine inspection

and testing of cement for the War and Navy Departments has increased to such an extent that a very considerable expansion in the

Bureau's facilities for work of this character has been necessary,

and still further expansion will be required in the immediate future.

Special problems in the fabrication and adaptability of concrete for

specific piu-poses and tests of a large variety of new or unusual concrete aggregates have occupied the entire time of an enlarged laboratory force. Considerable progress has also been made in the investigation of building stones, but less has been accomplished in this line

fof work than during the preceding year.

New Branch Laboratories at Denver and San Francisco.

At the beginning of the year the materials testing laboratories of'

the Reclamation Service at Denver and San Francisco were transferred to the Bureau, and were made immediately available for the

work of all (xovernment departments. As a result of the transfer

the testing work at these points was increased to such an extent that,

while all demands of the Reclamation Service were met, a much

larger portion of the work, especially during the latter part of the

year, was devoted to military and naval requirements. In the en- largement of the scope of the work at these laboratories it is intended

to gradually make them available for broader and more general

service, not only to the Government departments but also to the

public, particularly for service which can not properly be performed

by commercial or private laboratories.

Government Specification for Portland Cement.

The slandard specification for Portland cement which became

effective January 1, 1917, contained a clause to the effect that on and

after July 1, 1918, the Government specification would require an

increase in fineness, reducing the permissible residue on the standard

No. 200 sieve from 22 per cent to 20 per cent by weight. At a meeting of the Departmental Cement Committee held April 2, 1918, the

postponement of this requirement was discussed and eventually

recommended in the adoption of the following resolution:

Moved, that the requirement for fineness of cement in the present specification, as follows : " The United States Government specification requires that on and after July 1, 1918, the residue on the 200-uiesii sieve shall not exceed

20 per cent by weifiht," lie clianged to talie effect six (6) months after the close

of the \A ar with Germany instead of July 1, 1918.

This recommendation was subsequently ratified by the Departmental Conference and approved by the heads of the several departments. The change becomes effective July 1, 1918, and all copies of

Bureau of Standards Circular No. 33 (United States Government

Specification for Portland Cement) issued after Jime 1, 1918, contain an insert announcing this change in the specification.

To avoid any misunderstanding of the Government's attiau^e re- garding this change, it may be stated that the departmental committee in submitting its resolution expressed its unqualified belief in
140 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the value of the inci'eased fineness required in the specification. Upon

i-epresentations from the War Industries Board, however, and in

recognition of the conditions under which its invaluable service is being performed, the committee passed the resolution in order that

no unnecessarj' friction might be encountered hy the boai'd due to

additional restrictions upon the manufacture of cement in the midst

of war activities.

Routine Inspection and Testing of Cement.

The tremendous expansion of military and naval activities during

the year has been accompanied by a corresponding expansion in the

construction programs of the "War and Navy Departments, and the

facilities of the Bureau have been taxed to the utmost in providing

the inspection service required by the increased use of cement alone.

The appropriations of the Bureau for testing structural materials

have been entirelj'' inadequate to cover the costs of this work, and

its continuance throughout the year was made possible only by re- imbursements from the War and Navy Departments and the Shipping Board. Furthermore, the shortage of available and experienced insjDectors has been acute owing primarily to the fact that the

salaries established for this class of employees are not attractive to

men over the draft age. Nevertheless, the local boards have in the

majority of cases appreciated the military value of this inspection

service and have granted many of the Bureau's inspectors deferred

classification, without which the work would inevitably have suffered.

During the fiscal year 1917-18 cement was inspected at 78 mills

throughout the United States, as compared with 16 mills in 1916-

17. The increased service which has been rendered during the past

year is clearly shown in the following table, which contains the

monthly shipments of cement inspected and tested l)y the Bureau

during the 24 months from July, 1916, to June, 1918, inclusive:

Tabic Coinpuriufi Shipiiioits of Tested Cement iu HUH-19J7 mul 1917-inifi

Month.

.Tuly August

September

Dotober November.

December.

Januan' February .

March

April

May

June

Total

7 iinil 1!>l7-191fi.

Shipments of tested cement in barrels.

1916-1,<)17 1917-191S

36, m14, 941

oS, 765

.32, 150

27,.33S 16,102

29,063

43, 744

54, 525

.SI, 364 102,259

146,249

32,366

205, 959

1S3. 406 113,104 270,964

.335,999 18,71« 64,325

76, G46

605, 12S

76>;, 395

752,161

592, S.S5 3, 597, 354

Those totals do not include 72,000 barrels of rejected cement in

!'»1G-17 and 331,000 barrels of rejected cement in 1917-18. Rejections for 1917-18 were in fact larger than indicated, as records

Jire not available of cement rejected by the commercial laboratories
KEPORT OF DIEECTOE OF BUREAU OF STANDARDS. 141

acting under Bureau supervision. The total shipments for the past

jear inchide 168,731 barrels for the Panama Canal. Other State and

Federal departments served were Commerce, War, Navy, Interior,

Treasury, United States Shipping Board, Smithsonian Institution.

District of Columbia, Massachusetts State, and various State highway commissions.

It will be observed that the shipments of tested cement during

each of the last two months of the fiscal year 1918 were approximately one and one-half times the total for the entire preceding

fiscal vear. An increas'e of this magnitude in the inspection work

has necessarily involved a large increase in the personnel and facilities for this work, and tlje organization of the service has been en- larged to cover all cement mills in the country. Thus the new

branch laboratories in Denver and San Francisco have furnished

inspection at the widely distributed mills west of the Mississippi

Eiver, the Pittsburgh branch has provided similar service at the

mills in western Penns_ylvania and the Ohio River district, the

Northampton branch has served the New York and Lehigh (eastern

Pennsylvania and New Jersey) districts, and the AVashington laboratory has taken care of the Maryland and Virginia mills, as well as the overflow from the Lehigh district. Two well-known commercial

laboratories have, under Bureau supervision, furnished inspection

service at mills in the southeastern section of the country and also in

the vicinity of Detroit, Chicago, and St. Louis.

The employment of these commercial laboratories to provide inspection service in those sections of the country where the Bureau

has not yet established its own facilities has afforded an excellent

opportunity to compare the costs to the Government of testing and

inspecting cement as performed by its own laboratories and by outside laboratories. Assuming a sufficient volume of work to justify

the maintenance of branch laboratories, the cost figures of the past

year show that the Bureau laboratories are performing the required

service at verj' approximately one-half the contract prices now beingpaid the commercial laboratories. The volume of work near the close

of the year was such that the payments to these* two agent s was approximately equal to the cost of fully equipping a new branch cement

testing laboratory each month.

Viewing the matter from still another angle, the saving which

would accrue to the Government by its own cement testing through

the Bureau of Standards rather than through commercial laboratories would vary from 1 to 2 cents for every barrel of cement so

tested, the actual saving between these limits depending primarily

on the percentage of full capacity at which the laboratories were

operating. No more potent arguments can be advanced for adequate

appropriations to establish the necessary Government branch laboratories in the cement-producing districts.

Another important point may be cited with reference to appropriations. The United States Eailroad Administration has re- quested the Bureau to inspect and test cement for the railroads, an

obviously advantageous and economical arrangement for the Government, since it permits the maintenance of pretested and certified

stocks of cement ready for immediate shipments at every mill in the

country. At the close of the fiscal j'ear, howev er, no decision had

been reached as to the manner in which this service should be pro-
142 BEPOBT OF DIBECTOR OF BUREAU OF STANDARDS.

vided for; but it is apparent that adequate appropriations for meeting these additional requirements are necessary before the facilities

of the Bui'eau can be enlarged to the extent necessai-y for handling

the large volume of railroad work.

Development of Testing Methods, Standardization of Testing Apparatus, etc. Little progress has been made in the developinent of testing

methods owing to pressure of routine work, eiforts in this direction

being limited to comparisons with the commercial laboratories of

methods used and results obtained in the regular inspection work.

It appears, however, that radical improvements in routine testing

methods are greatly needed, and work of this nature must be undertaken at the earliest opportunity.

Some interesting preliminary work has been done in the calibration and comparison of testing machines. In the investigation work

on building stones a very imiform sample of marble was discovered,

from which a considerable number of test specimens were carefully

prepared and submitted for compression tests to various laboratories.

The range in results obtained on these specimens indicates a wide

variation in the performance of testing machines, and the development of reliable calibration methods, particularly for large machines,

is a problem requiring careful and urgent attention.

Investigation of the Value of Fine Grinding of Portland Cements.

The series of tests, started in 1916, to determine the effect of increased fineness on the cementing value of cement in mortar and concrete has been continued. The two year results show the same

marked decrease in strength with the finer ground cements as did the

tests of the previous year.

With knowledge of the general results of this investigation the

Department of Concrete Ship Construction of the United States

Shipping Board, Emergency Fleet Corporation, requested further

comparative tests on various cements produced in the southern districts, both as normally ground and as reground to a fineness of 90

per cent passing the No. 200 mesh sieve. These cements were tested

in 1:1:2, 1:1-1/2:3, and 1:2:4 concretes and in 1:2 mortar. In

practically all cases the increase in compressive strength obtained

with the finer cements was from 50 to 100 pounds per square inch for

each per cent increase in fineness. From all the data obtained in

this investigation the order of increase in strength which may be

expected from finer grinding hj ordinary methods is now fairly well

established, and the question of requiring higher fineness in the

standard specification for Portland cement is a purely economic one. There remains, however, the highly interesting and almost wholly

unattacked problem of producing cements of much higher fineness

than is possible by ordinary methods of grinding. It may confidently be expected that if practical methods can be found of reducing cement clinker to a very fine state of subdivision, a decided improvement in quality will result; to determine what degree of improvement may be obtained is properly the next step in this investigation. The importance of further progress along these lines is

commensurate with the difficulties to be overcome in develoiDing new

methods of grinding, and concentrated effort will be required to deal
JSEPOET OF DIRECTOR OF BUREAU OF STASTDAEDS. 143

with the new problem effectively. Fortunately some progress was

made before the war by the development of an air separator and an

air analyzer for the production and mechanical analysis of very fine

cements, to which reference was made in the last annual report.

These devices will enable a good beginning to be made as soon as conditions permit, but the problem is of such magnitude that little

progre,ss can be hoped for during the period of the war. Standard Cement Sieves.

Forty-three No. 200 sieves were standardized during the year.

Owing to the fact that the scarcity of 200-mesh cloth is now acute,

there is every prospect that the supply of high-grade cement testing

sieves will be cut off entirely.. The Bureau is already planning to use sieves for routine testing Avhich do not conform to the standard

specifications, and recommends that all users of cement sieves procure the standard fineness samples for the purpose of checking those

sieves which are not certified prior to purchase. Even if the correc- tion factors M'hich may be obtained by the use of these samples are considerably in excess of those permitted in the standard specifications, it is believed that the corrected fineness determinations will be

sufficiently reliable for mill control and routine testing.

Standard Fineness Samples.

The standard fineness samples of cement, prepared and issued by

the Bureau to enable the users of cement sieves to check the performance of their own sieves, are furnished in two degrees of fineness:

Xo. 4C)-d, of which 79.2 per cent passes the standard No. 200 sieve,

and No. 47-b. of which 88 per cent passes the standard No. 200

sieve. These samples are issued in hermetically sealed glass jars,

each containing approximately 160 grams of cement, and each is

accompanied by full directions for use. In view of the joresent

scarcity of good sieves, particularity of sieves conforming to the

standard specifications, these samples shoidd be more widely used.

During the year approximately 50 of these samples were used by

the Bureau, 43 were sold at a nominal price to owners of No. 200

sieves, and 15 were donated for imiversity work.

Durability of Stucco and Plaster.

The investigation of stucco and plaster, originally begun in 1911

and continued on a larger scale in 1915 and 1916, has included ex- perimental work only in connection with the construction of three

temporary testing laboratories erected on the Bureau grounds during

the past year. In view of the present interest in housing problems

it is Tuifortunate that greater progress could not have been made in

the development of improved specifications for stucco, but important

as this work undoubtedly is, it does not possess the essential and

immediate value of the work Avhich has necessarily displaced it. The most important contribution that could be made under the circumstances was the preparation and presentation of a paper at the

annual meeting of the Ajnerican Concrete Institute in June, 1918,

giving a resume of what has been accomplished in this investigation,

and containing suggestions for the improvement of stucco based upon

the results of experimental studies and field examinations already

made.
144 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Durability of Concrete in Sea Water.

In the early part of the year a comprehensive report was prepared and published in one of the leading technical periodicals on

the condition of sea-water concrete structures along the coasts of

the United States. This report was based on observations and

studies made by representatives of the bureau and the Portland Cement Association during the preceding year, and was the forerun- ner of a more complete and detailed report to be published as one

of the Bureau technologic papers dealing with this general subject.

Unforeseen changes, however, and demands upon the time of those

engaged in this investigation necessitated an indefinite postponement

of the preparation of the final report.

Durability of Concrete in Alkali Waters.

This investigation, started in 1913, was undertaken primarily be- cause of its importance to various branches of the Government using

cements and concretes in irrigated districts and the arid regions of

the West, where the alkali often becomes concentrated in the soil.

The investigation, Avhich is conducted in cooperation with the Reclamation Service, the Drainage Division of the Department of Agriculture, and the Portland Cement Association, has included the

pr,eparation of 8,000 specially prepared drain tile made in a commercial tile factory under the bureau's supervision, and a larger num

ber of concrete blocks using aggregates available for concrete in vari- ous parts of the West.

A progress report. Technologic Paper 95, issued in 1917, includes

tests made in 1916 after a period of exposure of three years for the drain

tile and one year for the concrete blocks. These results show that concrete and cement drain tile w'ill disintegrate in some of these soils

unless the best of materials are used and special care is exercised in

fabrication.

Although this investigation is only fairly well started, no field

work has been done since the fall of 1916, owing to other demandi*

upon the time of those in charge. It is hop^d that this work may be

again resumed in the near future, as the problem of conserving concrete structures exposed to alkali waters becomes more important as time goes on and the magnitude of the investment in these structures

increases.

Acceleration of the Hardening of Concrete.

As the result of some experiments made to develop a method to

accelerate the rate at which concrete increases in strength with age,

it Avas found that the addition of small quantities of calcium chloride

to the mixing water gave the most effective results. A comprehensive series of tests was inaugurated to determine further the amount

of acceleration in strength of concrete obtained in this maimer, and

to study the effect of such additions on the durability of concrete

and the effect of the addition of this salt on the liability to corrosion

of iron or steel embedded in mortar or concrete.

The results to date indicate that in concrete at the age of 2 'or 5

days, the addition of calcium chloride up to 10 per cent by weight

of Avater to the mixing water, results in an increase in strength over

similar concrete gauged Avith plain Avater of from 30 to 100 per cent,

the best results being obtained Avhen the gauging water contains from

4 to 6 per cent calcium chloride.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 145

Compressive strength tests of concretes gauged with water con- taining up to 10 per cent calcium chloride, at the age of 1 year, give

no indication that the addition of this salt has had deleterious effect on the durability of the concrete.

Corrosion tests that have been completed indicate that the presence

of calcium chloride, although the amoupt iised is relatively small, in

mortar slabs exposed to the weather cause appreciable corrosion of

the metal within a year. This appears to indicate that calcium

chloride should not be used in stuccos, and warns against the unrestricted use of this salt in reinforced concrete exposed to weather or

water.

Moisture and Temperature Changes on Concrete.

Field work in this investigation has consisted of making strain

gauge measui-ements on concrete roads and pavements to determine

the change in volume of the concrete under changing moisture and

temperature conditions, and to' determine the most effective distance

spticing of transverse joints in the slabs. The measurements show

that the concrete follows a rather definite annual cycle of volumetric

change. Laboratory work has consisted iri measuring with a portable comparator the volumetric changes in cement mortars, plasters,

and stuccos when they obtain their set and the progressive changes

in volume as they age. A special apparatus for determining the

absolute thermal coefficient of expansion of concretes and mortars

has been designed and is in the course of construction: but work on

the latter has had to be indefinitely postponed on account of the

assignment of shop facilities to military requirements. A report on

the work already accomplished is being prepared, but like most other

reports imrelated to war work, it is necessarily shelved for long

intervals.

Flat-Slab Floor Design.

At the request of the Bureau of Yards and Docks, Navy Department, a series of loading tests were inaugurated to determine the

relative merit of three types of flat-slab floors designed for the purpose of procuring a suitable design to adopt as a standard for warehouse construction. The floors to be tested are in storehouses being

built at the Submarine Base, New London, Conn. ; Naval Operating

Base. Hampton Roads, Va.. and United States Naw Yard, Charleston, S. C.

The test procedure consists of loading 9 representative adjacent

panels of each type floor with a superimposed load applied in regular

increments until a maximum load is attained equal to twice the

designed live load plus the dead load. As the load increments are applied, measurements are to be made with strain gauges to determine the stress in the reinforcing rods at 150 points and also the

stress in the concrete at 150 points on both top and bottom surfaces

of the floor. Deflections in the floor will also be determined at 41

points.

With the data obtained from these measurements, made when the

concrete is 60 days old, a comparison can be made between the different designs of floor, which vary greatly in the amount of steel reinforcements used.

86986—18 10
146 MiPORT OF DIBECTOa OF BUEEAU OF STANDAEDS.

Floor and Roof Failures.

The advice of the Bureau has been sought in connection with a number of interesting cases of floor and roof failures.

The floor of the Pension Office at Washington is composed of clay

tiles on a concrete base and has developed certain isolated areas in

which the tiles have separated and warped away from the base to

such an extent that they have broken down under traffic. Expansion

measurements upon the flooring materials have been made, but no

satisfactory explanation of the trouble has been found.

The floor of a dry dock at the Brooklyn Navy Yard has shown

considerable disintegration. An investigation of this failure indicated that freezing and inadequate drainage were largely responsible

for the trouble. A report is being prepared for the Navy Department embodying recommendations for repair of this structure.

The floor of the new Arlington Memorial amphitheater, which is composed of Vermont and Tennessee marble tiles, has shown a peculiar development of fine cracks in the Vermont marble. This case was reported just prior to the close of the fiscal year, and the investigation has not been completed.

The collapse of the steel truss and concrete roof of the Metropolitan Theater in Washington was partially investigated for the information that might be obtained. The immediate failure was found

to be due to freezing of the concrete and premature removal of

forms, although it w^as apparent that too small a factor of safety had

been allowed in the design. The case also calls attention to the need

for a more adequate system of building inspection.

Service Tests of Floors and Floor Treatments.

An abrasion machine has been designed and is in process of construction for the purpose of making wear tests on floors of concrete

and other materials. The action of the machine is designed to

simulate that of ordinary traffic. Progress in this work, however,

has been so frequently interrupted, and so much difficulty has been

experienced in procuring the component parts of the machine, that

there is little prospect of completing the apparatus during the next

fiscal year.

In the meantime a part of the program of this investigation is

being carried out in the application of numerous concrete floor treatments to a large number of floor areas and panels in one of the new

laboratories of the Biireau. These tests are qualitative and comparative only, but are actual service tests, and in the course of 2 or 3 years

should yield valuable information. The majority of the treatments

consist of the application of proprietary hardeners or dust preventives, together with a number of others that have been recommended

by various investigators, for example, linseed oil, soap, water glass,

etc. The scope of these tests also includes coverings of various sorts,

linoleum, congoleum, mastic coatings, etc. Concrete Aggregates.

At the request of the department of concrete ship construction,

T'nitod States Shipping Board, Emergency Fleet Corporation, a coniprelinisive series of tests was undertaken to develop or find a

niiiteriiil that would produce a concrete of high strength and low

Aveight per cubic foot. In this investigation the following materials,
REPORT or DIRECTOR OF BUREAU OF STANDARDS. 147

liiM'e liecMi tested as aggregates in relatively strong mixtures: Crushed

slags of different kinds; crushed clay tile, both hard and soft burned;

crushed light brick of several A^arieties; a special hollow clay aggregate prepared by the ceramic division of the Bureau; a clinker produced by the rapid firing of clay or shale, coke breeze, pumice stone,

vesicular basalt, and other volcanic, silicious, and calcareous rocks.

Tli.e irrst promising results were obtained with burned shale aggregates, which in tlie proportion of 1 [)art cement and 2 to 3 parts of

graded shale yielded a concrete having a compressive strength of

4,000 ])ounds per square inch and a weight of less than 110 pounds

per cubic foot.

A series of tests were also made on two blast-furnace slags, both as

fine and coarse aggi'egate, from producers in Connecticut and Alabama. Aside from some difference in working quality the concrete

and mortars from these materials were practicalh' equal in strength

to those obtained from sand, gTavel, and stone of good quality.

Field Control of Concrete.

In connection with the concrete-ship investigations an apparatus

has been desig'ned to check the consistency of concrete in the field;

that is, to control the amount of water required in mixing. This

apparatus is essentially a piece of drawn tubing 6 inches in diameter

and 1-2 inches long placed in a vertical position upon a horizontal

plate. The tube is filled with the freshly mixed concrete and then

mechanically lifted from the mass. The amount of settling of the

imsupported concrete is a function of the amount of water used, and

til us any predetermined consistency within the working limits can be

maintained.

Also in the same connection a field testing machine for determining the transverse strength of concrete beams has been designed. The

machine is simple in construction and can be easily set up on the site

of the work for the purpose of determining the strength of beam

specimens poured from the regular run concrete. Experiments with

this device indicate that under given conditions a fairly definite ratio

exists between the transverse strength and the compressive strength

of concrete, and the latter can therefore be checked without resort to

laboratory tests.

Effect of Reversal of Stress on Concrete Beams.

Few, if anj^ tests have been made on double reinfoi'cecl concrete

beams to ascertain the changes resulting from the rev ersal of stresses. With the advent of the reinforced concrete ship, a structure which

must undergo changes of stress due to the hogging, sagging, rolling,

etc., data of this nature has become of extreme importance.

A machine for applying loads in opposite directions to double

reinforced concrete beams has been designed and the construction is

80 per cent complete. This machine consists of 3 units in order that

owing to the long time reqidred for making a test 3 beams can be

tested at the same time. Considerable difficulty has been encountered

in getting the machine to operate as it was intended, and a number

of changes in the original design have been necessary.

Six beams have been made and 1 has been under test for several

weeks, having undergone 300,000 revei'sals of stress. The beam

under test is 8 feet 8 inches long, with a cross-section of 6 by 8 inches
148 EEPOEI- OF DIEEGTOK OF BUEEAU OF STANDARDS.

and is reinforced with 3 f-inch plain bars top and bottom, so placed

as to give an effective depth of 6 inches. The applied load at the

center of the beam is 5,000 pounds and the computed stresses according to the straight line deformation assumption are : Concrete, 2,000

pounds per square inch; tensile steel, 20,000 pounds per square inch,

and compressive steel, 6,000 pounds per square inch. The strain

gauge measurements taken on the steel show that these values are

slightly in excess of the actual stresses, but nevertheless the stresses are considerably larger than those used for actual working conditions.

On the first applications of the load the beam cracked and showed

considerable deflection. After the load was repeatedly applied for

several days it was found that the cracks had enlarged to a maximum

of 0.01 inch and the deflection had increased from 0.20 to 0.25 inch,

which was probably due to a slight slipping of the reinforcing bars.

Since that time no change in the beam has been noticed and the

cracks close so perfectly that they cannot be detected.

It is i^lanned to test beams of 1 : § : 1 g concrete, using fine aggregate,

and later to extend the investigation to cover leaner mixtures. Thus

far only plain round ba-rs have been used, but in the program now

proposed deformed bars will be used to ascertain their advantage

in increasing the number of and distributing the cracks. The reduction in size of the cracks would be of great practical advantage for

the end in view, even though the number were considerably increased.

Concrete Bulkheads for Ships.

The question, of reinforced concrete bulkheads for merchant ships

was brought to the attention of tlie Bureau when the Bureau of Construction and Repair of the Xavy Department asked that certain

designs submittecl for bulkheads of this type be investigated and

some design recommended for temporary bulkheads for seagoing

vessels.

A design Avas worked out for the Avorking conditions as submitted

by the Navy Department. This design called for a corrugated type

of construction, found necessary because of the requirement of making

the structure light as well as strong.

The original design was modified by a second design in which

triangular fillets were replaced by parabolic sections, thus reducing

the weight slightly. The later design was approved and a full-sized

specimen 17 feet high and 5 feet wide was made. In order to test this specimen under conditions approximating those of bulkheads

subjected to water pressure a large reinforced concrete testing frame

was built, into which the bulkhead specimen would fit. The frame

and bulkhead were to be bolted together top and bottom and a water

seal effected by bolting on a flexible rubber felt. That the test load

might be applied in excess of working loads a reinforced concrete

cap 9 inches thick was made to seal the top of the frame.

The construction of the bulkhead specimen and testing frame has

been completed, and the test will be made as soon as the devices for

measuring stresses and deformations are installed.

Concrete Oil-Storage Tanks.

The high cost and necessitj'^ for conservation of steel were the fundamental reasons for making a study of concrete to determine its

.suitability for oil storage.
BEPORT OF DIRECTOE OF BUREAU OF STANDARDS. 149

At the request of the Navy Department, which was contemplating

the construction of concrete tanks for fuel oil storage, a study was

made of numerous concrete tanks in which mineral oils were stored.

To supplement the information obtained from tlie field survey it was

decided to conduct a series of tests on small concrete tanks using a number of mineral oils from the lightest to the heaviest, also some

vegetable and some animal oils. AVith the coming of the reinforced

concrete ship has also come an increased need for knowledge of the

action of oils on concrete and its resistance to penetration.

The series of tests originally started consisted of 18 1:2:4 concrete tanks of 10 gallons capacity, which were filled with 11 varieties

of mineral oils, 5 of vegetable oils, and 2 of animal oils. Because of

the probability that oils will be part of the cargo of concrete ships a new series of tests was started using tanks of concrete similar to that

employed in the ship construction; i. e., 1 part cement to 2 or 3

parts of aggi'egate below one-half inch in size. Some of these tanks

of the richer concrete will be tested under a head of about 35 feet

and various coatings are to be used to determine their effect in minimizing the penetration of the lighter oils.

Experience with ordinaiy concrete tanks shows that for the heavier

oils there is but a slight loss, but with the lighter oils it is proved

that some oil-proof coating is essential to insure against losses that

are considerably in excess of those of steel tank storage, which is

considered as the best storage.

Xo injurious effects have been noticed with the exception of one

tank in which coconut oil was stored. In this tank- a slight disintegration of the walls was noted at the end of one month. The penetration of this particular oil is slight, but wherever it is allowed

to come in contact with concrete it will without doubt cause decomposition of the cementing material.

It is hoped that from this investigation results of economic value

ivill be obtained, not only for the departments immediately conjerned. but to the oil industry at large.

Automatic Freezing and Thawing Apparatus.

An apparatus has been constructed for the purpose of making a

large number of alternate freezings, and thawings on samples of

stone, brick, concrete, etc., to determine the effect of frost action on

such materials. The apparatus automatically shifts the specimens

from a cold chamber to a hot chamber at the intervals required for

freezing and thawing. Time has not been available to determine

completely the most effective operation of the apparatus, but preliminary experiments indicate that the relative durability of different materials, in so far as durability is related to frost action, can

be determined in the laboratory in a short period of time.

Investigation of Building Stones of the United States,

During the year tests have been made upon practically all of the

important commercial sandstones of the United States. A report of

tests on 50 American marbles has been completed and submitted for

publication. An investigation is also being carried out to establish

a basis for grading the Indiana limestones. Seventy-two samples

of this material have been collected from various quarries of the

State, and physical tests on many of the^se samples have been completed.
150 BEPOET OF DIEECTOE OF BUREAU OF STANDAEDS.

Miscellaneous Investigations.

A number of limited investigations apart from those specifically

mentioned in the foregoing paragraphs have been or are being con- ducted : 1. A series of tests is being made in connection with the concrete

ship work to determine the quality and properties of " gunite," that

is, concrete placed with the cement gun, in comparison with concrete

fabricated in the usual manner. The tests consist mainly of compressive strength determinations upon gunite built up in successive

operations, the study of different methods of operating the machine,

and the value of different mixtures.

2. The bureau was requested to determine the value of a proprietary material recommended as a plastic lining for the hulls of

wooden ships. The basis of the material was a magnesian oxychloride cement, and, as anticipated, complete and early failure oc- curred upon exposure to salt water. The manufacturer of this compound also represented that it was of special value as a roofing and

flashing material, whereupon he was requested to prepare a small

model for test. This model was exposed to the weather on the roof

of one of the bureau laboratories, and showed complete failure

within a few months.

3. A method of treating plaster of Paris, which was claimed to

give quick strength and hardness to casts made therefrom, was

found to have little or no value of itself. However, when the treated

material was mixed and allowed to set imder heavy pressure in a testing machine a product of much greater density and hardness

was obtained. Under the conditions of the latter test the value of

the treatment could not be definitely established.

4. A proprietary material which analysis showed to be essentially a mixture of one part asbestos and three parts Portland cement

was submitted as a suitable compound for the production of a light

strong concrete. Tests demonstrated that the mixtures recommended

by the manufacturers yielded a concrete weighing considerably less,

but of much lower strength than normal concrete.

5. Incident to the work for the Concrete Ship Department of the

United States Shipping Board, Emergency Fleet Corporation, 14

concrete mixers were tested to determine their effectiveness in mixing cement mortars. The performance of all of these mixers under

the prescribed conditions of the test was satisfactory, judging from

the compressive strength of the test specimens prepared from each

mix.

6. Some further data have been obtained on the value of the addition of hydrated lime to concrete mixtures. Tests were made on

density, compressive strength, and rate of drying of concrete containing additions of hydrated lime up to 20 per cent by weight of the ce- ment. Density was found to decrease slightly with the increase of

lime content, whereas very little effect upon compressive strength

and rate of drying was noted.

7. In connection with special work for the United States Shipping

Board, an investigation was made of the effect of vibrating the forms

for varying periods of time on the strength of concrete poured and

allowed to set under these conditions. The interesting conclusion

was reached that vigorous and continuous vibration for periods up
REPORT OF DIRECTOR OF BUREAU OF STA2JDARDS. 151

to three hours did not injure the concrete, and that only slight re- duction in strength resulted from intermittent vibration.

8. Some studies have been made of blended cements in which diatomaceous earths from two sources have been ground together with

Portland cement i)i various proportions. The results obtained in

concretes at early periods indicated that the blended cements were

inferior to normal Portland, but at 6 months a slight revers-al was

noted. In Adew of this unexpected development, a more comprehensive investigation will be undertaken to confirm these results.

Results of 1-year tests on concrete made from a slag cement were

completed. Concrete made of this cement and exposed to the weather

for 1 year completely disintegi-ated within this period.

Miscellansoiis Routine Tests.

During the year the following miscellaneous routine tests have

been made

For the Panama Canal: Granular analysis of 18 samples of sand,

4 samples of sand-blast sand, 4 samples of silica grit, 6 samples of

granulated cork; absorption tests on 10 samples of vitrified clay tile

conduit ; impact tests to determine the toughness of 6 samples of

opaque glass, blood-staining tests on 18 samples of clay tiles for use

in hospital floors.

For the Bureau of Yards and Docks: Physical tests including

granular analysis, specific gravity, weight per cubic foot, and com-

, pressive strength in cement mortar or concrete of lU samples of sand,

6 samples of gravel. 4 samples of crushed limestone. A sample of

ground red iron ore was tested in cement moi'tar to determine its

coloring effect. For this Bureau also a number of trips were taken

to Norfolk, Va.. to inspect concrete work and materials in connection

with the construction of the dry dock at that point; tests were made

on 6 samples of sand, 2 samples of gravel, and 1 sample of limestone.

For the United States Shipping Board : Thirty-three sands and 10

gravels from the South Atlantic Coast region were tested in concrete

and mortar. Three integral waterproofing materials were also tested

in concrete for their effect upon compression and absorption of the

latter.

' For the United States Engineer Office tests of sand, gravel, and

stone for use in the new Key Bridge at Washington were made.

In addition to the foregoing inclividual tests were made on 16 aggregates for mortar and concrete. Thirty samples of sandstone from

different portions of a well known quarry were tested for transverse

strength to determine the variation of the output.

The Constitution of Portland Cement.

Owing to the demands made on the Bureau by other departments

of the Government for help in testing the cement purchased by

them, the amount of investigative work on Portlancl cement was

largely reduced. It was found possible to determine quantitatively

(approximately) the constitution of a large number of cements

made by the Bureau of a widely varying composition, as a check on

determinations made previously by another petrographer. These

data have been plotted in such a manner as to show the effect of the

different amounts of each constituent on the compressive strength of n 1:1.5:4.5 gravel concrete. These curves show very strikingly that
152 REPOKT OF DIRECTOB OF BUBEAU OF SIANDAB0S.

the early strengths are developed by the tricalchiin silicate, while at

later periods the dicalcium silicate, which hydrates at a much slower

rate, adds considerably to the cementitious qualities. At the same

time it appears that the " fluxing materials," such as the alumina,

iron, etc., should be present in a certain definite amount, above or below which the strengths are reduced at all periods. The high-silica

cements in order to develop the same cementitious qualities as the

low-silica ones must have less of the " fluxing materials " present.

Hydraulic Cements Other Than Portland.

Since it was found that compounds formed b3'^ burning 65 to 75

per cent alumina with 35 to 25 per cent lime in a rotary kiln, when

ground, gave hydraulic cements of very high strength at early

periods (these results were given last year in the annual report and

will be published during the coming year in bulletin form), it was

decided to conduct an investigation for the purpose of making ce- ment of silica and lime only. Preliminary work on a small scale

showed the impossibilit}' of combining these two materials at the

temperature of the rotary kiln, without the aid of some fluxing material. It was then found that boracic acid and calcium fluoride

were very desirable and useful fluxes. With the aid of these a number of cements have been burned, not containing alumina, and with

a lime content of approximately TO per cent. There was no difficulty

in producing them in a rotarj' kiln. Their commercial use would

be small on account of their very slow time of setting. They are of

great interest, however, in helping to elucidate the behavior of the

compounds present in normal Portland cement.

Tests of Concrete Ship Sections.

The building of concrete ships has made necessary original investigations to determine the relative strengths and behaviors of ship

hulls under the loading conditions imposed by their cargoes and the

impact of waves. To simulate these conditions in the laboratory a number of model girders were constructed of cement with various

types of steel reinforcement and different arrangements of vertical

ribs and these were tested in such a manner as to best approximate

the conditions met with in practice. In a number of cases the applied loads sustained were higher than those anticipated by the designers and valuable information was obtained for marine architects

and engineers.

Tests of Columns.

The report covering the results of the investigation upon 18 large

bridge columns has been published as Technologic Paper No. 101.

The cohunns under consideration in this report were half-size models

of different chord members of the new municipal bridge at St. Louis,

the Chicago, Burlington & Quincy Eailroad bi-idge at Metroyjolis,

111., and the new railroad bridges at Memphis, Tenn. The specimens tested ranged in length from 15^ feet to 244 feet and in cross- sectional area from 42 to 110 square inches. They were constructed

of carbon, chrome, silicon, nickel, and Mayari steels. Some of the

columns are the largest which have ever been tested. The strengths

as determined from the tests ranged from 31,000 to 46.000 pounds

per square inch for the carbon-steel columns and from 48,000 to

05,700 pounds per square inch for the alloy-steel columns. The

largest load recorded in absolute value, 6,768,500 pounds, was borne
jiia^oirr ok imhector of bureau of standards. 153

by one of the nickel-steel columns having an area in cross-section of

110.3 square inches and a length of 24 feet, the ends of the column

being square. It was found that the strengths of 12 columns which

failed as units were approximately in accord with the yield points

of the component steels, the average strength of the columns in compression being nearly equal to the average of the yield points of the

component steels as determined by tensile tests. The range in A^ariation in individual cases was between 3.7 and 12.5 per cent in absolute

value. Four of the columns failed locally by bending at the ends,

and 2 more by localized failures in the lattice, these not developing

the full estimated strength of the members. Ten columns of the

series failed in smooth flat curves without irregular action of any

kind, showing it is easily possible to obtain integral action of the

steel in large built-up members.

An investigation has also been under way in cooperation with one

of the large bi'idge manufacturing corporations to obtain information as to the strength and other properties of columns constructed

of rolled angles and used so extensively in built-up trusses, towers,

and other frameworks. To date 167 columns varying in length from

3 to 25 feet and in dimensions from 2^ by 2^ inches to 6 by 6 inch

angles have been tested. It api^ears desirable after consultation with

the manufacturers to make further tests before completing the investigation.

Tests of Cement and Concrete.

The roTitine testing of cement and concrete for the public and the

different departments of the Government has been greater during the

past 3^ear than in any previous one in the history of this branch of

the Bureau. Owing to the inability to secure experienced testers

to carry on this work, it was necessary to curtail to a marked degree

all investigative work in this connection. There was sampled and

tested during the year 361,000 barrels of cement for Government

contracts, 221.000 barrels were shipped, 27.580 barrels were rejected

for not having fulfilled the requirements of the specifications, and

30,000 barrels were withdrawn by the manufacturers, after sampling

but before testing, as the latter had found the cement unsatisfactory.

The amount of rejected and withdrawn material may seem to be

excessive, but considering the present condition of the labor situation, necessitating the use of many new or partially experienced men,

this is not too large. It does illustrate the need, however, of constant testing to insure the securing of satisfactory material.

MISCELLANEOUS MATERIALS.

(Investigation and testing of miscellaneous materials, including lubricants, leather,

rubber, textiles, and paper ; the design of apparatus and machines for testing such materials ; the development of methods of test ; and the preparation of specifications for the purc.hase of miscellaneous materials by the Government.)

LUBRICANTS.

Lubrication of Airplane Motors.

Considerable work has been done on the problem of airplanemotor lubrication. This Bureau cooperated in the laboratory testing

of oils in connection with a series of motor tests carried out by the

Lubrication Section of the Signal Corps at the Washington Navy

Yard. Motor tests are now being made at the Bureau for the pur-
154 REPOKT OF DIRECTOK OF BUKEAU OF STANDABDS.

pose of comparing the value as lubricants of both asphalt base and

paraffin base oils, as well as colloidal graphite. It is hoped by a comparison of laboratory tests on oils with engine performance to

discover the physical and chemical properties indicative of the most

satisfactory lubricant, and to prepare specifications which shall in- sure the purchase by the Government of the best lubricants which

can be manufactured.

Specifications for Lubricating Oil Purchased by Government Departments.

The work of Avriting oil specifications for the General Supply Committee has been continued, and all oils are now purchased by specification. The method of buying on a basis of guaranteed lubrication

was found unsatisfactory and has been completely abandoned. The

question of viscosity of gasoline and its influence on engine performance is under investigation.

Investigation and Tests of Lubricating Oils.

The standardization of the Saybolt universal viscosimeter. mentioned on page 142 of report for 1917, has been completed, and the

i-esults have been published in Technologic Paper No. 112 and also

in a paper presented before the American Society for Testing Materials in June. Technologic Paper No. 86 on the test for resistance of

an oil to emulsification has been reprinted to meet the continued demand.

Testing of Lubricants.

During the year 555 samples of lubricants have been tested, and

170 letters have been written in answer to reqviest for information

concerning the testing of lubricants.

LEATHER.

Investigation of Leather Goods.

The annual report for the fiscal year ending June 30, 1917, con- tained an announcement of the inauguraiion of leather investigations with the cooperation of the National Association of Tanners,

together with a discussion of some of the preliminary work which

had been undertaken at that time. Since then the work has been

developed and expanded. With an increase in personnel, funds, and

ecjuipment, it has been possible to expedite several problems, both

physical and chemical, closely related to Army problems. However,

owing to the lack of laboratory space it has not been possible to

keep pace with the program which the Bureau has outlined. As

soon as the new Industrial Research laboratory is ready for occu-

])ancy such difficulties will be obviated and the expansion can profeed satisfactorily.

The chief problem which the Bureau has undertaken in connection

with Army shoes is the investigation of the wearing quality of sole

leather as related to the chemical treatment in the tanning and finishing processes.

There are six particular experiments in connection with oaktanned leather which are now under way to throw light upon this

problem. These are

(1) A comparison of the wearing quality of belting tannage with

sole tannage.
REPORT OF MRECTOK OF BUREAU OF STAXOARDS. 155

(2) A study of the effect on wearing quality of loading with

glucose as compared with the process of finishing with no glucose.

(3) A determination of the effect of oil on the Avearing quality- of

sole leather.

(4) A comparison of the wearing quality of leather containing a high percentage of water-soluble materials with leather containing

a low percentage of water-soluble materials.

(5) A comparison of the wearing qualities of leather of different

\ egetable tannage, viz, oak and hemlock.

(6) A comparison of. the wearing qualities of vegetable-tanned

leather with mineral-tanned leather.

The hides used in the above experiments have been carefully

selected by I'epresentatives of the Bureau and data regarding the

history of the hides have been obtained. The experiments are being,

conducted in three wa^'s:

(1) By service tests conducted with soldiers at Camp Meade, Md.

(2) By abrasion tests upon the bureau's wearing machine.

(3) By complete chemical analyses.

The exact location of the test soles and specimens on the hide is known, so that a comparison of the results should give valuable

information.

The Bureau has carried out a rather complete investigation of the

wearing quality at different points in the bend and has obtained some

very interesting results.

There have also been in progress wearing tests both with the

leather-testing machine and by means of service tests upon postmen

and soldiers in camp to determine the wearing quality of various

brands of fiber composition soles as compared among themselves

and as compared with sole leather. Some interesting and instructive data have been obtained and have been reported to the War and

Navy Departments.

These experiments are to be greatly enlarged in the near future,

and tests are to be made to determine the adaptability of fiber half

soles to camp repair work.

Wearing tests have been conducted on the leather-testing machine

to compare the wearing quality of lightly and lieavily rolled sole

leather. Tn addition to observing the relative a\ earing quality of

lightly and heavily rolled leather, the rate at which the wear progressed was also studied.

In cooperation with the Ordnance Department, this Bureau con- ducted tests on sides of russet harness leather and russet strap

leather. The sides were blocked off, numbered, and photographed

and subsequently subdivided into test specimens which were tested

for tensile strength, buckle-shearing resistance, and tearing resistance, with the view of ascertaining whether any relation exists

among these three physical properties.

A detailed report of the results of these tests has been transmitted

to the Ordnance Department,

Specifications for safety belts for aviators hnxe been furnished

the Chief Signal Officer of the Army.

At the request of the office of the Quartermaster General rubber

cements used in cementing leather to leather, leather to rubber, and

rubber to rubber were tested to ascertain the comparative values of

different brands.
156 BEPOKT OF DIRECTOK OF PUREAU OF STANDAJBDS.

The Bureau is studying the question of water absorption of sole

leather, the Use of waterproofing materials, the heat conductivity of

leather as compared with leather substitutes, viz, fiber composition

soles, and other problems of a kindred nature.

Service tests have been made for the War Department to determine

the relative water resisting properties of vegetable-tanned as compared with chrome-retanned upjier leather. The regulation Army

shoes used for this test were made with vegetable-tanned leather otv one shoe and retanned leather on the other.

The Bureau has cooperated with the Bureau of Fisheries in developing methods of tanning shark and other fish skins. As a result

of this work tanned skins have been produced of a quality that ren- ders them well adapted as a substitute for certain classes of leather.

Numerous tests of these tanned skins have been made to determine

their physical properties.

Routine Tests of Leather.

A part of the time of the personnel is consumed in conducting

routine tests for various Government departments, particularly the

office of the Quartermaster General and the Ordnance Department

of the Army and the General Supply Committee and the Panama

Canal. These tests consist chiefly in chemical analj^ses, the determination of tensile strength, ultimate elongation, tearing resistance and

other physical properties of leather belting, harness leather, strap

leather, lace leather, and leather fan belts. During the year a great

many samples of leather have been so tested and reported. There

have also been made tests of various materials more or less closely

connected with leather goods, e. g., shoestrings, rubber heels with steel

heel plates, fiber middle soles, etc. RUBBER.

Investigation and Testing of Rubber,

The physical work of the Bureau on rubber consists of

(1) The determination of its physical properties and the investigation of methods of testing.

(2) The investigation of rubber products of various kinds at the

request of Government offices to determine their adaptability under

special service conditions.

(3) The development of standard specifications for the purchase

of rubber goods l3y various Government offices. At this time the

Bureau is acting in advisory capacity in the development of standard

specifications for rubber and leather goods for the War Department.

(4) The testing of samples submitted by Government offices to determine if the material meets the requirements of the specifications

upon which it is purchased.

Cooperation with Technical Societies and Testing Laboratories

Representing Manufacturers and Consumers.

The Bureau has continued its cooperation Avith technical societies

and testing laboratories in developing specifications for and methods

of testing I'ubber goods. This work serves the double purpose of

keeping the Bureau in touch with progressive manufacturing practice and of rendering the Bureau's laboratory facilities available to

the industries.
KEPOBT OF DIEECTOE OF BTJEEAU OF STANDARDS. 157

Experimental Rubber Plant.

The Bureau's experimental plant, which includes machinery and

apparatus for compounding and vulcanizing rubber, has been utilized

during the past year, but the work has been handicapped to some ex- tent by the frequent demands of Government office for investigations

and tests of manufactured rubber products of various kinds.

During the past year a number of compounds have been mixed for

the use of the chemical section for checking their methods of analysis.

Tests of some of these compounds have resulted in the development

of methods for the analysis of lamj^black, glue, and other nitrogenous

matter. These results appear in the revised cop}^ of methods of

analysis formulated by the chemical section. In addition about 40

rubber compounds in which different organic accelerators were used,

were mixed, vulcanized, and tested to determine their physical properties. It is proposed to make compounds containing materials in

which sulphur appears in various forms, for the purpose of determining what effect they have on sulphur determinations.

In the manufacture of rubber goods organic accelerators have

come into general use. As yet very little has been published concern- ing the effect of these accelerators on the quality and life of rubber

articles. This Bureau plans during the coming year to carry through

a complete investigation on organic accelerators. The compounds

will be mixed here at the Bureau, all precautions for obtaining ac- curate results being carefully taken. Not only will the ordinary

tests of these various compounds be carried out, but an attempt will

be made to see if there is any relation between the natural aging

of rubber materials and accelerated agine, such as the effect of dry

heat, Sim's rays, and ultra-violet rays. The vulcanizing press is to

be equipped with mercury thermometers and means for automatic

temperature control which will enable careful regulation of the

actual vulcanizing temperatures.

The curtailing by the War Trade Board of the amount of crude

rubber that may be imported, coupled with the successful results

being obtained Avith cultivated Guayule in California, has opened up

another problem. The Bureau plans to investigate the possibilities

of substituting Guayule* for the higher grades of rubber in certain

classes of goods.

Solid-Rubber Truck Tire Tests.

At the request of the Quartermaster General of the Army, the

Bureau undertook the testing of a number of solid rubber truck

tires, with the view of securing standard specifications for military

use. These tires Avere not only subjected to the ordinary laboratory

tests but were tested for elasticity, hardness, and resistance to abrasion. From the results of the Bureau's tests considered in connection with the observed behavior of similar tires on the Mexican

border, specifications were drawn up for the purchase of solid truck

tires. These specifications with slight modifications have also been

used for the purchase of gun carriage tires.

In connection with the investigation of solid rubber tires tho

Bureau has made for, and in cooperation with, the Inspection Division of the Ordnance Department of the Army a series of tests to

study the adhesion between the tread stock and hard rubber base in

various makes of tires. A great difference in this adhesion was

found in the case of different tires which is in accord with the re-
158 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

suits of experience under service conditions. A study was also made

of the different degrees of elasticity in the tread stock of different

makes of tires. Specifications for solid tires now include requirements for adhesion and elasticity which are determined by tests at

the factory.

In order to maintain a satisfactory control over the quality of

rubber compounds used, inspectors for the Quartermaster and Ordnance Departments submit regularly to the Bureau samples of rubber for test and analysis as a check on the results obtained at the

factories.

Pneumatic Tires and Tubes for Automobiles, Motorcycles, and

Bicycles.

The bureau has undertaken the investigation of pneumatic tires

and inner tubes for the office of the Quartermaster General, with

the object of draAving up standard specifications for tires and tubes

for Army use. Between 30 and 40 of the standard nonskid makes

of both cord and fabric lires. 35 b ' 5 inches, and 20 inner tubes were

bought in the open market and submitted for investigation. It was

apparent that our regular force was not sufficient to carry out this

investigation within the time required and 6 enlisted men were detailed to assist in cutting and preparing samples for test. The tires and tubes have been tested in various ways. The rubber from the tubes and the treads and side walls of the carcass have

been analyzed and subjected to physical tests Avhile in their normal

condition and after having been given various accelerated heating

tests. A number of adhesion tests were made with samples taken

from various parts of the carcass betw'een the plies of fabric, fabric

and side wall, fabric and cushion, and breake)- and tread. The effect

of heat on the frictioning conqDound between the plies of fabric was

also determined. From these results specifications have been drawn

up for cord and fabric tires and inner tubes for Army use. The investigation is not entirely complete. A number of the tests that had

been planned are still to be conducted. It is proposed to carry out

actual natural aging tests on such material from tubes and casings

as may be left to check against the heating tests which will give

valuable information for future use. A number of standard makes of nonslrid motorcycle tires and

inner tubes were submitted by the Engineering Bureau, Motor Transport Section of the Quartermaster Department, for test, with the

object of drawing up specifications for motorcycle tires and tulies

for Army use. These tires and tubes were measured and examined

carefully, all necessary and important measurements were taken, and

the tires and. tubes were subjected to various accelerated aging and

physical tests as well as chemical analyses. The rubber from the

tubes, treads, and side walls of the casings w^ere subjected to tests for elasticity, strength, and elongation after 0, 4. 9. and 14 days in

dry heat at 160° F. and for the same periods of time in dry heat at

228° F. Froui the results obtained to date specifications have been

drawn up for the purchase of motorcycle tires for both the Quartermaster ;!nd Ordnance Departments of the Army. Various adhesion

and fal^/ric tests were also made. The tests are not entirely completed but they are expected to be finished within the next month.

_ A number of single-tube and double-tube single and doiible clincher

bicycle tires and bicycle inner tubes were tested for the Engineering
BEPOBT or DIRECTOR OF BUBEAU OF STANDABDS. 15^

Buroau. Motor Transport Section of the Quartennaster Department

of the Army. The results of these tests will be used in preparing

specifications for Army use. Airplane Materials.

Daring the past year a number of airplane cords, high-tension

cables for aviation engines and airplane shock absorbers were tested

for the Aviation Section of the Signal Corps.

Gas-Mask Materials.

The great demand for gas masks and gas-mask equipment, caused

hj the entrance of the United States into the present world war, has

opened a new line of work for this Bureau. The Bureau has been carI'ying out in cooperation with the Gas Defense Service and the

Bureau of Mines Experimental Station at American University various investigations on rubber materials, head strap elastics, check

and flutter valves, and eyepiece materials. The Bureau has also acted

in an advisorj^ capacity in drawing up specifications for and in designating methods of testing the various materials used in connection

with gas masks. Among the various materials tested for the Medical Department of the Gas Defense Service are rubber rings for

lens washers, elastic webbing for head straps, rubber mouthpieces,

rubber nose pads, and rupper stock for mouthpieces, check valves,

and flutter valves. The following materials were tested for the Bureau of Mines: Eubber mouthpiece stock, elastic webbing for head

straps, celluloid for eyepiece stock, adhesive tape and rubber flutter

valves.

Tests of Medical Supplies.

During the past ^-ear the Bureau has tested a number of samples of

adhesive tapes, hospital sheeting, open-center invalid ring air cushions,

and hot-Avater bottles for the Field Medical Supply Depot of the Army.

On several occasions samples submitted by manufacturers have been

sent to the Bureau to haA^e them rated in the order of best quality

as determined by the results of tests. On one occasion bid samples representing a proposed purchase of

70,000 hot-water bottles and invalid air cushions were submitted

with a request for an immediate report as to the relative suitability

of the various makes for purchase, based on considerations of quality

and cost. The desired information was furnished the following day.

The results of our examination and preliminary tests were in ac- cord with and verified by a detailed report, which was furnished later

!i.s a i-esult oi more extensive tests, including accelerated aging tests

in hot air and hot water.

Tests of Hose and Packing for the General Engineer Depot of the

Army.

A^t the request of the General Engineer Depot of the Ai-my the

Bureau has conducted numerous special tests of water, suction, and

fire hose, representing various commercial brands as well as hose

manufactured to definite specifications which vrere prepared with the

Bureau's cooperation. Special tests have also been made of rubber

packings for aeronautical instruments to determine the behavior of

different compounds under freezing cojiditions at high altitudes.
160 REPORT OF DIRF.CTOR OF BUREAU OF STANDARDS.

Tests of Fire Hose for Government Departments.

For several years past the Bureau has tested all rubber-lined fire

hose purchased by the District of Columbia Fii-e Department. Contracts for this hose are made under competitiA'e bids according to

specifications that have been revised by the Bureau of Standards.

This method of procedure has resulted in a material saving in cost

to the fire department and at the same time has served to maintain

a high standard quality and efiiciency of hose.

During the past year samples representing 10,000 feet of 2|^-inch

hose and 3,000 feet of 3-inch hose have been tested for the local fire

department under specifications which require that all delivered be

tested as a check on the original bid sample.

Tests have also been made on a number of sampk;s of fire hose submitted by the Panama Canal, the Post Office Department at Washington, D. C, and the General Engineer Depot of the Army.

Rubber Insulated Wire.

The Bureau has carried out further natural aging tests on rubber

insulation of wire in cooperation with a number of other testing

laboratories identified with the American Society of Testing ISIaterials. The object of these tests is to determine the relation between the

natural aging under atmospheric conditions as compared with the

effect of dry heat at 160'' F. The heating tests were carried out

several years ago. and this year completes the aging tests. The re- sults of this investigation will be carefullj^ studied and compared

with similar investigations that have been in progress at the Bureau

for several years.

The Bureau has also tested a number of samples of rubber-covered

wire for different branches of the War Department. Numerous samples of plain rubber-covered wire, waterproof insulated wire, hightension cables, submarine mine cables, underground cables and teleplone cables, have been tested for the Chief Signal Officer of the

War Department, the Coast Artillery Corps, the Torpedo Depot at

Fort Totten, N. Y., the Motor Transport Service of the Quartermaster Department, the Equipment Division Laboratory, and the

Panama Canal.

Tests of Miscellaneous Materials.

There were tested during the past year a total of 1.697 samples of

miscellaneous materials, an increase of 80 per cent over the previous

year. A large proportion of these tests were for the various branches

of the War Department and in many cases were of an urgent military nature. Many of the tests were of a semi-investigative character, requiring special equipment and preparation.

The following materials were submitted by the Equipment Division of the Ordnance Department for test : Cotton woven straps, rope

halter ties, lanj^ards. rope lariats, buckles, rings, hooks, thimbles,

metal snaps, etc. The Engineering Bureau of the Ordnance Department submitted

i-ubber fuse caps, rope lariats, hooks, links, thimbles, a number of

samples of dredging sleeves, etc. A number of specimens of frictioned cloth, O. D. uniform twill

and rubberized and combined sateen fabric, were tested for the Inspection Division of the Ordnance DeiDartment.
EEPOET OF DIRECTOR OF BUREAU OF STANDARDS. 161

Various samples of rubber-covered wire, submarine cables, underground cables, rubber tubing for water, oil, and gasoline were tested

for tlie Signal Corps of the Army.

A number of samples of leather preservatives, leather waterproofing compounds, rubber cements for shoes, rubber, etc., motorcycle

footpads, motorcycle handle bar grips and pedal grips, asphalt-saturated cloth for waterproofing, steering wheels for motor trucks, etc.,

were tested for the Quartermaster Department of the Army.

Samples of adhesive tajoe were tested for the Eesearch Division of

the Chemical Warfare Service. The Bureau acted in an advisory

capacity in drawing up methods of testing and specifications for adhesive tapes.

On several occasions samples of soft-laid flax shot line were tested

for the United States Coast Guard. These lines were tested with

special grips which were designed at the Bureau efpecially for the

purpose.

The following items are representative of the routine tests made

during the past year : Five hundred and fifty-five samples of lubricants; 485 samples of leather; 127 samples of rubber hose, such as air,

air-brake oil, water, fire, suction, steam, etc. ; TO samples of paclring

consisting of asbestos, rubber, etc. ; 64 samples of pneumatic tires,

consisting of automobile, bicycle, and motorcycle ; 65 samples of solid

truck and gun carriage tires; 149 samples of rubber-covered wire and

cables; 215 samples of gas-mask materials, consisting of mouthpieces, flutter valves, check valves, e5'epiece stocks, lens washers, etc.,

and smaller quantities of numerous other materials.

The greater part of the routine tests were made at the request of

Government departments in connection with the award of contracts

and to determine if the materials delivered on contracts were in ac- cordance with specifications.

TEXTILES.

Blanket Investigations. . About a year ago, the Quartermaster General of the Army, realizing that there existed a great need for more effective blankets with

regard to warmth, durability, and lightness, requested this Bureau

to investigate the possibility of replacing the present Army blanket

with one better adapted to the purpose. It was suggested that the

relative advantages of various kinds of raw fiber and of various

manufacturing procedures be given attention.

In accordance with this request, the Bureau has undertaken to

classify some of the commercial types of blankets according to their

respective abilities to resist the transmission of heat. The various

blanket manufacturers showed much interest in this work and readily

agreed to furnish us, free of charge, a considerable number of blanket

samples. These were tested for heat conductivity on an apparatus

specially designed for the purpose. The several results were compared with those obtained with the Army blanket. It was found

that the fiber composition did not materially affect the result, the

cotton blankets being as satisfactory as the wool within the limits of

the test. The factors vitally affecting the results were found to be

weight and method of manufacture.

86986—18 11
162 EEPOKT OF DIKECTOR OF BUREAU OF STANDARDS.

Consideration was next given to studying methods of manufacture.

In this work again the manufacturers showed a willingness to cooperate, but it was found that they could not be of material assistance

because their plants are designed for routine production and can not

be readily adapted to the construction of special fabrics for experimental purposes. This difficulty, it was seen, would apply with

equal force to similar work on clothing materials of all kinds, and

therefore it was decided to install a small woolen manufacturing

plant at this Bureau, where experimental fabrics could be made

under rigidly controlled conditions and test results could conse- quently be interpreted with reference to the manufacturing procedure

used. This plant is now being installed and should be in running

order very soon.

It has not been possible as 3' et to investigate the durability of these

materials owing to lack of the necessary materials and equipment.

This phase of the problem is of great importance from the viewpoint

of conserving the Nation's wool supply.

Uniform Fabrics.

An effort is being made to anticipate the demand for work, similar

to that outlined under " Blanket investigations," as applied to fabrics

for uniforms. The tremendous demands for woolen materials for

Army purposes is sure to cause a critical shortage in the wool supply.

This will have to be met either by increased efficiency of use, by

the use of substitutes or by importation from foreign countries. The

last alternative would involve the use of shipping much needed elsewhere. It is the purpose of the Bureau during the coming year to

study the use of substitutes and the adaptation of manufacturing

methods to specific service requirements in order to alleviate, in so far as possible, the threatened shortage. This work will be pursued

with the utmost vigor, provided the necessary equipment can be

obtained.

The textile work of the Bureau, particularly as applied to woolen

fabrics, has been seriously handicapped for lack of funds. In view

of the grave importance of properly clothing the men of our Army

and of providing them With blankets and other woolen equipment,

it is very necessary that the personnel and materials required be provided. The work has received the universal indorsement of Army

officials, manufacturers, and consumers, and it is believed that it constitutes one of the most promising fields for Bureau of endeavor.

The saving effected by an adequate appropriation would be many

times the expense involved, considering only the present year. The

woi-k done would be of a permanent nature and further saving in

subsequent years, due to work done this year, would therefore be

cumulative.

Airplane Fabrics.

At the beginning of the present war, it was evident that the flax

crops would not be sufficient to supply the demands for airplane wing

coverings. Inasmuch as this country grows but very little fiber flax

and has no machinery for spinning the proper yarns for airplane

fabrics, it became necessary to substitute our most abundant fiber.
EEPOET OF DIEECTOR OF BUREAU OF STANDARDS. 163

Accordingly the National Advisory Committee of Aeronautics re- quested that the Bureau investigate the possibility of finding a suitable substitute for the linen. The many previous experiments on cotton and silk had supposedly demonstrated that the substitution was

impossible. However, the Bureau under these unfavorable .conditions

enlisted the cooperation of the cotton manufacturers of this country

and began a series of experiments. The willingness of the manufacturers to assist was extremely gratifying, and throughout the entire

time they haA'e always been ready to provide samples o-f varying structure in the shortest possible time.

The properties of the satisfactory linen fabrics were studied and

the desirable properties of airplane wing coverings were investigated.

From these studies the characteristics of the theoretically perfect

fabric were determined. It then became necessary to duplicate

these properties in a practically possible fabric. As a result, a cotton

airplane fabric has been developed which is considered superior to

linen, and which has relieved a serious situation in ovir airplane

program. i The linen situation had developed to a point where it was necessary

for the countries associated with the United States in the war to look

for other fabrics, and England has already adopted our cotton fabric

and found it satisfactory.

Many experiments were performed on silk, and other fibers to be

had in fairly large quantities, but in most cases the results were not

encouraging.

The work along these lines is being carried on with the view to improving present ones, to develop satisfactory fabrics from other

fibers and to- provile satisfactory fabrics for new types of planes.

The enthusiasm of the manufacturers has been very gratifying.

Many manufacturers are offering practical cooperation on the various

problems involved.

Attaching of Fabrics to Planes.

The existing methods of attaching and tying fabrics to wing structures has caused in the past a considerable amount of trouble. The

Bureau has investigated methods of sewing seams, tying, etc., and

the materials used in these operations, and has succeeded in making

the conditions much more safe and satisfactory.

Inspection of Airplane Fabrics.

At the request of the Signal Corps, detailed methods of inspecting the airplane and balloon fabrics were outlined and put into

effect. The methods have been satisfactory.

Balloon Fabrics.

The Bureau, at the request of the balloon sections of the Army

and Navy, has experimented extensively on cloths to be used in the

manufacture of balloon fabrics. The foreign balloon fabrics were

made almost entirely of cotton and it was a comparatively easy matter for our manufacturers to duplicate these fabrics.

These fabrics are not all that could be desired and the cooperation

of the cotton manufacturers has enabled us to develop fabrics which

are much more satisfactory. These experiments are still in progress
164 EEPOKT OF DIEECTOR OF BUREAU OP STANDARDS.

and it is hoped that they may be completed in a comparatively short

time. These fabrics promise to be much more easily produced and

it is anticipated that they will satisfy the conditions of stresses in a balloon much more satisfactorily than the present ones. Balloon Seams.

Extensive exjDeriments on the design of balloon seams have

been carried out to determine a seam to most effectively resist the

system of stresses involved. It was found that in many cases a simpler seam than those used in foreign practice could be designed.

Parachute Fabrics.

The problem of obtaining satisfactory man and flare carrying parachutes was not particularly difficult, as the foreign silk fabrics could

be quite easily adapted to our manufacturing facilities. A very material assistance was given to the military departments in selecting

the best fabrics and in measuring the relative efficiency of our own

products.

Physics of Airplane Fabrics.

Our early experiments on airplane fabrics lead to the conclusion

that many of the factors influencing the behavior of fabrics were

not satisfactorily explained, for many of the experiments were more

or less impractical.

At the present time, the theory underlying the performance of airplane ancl balloon fabrics is little known, and the more recent developments in airplane design have caused us to turn our attention

to this field. The work is progressing rapidly, and it is anticipated

that more efficient fabrics will be evolved and that the airplane designer may predict the performance of any fabric with a reasonable

degree of certainty.'

Packing of Textiles.

At the request of the Quartermaster General a series of experiments were conducted to determine the smallest size of bale in which

a given quantity of the various materials could be packed without

injury to the fabrics.

The War Industries Board requested that an investigation be instituted to determine the most economical method of packing textiles

for the retail trade, with particular reference to the effect of the

method on the properties of the material. These experiments were

never completed, due to the lack of proper facilities, but much valuable information was collected. The importance of such an investigation is readily -realized when it is considered that in many cases large amounts of shijDping space may be saved without seriously injuring the materials.

Miscellaneous Military Materials.

A very limited amount of Avork has been done on such military

fabrics, as dugout blankets, stockinettes, gasmask fabric, stockmgs,

tentage, cordage, and the like.

Specifications for many ordinary materials have been written and.

placed in the hands of proper authorities.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 165

Test Methods.

The growing prominence of the necessity of testing textile materials, together with the introduction of many new fabrics, has made

it necessary to develop the art of testing to a much higher degree

than heretofore.

Several important methods of testing have been devised, particularly in regard to aeronautical fabrics, in order that the probable

performance of the materials may be anticipated.

The development of new test methods has been accompanied by

the necessity of developing new testing machines, all of which have

proven to be of material assistance in the selection of proper fabrics

for the right one.

Microscopy.

The importance of a microscopical examination of textile materials has long been established, but it was not until this year that we

were able to install a satisfactory microscopy laboratory. This laboratory has already been of tremendous value, particularly in the ex- amination of German and other foreign fabrics and in connection

with the study of rubberized fabrics.

Industrial Laboratory.

The pure research work of the section has been in the past severely

handicapped because of the inability of the research man to be supplied with samples of known value. To overcome this difficulty there

is now being installed a complete felt, woolen, and cotton mill for

the preparation of samples to be investigated as to their properties.

The A^alue of such a laboratory is realized when it is considered

that the textile industry has never scientifically investigated its

products. It is anticipated that the future will bring forth keen competition in textiles, and it would appear essential that the American

manufacturer should knoAv more exactly the factors governing the

quality of his output in order that he may more satisfactorily compete with other nations.

The importance of such information is emphasized when it is

considered that the large textile nations are now instituting elaborate plans for the thorough investigation of textiles, and that in

many cases the results of the investigations will be more or less constrained to distribution in their own country.

The National Council of Cotton Manufacturers of this country,'

which represents practically every cotton mill in the country, has

pledged its support to the furtherance of our work on cottons and

has offered every cooperation which we may desire.

The importance of industrial research on textiles is so very great

that it is urged that every effort be made to facilitate concentrated

investigations.

PAPER.

Investigation and Testing of Paper.

The general work of the paper section is divided into two parts,

namely, routine testing and research investigations. Under routine
166 KEPORT OF DIKECTOB OF BUEEAU OF STANDAEDS.

testing, is included the testing of samples of paper and paper products, for the various government establishments. In most cases

this work includes the testing of samples to determine compliance

with a standard specification or an accepted sample. Under routine

testing is also included the preparation of standard specifications

of paper for particular purposes. In some cases the development

of a standard specification may even require the development of

special tests designed to meet some special factor, by which the

quality of a material may be definitely recorded. The paper section

has assisted manj' of the governmental establishments in the preparation of standard specifications and is continually urging upon all

that paper can not be intelligently purchased upon any other

basis.

In the part designated research investigations is included all work

other than that of a purely routine nature. Under this heading are taken up the problems of the industry as applied directly to manufacturing technologly. Previous to the beginning of the war, the

paper section had under way a number of problems of importance

to the industry. The demand of the Government for paper and

paper products has grown so materially during the past year that

almost all of the research problems pertaining to commercial technical interests have had to be discontinued. The work on buttermilk

casein adhesives, filter paper, paper-making clays, sizing methods,

and other problems have not been abandoned, but have of necessity

given way to problems having a more direct war bearing.

Utilization of Wall and Plaster Board.

The use of wall board and plaster board as a building material

for the construction of military cantonments, Government warehouses, office buildings, and similar Government needs has developed

to a great extent in the past year. Wall board is a general term

covering those types of building material which are used as a substitute for wood lath and plaster in partitions and for sheathing on

the inside walls of buildings. The construction of the vast number

of Government buildings demanded in the prosecution of the war

required the use of a material that could be quicklj' erected, have a low cost, as well as adequate supply. This necessity was met by th6 use of over 100,000,000 square feet of wall board.

Wall boards are made of paper, built up of one or more layers or

plies that are cemented together with a binding agent such as silicate

of soda (water glass) or other adhesive. Plaster board is made of

3-ply construction. The inner ply is made of hydrated plaster of

Paris or gypsum, while the two outer plies are made of a special

paper. The finished boards are in thickness of three-sixteenths, one- fourth, and three-eights of an inch.

Plaster board has fire-retarding properties superior to ordinary

wood lath and plaster and far supei"ior to the' all-paper wall board.

The strength of this material together with its fire-retarding properties and other qualities make it ati excellent building material and

one that will undoubtedly come into more general use as its properties and usefulness become more generally known.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 167

The term wall board applies only to that type of wall covering

that is made entirelj'^ of old paper stock, ground wood pulp, or other

paper making fibers.

Through the "War Department, the Bureau was requested to assist

in the preparations of specifications and methods of testing to determine those qualities required. Special methods for testing this wall

board had to be devised, in order to duplicate as nearly as possible,

service conditions. Samples of all the commercial grades were se- cured and tested and their relative suitability determined. As the

War Department has already used great quantities of this material

and is contemplating using much more of it in the near future, the

need of complete data of the service of this type of building materials

can not be overestimated. The actual service rendered by this wall

board has been investigated at various cantonments and in buildings

lined with wall board and plaster board erected over a year ago. The

result of this general investigation has been to improve greatly

the quality of the wall and plaster boards used by the Government.

Much of these good results have been made possible by the hearty

cooperation of several of the large manufacturers.

Development of Special Papers.

As a result of a demand for special papers by several branches of

the military departments, the paper section has carried on experimental work to develop papers having special characteristics. An

extra strong paper has been produced, having tensile and bursting

strength greatly in excess of any commercial papers so far encountered. This paper can be produced commercially and has possibilities not only for certain military uses but also for warp threads in

making strong paper textiles. A detailed study has been made of

the control of the process of manufacture, with the result that duplicate lots are readily produced.

Special studies have been made of waterproof lining papers used

in wrapping goods for overseas shipments of military supplies.

This work has demonstrated the fact that it is necessary to use a craped or corrugated paper in wrapping the bales. This crape or corrugated feature adds the necessary stretch -to the paper wrapping,

thereby preventing the breaking open of the bale of goods when

handled roughly.

Paper-Testing Devices.

In connection with the development of papers of high tensile and

bursting strength, it was found necessary to develop a tearing test that would enable this quality to be expressed in numerical values.

The need of such a test is important and plans have been made to

construct an instrument that will measure this quality.

Means by which the sizing quality of paper could definitely be

expressed have always been in demand of the paper industry. The

chemical analysis of a paper does not give results that can be used

to show relative sizing effect. With this need in view, a modified

electrical conductivity method of determining the sizing quality of

a paper has been used successfully, developed, and indications point

to the fact that by this method sizing quality may be recorded in

numerical terms.
168 REPORT OF DIEECTOE OF BUREAU OF STANDARDS.

Filter Paper for Explosives Testing.

Through the efforts of this Bureau, a sufficient supply of a special

filter paper was obtained for the Navy Department. This paper is of the highest importance as it is required to determine the stability

of high explosives purchased by all the military branches.

Information Furnished on Paper.

Special assistance has been given in by this Bureau to the Federal Trade Commission in connection with the newsprint investigation; to the Council of National Defense in regard to importation

and use of china clay in the paper industries ; to the Shipping Board

relative to the use of clay, casein and rags in the pajDer industry; to

the Pulp and Paper Section, War Industries Board, in supplying

technical information (the Paper Section being represented on the

Pulp and Paper Section) relative to the pulp and paper industry; to

Ihe Bureau of Mines for coojDerative work in connection with the

development of a paper as a smoke-filtering medium; and to the

Joint Committee on Printing, and the several Government departments, as Avell as the General Supply Committee, in connection with

the preparation of specifications for paper and allied materials.

It is impossible to enumerate the whole range of inquiries that are constantly being received, but the following will outline in brief the

m.ore important ones

Pajjer containers.—Specifications of paper containers to be used

for shipment of axle grease and similar substances overseas. A. compact paper container was desired in connection with the conservation

of tin and steel, and also to provide a small compact package of axle

grease to be issued to drivers of motor cars, tractors, wagons, and gun

carriages.

Absorbent paper.—During the past year an absorbent material

has been produced and placed upon the market by several manufacturing comjDanies. This material is made from bleached chemical

pulp. In appearance it resembles ordinary absorbent cotton, with the

principal clitference in that it is made in very thin layers which

are very much lighter in weight than the lightest tissue paper. This

material is also very heavily craped. This wood pulp "cotton" is

coming into very important use as a surgical dressing to replace absorbent cotton. It will absorb practically as great a weight of moisture as cotton and has an added advantage of absorbing very much

more rapidly. The material being of a lower price than absorbent

cotton and being somewhat more easily handled, will undoubtedly

replace cotton for this class of work. Both the Army Medical Service and the American Red Cross are large users of this material and

the paper section has also been able to interest the Public Health

Service in this material.

Paper bandages.—The laboratory has recently received samples of

paper bandages made from specially prepared paper. A bandage of

this kind is not as resistant to moisture as a cotton cloth bandage, yet

it has a number of advantages in that it is lower in price and because

of the way in which it is made, it conforms more readily to wrapping around irregular surfaces. This paper bandage for surgical
EEPOKT OP DIRECTOE OP BUREAU OF STANDARDS. 169

dressings will undoubtedly come into more and more general use. They are not substitutes, but should be considered in the light of

new material, having certain advantages over the ordinary absorbent

cotton and cotton bandages.

Many inquiries have been received covering all phases of manufacturing details and the paper section has endeavored in every way

possible to supply the necessary information desired. Several American manufacturers of vegetable parchment paper used for wrapj^ing

meats, fish, butter, cheese, etc., have had difficulty with both the

Australian and New Zealand customs authorities in securing a correct classification for the American parchment papers. This matter

was called to the attention of this Bureau and after considerable

correspondence this Bureau was able to point out to the customs

authorities mentioned that their regulations did not in any Avay

restrict the American product. It was also called to their attention

that their method of testing did not enable anyone unfamiliar with

the subject to make a correct decision as to whether the paper was

or was not a true vegetable parchment paper. The Bureau endeavors

at all times to assist American manufacturers in broadening their

commercial field and is in a position to take up with foreign authorities the discussion of customs regulations which might tend to discriminate against the American product, especially in questions

where the regulations may not have been correctly interpreted.

Assistance to paper industry.—Many requests for standard samples and specifications used by the Government have been received

and complied with. In addition to this many specifications have

been prepared to meet the requirements of paper for special purposes.

The continual increase in the number of visitors is. an indication of

the growing interest which both the trade and the general public are taking in matters pertaining to paper and paper products. A great

many of these visitors are of the type that desire general information

relative to paper and paper testing and the possibilities of developing specifications for paper for particular purposes. Since the beginning of the war, however, there has been a steady increase in the

number of manufacturers who have visited the laboratory. The general purposes and aims of the laboratory are explained and every

effort is made to demonstrate the necessity for carefully controlled

experimental work. A number of large paper companies have

planned a way by which they propose to install a complete experimental equipment similar to the one here at this Bureau. Such inquiries are given every possible assistance, as it has been demonstrated

that a superior and more uniform product is secured from those mills

that are considering manufacturing problems from a scientific standpoint.

Summary of Tests.

The Bureau has tested for the Government Printing Office and

Government departments 5,277 samples of paper. It has tested for

public and private interests 420 samples of paper, making a total of

5,697 samples tested. This is an increase of 83 per cent over the

preceding year and indicates the increased use of this branch of theBureau's activities, brought on by war conditions.
170 EEPOBT OF DIRECTOR. OF BUREAU OF STANDARDS.

8. METALLURGY.

[Thermal analysis and structure of metals, heat treatment and its effect upon the properties

of metals and alloys, including the researches involved in determining the causes of metal

failures, cooling and heating curves; the investigation of hardening, annealing, tempering,

cementation; the determination of critical ranges; and the preparation of pure metals and

alloys.] Equipment.

In view of the fact that the Metallurgical Division has just completed removal into new and greatly enlarged quarters and is acquiring considerable new equipment, it may be of interest to mention

some of these items as an indication of what we are prepared to do

in metallurgical investigation and testing. The plan laid down is,

to be able to make any metal or alloy, give it any desired thermal

and mechanical treatments, and carry out any required test or investigation of its properties. The manufacturing scale adopted, up to

quarter-ton units, appears sufficient to warrant reaching " practical

conclusions.

The basement of the northwest laboratory contains the manufacturing units, comprising foundry, heat-treating and mechanical

plants, which last includes motor-driven rolling mill with 4:1 speed

control, 150-ton steam, hydraulic power press and shearing attachment, driven by 150-horsepower air compressor, a motor-driven

10-ton chain drawbench with attachment for drawing tubes, and

shop, with a 10-ton crane over all. The foundry includes both gas

and oil fired crucible furnaces, 2 of 200 and 1 of 50 pounds capacity, core ovens, molding equipment, casting pits, etc. ; a 150-kilovoltampere arc electric melting furnace of 600 pounds capacity is being

installed, and it is hoped to be able to install a 1 or 2 ton open-hearth

furnace; there is a laboratory attached to the foundry for research

work on sands.

The heat-treating plant comprises 1 semimuffle oil-fired furnace

7 by 2 by 1^ feet, with quenching tanks of oil and water 12 by 3 feet

provided with circulation pump, salt and metal baths, case hardening

furnace, several gas and electric muffle furnaces of various sizes,

5 electric resistance tube furnaces, 2 electric melting furnaces for

high temperatures, and there are being installed 2 large 50-kilovoltampere electric annealing furnaces to serve the rolling mill; one of

these, 14 feet long, is designed for rods and tubes and the other for

ingots. Additional furnace equipment for special researches includes

2 high-temperature vacuum furnaces with pumps, rheostats, and other

accessories and a number of small furnace units.

For thermal analysis there has just been delivered an Einthoven

galvanometer outfit which will be used in various experiments on the

properties of rapidly cooled alloys. This section also possesses three

complete sets of thermal analysis outfits and has recently designed

and put into operation a new type of furnace determining transition

points in alloys. New apparatus for determining electrical resistance

of alloys has been installed and considerable auxiliary apparatus

and supplies purchased, including porcelain, platinum, quartz,

thermocouples, galvanometers, resistances, tools, etc. Among the miscellaneous equipment an optical pyrometer including a micropyrometric outfit, apparatus for determining hardness,

Brinell and a scleroscope, also new microhardness instruments are being designed; a 10,000-pound testing machine; a 30-foot-pound
REPORT OP DIRECTOR OP BUREAU OP STANDARDS. 171

impact machine. (The heavy mechanical tests are made by the

Structm-al Materials Section.)

There is one room fitted up for physico-chemical research, electrochemical analysis, and equipment for examination of fusible plugs.

In addition to the general shop facilities of the Bureau there is at- lached to the Metallurgical Division a small shop containing saw,

grinder, miller, drill press, and lathes. The electrical equipment for

so much special apparatus is necessarily quite extensive and embraces

several power lines with alternating current and direct current and

a flexible set of transformers, rheostats, potentiometers, and other

instruments, etc. The metallographic facilities include adequate apparatus for cutting up, grinding, polishing, etching, and photographing metals.

The laboratory possesses three metallogTaphic outfits, a Zeies, Leitz,

and latest Bausch & Lomb model, and a varied assortment of accessories.

In the laboratory of chemical metallurgy are large electric vacuum

furnaces and auxiliaries for preparing pure metals; an outfit for

electrodeposition of iron, etc. : furnaces and other equipment for

preparing pure magnesia crucibles; apparatus for determination of

gases in steel, several for rapid determination of carbon by composition -and electrolytic method ; furnace for preparation of pure aluminum ; in addition to the usual chemical equipment.

Publications.

The practice has been continued of issuing circulars of information concerning metals and alloys. Thus a circular (No. 73) just is- sued on copper treats of its manufacture, physical properties, metallograph3^ together with information concerning effects of temperature and of impurities on physical properties and contains a comprehensive bibliography. Circulars are in press or in preparation

on "Aluminum and Its Light Allo5's," "Solders for Aluminum,"

"Bearing Metals," "Acid Resisting and Noncorrodible Metals,"

"Protective Metal Coatings," and the circular on metallographic test- ing is being revised.

Pending the preparation in the more comprehensive form of

printed circulars, information on certain subjects of general interest, or about which numerous inquiries are received, is disseminated in

"circular letters." The following, prepared this year, are typical:

" Sources of Information and Data on the Properties of Metals at

High Temperatures." " Mechanical Tests of Metals and Alloys and

High and Low Temperatures ; Sources of Information and Data."

The following papers by members of the Metallurgical Division

have appeared during the year: Typical Cases of the Deterioration

of Muntz Metal by Selective Corrosion, Bureau of Standards' Technologic Paper No. 103, American Institute of Metals, IX (p. 148,

1918) : Some Unusual Features in the Microstructure of Wrought

Iron, Bureau of Standards' Technologic Paper No. 97, Transactions

of American Institute of Mining Engineers (p. 1345, 1918) : Copper,

Bureau of Standards' Circular No. 73, Metalluroical and Chemical

Engineering (18, pp. 121, 192, 303, 357, 1918) ;"Rapid Determination of Carbon in Steel by the Barium Carbonate Titration

Method, Journal Industrial and Engineering Chemistry, (10, p. 520,

1918) ; Thermal Expansion of Alpha and of Beta Brass Between 0°

and 600° C, in Relation to the Mechanical Properties of Hetero-
172 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

geneous Brasses of the Muntz Metal Type, Bureau of Standards'

Scientific Paper No. 321, 1918, Journal American Institute of Metals

(11. No. 3. p. 396, 1918).

The following are in press: Structure of Commercial Zinc Coatings, Proceedings American Society for Testing Materials, XVIII,

1918 ; The Use of Mercury Solutions for Predicting Season Cracking

in Brass, Proceedings American Society for Testing Materials,

XVIII, 1918; Second Report on Ladle Test Ingots, Proceedings

American Society for Testing Materials, XVIII, 1918; Aluminum,

Bureau of Standards' Circular; Solders for Aluminum, Bureau of

Standards' Circular; Initial Stress and Corrosion Cracking of Brass,

Proceedings American Society for Testing Materials, XVIII, 1918

A Critical Study of the Ledebur Method for Determining Oxygen

in Steel.

The following are in preparation : Conservation of Tin in Solders,

Bearing Metals, and Bronzes, American Institute of Mining Engineers; Circular oaa Bearing Metals; Circular on Acid Resisting

and Noncorrodible Metals ; Circular on Types, Properties, Specifications, and Tests of Metal Coatings ; Manufacture and Testing of Tin

Fusible Boiler Plugs; A Modified Sample Collecting Sprengel

Pump ; The Embrittling Effects of Metal Coatings.

Metallurgical Tests.

The tests of metals executed the past year have been mainly for

the militai'y departments, and many of them were of such elaborate character they will be classed as investigations. Of the more

elaborate investigative tests may be noted : An examination of the

characteristics of centrifugally cast steel—which gives promise

of possibilities of advantageous use in replacing several lines of

steel forging, cutting down discards, machining and segregation,

and eliminating piping, blow holes, and forging; a study of

strains in cartridge cases as dependent on manufacturing methods

and the adaptability of accelerated stress-corrosion tests for predicting failure; the relation of grain size to distortion in cartridge

cases ; an exhaustive comparison of the relative merits of cold shearing and nick-and-break method for shell slugs; distinguishing between hard and soft rotating bands for shells ; several tests of armor

plate and numerous other materials for ordnance, aircraft, quartermaster and engineering departments of the Army and for the various

branches of the Navy; fusible tin boiler plugs for steam vessels;

recovery of tin; examination of a very large variety of coatings for

rust proofing; interesting points were the nonuniformity in electroplated coatings, uniforniity of sherardized coatings; brass plating,

the relations among the metals showing the superiority of zinc;

and a study of the "copper-clad" process; micro examination of

large (12-inch) chain links forged, welded and cast, tarnishing

tests on Benedict nickel and German silver ; heat treatments presenting special problems were very small compass needles, large (30-

inch) U-bars, long slender rods and very large sheets; service tests of the lead-base bearing metal, ulco; service tests of a special leadbase babbitt; investigation of cause of failure by cracking of brass

locomotive steam gauges; cause of cracking of case-hardened aero- plane engine cam follows ; failures of aeroplane crank shafts ; service

tests of rhotanium and palau (substitute for platinum) crucibles;

corrosion tests on several acid-resisting alloj^s; tests of numerous
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 173

commei-cial light aluminiTin alloys; causes of cracking of welded

Army aluminum canteens; determination of working temperatures

of machine gun barrels; tests of magnalium alloys of high optical reflectivity for mirrors, including the preparation of a series

of a considerable number of such alloys, a large number of steels

and alloys were examined by thermal analysis to locate their critical

points; the casting of numerous metals and alloys for instrument

parts and researches ; samples of meteoric iron for structural characteristics; numerous samples of platinum to determine purity and

causes of deterioration; a very serious type of failure known as

" flal^y " steel occurring in nickel-chromium and nickel , steel was

studied in great detail ; semisteel, cast iron and steel shells ; failed

gun forgings and other ordnance material to determine cause of

failure, suitability for use or special characteristics; valves for aircraft motors; machine-gun barrels; German rifle bullets; cartridge

clips, etc. A summary of the metallurgical tests is given below; their total

value in fees is $7,090.50. Of these tests items, 90 per cent were for

the various departments of the Government and 10 per cent for private individuals and corporations.

The activities incident to the carrying on of the war have made

many temporary changes necessary in the research program; new

problems have been taken up and work on the older ones has had in

some of the cases of necessity to be for the moment discontinued.

Heat treat- ment and

thermal analysis.

Metallographic (including physical,

chemical, and corrosion tests).

Fusible

plugs.

Miscel- laneous.

Grand

total. Irons and

steels.

Nonfer- rous

metals

Irons and

steels.

Alumi- num

alloys.

Brass and

bronze.

Identification

of metal and

process

of manufac- ture (metal

coatings).

other

metals.

For the Government: Bureau of ' hemistry 4 45

1 155

12

1

1 27

82

2

6

2

453

3

14 402

1

Bureau of Entomology 5

1 Bureau of Stan lards 118 6 6 25 Council of National De1 District of Columbia 2 1 Emergency Fleet Corpo1

1

11

Lighthouse Service Navy Department 2

15

7 9 657

2

9 Patent Office 2 Post Office Department 6 Smithsonian Institution 2 Steamboat-i nspeotion

Service 453 Treasury Department 3 United States National Museum 14 War Department 14 222 16 26

1

8 41 75

Total 132 261 23 3S 88 46 462 112 1,162 For the public 14 35 3 19 11 19 26 127

146 296 26 57 99 65 462 138 1,289
174 EEPOET OF DIEECTOR OF BUREAU OF STANDARDS.

Tests of New Alloys.

The war has brought out a number of new alloys, or modifications

and processes with new names, which have been submitted for examination usually with view to their military utility. Some of these

are : " Liberty metal," palau, rhotanium, various aluminum solders,

acerial, magnalium, magnalite, McAdamite, cooperite, ' al-calcium,

magnolia metal, ulco bearing metal, various metal coating processes,

the alloys dirigo, bario, ampco, cosmic, zelco, stellite, tinol, aterite,

sperlite. Siliman bronze, etc. Military Boards and Committees.

The International Aircraft Standards Board, organized August 8,

1917, with representatives of Canada, France, Great Britain, Italy,

and the United States, has held most of its meetings at the Bureau

of Standards. This board has done valuable work in reducing the

number and unifying specifications for aircraft materials purchased

in the United States. Eighty specifications, of which 67 covered

metals, have been issued for the board by the Bureau of Standards.

Several important lines of investigation have also been the outcome

of the deliberations of this board.

The Emergency Fleet Corporation has organized a committee on

Welding—in succession to others of the American Institute of Electrical Engineers, etc.—in which the Bureau of Standards was represented, and a distributed experimental program is under way.

The Advisory Committee for Aeronautics in aSTovember, 1917,

organized a light alloys committee. Several important experimental

contributions have already been made, mainly by the Bui'eau of

Standards, on aluminum and its alloys, and others are in preparation.

On the National Research Council's foreign service engineering

and body armor committeees the Bureau of Standards was represented.

Various members of the Metallurgical Division have been called in

as technical advisers by the several branches of the War Industries

Board, particularly on tin, steel, and platinum, and the Bureau of

Standards in consequence has undertaken considerable experimental

investigation, especially on tin conservation and substitutes.

In addition to formal committees with regular programs, there

have been held a great many conferences, at which the Bureau of

Standards' representatives have been present, called by the various

military department to discuss with manufacturers technical questions bearing on military materials and specifications.

Military Inventions.

The Metallurgical Division has assisted the several information,

patent, and military departments in the examination and development of military inventions relating to metals, manufacturing

processes, and various devices made of metals.

Information Furnished by Correspondence.

In addition to information furnished in personal interviews on

technical subjects, there is a very heavy correspondence maintained

on subjects relating to metals; that of the month of February, 1918,

here reproduced is typical both as to range and number of subiects.
REPORT OF DIRECTOB OF BUREAU OF STANDARDS. 175

Information has been furnished by correspondence on the following subjects: To the Navy, resistance to corrosion of aluminum

bronzes, criticism of bronze and brass specifications, corrosion of

copper plated clips, bolts, sheets, etc., zirconium steels, nickel-steel

for periscope tubes, oxyacetylene welding of steel pipes; to the

Army, on qiienching media for heattreating steels, noncorrosive

metals, copper rotating bands for projectiles, sheet aluminum, steel

for caterpillar treads of tanks, seamless and welded tubing, effect of

mercury on primer metals, gun-metal tests, tests of brass-coated

washers, on nickel-steel stock, melting points of brazing wire, nickelplated sheets, advice as to publication of " steel in aviation;" to miscellaneous parties, silver-plated articles, use of aluminum scrap,

substitution for tin in bearing metals, quality of fusible boiler plugs

and substitutes, several items regarding welding processes, aluminum solders, electric conductivity of " bario " metal, etc., production

of highest purity aluminum, a certain process of galvanizing,

standard brasses and bronzes, heat treatment of steel (several re- quests), optical pyrometers for metallurgical use, electrical welding

of aluminum, manufacture of bronze powder, steel coated by "Epicassit " process, tempering steel, formulae for galvanizing, galvanized culvert pipe situation, use of boron copper, bearing metals,

physical properties of copper, aluminum, zinc, etc., (several re- quests), platinum substitutes, manufacturers of iridium and of

tungsten steel, corrosion of iron and steel, methods of steel manufacture, alloys for aircraft, relative corrosion of metals, metals to take

engraving for instruments, cobalt-chromium steel thermal characteristics, foundry mixtures for molds, silicon-bronze characteristics,

brass formulae, aluminum alloys and nonmagnetic alloys, corrosion

of " alumo}^," casehardening, specifications for Government materials (several requests), manufacture of small metal articles, material for aircraft engine valves.

MICROSCOPY OF METALS.

(The microscopic examination of metals and alloys, investigation of flaws, defects, and

other imperfections in commercial metallic materials.)

Corrosion of Nonferrous Metals.

A contribution to this subject has been made in the form of a descriptive summary of typical cases illustrating this type of deterioration of metals. Much of this material has been submitted to the

Bureau for examination during the past 4 or 5 years.

Protective Metallic Coatings.

In a study of the effects of rustproofing on the brittleness of wires,

started at request of International Aircraft Standards Board, a preliminary examination was carried out with tensile tests of wires,

taking the elongation in tensile test as a measure of the brittleness.

While some conclusions as to effects of cleaning, plating, etc., could

be drawn, the results were not sufficiently definite and a new form of

test piece was required. It was decided to adopt the impact test,

and an impact machine of the Izod type was designed and built.

The experimental program covers the various compositions and sizes

of wires in common use, and the investigation is to be extended to

include especially the brittleness of small springs. In cooperation

with the American Society for Testing Materials a joint program is
176 REPORT 01" DIRECTOR OF BUREAU OE STANDARDS.

being carried out on zinc coatings, their properties, methods of test,

structure, and eflPects of various coatings on the base metal.

Microstructure of Wrought Iron.

The study of the modifications which the presence of phosphorus

may bring about in wrought iron has been completed and published.

(Bureau of Standards Technologic Paper 97.)

Valve Steel for Airplane Engines.

Investigation of the effect of the rate of temperature change on

the transformations and microstructure of an alloy steel used in

valves for aeroplane motor very nearly completed. This investigation is expected to throw considerable light on the nature of hardening of steels and the properties of alloy steels. The results obtained

will also contribute to theories of the hardening of steel.

Ladle Test-Ingot Investigation.

The second phase of this investigation as outlined in last year's

report, has been completed and a report made to the American Society for Testing Materials. Aluminum treatment of ladle test-ingots was shown by this work to give nonsegregated ladle-test ingots

of high and medium carbon steel, but such treatment has little advantage for low carbon steels. Recommendations were made as to adoption of desirable types of ladle test-ingots and as to a comparative

study during the year at certain works of test-ingots made with and

Avithout aluminum treatment.

HEAT-TREATMENT AND THERMAL ANALYSIS.

(Determination by tliermal analysis of critical temperature points and ranges in metals

and alloys, and the heat-treatment of these materials.)

Iron-Carbon Transformations.

The investigation of the transformations in pure iron-carbon alloys is nearing completion. The results are of practical as well as theoretical interest, as they form a basis for estimating the temperature of the transformations in steels by chemical analysis, which will

eventually eliminate the necessity for commercial apparatus for this

purpose, and they give a sound basis, which at present does not exist, on which to construct a theory of hardening.

Preparations are being made for the determination of the transformations in pure iron-carbon alloys containing various alloying

elements.

New Furnace for Thermal Analysis.

A furnace of a new type for obtaining thermal curves has been

constructed at the bureau. This furnace makes it possible to do at

least twice as much work in a given time as previous equipment, it uses a very small fraction of the power previously required, and a much greater temperature range and variation of rate is obtained

with a more uniform curve than was formerly attainable. This will

be described shortly.

Gun Erosion.

In cooperation with the Ordnance (Army) Department a comprehensive investigation is being made of the various factors affecting

gun erosion, particularly as applied to machine guns.
EEPOKT OF DIRECTOR OF BUREAU OP STANDARDS. 177

PHYSICAL PROPERTIES OF METALS AND ALLOYS.

(Determination of physical properties of metals and alloys ; correlation of physical properties with structure and constitution, and effect of temperature, mehanical working, etc., upon these properties.)

Light Aluminum Alloys.

One of the roost important investigations taken up because of its

military importance and urgency was that of the technical phases

of the manufacture and the properties of the light alloys of aluminum, both wrought and cast. Such alloys are of especial significance

in connection with the design and construction of aircraft, for which

their lightness and strength well fit them.

In order that this work might constantly best serve the needs of

the military departments, close contact has at all times been maintained with them, both through the Light Alloys Committee of the

National Advisory Council for Aeronautics and by personal conferences. Confidential reports have been issued from time to time—5 to

date—of the progress of this work.

One of the interesting results of this work has been the demonstration of the necessity for thorough investigation of fundamental facts

and phenomena as the only satisfactory basis for technical progress

in the art of manufacture. Thus, at the outset, interpretation of

tests results was confronted by an almost total ignorance on the

part of our present day metallurgy of some of the most fundamental

physico-chemical data of aluminum and its alloys. As the technical

phases of the work have proceeded therefore, the theoretical phases,

such as constitution, etc., have required more and more attention,

until at present it appears that further progress depends upon the

solution of several of these fundamental questions.

Several directions have been followed in this work:

Aluminum-Rich Alloys of the Three Ternary Alloy Systems.—

This is a study of the possibility of developing better commercial

rolling alloys for use in structural construction. A survey was made

of the mechanical properties of the rolled aluminum-rich alloys of

each of these alloy systems. From 8 to 12 compositions of each system were cast and rolled into sheet at the New Kensington plant of

the Aluminum Company of America, a representative of the Bureau

directing both the preparation and subsequent testing of the samples.

The copper series proved so superior in respect to mechanical properties in these tests that the other two series are practically eliminated from further consideration for purposes for which high

strength is desired; only this series, also, is to any extent subject to

heat treatment. The results of this investigation are described in

Confidential Report No. II. The investigation is completed.

The Heat Treatment of the Duralumin Type of Alloy.—Heat

treatment of the alloy known commercially as duralumin has been

practiced for several years, but apparently little improvement has

been made in .the actual heat treatment practice since the initial discovery of this property of the alloy by Wilm. The Bureau's investigation of this question has led to some very interesting discoveries bearing

on the theory of the effect of this treatment and to important alterations in existing practice of commercial heat treatment, resulting in

improved physical properties and reduced wastage from cracking

86986—18—12
178 KEPORT OF DIEECTOR OF BUREAU OF STANDARDS.

during treatment. These alterations have been adopted commercially. Confidential Eeports Nos. Ill and IV have been issued dealing Trith the results of this work.

The investigation is almost complete, but further work will be

done (1) to clear up more definitely the theory of hardening by heat

treatment, and (2) to ascertain the best heat treatment for the production of an alloy most resistant to alternating stresses. Light Aluminum Alloy Castings.—Tests are being made of different casting alloy compositions, cast in the Bureau's foundry, (1) to

discover alloys which will give better mechanical properties than

those in use at present, (2) to study the effect of heat treatment on

these alloj's, (3) to ascertain the effect of the impurities, iron and

silicon, on the properties of the alloys in the cast form, and (4) to

study the effect of melting and casting temperatures on those properties. To date about 40 heats of metal have been poured and tested

and. the results are indicative of the possibility of obtaining alloys

which are both harder and at the same time more ductile, hence

tougher, than those in use to-day; this is accomplished both by the

choice of a more suitable composition and the application of heat

treatment.

This work is being continued on ever increasing scale, as there

is a strong and growing commercial and military demand for better

casting alloys.

Alternating Stress Tests of Duralumin and of Commercial Light

Aluminum Casting Alloys.—The use of both rolled duralumin and of

aluminum casting alloys in aircraft construction demands a fuller

investigation into the resistance of these alloys to alternating stress than has ever been attempted hitherto. The materials for this work

have been assembled or produced at the Bureau, and many of the

tests made : the more rapid progress of this work only awaits the

completion of the remaining 5 testing machines at the shops.

" The Con^osion of Some Aluminum Alloys.—Tests are being made

and are almost completed of- the corrosion of different compositions

of both rolling and commercial casting alloys in the salt spray test. In connection with (6) below, also, exposure tests in sea water have

been undertaken of rolled duralumin in comparison with steel, copper, and brass. The results of these latter tests will naturally not

be available for several months.

The Protection of Duralumin Against Corrosion.—With the co- operation of the Navy Department and of the Aluminum Company

of America exposure tests in sea water have been planned and are about to be executed of duralumin coated with various types of

paints and varnishes. The results of these tests will indicate how

readily possible the protection of this metal by paint is, and are

desired chiefly for the information of those interested in aircraft

design and construction.

The Constitution and Metallogra'phy of Light Aluminum, Alloys.—

The necessity for clearing up a number of questions relating to the

structure and constitution of aluminum and its light alloys has

become increasingly apparent as a basis for further progress in the

art of the manufacture of the alloys, and has led to the undertaking

of the determination of (1) the structural identity of the constituents of the alloys of aluminum with iron, silicon, copper, magnesium,
BEPORT OF DIEECTOR OF BUREAU OF STANDARDS. 179

manganese, and nickel, and (2) the solubility at different temperatures of these constituents in aluminum in solid solution. Much of

this work is completed and one confidential report (No. V) gives

the solubility curve of CuAl,, the aluminum-rich compound of the

copper- aluminum series. These results, when complete, together

with the data of previous investigators, will practically complete our knowledge of the constitution of the aluminum-rich alloys of these

metals, and will serve to direct further work in the choice and

development of commercial alloys.

The work to date has shown the superiority in strength of both

casting and rolling alloys, of either zinc-copper or magnesium-copper

as an addition to aluminum. The National Physical Laboratory is

studying the zinc-copper combination, as far as rolling alloys are concerned; therefore our further efforts will be to improve the

duralumin type of alloy, either by slight alteration of composition

or by alteration of heat treatment.

The study of quite new rolling alloy compositions is considered

unnecessary foF the present.

One further problem that will be undertaken will be the possiblity

of spot welding duralumin.

At present beams and other structural members of duralumin for

aircraft construction are assembled by riveting. It would be desirable as expediting production of such members to assemble by spot

welding if this process could be shown to produce some reliable

joints.

Magnesium-Aluminum Alloys for Mirrors.

' There is under way an investigation for two branches of the Army,

an investigation of possiblities of producing large mirrors of the

magnesium-aluminum or magnalium type of alloy preserving high

reflecting power and sufficient strength and of nontarnishing properties. Considerable success has been attained.

Investigation of Railway Materials.

Owing to the demands upon the time of those engaged in this

work, made by work of a more urgent nature, there is little progress

to report upon these investigations, which were described in detail

in last year's report. The following are, however, nearly completed

Study of internal transverse fissures in rails ; the heating stresses in car wheels ; the distribution of temperature in cooling rails ; the decomposition of cementite in cast iron by annealing, and the investigation of ingot practice, including chemical and metallographic

surveys of several ingots, blooms and rails made by various processes.

The installation of new apparatus and equipment will greatly facilitate the prosecution of this work.

The Failure of Brass.

Two important phases of this subject are still under investigation.

The thermal expansivities of pure beta and of pure alpha brass

of composition found in heterogeneous alpha-beta brasses have been

determined from room temperature up to 600° C, and a difference

in these expansivities discovered sufficient, if fully effective, to produce moderately large initial stresses in a heterogeneous brass upon

cooling rapidly from the upper tem])erature. The effect of such
180 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

stresses upon the tensile properties of 60 to 40 brasses was studied.

The results of this investigation are embodied in Scientific Paper

No. 321.

Twelve samples of drawn manganese bronze rod have been ex- posed for over a year while under tension, of known value, to cor- rosion by water. The results of these tests will determine the safe

limits of stress allowable in this material when used for construction

purposes such as bolts, and exposed to atmospheric or water corrosion.

These tests are being continued; more test frames are being built

and naval brass will be added as a test material, and the effect of

combined externally applied and initial stress will be studied.

Considerable work has been done in connection with brass car- tridge cases submitted for metallographic examination by Ordnance

Inspection Division and some manufacturers in testing out various

solutions and in determining the effect of other conditions upon the

indications of this test—size of sample, condition of surface, etc. In

addition to the routine examination sufficient work was done to warrant embodying the results in printed form. This work should be

continued when our rolling mill is in working shape and material of

known preparation and physical properties can be readily obtained.

Acceleration Tests for Season Cracking and for Initial Stress.

With the aid of the new drawbench rods will be produced with

varying amount and distribution of initial stress. These will be

tested for both season and accelerated corrosion cracking (in mercury salt solution). The results will define the possibility of season cracking more definitely than heretofore both in terms of initial

stress and of the results of the accelerated corrosion tests. The Elimination of Initial Stress by Annealing.

The object of this investigation is to determine the temperature

limit and periods of annealing necessary for the elimination of initial

stress in different compositions of brasses. In rods of simple section

initial stresses, producing season cracking, are most readily eliminated by the process of springing, such as by rolling in a straightening machine, but this method can not be applied to articles of irregular shape, stampings, etc., for which annealing may be necessary.

Arc Welding.

In cooperation with the Electric Welding Committee of the Emergency Fleet Corporation, an extensive program of investigation and

tests of arc welds of ship plate has been undertaken. Besides usual

tests which will be made by Division VII-1, special study will be

made of the causes of brittleness in such welds and of the means

for producing sound welds. This work is just beginning to get under

way, and materials and welded specimens are being furnished by

manufacturers.

Fusible Metals and Alloys.

The manufacture of fusible plugs.—This investigation is almost

concluded. Some of the final conclusions are

1. For_ casings material only bronzes of one of the following

compositions should be used
REPOET OF DIRECTOR OF BUREAU OF STANDARDS, 181

I. II.

Cu 88 87 Sn 10 7 Zn 2 .5 Pb 1

2. Before pouring on the tin the casing should not be heated to

oA'er 300° C, while the casing should be tinned on the inside before

pouring.

The effect of small amounts of impurities on the melting point of

tin is now being studied. Antimony in small amounts, up to about

0.25 per cent lowers the melting point slightly, while quantities

above 0.25 per cent raise the melting point considerably. The effect

of copper, zinc, and lead is now being studied.

Aluminum Solders.

An investigation of a few commercial aluminum solders, and also

some specially made up at the Bureau, has been completed. The re- sults obtained are:

1. A soldered aluminum joint is rapidly attached when exposed to

moisture, and is disintegrated due to the fact that the soldering alloys are all electronegative to aluminum.

2. Joints made by soldering should always be protected against

this disintegration by either painting or varnishing, except in case of very heavy joints, such as repairs to castings, where corrosion at

the joint surface would be of little consequence.

3. Solders should be applied without flux, and their composition

rnay be varied within very wide limits. The two following general

types are recommended:

Zn. Al.

Sn.

.per cent, .per cent.

15-50.

Remainder.

II

8-15. 5-12. Remainder.

4, The higher the temperature at which the "tinning" is done the

better the adhesion of tinned layer,

5, The joint between previously tinned surfaces may be made by

ordinary methods, and with ordinary soft solder.

Tin Conservation.

All the tin used in the United States is imported, and there appearing a threatened shortage the Bureau has assisted the War

Industries Board, after conferences and extended correspondence

with manufacturers and consumers of articles containing tin, in

making a program of -limitation in its use and development of substitutes. The experimental worlc has followed the lines of finding

suitable solders, reduction of tin in bearing metals, modifying

bronzes, and recovering tin scrap. Suggestions to the Government

departments concerning modification of specifications to conserve tin

haA^e also been made.
182 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Cadmium Solders.

From the investigation as it has progressed so far it was found

that cadmium solders of the following compositions:

I II III IV

Pb 90 80 85 75 Cd 10 10 10 10 Sn 10 5 15

may be used to solder tin plate, terneplate, brass, and copper as the

ordinary tin-lead soft solders. The manufacture and use of the

90-10 mixture is rather difficult, due to the extreme ease with which

it oxidizes in the molten condition. The preferred composition is 80 per cent Pb, 10 per cent Cd, and 10 per cent Sn, and it has been

tried out with success on roofing materials, tin cans, and tests on fireextinguishers and automobile radiators are now in progress.

Bearing Metals.

Service tests of different compositions of bearing metals have been

made with a view of determining the adaptability of certain leadbase babbitts hardened with alkali or alkali-earth metals. It was

found that in some respects they were superior to genuine babbitt

and their use is being recommended in certain cases. The information assembled on this topic and the few tests which

have been made on special bearing metals indicate a need for a systematization of our ideas concerning bearing metals in general, the

advantages and disadvantages of different types, as well as some

more extended study of the behavior of different compositions of

both babbitts and bronzes in service. A circular is in preparation

dealing with bearing metals, and upon its completion a program of

bearing metal investigation will be mapped out.

Metals at High Temperatures,

It is hoped to be able to carry out experiments on interrelations of

stresses and strains and the phenomena of annealing and hardening

including effects of sizes and geometrical shapes, as well as more

thoroughly quantitative studies of mass as related to heating and

cooling rates. Another problem to be taken up is that of the tensile properties of

metals at high temperatures.

The constantly increasing use of metals and alloys at elevated temperatures, such as in turbine blades, pistons, etc., demands a thorough investigation into the physical properties at higher temperatures. Particularly a knowledge of the stresses which will be borne

by metals and alloys at these temperatures without yielding is desired on every hand.

Apparatus has been designed for this work, which it is hoped,

will be continued in the near future.

In a study of the heat treatment of various high-alloy steels, it is

hoped to determine more completely the relations among the alloys

in their effect on iron alone, and to proceed from that to the steels.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 183

In the quenching of steels, quenching data in the literature refer

to " quenching in oil," " in hot water," etc. It is proposed to put all

such treatment in a standardized basis, e. g., " a cooling rate of 93°

C. per second through the transformation range," etc., such data being obtained by use of the Einthoven galvanometer. Studies of

grain size, hardness, and difference between inside and outside of

specimen will be included.

The quenching speeds of various quenching media are also to be

studied, to add to the somewhat meager data now available. The

conditions which make for deformation of long, slender rods in

quenching will also be studied.

Copper Plugs for Testing Cartridge Powders.

At the request of one of the powder companies the preparation,

manufacture, and testing of copper plugs for control of cartridge

'powders is being planned. It appears that the uniformity of these

plugs is very uncertain and the standard variable. It is probable

that greater attention will have to be paid to grain size, conditions of

annealing, freedom from oxide, and other factors.

Metals for Instrument Parts.

A study is being inaugurated of the composition and thermal treatment of metals suitable for certain aeronautical instruments, such as recording barometers, altimeters, etc., with the object of diminishing

the elastic aftereffects which are usually so troublesome.

Preparation of Metal Specifications.

In addition to the specification AVork of the American Society for

Testing Materials and of the International Aircraft Standards

Board, the Metallurgical Division has assisted the several Army and

Navy teclmical bureaus and the British Imperial Munitions Board in

drawing up metal specifications, and a great deal of testing and

experimentnl research has been carried out in connection with defining and fulfilling specifications. This Avork has necessitated inmimerable conferences Avith military officers and has been imdoubtedly

one of the most useful phases of this year's work, as it certainly is one

of the nlost far-reaching.

From our experience the past year it would seem wise to endeavor

to establish a single board for metal specifications for specifications

for the Army, on which the Bureau of Standards should be represented ; there is at present considerable duplication of effort and con- fusion and some of the militar}^ departments need the advice and

experimental facilities the Bureau of Standards can offer.

A very comjDlete set of American metal specifications was furnished the French War Ministry's Committee on Metallurgical

Standards.

METALLURGICAL CHEMISTRY.

(Preparation of metals and alloys from their ores ; development of analytical methods

for iron and steel ; and preparation of pure metals.)

Electrolytic Carbon Method.

The method as outlined in last year's report has been further improved and simplified. A special procedure for determining elec-.

trolytic resistances has been developed, in which use is made of commercial 25 or 60 cycle alternating current in connection with the
184 BEPORT OF DIRECTOE OF BUREAU OP STANDARDS.

Weibel galvanometer as a zero instrument. This method has proved

much more satisfactory and is much simpler than the high frequency

alternating current generator and telephone as zero instrument formerly used. A simplified gas absorption vessel with an adjustable

cell constant replaces the fragile absorption apparatus used last year

this has the advantage over the latter of robustness and of being

easier to build and easier to keep in working order. An improved

chart for reading carbon percentage from the observed resistance

and temperature has been devised. This replaces cumbersome tables

and series of curves previously used for this purpose, and at the same

time is more accurate. It is believed that this apparatus is now in its

final form, and a set of 6 outfits for commercial use is being built.

By this method an accurate determination of carbon in steel can now

be made in 4:^ minutes.

Rapid Determination of Carbon in Steel by the Barium Carbonate

Titration Method.

. Means for increasing by 50 per cent the output of work when using

this method are described in a paper in the Journal of Industrial &

Engineering Chemistry. This paper describes the investigations

made at the Bureau for increasing the speed of this method without

much sacrifice in accuracy.

Nitrogen in Steel.

Several experimental forms of apparatus for the absorption of the

nitrogen of this method have been built and tried. The most promising form is a steel test tube cooled by water jacket at the top and

heated b}^ an electric furnace to 800° to 900°. This tube incloses a hard glass test tube which contains a calcium inclosed in another iron

tube. The space between the scale and glass tubes is evacuated to

'

20 to 30 millimeters before heating, and the collapsing of the glass

tube is thus prevented; the glass tube is evacuated to 0.01 to 0.001

millimeter before heating. This apparatus is joined to the gas

burette containing the nitrogen and to a McLoed gauge and the

absorption of the gas followed by change of pressure. One hard

glass tube serves for many determinations.

Goeren's Method for Determining Gases in Steels.

An electric vacuum furnace for this work, with carbon resistor

and having special features, is now about complete in the shop. A

satisfactory new form of sample-collecting mercury pump has also

been built and fully tested. The pump originally intended for this

work has undergone several modifications in the glass-blowing shop,

and it is hoped that this will now be satisfactory. Several practical

applications of this method of determining gases in steels are indicated by recent metallurgical problems brought to the Bureau by military departments of the Government and by commercial firms, and

it is expected that much progress will be made in these studies during the coming year.

Determination of Gases by the Goutal Method.

Before completing the intended paper on this subject announced

in last year's report, it was thought advisable to check some of the

results previously obtained, using specially prepared reagents and
REPOET OF DIEECTOK OF BUEEAU OF STANDARDS. 185

extra precautions. The results of this additional work fully con- firmed the earlier conclusions.

Critical Study of the Ledebur Method for Determining Oxygen in

Steel.

In this case, also, it was thought desirable before publishing the

paper to make some searching investigation of certain sources of

error, which work required several weeks. The work is now considered complete and the paper is in the, hands of the Bureau Editorial Committee.

Oxygen Content (by the Ledebur Method) of Steels Deoxidized in

Various Ways.

The work referred to in last year's report has been completed as

to oxygen determination, and physical tests of this steel so prepared

are about to be made. The chemical work indicates that the various

methods of deoxidation used—namely, ferromanganese, ferrosilicon,

aluminum, and titanium—have yielded steels with oxygen contents

nearly identical, as shown by the Ledebur method.

Equilibrium Between Iron Oxide, Carbon, and Hydrogen.

The work on the Ledebur method, already referred to, made neces- sary an investigation of certain questions connected with this equilibrium. This work has now been completed and a paper describing it is being prepared. As a result of this investigation it is shown that

carbon alone (as iron carbide in this case) reduces ferrous oxide at

800° to 900°, with formation of carbon monoxide and dioxide; as soon as hydrogen is introduced there is a partition of the reducing

action between the hydrogen and carbide and the proportions of the

reduction products (carbon dioxide, carbon monoxide, and water

vapor) formed vary with the rate of passage of the hydrogen. With

very low rates not more than 20 per cent of the iron oxide is reduced

by that gas ; a rate of not less than 4 liters per hour is necessary to

effect a 90 per cent reduction by hydrogen alone. This investigation

showed among other things, that the rate of hydrogen passing in

the Ledebur method should not be less than 40 liters per hour.

Determination of Carbon Monoxide as Obtained from Steels.

, Carbon monoxide is an important constituent of the gases extracted

from steel when this metal is melted in vacuo. Certain hydrocarbons,

produced by secondary reaction, are also present in these gases. Consequently, in order to determine carbon monoxide in such mixtures

it is desirable to find a combustion method which will burn the car- bon monoxide without affecting the hydrocarbons present. Tests

have been made of a method using copper oxide at 250° as oxidizing

agent, and it has been shown that fractional combustion of carbon

monoxide is successfully effected in this way, provided unsaturated

hydrocarbons are absent. Absorbents for the latter are now being

investigated and it is believed that suitable ones have been found. A

special form of electric furnace for heating several copper oxide

reaction tubes in series has been designed and used for this work.

Special Alloy Work.

The apparatus for producing electrolytic iron and melting it in

vacuo has been moved to the new chemistry building where it has

been installed with improvements and additions and is now produc-
186 REPORT OF DIRECTOR OF BUEEAU OF STANDARDS.

mg. The vacuum furnace for producing large ingots has been improved until it is now satisfactory. Difficulty was experienced in

making crucibles of the tall narrow form wanted for melting pure

iron-carbon alloys, this being due to the fact that no clay or other

binder containing silica could be used for bonding the pure magnesia, on account of the contamination by silicon of melts made in

crucibles so bonded. This difficulty was not met in our previous

work where smaller quantities of iron were melted. Magnesia, imfortunately, has little strength of high temperatures, so that a bond

of some kind is necessary. Our investigations have shown that

alumina can probably be used successfully as a binder and careful

analyses have thus far shown no contamination of the melts by re- duced aluminum. Crucibles are either molded under pressure and

placed in supporting crucibles of Acheson gi^aphite or a lining of

the magnesia-alumina material is ranjmed into an Acheson gTaphite

crucible. Several large vacuum melting ingots have been produced.

The present procedure for making" such ignots, devised during the

past few months, consists in melting in a gas-fired furnace the electrolytic iron mixed with enough pure carbon to saturate it (in order

to secure a low melting point alloy). The crucibles used for this

work are commercial plumbago crucibles protected by a rammed-in

liner of pure Acheson graphite powder bonded with glucose. The

iron-carbon alloys so produced are melted in the vacuum furnace,

together with enough pure iron and iron oxide to lower the carbon

cortent to whatever is desired.

Some method of premelting the electrol3^tic iron before melting

in the vacuum furnace, such as that just described, is very desirable,

since not enough of the unmelted electrolytic iron can be introduced

at one filling of the vacuum furnace to make an ingot of the size

wanted, and the vacuum furnace can not be opened for refilling until

it is cool, which is wasteful of time and current.

As soon as a sufficient number of iron-carbon and pure iron ingots are produced these will be used as starting materials for the manganese-iron-sulphur carbon investigations described inider the section

of this report: "Manganese and Deoxidation Eesearches."

Improvements in the Bureau's methods of making pure magnesia

with a view to svibstituting the now very expensive acetic acid are being investigated with some promise of success. Pure Aluminum.

Eesearches at the Bureau of a military character have shown the

possibility of obtaining remarkable properties in the metal and its

alloys by the use of aluminum purer than that commercially supplied. Accordingly, special apparatus has been devised and materials have been assembled at the Bureau for carrying on an investigation with this end in view. The apparatus for electrolysis

consists of a steel crucible lined with a pure Achfeson graphite liner

for holding the electrolyte and a gas furnace for keeping the contents

of the crucible molten. A movable Acheson graphite rod set axiallj''

in the crucible serves as anode, and the crucible is arranged so the

aluminum can be tapped off as desired. As soon as some uncompleted

shop work is done the preparation of aluminum will be begun.
BEPOBT OF DIKECTOE OF BUEEATJ OF STANDARDS. 187

Plans have been devised for making still purer alumina if this is

found to be desirable.

Manganese and Deoxidation Researches.

The proposition for an investigation of the use of manganese and

other agents for the deoxidation of steel, with a view to conservation

or substitution of manganese, with proposition originated in this

Bureau as being very desirable from a military point of view, has

been much extended. The Bureau of Mines and the National Eesearch Council are now cooperating on this problem and the co- operation of other agencies is being enlisted.

As has already been emphasized in -special reports on this subject,

manganese is an essential element in present processes of making

steel and the domestic supply of manganese ores is so inadequate that

there is serious dependence on foreign sources, which is dangerous

in war times. Hence, conservation of, and substitutes for, this metal

are highly desirable.

Oil-Proofing Concrete Liners.

At the request of the Emergency Fleet Corporation work has been

started with a view to finding means for rendering concrete ships

impervious to light mineral oils. The methods suggested consist in

covering with lead sheets, cast lead, sprayed lead, shellac, neat cement

shot from a gun, barium sulphate, sodimn silicate. Experimental

investigations fire being started on what seem to be promising lines.

FOUNDRY.

(Experimental and practical castings of metals, including special alloys for research and specialized purposes and practical foundry research.! Foundry Investigations and Tests.

The investigation of casting methods and types of test bars as carried out by five foundries in an identical program and using metal

cast in one heat has been completed and the physical properties of the

brass determined. The metals used were Government bronze (88 Cu,

10 Sn, 2 Zn) and a modification containing 88 Cu, 8 Sn, 4 Zn. The

residts are ready for publication.

The effect on the physical properties of small additions of various

metals to Government bronze is being studied systematically, and

similarly for addition to aluminum. Special alloys suitable for

castings are also made and examined as requested.

The type of test bar for different nonferrous alloys is being inA^estigated.

The foundry serves the Bureau and the research laboratories of

other departments and Washington institutions in preparing a great

variety of kinds and types of metal and alloy castings. The new

quarters have greatly extended its possibilities for service and

research.

Sand Investigations.

This question has been taken up anew with regard to (1) reclaiming " burnt " steel foundry sand, (2) the production of artificial sands

and establishment of standards, and (3) development of tests of sand

qualities. The first has already given promise of demonstrating to
188 BEPORT OF DIEECTOE OF BUEEAU OF STANDAEDS.

some foundries the reclaiming of 90 per cent of the sand at a reasonable cost. The Washington Navy Yard foundry and others are co- operating in this work.

Experimental and Practical Casting.

The foundry has made the following castings for experimental

and special technical uses.

Metal. Castings. Patterns. Weight

255

241

1,701

16

10

1 21

13

76

84

334

14

5

13

8

Eg.

1.38. 63

420. 75

1,244. 50 12.00

132. 00 3S.70

6. 66

39 50

424. 53

Brass

Tin

Total .' 2,249 516 2, 452. 27

9. CERAMICS.

[Development of new uses for clays; replacement of imported by native materials; improve- ment of quality of products; designing and conducting tests for quality; standards of quality; routine tests for Government purchases; acting in advisory capacity as to conservation of

fuel and transportation for ceramics ; acting as clearing house for collection and dissemination of information.]

CLAY PRODUCTS.

(Investigation of building tile, and other clay products; industrial and educational

cooperation ; design of new equipment ; development of enamels for iron and copper

studies of kiln efficiency ; new uses for clay products ; improvement of quality of products ; manufacture of certain porcelains for Government use.) Investigation of Building Tile.

The report covering the investigation of building tile is in the

hands of Publication Committee. This report presents the results of

compression and absorption tests on several hundred hollow building

tile. The strengths in compression varied from 4,000 to over 10,000

pounds per square inch of net section of tile when tested on end,

and approximately from one-half to three-fourths of these amounts

when tested on edge or flat. The tile absorbed from 4 to 11 per cent of water. The relative

absorption power of a tile gives a fair indication of its strength, a

vitrified tile absorbing least water, being hardest, and carrying the

greatest compression load.

Industrial Cooperation and Dissemination of Technical Information

Concerning Ceramic Products.

Cooperation is being maintained by the Bureau with many concerns and individuals with reference to industrial problems, both by

correspondence and consultation. The volume of this work is constantly growing larger. Extensive cooperation is being conducted

also with a number of technical organizations, such as the National
EEPOBT OF DIRECTOR OP BUREAU OE STANDARDS. 189

Brick Manufacturers' Association, the National Hollow Tile Manufacturers' Association, the National Terra Cotta Society, the Refractories Manufacturers' Association, the United States Potters' Association, the American Society for Testing Materials, the American

Ceramic Society, etc. Design of New Equipment.

All of the drawings for the nqw Idlns, furnaces, and machinery

to be erected in the new ceramic laboratory now under construction

at Washington have been practically completed.

Enamels for Copper.

Work has been begun on enamels for copper as applied to dials to

watches, scientific instruments, etc., for the purpose of displacing the

enamels formerly imported from Germany.

Iron Enamels.

Two papers have been completed dealing with the subject of vitre- ous enamels applied to cast iron and steel. Since the literature dealing with this important industry is exceedingly meager, these contributions, which are voluminous and partake of the character of

textbooks, should prove of considerable value to manufacturers and

others interested in enameling.

Efficiency Studies of Ceramic Kilns.

A paper has been completed dealing with the study of the heat

losses determined on a tunnel kiln and a down-draft kiln fired with

producer gas.

The Use of Clay in Chemical Reactions.

Advice as to the best methods for selecting clays especially active

in promoting certain gas reactions has been submitted to military

authorities at their request.

Clay Aggregate for Concrete.

Work has been done in the production of a hard-burned but light

clay aggregate for .concrete for a special purpose with very satisfactory results, resulting in a concrete which is strong though of low

lump specific gravity. Similarly, sand from crushed hard-fired clays

was found to give good results.

Cooperation with the War Industries Board.

The services of the Ceramic Division have been called upon by the

board upon the questions of replacing clays formerly imported from

Eu.rope, the proposed embargo upon English kaolins and ball clays,

and the most economical distribution of refractories from the iron,

steel, and coke industries.

Cooperation with the United States Fuel Administration.

Assistance is being rendered the Industrial Furnace Section in con- nection with a campaigTi aiming to bring about greater fuel efficiency

in the firing of ceramic kilns, glass furnaces, etc.
190 KEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

Cooperation with the United States Potters' Association.

The Bureau has arranged with this association for an extensive

stud}- of possible combinations for wliite-ware pottery, using American clan's exchisively. This work is to be done at 11 potteries in

East Liverpool, Ohio.

Clay Survey.

Standardized tests of clays have been worked out for use in the

general survey of the kaolin and cla:y resources of the United States,

conducted by cooperation with the National Research Council, the

United States Geological Survey, the Bureau of Mines, the Association of State Geologists, different State surveys, and the ceramic

schools.

Pottery Saggers.

In the manufacture of pottery the breakage of the refractory

containers (saggers) used to protect the ware during burning is a heavy item of expense. This is still more true in the manufacture

of hard fire porcelain. By improving the quality of these refractories the manufacturing losses can be decreased very gi'eatly. Work

has been done in this connection, and the load carrying capacity of

the saggers improved decidedly. These studies are being continued

with reference to containers for special hard fire products like spark

plugs, grinding wheels, etc. Refractories for Marine Boilers.

A new type of refractory combining the qualities of porosity, light

weight, and high refractoriness has been worked out and the results

submitted to the Navy.

Work on Refractories.

The work done in the past justified an attempt to prepare general

specifications for clay fire brick. As a result this was done and the

pi'oposed requirements for four classes of refractories submitted to

the Refractories Manufacturers' Association, the Mellon Institute at

Pittsburgh, and others for criticism. Checkwork done at the Mellon

Institute has shown the specifications to be fair and reasonable.

" Specifications for silica refractories are likewise being prepared.

A technologic paper on the subject of the sizing of calcined clay

(grog) used in the building of refractory bodies has been published.

It was shown that the density and strength of fire-clay materials

hinge to a considerable degree upon the proper combination of sizes

of grain.

Another technologic paper dealing with the structure and the

manufacture of silica refractories is being printed. Similarly, a paper giving the results of tests upon 60 brands of American fire

brick has been completed.

Refractor}^ Porcelain.

Continued progress has been made in the development of refractory porcelain, formerly obtained from Germany, and the technique

has been perfected so that it has been possible to make pyrometer

tubes over 7 feet long.
EEPOBT OF DIBECTOE OP BUEEAU OP STANDARDS. 191

Spark Plugs for Airplanes.

In cooperation with the Washington laboratory of the Bureau of

Standards an extensive research was undertaken for the purpose of

producing a porcelain-like body which shows a high electrical resistance at temperatures up to 600° C. and at the same time good

mechanical strength when subjected to shocks and sudden heating

and cooling. Such a body has been produced and is now being

worked commercially. It has been shown in this work that the

presence of feldspar is particularly injurious to the development

of high electric resistance at the temperatures to which spark plugs

are carried. This mineral constituent has therefore been eliminated.

At the same time, the content of sillimanite in the finished porcelain

has been greatly increased by the use of suitable calcines.

Crucible Clays.

Additional work has been done in the study of suitable clays by

making up several sets of crucibles from different mixtures of typical

clays and graphite. The most promising compositions resulted in

a life of the crucible yielding from 25 to 30 melts.

Architectural Terra Cotta.

A large majority of the manufacturers of this decorative building

material have submitted samples of their product to the Bureau for

the purpose of determining the general p)hysical properties. These

samples were in the form of a specially made open box and also in

the form of pieces left over from structures built by the manufacturers. There were thus obtained for testing, pieces especially

made for testing purpose and pieces made in the ordinary course of

manufacture. These were tested for strength in compression and

their ability to withstand both natural and artificial freezmg (produced by the crystallization of sodium sulphate) . In addition the

absorption at various periods was determined.

Wliile in general the results show that increased strength is accompanied by decreasing absorption and increasing ability to withstand

freezing, yet there were such exceptions to the statement that further

work is necessary, especially in investigating the burning of the

clays used. It was gratifying to find, by the compression tests, that

practically all the pieces were able to withstand stresses greater than

those which would be imposed upon them in structures. It was

also found that test pieces specially burned for testing purposes, do

not frequently give a true indication of the properties of the material

burned as a piece for structural purposes.

Hard-Fire Porcelain. , The study of this subject has been prosecuted vigorously and a

large amount of data has been obtained. Over 120 porcelain compositions have been made and tested. It has been found possible to fix

the limits of composition for the several types of porcelain and to

demonstrate the effect of the reducing or oxidizing conditions during

firing. Particular attention has been paid to the subject of chemical

porcelain and a new type of body produced which possesses valuable properties. Cooperative work in this connection has been done
192 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

with two manufacturing concerns. In one case it was found possible to improve the quality of the product decidedly as well as to

increase the yield of the first-class ware.

Particular attention has been given to the development of a true

hard-fire porcelain from American materials and assistance has been

rendered prospective manufacturers to make the new industry possible. One pottery of this type is already in course of construction

and the new development should result in the elimination of such

porcelain imported formerly from Austria and Germany.

GLASS.

(Examination of raw materials for glass and for glass pots; development im- proved methods for making glass pots ; design of plant for manufacture of glass pots on large scale ; manufacture of a particular quality of optical glass on large scale for Government use.) Examination of Raw Materials for Optical Glass Manufacture.

A large number of samples of sand, potash, soda ash, limestone,

lead oxide, barium carbonate have been analyzed with reference to

their content of impurities which are objectionable for the production

of fine optical glass.

Casting Process.

Owing to the desirability of replacing expensive hand processes

by quicker methods the question of making glass pots, crucibles, etc., by pouring the liquid mass into plaster molds was taken up and

solved successfully. Owing to the heavy and massive articles thus

to be made special mold constructions and means of handling had to

be worked out. A plant for casting heavy ware was erected which is capable of producing 2 to 3 glass pots per day. The economic

phases of the process were studied in detail and drawings prepared

showing the arrangement of machinery and accessory apparatus, to- gether with a description of the manipulations involved. This information has been given to 5 producers of glass pots, and is available to any concern which is interested.

Glass Pots.

One of the fundamental problems connected with the production

of optical glass is the use of pots resistant to the corrosive action of

these glasses and very low in iron content. For this reason the

clay products laboratory has devoted considerable attention to this

work with the result that a very satisfactory composition of the

nature of porcelain has been worked out. which resists even the violent corroding action of the heavy barium glasses. Since the commercial pots are entirely unsuited ^or this purpose, instructions con- cerning the composition and making of the porcelain pots thus developed have been imparted to 5 commercial concerns, of which 3 are now producing them. These data have been published also in

articles appearing in Metallurgical and Chemical Engineering and

the Journal of the American Ceramic Society.
.EEPOET OF DIRECTOR OF BUREAU OP STANDARDS. 193

It has been found possible also to reduce the cost of the porcelain

jDots by making use of the bisque waste from white ware potteries,

which formerly was thrown away or sold at a negligible figvire.

Since this material makes up practically one-half of the composition

the cost of the white glass pots is aliout the same as that of the

ordinary ones. The porcelain pots are being ma,de at the Pittsburgh

laboratory both by the usual hand molding and the casting methods.

The porcelain composition is being used also for the stirring rods

required to mix the fused glass.

Optical Glass.

The optical glass laboratory erected during the summer of 1917

is now in operation and during the year 200 melts have been made

in large pots. Eight gas-fired furnaces are in operation, with the

necessary complement of heating, softening down, and annealing

furnaces. About 5 melts of glass are being made per week. The

processes of manufacturing optical glass have been mastered in practically every detail and 7 types of optical glass have already been

made varying in index of refraction from the lowest to the highest

A^alues.

The problem of surfacing glass has also been studied and a set of machines for grinding and polishing has been installed. Much

study has been given to the problem of rapid though rigid inspection

and apparatus installed at the Pittsburgh laboratory, at the plant

of the Pitsburgh Plate Glass Co., and of the National Optical Glass

Co., at Washington, Pa. The Bureau of Standards laboratory advocates inspection through the edges of the glass plates as being more

rigid and detecting imperfections, such as striae, which readily

escape observation when the glass is examined flatwise.

The Pittsburgh glass laboratory ships monthly more than a ton

and a half of rigidly inspected glass. For the purpose of utilizing

small pieces of good glass a press has been set up for making the

blanks of small lenses. Additional presses for making prisms and

other blanks are about to be installed. In addition to the productive

work, researches in connection with improvements in the manufacture of optical glass are being conducted constantly and the mass of

information thus accumulating is certain to be of great value in es- tablishing all the details of production on a firm basis, a condition

which will assist in making this country independent of any German supply of optical glass.

Cooperative work was conducted with 3 commercial plants with

reference to the production of optical glass and with 6 factories in

connection with manufacturing problems relating to staple articles.

Work has also been done on special colored glasses for special applications and on the problem of producing glass for artificial eyes,

all of which has been successful.

All plans and designs for the new glass laboratory now being

built on the grounds on the Bureau of Standards at Washington

have been completed and the contracts signed.

86986—18 13
194 KEPORT OF DIRECTOH OF BUREAU OF STANDAHDS.

LIME, GYPSUM, ETC.

(Investigation of proper quality of lime for different chemical industries; development of standard specifications for lime and gypsum as building materials ; laboratory

and technical work to determine the qualities of the product ; development of methods

of testing for plasticity, sand-carrying capacity, soundness, etc. ; routine tests of material

purchased by the Government ; consultation as to the availability of different qualities of material at the markets and for the purpose specified ; determination of the value

of an addition of hydrated lime to concrete.)

The Use of Hydrated Lime in Concrete.

The use of hydrated lime as one of the ingredients of Portland

cement concrete lias been rapidly increasing during the past few

years. From observations made under working conditions some engi- neers and contractors make the following claims as to the benefits

derived through this practice: Concrete containing hydrated lime

requires less water for mixing, is more plastic, separates into gravel

and mortar less readily, flows down chutes and into forms more readily, is stronger, denser, and more impermeable to water than concrete

not containing hydrated lime.

Since very little experimental work had been done for the purpose

of determining the validity of these claims, it was decided to conduct

an extensive investigation with this object in view.

Laboratory work in this investigation has been in progress for two

years. The following physical properties of concrete have been

studied: Compressive strength, bond strength with steel, expansion

and contraction with time, amount of water absorption, density of

the fresh concrete, modulus of elasticity.

The results have not been completely analyzed on account of the

difficulty of choosing the proper basis for comparison. On this

account the general tendencies noted in the annual report for 1917

were inaccurate in degree and the statements therein given are to be

modified to agree with the present understanding of the effect of

different factors upon properties of concrete. At the present time

the most comprehensive and logical basis of comparison seems to be a

factor known as the water-ratio. This factor, which bears a mathematical relation to compressive strength, is found by dividing the

volume of water by the volume of cement used in the concrete. Using

this factor as a basis the results show that concrete containing

hydrated lime is on the average stronger than concrete without lime,

the increase in strength being the more pronounced in air storage

specimens and in concretes having the higher water-ratios. Kesults

for the other properties mentioned have not yet been compiled for

comparison in this manner.

In regard to the remaining properties, it may, however, be said

that the laboratory specimens having all been made with great care did not give so large a degi'ee of difference in properties due to the

introduction of hydrated lime as is claimed by contractors and engi- neers to occur under the conditions of construction work. Moreover,

the laboratory results told nothing of the effect upon time of flow

down chutes, plasticity, degree of segregation, etc. For this reason it has been decided to conduct an extensive investigation under working conditions. Preliminary work will be con- ducted by use of an experimental concrete plant now erected. Following this, observations will be made at various large construction

works.
BEPOET OF DIBECTOR OF BUREAU OF STANDARDS. 195

Properties o£ Hydrated Limes.

The commercial product known as hydrated lime has been upon

the market comparatively few years, and although it is manufactured by about 85 companies no complete determinations of its physical and chemical properties had been made. About all that has

been known concerning this product is that it has replaced quicklime

for a number of the purposes of construction.

During the past three years physical and chemical tests have been

made upon 54 samples of hydrated lime collected from all parts of the

country. The data affords a fairly complete knowledge of the properties of this product valuable alike to producer and consumer, en- abling them to improve the quality and to write accurate specifications.

Plasticity of Hydrated Limes.

Lime manufacturers have become accustomed to use the term plastic lime as meaning a lime producing a paste when slaked and allowed to stand with water, this paste being capable of retaining its

water long enough to be spread easily and smoothly upon an absorbent surface such as is provided by the brown coat wall plaster.

Under these conditions the rate of change of plasticity is more

important than the absolute plasticity.

The Bureau has designed an instrument now known as the Emley

plasticimeter for the purpose of measuring the relative rate of change

in the forces acting between a paste and a trowel while the paste is

drying out upon an absorbent surface.

By this means lime pastes have been classified into plastic and nonplastic pastes, using the manufacturers' definitions. About 25 hydrated limes from all parts of the country have been tested.

A mathematical definition of plasticity as applied to the use of

lime was not obtained and until considerable more work has been

done along this line, it will be necessarj^ to use the trade definitions.

Sand-Lime Brick.

The sand-lime brick industry has been seriously hampered during

the past year by inability to obtain lime and coal when needed. The

principal technical problem at the present time is hence the saving

of coal required to produce steam in the steaming process. On ac- count of lack of help the Bureau has not yet been able to attack this

problem.

Another important problem is the production of brick of better

quality. This involves quality and proportions of the materials,

methods of molding, and steaming. One phase of this problem has

been attacked, namely, the effect of the size of grain of the sand upon

compressive strength of the brick. Three sizes of sands were mixed

in 63 different proportions. These sizes were 10 to 40 mesh, 40 to

100 mesh, and 100 to dust. The strongest brick were obtained with

mixtures of 30 to 60 per cent 100-to-clust sand, 40 to 70 per cent 10

to 40 mesh sand, and to 20 per cent of 40 to 100 mesh sand. The

strongest specimens (li-inch by 2|-inch cylinders) had a compressive

strength of 6,500 pounds j^er square inch.

Gypsum Products.

No extensive determinations have been made of the properties of

gypsum products from mills in this country. There exist no standard

specifications for these products.
196 REPORT OF DIRECTOR OF BUREAU OP STANDARDS.

In order to obtain the necessary knowledge it has been decided to

conduct an extensive investigation upon gypsum products from vari- ous parts of the country. The preliminary work is now in progress

and consists of heating a very pure gypsum to different temperatures

and determining such properties as compressive and tensile strength,

time of set, optical properties, etc. The data obtained will afford first-hand knowledge of the quality

of the products and enable the Bureau to cooperate with the organizations interested in drawing up standard specifications.

Dolomite as a Refractory.

In many metallurgical furnaces it is necessary to use brick which

are chemically of a basic nature. Magnesite brick are so used at

the present time but are very high in cost. There are large deposits

of dolomite all over the country. If the proper flux could be found

to bind and coat dolomite particles so as to prevent rapid hydration

of the lime, a dolomite brick could be produced which would replace

to a great extent the magnesite brick.

Some work was done along this line but it had to be discontinued on account of lack of help and was not carried out to a

practical conclusion. A number of different compositions were used.

The most promising composition will be described.

The brick was made of two parts, one of burned material known as grog which formed the skeleton of the brick, the other part of un- burned material known as binder. The grog portion was made by

burning to a temperature of 1500° C. a mixture of 90 per cent dolomitic hydrated lime and 10 per cent of a special flux, the mixture

being ground to pass a 100-mesh sieve. The flux was produced by

burning to a temperature of 1400° C. a mixture of equal weights of

dolomitic hydrated lime and impure bauxite, ground to pass a 100-

mesh sieve. The binder consisted of 85 per cent of the dolomitic

hydrated lime and 15 per cent of the flux.

The brick were made by mixing thoroughly 70 per cent of the grog

(of 6 to 40 mesh size) with 29 per cent of the binder and 1 per cent

of iron oxide, and molding in a power press. The brick was dried

in an oven at 110° C. and burned to a temperature of about 1500° C.

and Seger cone 20.

The specimens molded with a pressure of 2,500 pounds per square

inch appeared to be most satisfactor3^ Some of the specimens when

placed in water resisted hydration for 6 days. Others when left

in the open air in the laboratory remained very hard and did not

begin to hydrate until they had stood for 6 months. These results

would indicate that such a bricl^ placed in a furnace would resist

hydration and disintegration for a much longer time.

Hydrated lime was used because a large supply was on hand at

the laboratory. For the grog portion and for the flux the hydrated

lime could be replaced by ground dolomitic limestone. The binder

must be a finely ground material which will not hydrate and cause

disintegration in drying and burning. The possibilities for this

purpose are hydrated lime, ground dolomitic limestone, ground slag,

Portland cement.

The question of costs has not been gone into nor has any attempt

been made at a practical application of the method, but the results

indicate that the problem can be solved by sufficient experimental

work.
III. THE OFFICE.

[Office management;' finance and accounts; personnel actions and records; editorial work,

printing, publicity; property and stores, including distribution and accounting; mail and

files, including test records; scientific library; dispatch, including all forms of trans- portation and communication; purchasing; stenography, typewriting, and duplicating;

and information service.] The Office Division handles the general business of the Bureau.

The aim is to leave the scientific divisions free for the scientific and

technical work, although some dovetailing of functions is essential.

The office is organized with 10 sections, with representative clerks

assigned for the office work for each division. These sections are designated as follows : administrative, finance, personnel, publicity,

property and stores, mail and files, library, dispatch, purchases, coi^ying (detailed to division offices), information. Each section has a

definite function, and it is the aim that each section shall handle all Bureau business which properly pertains to such function. This

IDolicy is equally true of the scientific sections and the sections of the

mechanical plant.

The new policy of providing central office overhead allotment

from all funds permitted prompt expansion and organization of

the office work on a more efficient basis as called for by war conditions. The loss by military demands of nearly all clerks in the 10 sec- tions of the office resulted in hardship and temporary ineffectiveness,

which careful reorganization and improved methods have partially

remedied. In several sections it is not yet possible to render the most

effective service because of the inexperience of new clerks and the

highly technical character of the subject matter of the Bureau's work.

Eapid progress, however, has been made in bringing the office work

to the new standard of efficiency demanded.

It is a pleasure to refer to the unstinted efforts of the entire office

force to carry the expanded work under the trying war-time conditions of the past year. The spirit of service has been excellent with

no trace of the spirit of mere timeserving. The gratifying work of

the past year toward winning the war was made possible by the

enthusiastic support of the entire office staff.

FINANCE.

[Records of appropriations and allotments; order and voucher accounts; balances; reim- bursements; checking commercial, construction, and travel expense vouchers; pay rolls; test fees; fiscal statistics.] During the year this section has handled accounts aggregating

$3,414,345.50. In addition to 26 direct appropriations for the

Biireau, $1,395,000 was assigned by the President to the Bureau

from the National Security and Defense fund for the purpose of

erecting war buildings to provide additional laboratory space needed

197
198 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

to meet the demands of war problems and for specific researches in

connection with the Avar. Other departments of the Government

allotted $218,000 to the Bureau to cover the cost of special cooperative Avar researches undertaken by the Bureau at their request. The

erection of the emergency war buildings on a cost plus basis necessitated the checking by the Accounts Section of the material and

labor entering into their construction. The personnel was increased

to enable the section to care for the extra financial Avork involved.

A ncAv card accounting system for handling accounts Avas devised

early in the year and assisted greatly in expediting the accounting

work.

A card system is being introduced for pay rolls in connection Avith

the new clerk to be assigned to this work and Avill place this work

on a more efficient basis.

Appropriation Statements.

The following statement shows the amount and object of each appropriation proA'ided for the Bureau for the fiscal year 1918, the disbursement during the 3'ear, the amount of unfilled and unpaid orders

at the close of the year, and the unexpended balance remaining at the

close of business June 30, 1918:

Appropriation. Total appropriation. Disburse- ments. Liability.

Salaries Kqiiipment

General expenses Repairs and alterations Grounds

Hiijh-potential investigation

Testing structural materials Testing macliines

Investigation of fire-resisting properties

Public-utility standards

Investigation of railway materials Testing miscellaneous materials Radio research Color standardization

Investigation of clay products

Physical constants Standardizing mechanical appliances

Investigation of optical glass Testing railroad scales Additional land Radio laboratory Chemical laboratory

MUitary research, 1917-1918 Gage standardization Equipping chemical laboratory

Repairs, power plant

NATIONAL SECtJRITY AND DEFENSE.

Production of optical glass New building

Metallurgical work

Production of fabrics Industrial laboratory Roberts' coke oven Thermite investigation

Total

S348, 900. 00

55,000. 00

35, one. 00 5,000.00

6,000.00

15, 000. 00

a 154, 130. 62 30,000.00

25,000. 00

50,000. 00

15, 000. 00 20,000.00

10,000. 00

10, 000. 00

10,000. 00

5,000. 00 10,000.00

10,000. 00 40,000.00

25, 000. 00

90, OOC. 00

200, 000. 00

b 577, 176. 88

c 226, 138. 00

35,000. 00 12,000.00

75,000. 00 250,000.00

100,000.00

35, 000. 00

925,000.00

5,000. 00 5,000.00

S303, 420. 27

44, 138. 18

27, 000. 00 4,423.19

4, 763. 11 11,189. 45 132,403.33

22,674. 05

22, 255. 75

45, 904. 19

11,495. 78

19,120. 86 8,495.41

8, 358. 54

9, 994. 53

4, 737. 32 9,510.66

9,002.37

28, 557. 71

515,952. 62

10, 639. 23

6, 136. 54

572. 25

1, 232. 13

3,810. 55

21,727. 29

7, 240. 85

2, 731. 68 4,095.81

3, 504. 22

879. 14

1, 474. 33

1,631. 43

3. 00

251. 53 139.49

958. 90

11,442. 29

58,096.28

197,236.48

361,512.41

141,604.47

24, 558. 89

23, 569. 37

319. 55

215,664. 47

84, 533. 53

10,440. 84

11, 870. 00

74,539.86

232, 552. 39

40, 579. 65

326. 75

257, 360. 76 1,929.15

7.00

17

59: 34: 415:2

460. 14

447. 61

420. 35

673. 25

; 547. 71

, 993. 60

699. 39

3,414,315.50 2,118,067.37 972, 063. 09

a Includes reimbursement of 84,130.62.

b Includes reimbursement of S109, 176.88 and allotments from War Department to amount of 3218,000.

c Includes reimbursement of $1,138.
REPOET OF DIRECTOR OF BUREAU OF STANDARDS. 199

The following statement shows the condition of the appropriation

for the two preceding fiscal years at the close of business June 30,

1918:

FISCAL YEAR 1916.

Appropriation. Total appropriation. Disburse- ments. Liability. Balance.

Salaries Eqiiipment

General expenses

Repairs and alterations Grounds

High-potential investigation

Refrigeration constants Testing stnictural materials Testing machines

Investigation of fire-resisting properties

Public-utility standards Railway materials Testing miscellaneous materials Current-meter testing tank

Heating system, north laboratory

Radio research ; .

." Testing railroad scales, etc

Total

S29S, 780. 00

50, 000. 00

27, 000. 00

2,000. 00

6,000. 00

15,000. 00

15,000. 00

100, 000. 00

30, 000. 00

25, 000. 00

25,000. 00

15, 000. 00

20,000. 00 3,000.00

3.000. 00

a 12; 308. 74

40,000. 00

S283, 079. 84

48, 175. 29

26, 645. 24 1,977.78

5,901.11 14,908.67

14,923. 23

99,437. 16 29,899.16

24,888.12

24, 800. 99

14,514. 15 19,999.96 2,998.34

2,520. 54

12,141.49 27,751.80

S406. 43

245. 55 8.10

43. 25

'i27.'53'

59.00

'i75.'5i'

12, 248. 20

687, 088. 74 654,582.87 13,313.57

815, 700. 16

1,418. 28

109.21 14.12

93. 89

48.08

76. 77

435. 31

100. 84

52. 88

199. 01

310. 34

.04 1.66

479. 46

167. 25

19,212.30

a Includes reimbursement of 82,308.74.

FISCAL YEAR 1917.

Appropriation.

Salaries Equipment

General expenses

Repairs and alterations Grounds

High-potential investigation

Refrigeration constants Testing structm'al materials Testing machines

Investigation of fire-resisting properties

PubUc-utility standards Railway materials Testing miscellaneous materials Radio research Color standardization Clay products

Physical constants Standardizing mechanical appliances. .

.

Testing railroad scales, etc

Total

Total appropriation.

S311,720. 00

50,000. 00

28, 500. 00 5,000.00

6,000. 00

15, 000. 00 15,000.00

100,000. 00

30, 000. 00 25,000.00 40,000.00

15,000. 00

20,000. 00

a 15,359. 71

10, 000. 00

10,000. 00 5,000.00

10,000. 00 40,000.00

751,579. 71

Disburse- ments.

,777.80

46, 180. 70 27,382.62

2,612.44

5, 449. 30

14,876.43 14,942.26

98,634. 74

29, 536. 44 24,921.59

39, 627. 27

14, 763. 43

19,903.38

10, 460. 69

8,899.35

9, 973. 39 4,369.12

9,410. 64

35,599. 63

707,321.22

Liability.

83,819. 30

878.35 2,153.80

497. 37

10.16 15.00 635.84

209. 22

103.92 185.40

4,173. 25

992. 10

153.86

416. 07 4,400.37

18,644. 01

Balance.

821,942.20

239.03

233. 76 53.33

113. 45

42. 71 729.44

.254.32 78.44

268. 81 51.11 96.67

725. 72

108. 57 26.61

477. 02

173. 29

25, 614. 48

o Includes reimbursement for 85,359.71. Summary of Tests.

The work of the Bureau involves, among other things, a large

amount of testing of standards, measuring instruments, and materials. It involves primarily the investigation of the scientific principles underlying the tests, the studying of existing methods, and the

development of new standard tests of determinate accuracy. For

each test a reasonable fee is charged, except when made for the

National or State Governments.

During the fiscal year 1918 the Bureau made 312,563 tests and inspected 3,727,352 incandescent lamps at various factories for other

departments of the Government. Of the total tests, 31,571 were for
200 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the Government and 280,992 for the public. The testing was distributed as follows, according to the nature of the tests: Length

measures, 1,064; mass, 1,815; capacity, 504; temperature, 282,094;

hydrometry, 2.088; miscellaneous^ 30; optical, 2,126; time, 2,064;

electrical, 1,910; photometry, 4,874; chemical, 4,589; engineering

(miscellaneous), 740; engineering (instruments). 202; structural materials. 3,423; paper and textiles, 4.618; metallurgical, 34; aeronautical instruments, 388. The estimated fees amount to $102,878.63, of

which $16,626.97 was collected on account of tests for the public.

The fees noted for Government tests are included merely for comparison purposes, as no charge is made for tests performed for the

National or State Governments.

Number and value of tests completed, fiscal year ending June 30, 1918.

Nature of test.

For Government. For public. Total.

Number. Value. Number. Value. Number. Value.

790 $1,013.35 274 S420. 75 1,064 81,434.10

(i61 606. 20 1, 1.54 555. 20 1,815 1,161.40

363 3.54. 00 141 163. 70 504 517. 70 2,069 3,131.70 57 289. 50 2,126 3,421.20

1,440 1, 348. 70 648 855. 10 2,088 2, 203. 80

16 36. .50 14 25. 50 30 62.00 Time 2, 062 217. 70 2 7.00 2,064 224.70

8,021 1, 874. 78 274,073 3,014.00 282, 094 4, 888. 78 1,344 4, 611.55 566 2, 937.47 1,910 7, 549. 02 Photometry a 4, 750 19, 174. 70 124 255. 00 4,874 19,429.70

901 4, 463. 23 3,688 7, 232. 85 4, .589 11,696. 08 Phy^ioil and mi>ehan!cal te?ts: Knijineerinp;, niUoellaneoiLS 723 2, 335. 00 17 18.00 740 2, 3.53. 00

165 88(). 00 37 196. 00 202 1,082.00

3, 363 28, 174. 25 60 184.90 3,423 28, .359. 15 4.489 15, 777. 00 129 .391..50 4, 618 16, 108. 50

27 197. 50 7 72.00 34 209. 50 Aeronautical instruments 387 2, 049. .50 1 8. 50 388 2, 058. 00

Total . .

.' 31, 571 86,251.06 280, 992 16, 626. 97 312,563 102,878.63

a In addition the B .treau inspected 3,727,352 incandescent lamps at various factories for other departments

of the Government, the fees for which would amoimt to $9,318.38.

b Of these tests, 2,407, amounting to $21,722.25, were chemical tests made on structural materials.

Statement shoioing the nuiiiljcr and raliic of tests made for the Governineni

and the public (it the Pittshwrgh laboratonj of the Bureau of Standards during the fi.scal near 1917-1918.

Nature of test.

For Government. For public. Total.

Number. Value. Number. Value. Number. Value.

CEMENT.

2, 507 404

89

6

95

$7, 275. 00

1, 424. 00

570. 00

65. 00

668. 00

4 $18.00 2,531 404

109

6

149

$7, 293. 00

1, 424. 00

641.00

65.00

909. 00

CLAY PRODUCTS.

20 71.00

MISCELLANEOUS.

54 241. 00

a In addition, preliminary tests, for which no fee is charged, were made on 52 samples of clay.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 201

PERSONNEL.

[Organization charts of divisions, staff status, individual records of all employees, in- cluding military employees; personnel changes, directories, systems of examinations;

records of leave, tardiness, delinquency, and efficiency; passes and credential cards, in- jury and first-aid records and reports, and records of employees who have entered

military service.] Personnel Changes.

During the fiscal year 1917-18 the Bureau staff comprised 278 statutory emploj^ees, and about 839 engaged in research and investigations

especially authorized by Congress. The statutory positions included

170 scientific positions, 37 office assistants, 46 engaged in the operation of the x^lant, and 25 in the construction. In addition to the

above there were 288 employees detailed from other Government

departments or organizations for work in the Bureau, making a grand total of 1,405 emploj'ees. There were 2,955 personnel changes

during the year, of which 757 were separations from the Bureau,

288 resignations, 568 promotions, and 1,533 appointments. The high

labor turnover reflects the war conditions. The enterprise of the

members of the personnel section has met the emergency with effectiveness.

Appointments.

Number. Total. Competitive 433

Excepted 10

Unclassified 70

Total permanent 513

Total temporary 1, 070

Total appointments 1, 583

Separations.

Number. Total. From competitive positions 241

From excepted positions 17

From classified positions . 80

Total permanent . 288

Total temporary 469

Total separations 757

Promotions and Other Changes.

Number Total. Promotions . 586

Reductions 8

Miscellaneous changes 21

Total personnel changes 2, 955

Efficiency Methods.

The complexity of the personnel classes, the unusual technical

qualifications required, the sudden demands for assistance in emergencies, and the high labor turnover are probably unique in a Federal

bureau and have called for efficient planning of methods. New and

effective methods were devised and put into operation to facilitate

the work, with notable gain in promptness, economy, and efficiency.

These include a series of routing slips covering each set routine, as automatic check against omission. Visible indexes were installed,

forms and routine were standardized, a daily journal was adopted,
202 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

greatly economizing labor in making recoixonendations. Without

these improvements in practically every detail of the work of the

personnel section, the work could not have been carried. The results

shown in this work during the past year have been gratifying.

PUBLICATION.

[Editorial work, routing of manuscripts and proof documents; archives, publication stock

distribution, abstracts of publications.]

The necessity of having the results of the various investigations

conducted by the Bureau, available for ready reference throughout

the country, makes it imperative that these results be published in

pamphlet or book form, in numbers sufficient to provide for widespread distribution.

The results of these investigations are published in pamphlet form,

and in the following pages are given descriptive lists of these papers.

The papers are issued in four separate series: (1) Scientific papers;

(2) technologic papers; (3) circulars; and (4) miscellaneous publications. They cover a wide range of subjects in the field of phj^sical

measurements and the properties of materials and are issued for

general distribution to the scientific, technical, and industrial interests concerned with the subjects treated. Single copies of these

publications are sent upon request to scientists specializing in the

subjects treated, to those collaborating with the Bureau in its investigations, to organizations exchanging like courtesies with the

Bureau, and to depository libraries. Others, however, may purchase

them from the Superintendent of Documents. It is assumed that

individuals generally are interested in a particular class of work,

hence this method of distribution has been adopted in order that

each may secure readily the particular information desired.

Publication.

During the past fiscal year the Bureau issued 53 publications, of

which 46 were new and 7 were revised editions. In addition, approximately 23 publications were reprinted, owing to the urgent demand for them. The new publications include 15 scientific papers,

16 technical papers, 11 circulars, and 3 numbers of the Bulletin of

the Bureau of Standards.

Printing.

During the year 366 printing requisitions other than for publications were prepared. These are for the certificates for tests and the

necessary administrative blanks and record books.

Distribution.

Under normal conditions the work of handling requests for publications is completed daily. The efficiency will unquestionably be

increased when the adequate space is provided for the work of

handling publication stocks. The need for a small stock at the

Bureau is imperative, but the congested condition of the room has

occasionally resulted in delays. The new plan for handling re- quests for publications has worked very satisfactorily.

New Publications.

During the fiscal year the following scientific papers were issued

A Method for Testing Current Transformers; Some Electrical Prop-
KEPOKT OF DIBECTOE OF BUKEAU OF STANDARDS. 203

erties of Silver Sulphide; Axial Aberrations of Lenses; Wave

Length Measurements in Spectra from 5600A to 9600A; Specific

Heat of Liquid Ammonia ; The Latent Heat of Pressure Variation

of Liquid Ammonia; Latent Heat of Vaporization of Ammonia;

Gas Interferometer Calibration; The Resonance and Ionization

Potentials for Electrons in Cadmium Vapor; The Application of

Dicyanin to Stellar Spectroscopy; Instruments and Methods of

Radiometry, III; Selective Radiometry; Additions to the Formula

for the Calculation of Mutual and Self-Inductance ; Thermal Expansion of Alpha and Beta Brass; Photo-Electric Sensitivity of

Various Substances; Some Characteristics of the Marvin Pyrheliometer.

The following new technological papers were issued: Crystalline

Changes in Wrought Iron ; Effects of Heat on Celluloid and Similar

Materials; Gas Mantle Lighting Conditions in Ten Large Cities in

the United States; Determination of Absolute Viscosity by Short

Tube Viscosimeters ; Investigation of Large Bridge Columns ; Properties of Portland Cement Having a High Magnesia Content ; Typical Cases of the Deterioration of Muntz Metal by Selective Corrosion ; Effect of the Size of Grog in Fire Clay Bodies ; Comparative

Tests of Porcelain Laboratory Ware ; Stabilized Platform Weighing

Scale of Novel Design; Comparative Tests of Chemical Glassware;

Ground Connections for Electrical Systems; Clay and Porcelain

Pots for Optical Glass ; The Influence of Quality of Gas and Other

Factors Upon the Efficiency of Gas Mantle Lamps; Compressive

Strength of Large Brick Piers; Standardization of the Saybolt

Universal Viscosimeter.

The following new circulars were issued: Combined Table of

Sizes in the Principal Wire Gages; Public Utility Service, Standards of Quality and Safety ; Paint and Varnish ; Materials for the

Household; Rules and Regulations Promulgated under Authority

of the Federal Standard Barrel Law ; The Scope and Application of

the National Electrical Safety Code; Copper; Radio Measurements

and Instruments; Safety for the Household.

The Annual Report of the Director of the Bureau of Standards

for the Fiscal Year ended June 30, 1917, is the only new miscel*-

laneous publication issued during the year.

PROPERTY AND STORES.

[Property inspection, quantity and quality checking; accession, recording; accountability,

charge and release; condemnation and disposal; stores, stock distribution and renewals.]

The office has prepared and issued to the responsible officers of the

Bureau a standard stock catalogue listing in detail the items carried

in stock in the storeroom. This catalogue contained the principal

articles required for use in the offices and laboratories of the

Bureau. The central stock room purchased and stored approximately

$43,000 worth of material. This involved the handling of the approximately 19,200 items for the central storeroom. In addition, approximately $37,000 worth of standard stock was distributed to the

laboratories, including 19,800 stores requisition and 104,000 items

issued. During the last part of the year the work of the storeroom

increased by about 40 per cent.
204 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Equipment Records.

The work of accession and recording of inventoried equipment

comprises the writing of 28,000 cards and 19,700 pieces of equipment. The growth of this work has in the past 6 months increased 50

per cent.

Progress.

A perpetual inventory metliod showing at a glance all items car- ried in stock and the quantities on hand has been initiated in the

storeroom. Adequate housing for the overflow stock has been fitted

up, but the rapid growth in this section will necessitate permanent

provision of larger space.

PURCHASE.

[Trade catalogues and dealers' lists; requisition inspection; preparation of orders, bids and orders, order follow-up; purchase and transportation checking.]

The activities of this section increased 100 per cent during the past

year, necessitating the reorganization of the office and the separation

of this section from the storeroom and finance sections.

The rapid expansion of the Bureau's work during the year caused

by the war resulted in a very large increase in the number of orders

placed, 8,069 orders being the total number, 5,440 largely for technical materials and apparatus.

The Purchase Section maintains a file of scientific and industrial

catalogues for consultation. The variety of technical equipment and

supplies required calls for investigation which takes a considerable

part of the time of those concerned. Records are kept of the purchases and quotations in such form that they may be readily consulted in future cases. MAIL AND FILES.

[Handling of correspondence, including business and technical communications of all kinds; the accession, distribution, and filing of such papers; test records.]

No section in the Bureau has suffered a more complete loss of ex- perienced and skilled assistants than the section of mail and files. The loss of the entire staff of 6 men, with the experience which they

had acquired in their years of service, could not be made up

promptly. The war caused a rapid increase in the work and it became necessary to route military mail to secure promptness on urgent

cases and confidential handling on other cases, and systematic followup for all military matters. A new system of record and follow-up

was devised and put into effect in the director's office, with marked

increase in the , efficiency of such work. The volume of correspondence increased very greatly and a new classification is now being

installed.

LIBRARY.

[Maintenance of scientific and technical library; bibliography; accessioning new books;

loan and accountability records; assistance to technical staff, and rebinding.]

The Bureau maintains "a scientific library, containing 16,339 ac- cessioned volumes. Three hundred and forty-two scientific and

technical periodicals ai*e currently received. This is an increase of

45 over the previous year. The number does not include 96 different

journals which fail to reach the Bureau on account of the war. Of

the latter, 74 are German journals.
EEPOET OF DIEECTOB OF BUBEAU OF STANDAEDS. 205

Important Accessions.

The library has been fortunate in being able to secure a large

number of missing numbers and volumes of important journals and

to complete a number of the more important sets. This was not ac- complished without the most careful scrutiny of the catalogues of

second-hand works, published in America and Europe.

Equipment and Space.

While the library is in congested quarters, the equipment is modern and effective for its purpose. Additional space, however, is

urgently called for in order that the centralization demanded by

efficiency may be completed.

DISPATCH.

[Transportation and communication of all kinds, comprising telephone and telegraph

service, express, freight and mail shipments, drayage, and messenger service.] The work of this section has been somewhat divided, owing to the

rapid growth of the Bureau and the failure thus far to, fully centralize the dispatch service. Plans have been perfected for the consolidation, and it is expected that this will be accomplished in the very near

future. The work of the section has expanded very greatly requiring now the service of five trucks and three automobiles. The fact

that the work of the Bureau is distributed in approximately 18 buildings and that the Bureau is located at a distance from the center of

the city, has made the work of dispatch more than usually difficult,

especially under war-time conditions.

COPYING SECTION.

[Editing rough drafts of letters, reports, and manuscripts; stenography; typewriting; and

mimeography. ] For convenience, and at some sacrifice of efficiency, the staff in

this' section is detailed to the several divisions of the Bureau. The

copying of manuscripts of technical reports of researches and tests,

and the work of technical correspondence,' has grown very rapidly

during the year. The rapid expansion of the entire Bureau and the

urgency of the utmost dispatch of obtaining and publishing results

has necessitated a very large addition to the staff of clerks engaged

in the general work of stenography and typewriting. The sacrifice in

efficiency is believed to be justified at present, since centralization

would require commodious and suitable quarters. Attention is called

to the urgent need for an office building of the modern type, designed

and constructed throughout for the specialized work of the various

sections of the office.INFORMATION SECTION.

[ Re<}uesting, receiving, distributing, and filing of scientific and technical information of a military bearing; maintenance of a progress-of-work chart and follow-up system covering all tests, subjects of inquiry, investigations, and researches in progress for the military services.] Progress-o£-Work Records.

Some time after the entry of the United States into the war it

became apparent that in order efficiently to care for the large amount
206 EEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

of military work regularly coming into the Bureau, it would be

necessary to inaugurate some form of central progress-of-work

record. Accordingly, a very efficient yet simple method was developed by which all the military tests, investigations, and inquiries

for information are recorded at the time of their receipt. Thereafter, by a very simple notation, entries are made indicating the

progress of the work up to the stage of the completion and mailing

of the final report.

The system used, which is a novel one specially developed for the

work, was described in the Journal of the Franklin Institute.

The operation of the system is so carried out as to interpose

no delay in the progress of an incoming inquiry or request.

The aggregate of the entries currently carried on the chart is now

very large in number and the record obtained, which is continuall}^

up to date, affords at all times a concise, clear-cut representation of

the Bureau's activities carried on for the military services in all

lines of testing, investigation, research, and compilation of technical

information in answer to inquiries. Moreover, the chart discloses

all cases in which abnormal delays are occurring in the carrying

out of work and by the collateral employment of a follow-up or reminder system, enables the necessary corrective measures to be

taken to eliminate serious and preventable causes of delay. The

use of this system has already been efficacious in detecting and indicating means for correction of conditions likely to interfere with

the promptest possible handling of military work.

Distribution of Military Information.

On account of the rapid changes occurring in modern warfare,

with its tremendous employment of scientific and technologic re- sources, methods of combat and communication in use to-day are

likely to be fundamentally improved or completely replaced in a very

short time by a single new invention or scientific discovery. Therefore, the rapid circulation of accurate and dependable technical information to all workers in scientific and technologic fields having

military application is of paramount importance. On this account

and to care for the considerable mass of technical information cov- ering every conceivable branch of physical and chemical science

which the Bureau receives from the various offices of the War and

NaA'y Departments and from research agencies of civilian character

engaged in military problems here and abroad, an Information Section has been inaugurated, in which all manner of confidential information of the types just described is received. Notices of receipt

and abstracts of such information are forwarded to those technical

sections of the Bureau concerned with the particular subject of each

document and other necessary matters relating to the distribution

and dispatch of such reports are cared for.

Respectfully,

S. W. Stratton, Director.

To Hon. William C. Eedfield,

Secretary of Commerce.

o