31

Annual Report

of the

Director of the Bureau of Standards

to the

Secretary of Commerce and Labor

(01 the

Fiscal Year Ended June 30, 1 91

WASHINGTON

GOVERNMENT PRINTING OFFICE

1912

Annual Report

of the

Director of the Bureau of Standar

to the

Secretary of Commerce and Labor

for the

Fiscal Year Ended June 30, 191 1

WASHINGTON

GOVERNMENT PRINTING OFFICE

1912

REPORT

OF THE

DIRECTOR OF THE BUREAU OF STANDARDS.

Department of Commerce and Labor,

Bureau or Standards,

Washington, July 1, 1911.

Sir : I have the honor to submit the following report of the work

of the Bureau of Standards for the fiscal year ended June 30, 1911

:

The work of the Bureau has shown steady progress in its various

divisions. The number of tests increased to considerably more than

double that of the previous year. This growth is due to the steadily

increasing interest of the industries in applying scientific data and

principles to manufacturing. The great demand for investigations

and information has taxed the available force to meet it. A noteworthy feature of the year's progress has been in the investigation

and testing of structural materials. The completion of extended investigations affecting the fundamental electrical units and standards

is also of special interest.

ELECTRICITY.

On the 1st of January, 1911, the Bureau adopted the new value

for the international volt in accordance with the recommendation

of the International Committee on Electrical Units and Standards.

This unit was adopted at the same time in England, France, Germany, and many other countries, thus securing, for the first time,

close international agreement in the measurement of electrical voltage

and current. This agreement was reached as a result of the co- operative investigation which was made at the Bureau of Standards

by representatives of several national standardizing laboratories, an

account of which was given in my report of one year ago. The

investigations carried on during this period of cooperation have

been continued with a view of further perfecting the official specification of standard cells and the silver voltameter.

electrical standards.

The investigation on the absolute measurement of current, which

is of great importance in connection with electrical standards, has

3
4 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

been completed and the results prepared for publication. The object

of this research has been not simply to obtain a more accurate value

of standard cells in terms of resistance standards and the absolute

ampere, but also to develop and perfect the form of ampere balance

employed.

The construction of four primary mercurial resistance standards,

in accordance with the specifications adopted by the London International Electrical Conference of 1908, has been practically completed.

The data from which the resistance assigned to the four standards

are calculated were all determined to a high degree of precision, and

the measured differences of the four tubes agree with the calculated

differences to within 5 parts per million, indicating the possibilities

when the same procedure is followed throughout.

The differences between the Bureau standards and those previously

constructed in other national laboratories are somewhat greater, as might be expected.

Two of these laboratories are undertaking the construction of new

standards in accordance with the more rigorous London specifications here employed. The comparison of the new tubes with the

Bureau tubes will furnish a better basis for estimating the accuracy

attainable in the reproduction of the international ohm.

PRECISION RESISTANCE MEASUREMENTS.

This work includes the investigation of methods of resistance measurements, the design and investigation of resistance standards, the

determination of the various electrical properties of conductors and

the testing of resistance standards, bridges, precision rheostats, potentiometers, etc. During the past year there has been an increase in the number of

resistance standards and other apparatus tested.

Apparatus for the accurate establishment of a resistance ratio of

10 to 1 has been constructed according to the Bureau specifications

and now replaces the apparatus formerly used in " building up."

A few resistance standards have been constructed, using a new

alloy. While these have been under observation only a few months,

the indications are that the new alloy will be found to be as good or

better than manganin for use in resistance standards and resistance

apparatus.

A study has been made both of resistance standards having four

terminals and of the Thomson bridge. The results of this investigation are to be published in the Bulletin of the Bureau.

ELECTRICAL MEASURING INSTRUMENTS.

During the year an extended investigation of direct current switchboard instruments was completed and the results prepared for publi-
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 5

cation in order to make the detailed data available to manufacturers

and users of instruments. An electrodynamometer capable of carrying currents up to 5,000 amperes has been designed and constructed.

A careful study of current transformers and of the methods used in

determining their constants has been carried out. The results of this

investigation are being published, as are also descriptions of some

new types of potentiometers especially designed for the rapid and

accurate testing of electrical measuring instruments and for the accu- rate measurements necessary in electrical engineering. A device for

measuring the torque of instruments was designed and constructed

and a description of it published. During the year a relatively large

number of tests requiring the measurement of torque were made. A

standard variable self and mutual inductance was constructed for use

in general testing work. Several other investigations have been

undertaken in connection with the development of new lines of electrical instruments, and with improvements in existing types.

Upon the renewal of the contracts for supplying light and power

to the departments, the Bureau was requested by the various departments, at the suggestion of the Secretary of the Treasur3r

, to test the

electric meters measuring the power supplied to the various Government buildings in the District of Columbia.

The tests made during the year included 27 ammeters, 20 voltmeters, 17 wattmeters, 94 watthour meters, 3 power-factor meters, 15

current transformers, 20 insulation tests with high voltage, 2 arc lamps, 33 electric fans, 19 dry cells, and 4 miscellaneous tests—a total

of 269 pieces.

ELECTRICAL RESISTIVITY OF COPPER.

The results of the investigation to determine the electrical conductivity and temperature coefficient of average commercial highgrade copper were published during the year. A reasonable agreement was found for samples from different sources, and satisfactory

average values were obtained. The measurements were made with

an unusually high accuracy, which was made possible by a specially

designed and constructed apparatus. It was discovered that the temperature coefficient and conductivity are substantially proportional.

This relation has been corroborated by work done at the Reichsanstalt, of Germany, and has a number of useful consequences. It was

also found that bending and winding do not change the temperature

coefficient, and consequently the internal temperature of dynamos

and instruments may be calculated from resistance measurements with

greater confidence than heretofore. The results of this investigation are the basis of new standard values for the conductivity and temperature coefficient of copper which it is expected will soon be adopted

internationally, A circular has been prepared containing informa-
6 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

tion about wire gages, etc., and a complete set of copper wire tables.

The tables have been adopted as the official wire tables of the American Institute of Electrical Engineers, replacing their old Wire

Table of 1893. The Standards Committee of the American Institute cooperated with the Bureau by suggesting the investigation and

by their advice and criticisms in the preparation of the circular. The

Standards Committee and the Bureau have also cooperated in the

consideration of such questions as electric cable standardization, and

the definition and value of the horsepower.

MAGNETISM.

A series of samples of transformer steel have been exchanged

among the several national laboratories for the purpose of comparing the methods of core-loss measurement. The resulting data show

that the various laboratories and methods now yield results that do

not differ by more than 1 per cent.

A series of rods for use in comparing the methods of measurement

of normal induction and permeability are being exchanged in the

same way, and while the data thus far obtained show that greater

variations exist the differences are not excessive. These intercomparisons are bringing to light heretofore unnoticed sources of error, and future intercomparisons will undoubtedly show closer agreement.

Much attention has been paid to the methods of commercial test- ing. In cooperation with the Committee on the Magnetic Testing

of Iron and Steel of the American Society for Testing Materials,

considerable progress has been made toward the standardization of

the methods of magnetic testing in commercial laboratories. For the

core-loss measurement agreement has been reached as to the size of

the specimen and all the details of apparatus and procedure to be

used in commercial testing; for permeability measurements the details of specimens and apparatus are not defined, but the general

method has been agreed upon.

A number of magnet steels obtained from various sources both in

this country and abroad have been studied and their relative values

for use as permanent magnets investigated. This is part of the general plan to accumulate data on the magnetic properties of all the

commercial steels.

Data are being collected on the relation between the magnetic and

mechanical properties of commercial steels with a view to finding

some simple magnetic test which may supplement or replace some of

the mechanical tests and thus avoid the destruction of the material

under examination.
REPORT OP DIRECTOR OF BUREAU OF STANDARDS. 7

ELECTRICAL TESTING.

The amount of electrical testing for the past year has exceeded that

of any previous year. The following instruments and materials have

been tested

:

For State and National institutions and for the public, exclusive of

the testing done for the other divisions of the Bureau, 78 resistance

standards, 5 resistance bridges, 5 potentiometers, 58 standard cells,

and 6 miscellaneous pieces of resistance apparatus have been tested

and the electrical properties of 35 samples of conductors determined.

Under the head of inductance and capacity measurements 104

pieces of apparatus have been tested, including wave meters; self and

mutual inductances, both constant and variable ; condensers, in which

the direct current and alternating current values are sometimes determined separately (temperature coefficient and absorption also being

determined in addition to the capacity) ; and the residual capacity of

resistance coils—the total number of tests amounting to 325.

In the section of electrical measuring instruments there were tested

27 ammeters, 20 voltmeters, 17 wattmeters, 94 watthour meters, 3

power factor meters, 15 current transformers, 20 insulation tests with

high voltage, 2 arc lamps, 33 electric fans, 19 dry cells, and 4 miscellaneous tests—a total of 269 pieces.

In the magnetic laboratory 46 samples have been tested for core

loss, 26 samples for normal induction and hysteresis, and 8 miscellaneous tests were made on magnetic standards and induction coils.

PHOTOMETRY.

In the photometric section the work is divided into three parts, as follows : First, the preparation and testing of photometric standards

and the intercomparison with foreign laboratories of the primary

standards with a view to maintaining the international standard of

candlepower; second, the photometry of gas standards and the test- ing of various kinds of sources of illumination ; third, the inspection

and testing for candlepower efficiency and life of incandescent electric

lamps purchased by the various Government departments.

During the year a large amount of work has been done in making

a thorough intercomparison of our primary standards and in the

preparation and study of new standards especially of different makes

of drawn-wire tungsten filament lamps. Considerable time has been

given to a study of the precision of photometric measurements and

of the reproducibility and constancy of electric incandescent filament

photometric standards. Sixty-five carbon and 25 tungsten standards

have been furnished to the various bureaus of the Government or

sold to the public; and in addition, 96 carbon, 32 tantalum, and 80
8 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

tungsten lamps have been standardized, making a total of 298 standards of all kinds.

Up to the present time the international unit of candlepower has

been maintained entirely by means of carbon filament lamps. The

advent of the tungsten and other high-efficiency lamps has made it highly desirable to have high-efficiency primary standards also, be-, cause of the difficulty of comparing light sources of different color.

In order that the international unit may be properly maintained at

the higher efficiency, we have agreed with the National Physical

Laboratory of England to interchange a number of tungsten lamps

standardized at about watts per candle efficiency. These lamps

have been selected and are being carefully prepared for this purpose.

In connection with the inspection and life testing, 941,000 lamps

have been inspected by the traveling inspectors of the Bureau, who

inspect lamps at the factories and take samples for life test at the

Bureau; 3,843 of these samples have been tested at the Bureau for

candlepower and life. The result of this work is to enable the Government to buy lamps on specifications and to assure itself that the

lamps delivered meet the standard of the specifications. It also has

a tendenc}7 to standardize the output of the manufacturers and to

improve the quality of the lamps furnished to the public.

The work on flame standards of candlepower was continued and

a satisfactory determination of the effect of atmospheric conditions

on those standards was completed. This work has an immediate

practical application in the improvement of the methods of testing

illuminating gas. The results already obtained and published have

contributed to the progress which is being made in this line in many

cities, and have given rise to much correspondence in which the Bureau has been able to furnish information based on our experience

with these standards. Another result of the interest aroused in accurate methods of gas testing has been an increase of 100 per cent over

the preceding year in the number of flame standards submitted for

test. A large amount of time has been expended in the collection of

information regarding other details of the inspection of the gas

service in cities and towns of all sizes, for the purpose of combining

the best features of present practice in a circular of information

which may serve as a guide for local authorities in drafting regulations.

The legislative regulations for locomotive headlights proposed or enacted in several States led to a large amount of work on the part of

the Bureau in making measurements of various types of headlights to

obtain data on which a fair interpretation of such regulations could

be based. Considerable time was given also to measurements of arc and gas lamps used in the parks of the District of Columbia, with

the result that modifications have been made in the street gas lamps
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 9

of the District, which increase the light produced by 50 per cent without any additional cost to the Government.

Four portable photometers were calibrated, three being for Government or municipal officers, and a number of special lights were

measured for manufacturers.

INVESTIGATIONS IN ELECTROLYSIS.

During the past year an extensive investigation into the subject of

electrolysis has been in progress. This subject is one of great practical importance, not only to engineering interests, but to municipalities and the general public. Damage to water and gas pipes

and other underground structures by stray electric currents has long

been a source of serious trouble, and although much work has been

done by private interests with the view of mitigating the evil a great deal of investigational work remains to be done before remedial measures can be applied with satisfactory precision. Also during

the last few years a great deal of attention has been drawn to the

possibility of damage to reenforced concrete structures, due to stray

currents, and much alarm has been created in some quarters lest

great damage to buildings, bridges, etc., may result from this cause. Although the possibility of damage of this sort had been established, little was known before this investigation was started in

regard to the extent of the damage that had occurred, the conditions

under which trouble might be expected, or the best method of mitigating the evil.

The present investigation was undertaken in response to requests

from important engineering interests, and in carrying out the work

the Bureau has had the hearty cooperation of many engineers, cor- porations, and municipalities, they in some instances undertaking

considerable expense in order to assist the Bureau in making the

investigations. During the last half of 1910 the work was confined

mainly to investigations relating to electrolysis of reenforced concrete, owing to limitations of equipment and personnel, but early

in the present year the work was broadened to include investigations

into the general subject of electrolysis, particular attention being

given to methods of preventing trouble from this source. A great

deal of valuable information has already been obtained, but much

important work remains to be done, and it is planned to continue

the work during the coming year.

WEIGHTS AND MEASURES.

The work of the division of weights and measures consists of the

custody and maintenance of the standards of length, mass, volume,

density, etc., keeping these standards available to the public, and

compiling and distributing information relative to them. It has also

34365°—12 2
10 REPORT OF DIRECTOR OE BUREAU OF STANDARDS.

for one of its objects the general improvement of weights and measures conditions throughout the country.

LENGTH AND EXPANSION MEASUREMENTS.

During the year experiments have been made to secure data for use in designing apparatus to control temperatures in length measurements. Valuable information was obtained from a study of the

influence of various conditions on the linear distribution of the temperature of the air within a jacketed cylindrical tube heated by oil

circulating between the tube and its jacket. This arrangement

proved to be a simple and satisfactory means of securing great uniformity of temperature in long specimens. During the latter part

of the year the thermal expansivity of 25 different specimens was

determined for temperatures ranging from —25° to —|-1T2 C and

it is planned to considerably extend this range in the final comparator. In the work referred to above, the temperatures were measured

with a copper-constantan thermoelement whose equations and curve were deduced from potentiometer observations of the electromotive

force when one junction was in melting ice while the other was

successively in a mixture of solid carbon dioxide and gasoline, in

steam, and in the vapor of boiling naphthaline.

During the year about 240 length measures of various kinds were

tested, somewhat less than half being for either the Federal or State

Governments. Those for the Federal Government included invar

tapes for the Coast and Geodetic Survey and the United States

Geological Survey. Other length-measuring apparatus tested for

the Federal or State Governments included level rods, paper micrometer gages, and standard }<ards and meters for States. Of the

length measurements made for others, the major part were steel tapes

for surveyors and constructors, though no inconsiderable part of the

work came from municipalities whose interest in the inspection of

the weights and measures used in trade has been stimulated by the

conditions found in the investigation by the Bureau of weights and

measures conditions throughout the country.

The equipment for length measurements has been added to by the

purchase of an invar meter bar having approximately the coefficient

of expansion of platinum, with the graduations ruled on a platinum

strip inlaid in the bar. Apparatus for determination of expansivity

has also been developed and tested. Some improvements have also

been made in the apparatus used for calibrating length standards.

A number of check measurements have been made on the working

standards used in the length work, and considerable progress has

been made in the more accurate calibration of the bench standards

used in the steel tape comparison.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 11

CAPACITY MEASURES.

The number of metal capacity measures tested during the year was

more than double that of the previous year, about one-fourth being

for the Federal or State Governments. Those for the Federal or State Governments included standards for Porto Eico, the Panama

Railroad, and the States of Wisconsin and Alabama. Standards

were also tested for several city governments and manufacturers.

A number of cubic-foot bottles, for use in testing gas-meter provers,

were also tested.

About 9.000 pieces of volumetric glassware were tested during the

year, practically all of it being for the Federal Government.

MASS.

The number of tests of weights more than doubled during the year,

and, in consequence, it was impossible to give the tests as prompt

attention as could be desired. This applies particularly to tests for

those States which are now preparing to establish weights and measures inspection departments for the protection of the purchasing

public and those merchants who desire to conduct their business on

an honest basis.

By act of Congress, the old troy pound of the mint at Philadelphia

was superseded by the standard of the Bureau, and for all purposes

in the United States there is now a single standard of mass. This in

no wise changes the actual value of the mint weights, but substitutes

the platinum-iridium kilogram for the old brass mint pound as the

fundamental standard.

DENSITY.

Several very important density determinations were completed

during the last year. That on the density and thermal expansion of

ethyl alcohol and its mixtures with water will soon be published and

should prove a valuable contribution to those industries engaged in

the production of alcohol or to those using it. TVork on the density

and thermal expansion of Unseed oil and turpentine was also carried

on. Tables were computed for obtaining the density of linseed oil

at any temperature between 10° and 40° C from its density at any

other temperature within the same range.

Tables were also prepared for converting from pounds to gallons,

and vice versa. The investigations were undertaken at the request

of the American Society for Testing Materials and others interested.

The number of hydrometers tested during the year exceeded 2,400.

most of them being alcoholometers for the Internal-Revenue Service.

TIME.

In August, 1910, a direct wire to the United States Naval Observatory was installed for the transmission of the noon signal. The
12 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

previous use of the noon signal as transmitted by wireless telegraph

had proven unsatisfactory, partly by reason of the irregularity with

which it was sent from the wireless station and partly because of the

lack of suitable instruments for recording it. At the request of the Supervising Architect of the Treasury Department the Bureau made a comparative test of a number of different systems of master and secondary clocks suitable for installation

in public buildings, the test covering a period of six months. The

various makers were invited to submit a set of their clocks, and the

systems of the six makers who accepted the invitation were installed

the latter part of July, 1910. Daily comparisons of the clocks were

made to determine the uniformity of rate of the master clock and

to note any irregularity in the performance of the secondaries. The

clock movements were examined and rated as to workmanship, and

estimates were made of the cost of maintenance of the various systems.

These results, together with other tests and examinations of the

operation and reliability of the systems as a whole, were reported to

the Supervising Architect and will be used by him in awarding

contracts for the installation of clock systems in Government

buildings.

ANEROID BAROMETERS.

A study of the sources of error in aneroid barometers has been

undertaken in connection with the development of standard methods

for testing. A thorough investigation of mechanical accuracy,

elastic lag, temperature compensation, and permanence is necessitated

by the fact that under different conditions a commercial aneroid

of the best quality may differ by several per cent in its indications

of a given pressure change.

Experiments which have already served to determine qualitatively

the various sources of error and their relative significance will be

supplemented by an intercomparison of representative aneroids of

different types and sizes to be furnished by makers and dealers who

have expressed their desire for cooperation.

The investigation has for some time been urged by manufacturers.

They desire to see established a method of testing which will make a proper distinction between defects of workmanship and errors physically inherent, as well as a uniform and authoritative system of cer- tifying and rejecting. The work is of no less importance to the

public, for all who must use aneroid barometers are at a loss to know

with how much confidence the corrections obtained in the laboratory

may be applied under the diverse conditions of practice. The increasing dependence of aviators upon aneroid altitude measurements

adds to the present importance of the problem.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 13

TRADE WEIGHTS AND MEASURES INVESTIGATION.

The investigation of trade weights and measures conditions throughout the country, for which Congress made special provision, has

practically been completed and will form the subject of a special

report. Every State in the Union, with the exception of Arkansas

and Oklahoma; has been visited, and inspections in the two mentioned

will be made early in the coming year.

During the two years that this investigation has been in progress

8,630 scales have been tested, of which 3,607, or 41.8 per cent, were incorrect. The total number of weights tested was 10,929, of which

2,231 were incorrect. The number of dry and liquid measures tested

was 6,088, of which 2,018, or approximately 33 per cent, were incorrect. Of the incorrect apparatus found, a large proportion of it discriminated against the consumer and, consequently, furnished the

strongest argument for the establishment of inspection services by

the States. The investigation has attracted the widest attention and

has resulted in the enactment by the States of either laws to render

efficient the old weights and measures laws or else entirely new laws.

During the year the legislatures of 35 States gave consideration to

bills to either establish weights and measures laws or amend those

already on the statute books, and 25 States passed important legislation on the subject. The indications are that all the States are thoroughly alive to the importance of the matter and that in a few

years every State in the Union will have provided means to guarantee

the integrity of the weights and measures used in trade.

To insure uniformity in the State laws, a model law was drafted

by the Bureau, and this law, with minor modifications to suit local

conditions, has been adopted in a number of the States. The Bureau

also drafted a model weights and measures ordinance for municipalities, for which there was urgent demand. A list of apparatus suitable for State and city sealers was also prepared in response to

numerous requests for advice as to the proper equipment for such

officials. The Bureau has also rendered aid to the States in the

establishment of their inspection departments, sometimes by detailing an expert in the work and sometimes by correspondence.

An investigation to determine the variation in the weight of food

products put up in package form, with time and under different

atmospheric conditions^ was conducted with a view to securing information of value in establishing tolerances on the net weight or measure of manufactured food products put up in packages. A

large number of the more common articles, such as cereals, crackers,

dried fruit, etc., were purchased and divided into three lots, the first

of which was kept in a room at normal temperature and humidity,

the second in a room where the air was quite moist, and the third in
14 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

a room where the air was quite dry and at a high temperature.

Weighings were made at regular intervals, and the temperatures and

humidity were also observed. The results will be of great value in

establishing permissible variation in the weight of such commodities

in case a net-weight law is passed by Congress, and they will also be

of much assistance in answering many questions that will arise in

the consideration of such a possible law.

The time has now arrived when the power granted to Congress

to fix the standard of weights and measures, by paragraph 5 of sec- tion 8 of Article I of the Constitution of the United States, should

be exercised.

The practice of selling by gross weights, which enables the manufacturer to deliver an unknown amount; the selling of manufactured

food products in packages; the development of transportation facilities, which has greatly increased the shipment of fruit and vegetables

from one part of the country to another, have created a demand for

the standardizing of packages, barrels, boxes, crates, baskets, etc.,

that can only be met by national legislation. The attempt to correct

some of the evils by State legislation, which compels the merchants

doing an interstate business to conform to different requirements

for different States, has only complicated the situation. What is needed is

1. A national law defining and fixing the usual weights and

measures that may be used in everyday trade.

2. A law fixing the sizes of the more common shipping units, such

as barrels, bales (of cotton), boxes, baskets (fruit), etc.

3. A law requiring the net weight, measure, or numerical count to

be plainly stated upon the outside of all commodities put up in

sealed packages.

Also a law to eliminate the manufacture and sale of apparatus

designed to facilitate fraud.

Briefly, the provisions of such bill should also require each manufacturer of commercial apparatus in the country to submit a sample

of the various types of scales, weights, and measures made by him

and sold for commercial use; to empower the Bureau of Standards

to examine and test such apparatus as regards type, and thus to determine whether the type is a satisfactory one and does not facilitate

the perpetration of fraud, the Bureau to issue certificates for such

type of apparatus conforming to certain standard specifications,

which certificate would allow the manufacturer to manufacture and

sell throughout the country such certified apparatus, and, finally, to

require that no apparatus failing of certification by the Bureau may

be manufactured and sold in the United States.

Such a law would be of great assistance to the manufacturers

in making a. standard product, and would avoid the necessity of each
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 15

State establishing regulations, which are certain to lack uniformity.

It would, furthermore, be a great help to the local officials in eliminating fraud in commercial dealings, and would, it is believed, tend

to greatly improve existing conditions. It would also be a protection to the merchants, since they could feel assured that any apparatus purchased for commercial use by them would be of satisfactory

construction.

THERMOMETRY, PYROMETRY, AND HEAT MEASUREMENTS.

The work of this division is primarily the maintenance of a standard scale of temperature always available to the public for reference,

and, secondarily, the making of tests and the investigation of problems of all sorts in which accuracy in the measurements of temperatures is essential.

THERMOMETRY.

A total of 18,693 thermometers were tested during the year, made

up as follows: 236 ordinary calorimetric thermometers and 49 Beckmann calorimetric thermometers, graduated to 0.01° or 0.02°, for use mainly on the determination of the heating values of fuels; 965 laboratory and special thermometers for the general purposes of temperature measurement in the interval —30° to 500° C ; 17,431 clinical

thermometers, for the use of physicians, and 12 sterilization (melting

point) thermometers.

Work was continued during the year on the calibration of a number of primary standard mercurial thermometers, made of different

glasses, for use as standards in the interval 100° to 500° C.

Electrically heated oil bath and copper block thermometer comparators were designed to facilitate the testing of thermometers in

the interval 100° to 500° C, with the highest accuracy, and were

constructed in the instrument shop of the Bureau.

An investigation was completed and published during the year on

the reproducibility (0.03° to 0.05°) of the sulphur boiling point

(444.7°), its use as a fixed point for the calibration of platinum re- sistance thermometers, with a discussion of the temperature scale

defined by means of such thermometers calibrated at the temperatures of melting ice, steam, and sulphur vapor, which is the method

used to define the standard temperature scale of this Bureau in the

interval 100° to 500° C. The remarkable agreement of the scale so defined with the scale of the gas thermometer and with the absolute

scale, as indicated by some work only recently completed and published abroad, would seem to lend hope that international agreement

may soon be reached on the standard scale of temperature above

100° C, such as now obtains in the interval 0° to 100° C.
16 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The work of designing, constructing, and testing the apparatus

needed in the repetition of the Joule-Kelvin porous plug experiment

has continued with some interruptions.

A critical account of two methods of determining the stem correc- tion of the mercurial thermometer, supplementary to the information

given in Bureau Circular No. 8, has been prepared and will be published shortly in the Bulletin.

Bureau Circular No. 8, giving information on the construction,

use, and testing of mercurial thermometers, and Circular No. 5,

giving similar information relating to clinical thermometers, have

been revised and enlarged and are now in press.

CALORIMETRY.

During the year the necessary preliminary work on the determination of the heats of combustion of napthalene and benzoic acid was

completed, so that samples of these substances, with certified values

as to the heat of combustion, have been issued. Standard sugar has

been supplied as heretofore, but with the thermal constants determined in this laboratory. Bureau Circular No. 11, on the standardization of bomb calorimeters, has been issued to accompany the

samples and to furnish information to users of these instruments for

the testing of the heat values of fuels. Considerable work was done

on methods of purifying the above-mentioned materials and on the

determination of their heats of combustion when purified in different

ways, as a basis for certification.

There were sent out during the year 93 standard combustion

samples, which were used by chemists and engineers for the standardization of their calorimetric apparatus. The introduction of these

standard samples has alreadjr done much to increase the accuracy of

and to reduce the results of fuel tests to a uniform and comparable

basis.

Incidental to the determination of the water equivalents of the

calorimeters, used in the above work, by electrical methods, a series

of determinations of the water equivalent of the calorimeter without

the bomb were also made. From these a series of values of the

mechanical equivalent of heat, J, based on the electric units is readily

calculated. A series of values were thus obtained consistent to 1 in

10,000. Some further work should be done before publication of

final results.

A new calorimeter, the important features of which are arrangements to define, as closely as possible, the limits of the calorimetric

mass, combined with convenience in manipulation, has been designed

and was constructed in the instrument shop. The outer water jacket

has provision for electric heating and thermostatic control, as well as means of working according to the adiabatic method of Richards.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 17

A new wheatstone and double-Kelvin bridge for use with resistance

thermometers was completed and is now in use. Some improvements

in the B. S. type of calorimefric resistance thermometers have been

made and one firm of instrument makers has undertaken their manufacture. A number of these thermometers have been standardized

for outside users. A new type of slide wire bridge for use with these

thermometers was outlined and is now being made by the same instrument makers. Installations of this kind have already been adopted

by one of the bureaus of the Government and by otber laboratories.

In connection with the calorimetric work on standard combustion

samples it became necessary to have pure oxj'gen in large quantity

and under high pressure. A very complete plant for this purpose

has been designed and constructed and is now installed.

A considerable amount of work was done on the determination of

the efficiency of commercial gas calorimeters, as well as on the intercomparison of different types. Some work was also done, incidentally, to determine the most reliable methods of testing the gas

meters used with these calorimeters and on the accuracy attainable

with such meters.

PYROMETRY.

The high-temperature tests may be summarized as follows: 28

thermocouples, 12 pyrometer galvanometers, 3 Fery total radiation

pyrometers, 1 Wanner optical p}7 rometer, and 8 platinum resistance

theremometers, for the measurement and control of high temperatures in various industrial operations; 1 electric resistance furnace;

21 melting point determinations of fire bricks, refractories, blastfurnace slags, and alloys; 12 Seger cones; the fire-resisting qualities

of 4 samples of brick and terra cotta ; and the heating and cooling curves of a number of steels of different composition.

In addition to the tests enumerated above, several tests were made

in the works with a view to demonstrating the application of various

pyrometric methods to industrial problems. Among these ma}' be

mentioned the measurement of the temperature in a large copper

converter at the Baltimore Copper Works, by means, of optical pyrometers; the measurement of the temperatures of molten steel when

tapped from the furnace, when being poured into the molds, and the

temperature of forging, at the Firth- Sterling Ordnance Works.

Simultaneous measurements with thermoelectric and optical pyrometers gave as a preliminary value for the emissivity of molten steel

for red light ere d=0.4.

Considerable work was done during the year on the calibration of

a number of new pyrometer lamps and thermocouples for use as the

high-temperature standards of the Bureau.

34365°—12 3
18 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The existing data on the melting points of the chemical elements

have been collected and digested and will be published in the near

future as a circular of information.

A large amount of work has been done on the determination of

the critical points of steels, from the so-called heating and cooling

curves, using different methods of observation. A special vacuum

furnace has been constructed for this work, with automatic control

of the rate of heating. A series of carbon steels of known composition were kindly furnished for this work by Prof. H. M. Howe, a member of the visiting committee of this Bureau. It is hoped to

extend this work to other special steels, pure iron, etc., with a view

to determining the effect of rate of heating, of the surrounding at- mosphere, and of the size and heat capacity of the specimen on the

location of the critical points.

Methods have been developed for the determination of the melting points of refractory materials by means of heating curves taken

on the specimen as it is heated in a vacuum electric furnace, the

temperatures being measured with an optical pyrometer. The

methods have been applied to a number of refractory oxides and

minerals, to clay, magnesia, bauxite, silica, and chromite fire bricks,

and to blast-furnace slags, etc. Most of the necessary apparatus, including a large vacuum electric

resistance furnace, has been constructed for the determination of the

thermal conductivities of commercial refractory materials at high

temperatures.

An improved method of computing the constant C2 of Planck's

radiation equation from observed energy curves was devised by a member of the division in collaboration with a member of the electrical division and has been published in the Bulletin.

There is considerable demand on the Bureau to furnish materials

of known melting points, i. e., standard temperature samples, similar

to the standard combustion samples now furnished, to enable users of high-temperature measuring instruments to obtain a convenient

check on their accuracy from time to time. Some work has already

been done, with this end in view, on the reproducibility of the melting points of metals and salts obtained from different sources. As soon as the necessary assistance can be provided, the determination of the thermal conductivities of materials used for the purposes

of heat insulation should be undertaken. The great importance of

this problem has been strongly emphasized by the refrigeration

industries.

Owing to the great increase in the work of testing, little or no progress has been made during the year on some important investigations relating to the establishment of the standard temperature scale.

It is earnestly hoped that the necessary assistance can be provided to
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 19

take care of the testing work so that the men who are especially

trained for these investigations may carry them to an early conclusion.

MISCELLANEOUS.

Other tests carried out in this division were as follows; The freezing points of 5 solutions of calcium chlorides of different concentrations; 3 thermographs: the flash points and viscosities of 27 samples

of lubricating oils. An important feature of the work of this division is the corre- spondence carried on with many technical and scientific men, and

relating to the applications of thermometers, pyrometers, and calorimeters to industrial and scientific problems.

A large number of intercomparisons were made between the Engler,

Saybolt, and Eedwood viscosimeters, as a result of which it is hoped

to publish transformation tables to enable technical men to express the

results obtained with any one instrument on the scale of the other two.

A course of lectures by a member of this division, given at the re- quest of the Navy Department before officers of the School of Marine

Engineering at Annapolis, led to a study of certain points in steam

turbine design and to the development of a convenient practical

method for determining the reheat factor. The results, which will

appear in the Bulletin, were published in condensed form in Vol.

XXIII, No. 2, of the Journal of the American Society of Naval

Engineers.

One of the members of this division gave a lecture before the scientific staff of a large manufacturing plant on recent developments in

the field of high temperatures, and contributed a paper to one of the

large technical schools on the relation of the work of this division to

the public.

OPTICS.

During the year important researches were made in this division,

which includes radiometry, spectroscopy and applied optics, polarimetry, and interferometry. These researches supplement other

methods for determining the physical constants and properties of materials, and are very valuable for this purpose. Besides conducting

the researches, many optical tests have been made for the Government

and the public, such as telescopic and photographic lenses, prisms,

samples of glass, polariscopic apparatus, and sugar analyses.

RADIOMETRY.

During the year work was continued on the radiation constants of

a complete radiator, using as a source of radiation a uniformly heated

inclosure—the so-called " black body "—which gives a somewhat

lower value of the radiation constants than was previously obtained.
20 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The results of investigations made of this subject during the past

three years are being prepared for publication.

The increased refinement demanded in the investigation of instruments and methods used in radiometry has resulted in the production of a steadier and more reliable radiometer. During the past

four years various bolometers, thermopiles, and radiomicrometers

have been constructed and tested on various researches. The latest

attainment is a spectroradiometric outfit consisting of a vacuum

bolometer, a storage battery and a galvanometer, which for speed,

steadiness, accuracy, wide range of variation in sensitivity, and con- venience in operation, stands unique. The results of the above investigations and the latest attainments of various other experimenters

are being prepared for publication.

An account was published of an investigation of the selective

absorption and emission of the acetylene flame, and of the selective

emission of the Welsbach gas mantle and of the same material when

formed into solid rods and heated electrically. It is shown that the

peculiarities of these two types of illuminants can be explained on a purely thermal basis. This is the third paper issued on the selective

radiation of various substances, and the investigation is to be continued.

An investigation was completed on light filters (solutions) which

have a high transmission in the visible spectrum and absorb all the

infra-red rays; also an investigation of substances (opals) containing

water of crystallization. This is really a new method for the investigation of the condition of water in minerals. The radiometric test finds no distinction between " water of crystallization," " dissolved

water," and " water of solid solution," all giving the absorption

spectrum of water in its free liquid state. The results of these investigations will soon be ready for publication.

The investigation of the various types of radiometers for measuring

radiant energy in absolute units has been continued, with a view to

the development of a standard instrument. None of the instruments thus far investigated fulfills the requirements of a primary

standard.

These radiometric investigations are of fundamental importance in

connection with the various determinations of the properties of

materials. Many are undertaken as a result of requests for information which is not in existence, as, for example, the light filters, which

were desired by psychologists desiring intense luminous stimuli free

from infra-red radiation.

POLARIMETRY.

Excellent progress has been made in the various polarimetric investigations during the past year, in addition to equipping the new

quarters devoted to this work. The determination of the 100° point
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 21

of saccharimeters—the most important problem at present in sac- charimetry—has been continued. Throughout the sugar and sirup

industries, the saccharimeter is the fundamental instrument in standardization. As a requisite of this work, sugar of the highest purity

has been prepared from the widest possible variety of sources. This

problem has also necessitated further study of intense sodium light

sources. The installation of the large electromagnet has been completed

and it is now in use. This instrument was installed for the purpose

of studying the peculiar effect of magnetism upon light waves, twisting their plane of vibration and changing their lengths.

A number of improvements have been made in the new type of

polariscope designed at the Bureau, the most important being an

auxiliary fine adjustment to make available the full sensitiveness of

the instrument for especially accurate work. Its many superior

features have caused a wide commercial and scientific demand for this

instrument.

The testing of sugar and sirup samples for the Treasury Department, to check the analyses made at the larger customs laboratories,

has been continued. The differences between the results obtained at

these laboratories and at the Bureau have been reduced to below 0.2

per cent—the closest agreement yet attained.

The demand for samples of sugar of highest purity, for standardizing polarimeters and calorimeters, has increased considerably, and 85

samples were supplied during the year. The preparation of these

samples will be of great value to the industries, since the heat value

of fuels is determined upon the standard basis established by them.

In addition to the above, 1,351 polarimetric tests were made.

SPECTROSCOPY AND APPLIED OPTICS.

Conducting helium gas has been further investigated in regard to

suitability for furnishing a primary light standard with good results as regards reproducibility of color and intensity. A spectroscopic

studjr of the causes of deterioration in certain commercial vacuum

bulbs is in progress. A number of vacuum tubes of special form

filled with gases of certified purity have been prepared upon request.

A number of photographic objectives, reading microscopes, oculars,

and field glasses have been tested for the Government and for dealers.

Methods of testing have been further developed. A circular of information has been issued, dealing with optical instruments.

A great many determinations of refractive indices have been made

and refractometer test plates standardized. A number of the best

refractometers have been added to the equipment. A set of prisms

for secondary standards has been prepared.
22 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Tests of absorption made during the year include blocks of optical

glasses, standard absorbing screens for manufacturers of smoke-testing instruments, and the spectral absorption of numerous optical

glasses designed to protect the eye from injury by ultra-violet radiation. A circular of information dealing chiefly with absorbing materials has been prepared and published.

Tests made include coefficients of diffuse reflection of wall cover- ings and the spectral reflection of optical papers. A new method for

the absolute determination of the coefficient of diffuse reflection has

been devised and developed.

In colorimetry the wave length of the dominant hue and the per

cent white impurity in a number of secondary color standards have

been determined. A new form of colorimeter for making such absolute determinations has been designed and is being constructed. A

new instrument for determining the constants of the natural-color

scale has also been designed.

Investigations of the size, shape, and distribution of the grains in

photographic plates in relation to resolving power, definition, and

halation and the effect of exposure and development have been continued.

In physiological optics, work has related chiefly to color sensibility

and the injurious effect of ultra-violet light on the eye.

INTERFEROMETRY.

The determination of relative wave lengths of light has been continued. A table of 10 wave lengths in the spectrum of neon has been

completed. Experience has shown that the neon lamp will be especially useful in interference measurements, and it is thought that its extended use will increase the practical applications of such measurements. The new table will be of use in this connection, as well as in

spectroscopy where the wave lengths are needed as reference standards. Preliminary arrangements have been made for determining

coefficients of expansion by interference methods.

CHEMISTRY.

The following research problems have been completed during the

year and the results have either been published or are being prepared for publication: A convenient potash bulb; the action of sunlight and air upon some lubricating oils; the behavior of high-boiling mineral oils on heating in air ; the determination of total sulphur

in india rubber ; the influence of added fatty oils, etc., upon the car- bonation of mineral lubricating oils; the determination of vanadium

in vanadium and chrome-vanadium steels ; the determination of manganese in vanadium and chrome-vanadium steels; the determination

of chromium in chrome and chrome-vanadium steels; the determina-
REPORT OF DIRECTOR OP BUREAU OF STANDARDS. 23

tion of manganese by the sodium bismuthate method; the density

and thermal expansion of ethyl alcohol and of its mixtures with

water in collaboration with the division of weights and measures;

the theory and use of the silver voltameter in collaboration with the

electrical division; a new apparatus for vacuum sublimation; and

apparatus for the preparation of pure oxygen on a large scale.

The following are some of the lines of research work in progress

:

Testing of monel metal as to its value for many forms of laboratory

utensils and appliances that are now made mostly of iron; the test- ing of sodium oxalate to be used as a primary standard in the determinations of iron, manganese, and other substances; analysis of

phosphate rock, preliminary to the issuing of this material for checking analytical methods; the chemistry of the silver coulometer; the

preparation of pure organic substances for calorimetric work; the

preparation and purification of materials for the mercury-cadmium

cell ; the atomic weight of bromine ; the composition of the printing

inks used at the Government Printing Office; study of gas-testing

methods; study of underground electrolysis, in cooperation with the

electrical division; paper research problems; investigation of the

value of various materials used as waterproofing, damp proofing,

and roofing coatings; and a study of the resistance to corrosion of

the various types of ferrous metals.

One of the members of this division is chairman of a committee

of the American Society for Testing Materials having in charge an

extended series of service exposure tests of white pigments, in which

the Bureau will cooperate. Another member is chairman of a committee of the American Chemical Society charged with an investigation of the quality of laboratory utensils of platinum. The Bureau

cooperates in this work by placing facilities and material at the disposition of the committee.

Several members of this division devoted much time during the

year to assisting the President's Commission on Economy and Efficiency to draw up systematic schemes of classification for chemical

supplies and apparatus.

Of the Bureau's series of analyzed samples there were issued, on

request, 1,209 irons and steels and 274 ores, a total of 1,483, over double the number issued for the previous fiscal year. The large

increase was in part due to the demand for the four iron-ore samples which became available for distribution during the year. The

continued and increasing demand for these samples and for others

not yet ready fully justifies the Bureau in adding to its list. The

experience gained in analyzing materials of this character is alone

a valuable return for the outlay of time and money expended in

their preparation. A new form of mixer for metal samples has been

devised and has been tried out with success in most cases.
24 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Nearly 9,000 tests were made by this division during the past

year, which is a very large increase over the work of the previous

years. This increase is mainly due to the demand on the part of the

Government departments for tests to determine whether or not deliveries of materials and apparatus conformed to the specifications

upon which they were purchased, and to assuming the testing work

formerly done in other Government laboratories. By far the greater

number of these tests were made for the Government—3,221 being

made for the Supervising Architect's Office; 2,454 for the Isthmian

Canal Commission; 2,021 for the Government Printing Office; 794

for the General Supply Committee ; and a lesser number for 19 other

branches of the Government service and for States, municipalities,

universities, and private parties. Of these, 2,774 were of irons, steels,

and other metals: 712 of cements; 298 of asphalts, coal tars, etc.; 1,852 of paints and paint material ; 35 of waxes ; 121 of rubber ; 2,950

for papers, pens, inks, typewriter ribbons, of which 2,571 were for

papers; and more than 100 miscellaneous items. Many of these

materials require an average of about 12 determinations per sample.

In view of the fact that the Bureau has increased to a considerable extent the chemical examination of structural materials, the

character of the examination required upon these materials will be

described briefly.

The asphaltic materials and felts are used in building construction

on foundations and roofs as a waterproof medium. They are ex- amined to determine their specific gravity, general character at various temperatures, loss in weight on heating and effect of such

heating, per cent soluble in various organic solvents, amount of ash,

etc. The roofing felts are also examined to determine the amount of

felts and saturation matter and percentage of wool and cotton fiber

in the felt. These tests give a general indication of the character

and origin of the materials and their probable value as waterproofing

mediums.

Cements are tested to determine their specific gravity, fineness of

grinding, time of setting, soundness in air, water, and steam, and tensile strength neat and when mixed as mortar with standard sand. In

addition to the above physical tests, complete chemical analyses are made on practically all the samples submitted. The information obtained from such tests determines whether the materials meet the prescribed specifications and indicates their general quality. The tests

are, however, inadequate to determine fully the quality of the material, and no truly satisfactory tests have as yet been developed for

this purpose.

Terneplate is sheet iron or steel coated with an alloy of lead and

tin, and is used in metal roofing. It is tested to determine the weight

per square foot, the amount and composition of the coating, and the
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 25

black plate to which the coating is applied is analyzed to determine

its general character. The galvanized sheets are examined in a similar manner, to determine the amount and character of coating and

character of base.

Most of the ferrous metals axe samples of various grades of steel

and iron submitted by the Isthmian Canal Commission. They include not only different grades of structural steel but also various

steels used in locomotive and car construction and special alloy steels.

The nonferrous metals cover a wide range of brasses, bronzes,

white metal alloys, etc., used by the Isthmian Canal Commission for

fittings, bearings, etc. Most of the paint materials are submitted by the Supervising

Architect's Office, for use in the public buildings being erected by

that office. The oil driers are examined to determine the amount of

oil and volatile matter present, the amount and character of metallic

oxides used as the drying agents, the character of the volatile matter, and the actual drying effect of a fixed amount of the driers with

standard linseed oils and turpentines. The linseed oils are tested for

purity by determining certain constants, as specific gravity, iodine

absorption, saponification value, acid value, flash point, etc. Limiting

values have been set for these constants, and linseed oils to be considered pure must come within these limits. The amount of pigment, oil, and volatile matter is determined in the paints and the

character and composition of each is then determined. The time of

drying and character of the film are also determined.

The oil varnishes are examined to determine approximately (no

accurate method having been developed) the amount of oil, gum, and

volatile matter they contain. The acid value and the ash, showing

what oxides have been used as driers, are also determined. The volatile matter is tested for boiling point, specific gravity, action of con- centrated sulphuric acid, etc., to determine the presence and amount

of petroleum products and turpentine. Further tests are also made

to detect the presence of rosin. The spirit varnishes are examined

in a similar manner to determine the amount of gum and volatile

' matter and their character.

In addition to this routine examination of Government purchases,

there is a constant attempt to improve the method of anabysis in each

case, so as to furnish additional information regarding the character

and quality of the materials tested.

The results of this work will be of great value in the development

of improved specifications by a comparison of laboratory records with

the behavior of the material under service conditions.

Special laboratory tests, also, have to be developed to produce in

a relatively short time the same effect as long-time service exposure.

In this line a program has been outlined covering an investigation
26 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

of the value of various materials used as waterproofing, damp proofing, and roofing coatings. This will include exposure of these materials to normal and abnormal conditions of service, with physical and

chemical laboratory tests, and the study of the data thus obtained.

ENGINEERING INSTRUMENTS.

The work of the engineering instrument section has consisted

chiefly of the rating of water-current meters for the Geological Survey, Reclamation Service, and the State water resources offices, and

the development of methods for the testing of speed-measuring instruments, such as speedometers, tachometers, and taximeters. A

careful study has been made of practically all the various types of

speedometers at present on the market and the results are now ready

for publication.

At the request of the General Supply Committee, a preliminary

study was made of two types of fire extinguishers submitted by them

and many extinguishers now in service in the departments were

examined. This work has been reported to the committee and at

their request is to be continued.

Among the instruments calibrated during the year are 162 watercurrent meters, 38 pressure gages, 13 speedometers, 4 fire extinguishers. 2 anemometers, and 2 gasometers.

STRUCTURAL, ENGINEERING, AND MISCELLANEOUS MATERIALS.

STRUCTURAL MATERIALS.

The number of routine tests of structural materials made during

the year was approximately double the combined tests of a similar

nature made by the Geological Survey and the Bureau of Standards

during the preceding fiscal year. This was made possible by reor- ganizing and improving the routine methods. The results thus far

attained indicate that the Bureau will be of material aid to the industries concerned particularly by the standardization of apparatus

and methods of testing.

At the beginning of the year the testing and investigation of

structural materials by the Bureau was augmented by the work of

that nature formerly conducted by the United States Geological Survey, and the laboratories, equipment, and personnel for this work were

formally transferred. Previous to this time the work was carried on by the Geological Survey in four laboratories—one in Pittsburgh,

Pa., which conducted tests and investigations of ceramics, cements,

lime, steel, and miscellaneous structural materials; one in Washington, which tested structural and miscellaneous materials, mainly for

the Supervising Architect's Office ; one at Northampton, Pa., for the

testing of cement, principally for the Isthmian Canal Commission,
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 27

and one at Atlantic City, N. J., for conducting an investigation of the

effect of sea water upon concretes and protective coatings.

The equipment transferred consisted of one 100,000-pound, three

200.000-pound, and one 600,000-pound testing machines, and a new

10,000,000-pound Olsen testing machine not then delivered by the

maker, as well as various smaller machines for testing cement and

clay products, together with miscellaneous laboratory apparatus for

this work, and office furniture.

The testing work and investigations in progress at the time of the

transfer were continued, but some changes were made in the arrangement of the laboratories and distribution of the work. The work

of the Washington laboratory was moved to the Bureau of Standards

buildings as soon as the necessary laboratory space could be equipped

with facilities for the work.

While the testing was not disturbed by the transfer, it was neces- sary to devote considerable time to reorganizing the work and coordinating it with the similar established testing work of the Bureau.

Much has been done in collating and preparing for publication the

unpublished data accumulated prior to the transfer. This data consists of results of many investigations, of which some were started as early as 1906. Practically all of the results of these tests were uncollated and considerable time was required for verification, calculation, study, and preparation of the manuscripts. The following

reports have been prepared for publication : " The Strength of Reinforced Concrete Beams—Results of Tests of 333 Beams (first series) ;" " Tests of the Absorptive and Permeable Properties of Portland

Cement Mortars and Concretes, Together With Tests of Damp-proofing and Waterproofing Compounds and Materials; " " The Effect of

High-Pressure Steam on the Crushing Strength of Portland Cement

Mortar and Concrete; " and " Lime: Its Properties and Uses."

The investigation and testing of structural materials comprises

both chemical and physical tests. The chemical work is in general

done by the division of chemistry and is described elsewhere in this

report. The more important of these materials are cements, ceramics,

lime, metals, and protective coatings. The work on these materials

will be discussed under their respective heads.

CEMENT.

Over 23,900 samples of cement, representing over 2,300,000 barrels, were tested at the Washington, Pittsburgh, Northampton, and Allentown laboratories. This required a total of over 521,000 physical

tests, consisting of determinations of tensile strength, soundness,

time of setting, specific gravity, and fineness. During the preceding

year less than 12,700 samples were tested in the combined laboratories

of the Geological Survey and Bureau of Standards.
28 REPORT OF DIRECTOR OP BUREAU OF STANDARDS.

Practically all tests were made for the Government departments,

each laboratory inspecting and testing the cement purchased in its

particular field. All cement used in the construction of Federal

buildings throughout the country, and miscellaneous samples received

from other Government departments and the public, were tested in

Washington. Cement purchased in the vicinity of Pittsburgh, by the

Navy and War Departments, was inspected at the mill and shipped

under the supervision of the Pittsburgh laboratory. The cement for

the Isthmian Canal was tested at Northampton, Pa. It was found

expedient to establish also a temporary laboratory at Allentown, Pa.,

to take care of sampling at the mills and testing the cement purchased

by the Navy and War Departments in that vicinity.

At the present time each branch of the Government is purchasing

cement upon a different specification, although the same quantity of

material is desired. In an endeavor to obtain one standard, engineers

from all departments of the Government using cement were called

into conference at the Bureau to consider the unification of existing cement specifications and the preparation of a single standard

specification for use throughout the United States.

The investigation of the action of sea water on cements, mortars,

and concretes was continued at the Atlantic City laboratory. The

work done was somewhat in excess of that of the preceding year.

The results so far obtained have been tabulated and studied and a preliminary report is in course of publication. Tests to determine

the effect of alkali water on cement mortars and concretes were

continued and practically completed.

A short series of tests was made at the Pittsburgh laboratory on

the use of pulverized tufa and pulverized sand, to determine the

effect of these on the strength of mortars when replacing part of the

cement.

CERAMICS.

This work is largely conducted at the Pittsburgh laboratory,

although some testing and investigative work is done in the Washington laboratory. During the year it was devoted to. the testing

of clays and clay products for various Government departments and

making investigative tests for the public. Research was also con- ducted on the development of the toughness of burnt clay, representing typical materials. In connection with this work, sand-blast

apparatus was designed and constructed, and data on the relative

merits of the sand blast and rattler tests were obtained. The study

of the relation between the porosity and crushing strength of burnt

clay was pursued, and the work was almost completed. The study

of different methods for determining the absorption, porosity, permeability, and specific gravity of building brick has been extended.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 29

An investigation on the technical control of the colloid matter of

clay was completed and the matter is being prepared for publication.

An investigation of the effect of preliminary heat treatment upon

the drying of clays was also completed and published during the year.

LIME.

This work has been carried on at the Pittsburgh laboratory. It consisted of the determination of the effect of the burning temperature of lime upon its properties, including porosity, specific gravity,

rate of hydration, and content of carbon dioxide. Tests were also

developed and instruments were designed for testing commercial

limes. These tests are to be used in measuring the rate of hydration,

plasticity, sand carrying capacity, color, yield, hardness, shrinkage,

time of setting, and crushing and tensile strength. A calorimeter,

slaking machine, and viscosimeter were designed and constructed.

These tests were applied to a number of synthetic mixtures in order

to determine the effect of impurities. The relative rate of carbonation of quick and hydrated lime was also measured. The effect of

temperature, size of stone, and porosity on the rate of decomposition,

was studied. Continuing the policy of keeping in close contact with

plant operations, three lime plants were visited. As previously stated a circular was prepared and issued on the properties and uses of lime.

There has been a very large demand for this circular from producers

and users of lime.

METALS.

The testing and investigation of metals are conducted at both the

Washington and Pittsburgh laboratories. Practically all of the tests were made for the Government, for the purpose of determining

whether or not the material delivered complied with the specifications.

This material consisted of structural steel members, angle bars, turn

buckles, car couplers, chain triplets, wire ropes, iron and steel cast- ings, bronzes, babbitts, metal roofing, galvanized sheets, various steels

used in locomotive and car construction, special alloy steels, wire rope,

white metal alloys, etc. In extending the testing and investigation of metals, and permitting a practical application of the research work in the laboratory,

strain measurements were made during the year on structures of

magnitude, such as railway bridges of large span, the lofty types

of architectural structures, and steam boilers under hydrostatic pressures. These strain measurements, taken in conjunction with the

laboratory tests of the physical properties of the component parts of

structures, give a complete history and record of the material for

engineering purposes.
30 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The strain measurements upon steam boilers indicate that it may

be feasible to judge the efficiency of the material in the design of

boilers of different types, by means of such measurements over the

usual range of hydrostatic test pressures; that is, this system may

enable rational rules and formulas to be developed governing the

allowable steam pressures under which the boilers may be used. This

information may be obtained upon boilers of current manufacture

without in any way impairing their usefulness or subsequent service

condition.

The strain measurements during the year comprised observations on the large structural members and main trusses of the Bankers'

Trust Company building in New York City, on structural members

of the New York City bridges, on members of the Pittsburgh and

Lake Erie Railroad bridge over the Ohio River at Beaver, Pa., on

the Missouri River Bridge at Kansas City, Mo., on steam boilers at Providence, R. I., and preparations are being made to begin this

work on the massive lock gates of the Isthmian Canal.

PROTECTIVE COATINGS.

This material was tested by the Washington laboratory, mainly

for the Supervising Architect's Office, and included asphalts and coal

tars, felt, paint and paint materials, linseed oil, oil driers, varnishes,

etc. As these tests are mainly chemical in their nature, these materials are treated more particularly under the heading of " Chemistry."

MISCELLANEOUS MATERIALS.

A large number of miscellaneous materials were tested for the

Government departments, including rubber belting, rubber bands,

packings, various types of hose, belting, belt lacing, etc. In many

cases investigations have been made with a view to the preparation

of standard specifications for these miscellaneous materials, and it has also been necessary to do considerable work in the development

of methods of testing.

NEW TESTING MACHINES.

The installation of the two Emery testing machines in the Washington laboratory is practically complete so far as pertains to the

machines proper. The work is in an advanced state on the weighing

mechanism of each machine. These machines will be provided with

an improved type of hydraulic accumulator, and it is believed that

with the completion of this equipment the Bureau will be provided

with testing apparatus superior to any other in existence.

At the Pittsburgh laboratory a new building is being erected for

the housing of the 10,000,000-pound Olsen testing machine. This is
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 31

the most powerful testing machine which has been constructed. It

is of the vertical type and is especially adapted to the testing of large

masonry columns. For the handling of large specimens, the testing

machine is being provided with the necessary traveling cranes and

other hoisting facilities. The Pittsburgh laboratory also has a vertical testing machine of 600,000 pounds capacity and several types

of commercial testing machines. The two laboratories will be well

adapted for making investigative tests on the physical properties of

structural materials of all classes.

PAPER AND TEXTILES.

The testing of papers, textiles, and cordage has extended to practicalry every department of the Government.

Assistance has been rendered numerous State and city governments in selecting standard papers, and analyses have been made for

dealers and manufacturers.

The equipment for extending paper investigation and preparing

experimental papers has been supplemented and some preliminary

work accomplished.

The equipment for the conditioning of textile materials has been

nearly completed. Some investigation has been made of the accuracy

obtainable in the determination of yarn counts both in the yarn and

finished fabric. A study of the experimental sampling, scouring,

and conditioning of wool is in progress and has already yielded some

interesting results.

There were tested 3,276 papers, 1,207 samples of cordage, and 606

textiles. It has rendered extensive assistance to the General Supph7 Committee in the preparation of specifications, the testing of samples,

and in expert service on its several subcommittees in the making of

awards.

It has also assisted committees of Congress, the President's Commission on Economy and Efficiency, the Tariff Board, and several

departments in the collection of technical data.

THE OFFICE.

LIBRARY.

The library contains 7,528 accessioned volumes (including a few

bound pamphlets), almost exclusively of a scientific and technical

character. During the year the Library of Congress has transferred

to the Bureau the second copies of books deposited for copyright,

bearing on physics, testing of materials, and allied subjects, in all

560 volumes. The Library of Congress and other libraries have

freely loaned books to the Bureau as in previous years. The number

of periodicals currently received has been 270, most of them being

obtained through exchange with the Bulletin of the Bureau.
32 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

PUBLICATIONS.

During the year 29 new scientific papers were published, giving

results of investigations conducted by the Bureau. Eleven revised

editions of circulars were printed, and 6 new circulars issued upon the

following subjects: "The Standardization of Bomb Calorimeters,"

" Publications of the Bureau of Standards," " The Testing and Properties of Optical Instruments," " The Determination of the Optical

Properties of Materials," " Announcement of a Change in the Value

of the International Volt," and " Lime : Its Properties and Uses."

The results of technologic investigations are being prepared for

publication in a new series of publications, to be called " Technologic

Papers of the Bureau of Standards." The first number of this series

is entitled " Effect of Preliminary Heating Treatment on the Drying

of Clays."

PERSONNEL.

The personnel of the Bureau, including the Director, as provided

by Congress, for the past fiscal year, consisted of 192 persons, classified as follows:

Laboratory : 1 chief physicist, 1 chief chemist, 2 associate chemists,

2 phj^sicists, 12 associate physicists, 32 assistant physicists, 7 assistant

chemists, 38 laboratory assistants, 15 aids, 12 laboratory apprentices,

and 3 laboratory helpers; total, 125.

Office : 1 secretary, 1 storekeeper, 1 librarian, 14 clerks, 1 packer

and shipper, 5 messenger boys ; total, 23.

Operation of plant : 1 superintendent of mechanical plant, 4 as- sistant engineers, 2 electricians, 3 firemen, 3 watchmen, 1 messenger,

5 skilled laborers, 4 laborers, 3 janitors, 2 female laborers, 1 telephone

operator, 1 elevator boy; total, 30.

Construction : 1 chief mechanician, 8 mechanicians, 2 skilled woodworkers, 1 draftsman, 1 glass blower ; total, 13.

In addition to the foregoing, approximately 77 persons have been

employed in special research and other work, being paid from the

appropriations provided by Congress for conducting these investigations. The number of the emploj'-ees engaged in this class of work

varies from time to time in accordance with the needs of the service.

SUMMARY OF TESTS.

The work of the Bureau involves, among other things, a large

amount of testing of standards, measuring instruments, and materials.

A certain amount of this work is already organized upon an accurate

routine basis. Much of it, however, involves investigation of the

scientific principles underlying the test, a study of existing methods,

and the development of new standard tests of known accuracy. In
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 33

such cases, the research which must precede the actual testing is a most important function of the Bureau. For the test a reasonable fee

is charged, except when made for the National or State governments.

The corresponding amounts for Government testing are of interest,

however, and are added to the statement of tests which follows

:

Number and Value of Tests Completed, Fiscal Year ended June 30, 1911.

Nature of test.

For Government. For public. Total.

Number. Value. Number. Value. Number. Value.

179 $586.45 132 S353. 80 311 S940. 25 2,884 1,347.40 816 377. 70 3,700 1, 725. 10 7,334 2, 497. 45 337 321. 05 7,671 2,818.50

3,392 1,119. 63 15,834 3, 463. 29 19,226 4,582.92 Hydrometry 2,339 ' 2,355.00 103 169. 25 2,442 2,524.25 217 426.00 5 9. 00 222 435. 00

1,314 1,343.50 23 39.20 1,337 1,382.70

149 1,008.55 362 1,759.25 511 2,767.80 Photometry 1 3,612 8,569.00 308 1, 178. 70 3,920 9, 747. 70 9,907 33,297.75 126 2,582.94 10,033 35,880. 69 Physical and mechanical tests: Engineering (miscellaneous) 2,316 2,501.25 232 157. 00 2,548 2, 658. 25 Engineering instruments 192 872. 00 26 108. 50 218 980. 50 Structural materials 24, 350 46,599. 08 93 454. 00 24,443 47,053.08 Paper and textiles 3,384 6, 134. 50 133 160. 79 3,517 6,295.29

Total 61,569 108,657.56 18,530 11, 134. 47 80,099 119,792.03

1 Besides the foregoing, the Bureau inspected 942,059 incandescent lamps at various factories for other departments of the Government, the fees for which would amount to S6.674.75 additional.

2 3,314 tests, amounting to $23,738.61, were chemical tests made on structural materials. The number of tests made for the Government during the fiscal

year 1911, exclusive of lamps inspected at factory; was 173 per cent

greater than in the preceding year, and the number of tests for the

public was 52 per cent greater, the increase in tests for both Government and public amounting to 154 per cent. The receipts for tests were as follows

:

Total receipts, 1911 $10,880.73

Received prior to July 1, 1910, for tests completed in fiscal year 1911 $200. 43

Outstanding fees 387. 64

Refunds 8. 04

596. 11

11, 476. 84

Received for tests completed, fiscal year 1910 136.00

Received for tests in progress at close of fiscal year 1911__ 206. 37

342. 37

Fee for tests completed, fiscal year 1911 11,134.47

FINANCIAL STATEMENT.

The following statement shows the amount and object of each

appropriation provided for the Bureau for the fiscal year 1911, the

disbursement during the year, the amount of unfilled and unpaid
34 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

orders at the close of the year, and the unexpended balance remaining

at the close of business June 30, 1911

:

Appropriation. Total appropriation. Disburse- ment. Liability. Balance.

S201, 440. 00 $181,406. 84 $8, 153. 43 $11,879.73

46, 000. 00 38,364. 18 7,476.75 159. 07 Hon oi'dl OYnpncpc 17Li. filfi UJ.U. OU"}fi 1 175. 04 90S fill 3,000. 00 2, 192. 65 '614^88 192. 47

175,000. 00 174, 720. 01 70.00 209. 99 Investigating effects of electric currents 15,000. 00 11,587.65 3,361.71 50. 04 Testing machine (continued) 180, 000. 00 135,883.88 43, 901. 88 214.24 Testing structural materials 50,000.00 44,308. 14 5,544.62 147. 24

10, 000. 00 7,466.59 1,839. 18 694. 23 Testing of structural materials of the United States.

.

Testing machine at Pittsburgh, Pa

15,000. 00 15,000.00

25,000. 00 146. 00 24, 854. 00

Total 739,440.00 628, 692. 30 72, 137. 49 38, 610. 21

The following statement shows the condition of the appropriations

for the preceding two fiscal years at the close of business June 30,

1911:

Appropriation.

1909 1910

Total appropriation. Disburse- ment.Liability. Balance. Total appropriation. Disburse- ment.

Liability. Balance.

Salaries $141,540.00 41,000.00

15,000.00 3,000.00

$138, 765. 11

40, 906. 27

14,097.20 2,997.22

$2, 774. 89

93.73

898. 80 2.78

$165,280.00

46, 000. 00

17,500.00 3,000.00

10,000. 00

10,000.00

4,000. 00

$160. 455. 01

44, 149. 27

17,200.70 2,963.63

9,951.36

7, 633. 82 4,000.00

$4,824.99

70. 66

68.59

36.37

34.90

2,366.18

Equipment $1,780.07

230. 71 General ex- penses Grounds$4.00

Gaslight stand13.74 Weights and

Total 200,540.00 196,765.80 4.00 3, 770. 20 255, 780. 00 246,353. 79 2,024. 52 7,401.69

Respectfully,

S. W. Stratton, Director.

To Hon. Charles Nagel,

Secretary of Commerce and Labor.

o