Annual Report

Director of the Bureau of Standards

(0 the

Secretary of Commerce and Labor

for the

Fiscal Year Ejided June 30, 1912

WASHINGTON

GOVERNMENT PRINTING OFnCE

1913

Annual Report

of the

Director of the Bureau of Standar

to the

Secretary of Commerce and Labor

for the

Fiscal Year Ended June 30, 1912

WASHINGTON

GOVERNMENT PRINTING OFFICE

1913

REPORT

OF THE

DIRECTOR OF THE BUREAU OF STANDARDS.

Department of Commerce and Labor,

Bureau of Standards,

Washington, July 1, 1912.

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, 1912.

At no time has the Bureau had so many demands for its cooperation in regard to industrial standards, in devising standard methods

of measurement and test, and in researches involving precise measurement. The Bureau has continued with gratifying results its policy

of cooperation with all technical interests concerned. A. few actual

cases will illustrate the cooperation which the Bureau is aiming to

bring about in every field. For example, through such international

cooperation the electrical units and standards of England. France.

Germany, and the United States are noAV in close agreement. Largelythrough the Bureau's efforts, the standardizing institutions of these

countries cooperate with the Bureau in still further efforts to enhance

their accuracy. In cooperation with the Federal departments, the

Bureau has, during the year, secured the adoption for the entire

Government of standard specifications for Portland cement and is

working toward unifying specifications for other materials.

An important case of cooperation with the States is the annual

conference of State officials of Aveights and measures at the Bureau

of Standards. Through this means and without special legislation

harmonious relations have been brought about Avith the States.

Model laws and regulations have been drafted and inspection services

established. The outlook is full of promise for the success of the

nation-Avide movement for honest Aveights and measures in daily

trade.

In cooperation Avith the technical electrical interests, the Bureau

has prepared reliable copper-wire tables Avhich have been adopted

as standard by that industry, which has also accepted the Bureau's

definition of the horsepoAver in terms of scientific units.

3
4 KEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

These are several of manj'^ cases of cooperation which have been

effective in their results. Much of the success of the Bureau's work

has been due to the most hearty cooperation of manufacturers, consimiers, and technical exj)erts—especially where the results would

enure to the benefit of all. In this way the Bureau avails itself of

existing knowledge in each field and of the aid of specialists in daily

touch with each subject, and the results of the Bureau's work find

through these channels the most ready acceptance and application.

Standardization of industrial processes and products and the application of precise methods in science and technology have made it imperative that the Bureau keep in close touch with the advancing

needs for such work and, as far as practicable, be prepared to meet

such demands. The quality of materials depends upon their physical

and chemical properties, each of which may be measured and standardized exactly as their dimensions are standardized. While this

fact is already becoming a most fruitful factor in industry, its full

application must quicken industrial progress to an extent which can hardly be overestimated. Upon this view that quality may be

measured rests the importance of the movement for unified specifications for materials. Here the Bureau brings together the ex- perience of manufacturer and user, and the best judgment of technical specialists concerning each factor which affects the quality.

After a searching inquiry by correspondence, conference, and experiment, a specification is developed in which tests and attainable limits are set for the measure of each propert}' of the material, with a view

to the establishment of a standard of quality best adapted for the use intended. Such standard specifications result in more perfect

understanding between the maker, the user, and the testing laboratory. Upon the determination of the properties of materials rests the adaptation of them to the uses of mankind. The " standard

specification " based upon the accurately measured properties of

material which constitute its " quality " and the " standard test which determines those properties are indispensable in the efficient

and economical use of materials.

With the modern demand for constancy and high precision in the

standards and the elaborate means for their care, the custody anil

maintenance of the standards becomes a highh^ technical laboratory

operation. The standard temperature scale and the electrical standards are examjjles. The testing of standards assumes a special imjDortance from the fact that many of the tests fix the standard for

imjDortant branches of industry. Likewise, the Bureau's calibration

of the State standards for 10 States during the year sets the standard

of trade weights and measures for those States. A similar case is the testing of gas standards for cities. The comparison of sciep^tific
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 5

iiucl industrial standards sets the standard measures for commerce

and technology. In some cases the Bureau's testing is on an extensive

scale, as, for example, the testing during the year of 18,000 thermometers, 9,000 capacity measures, 3,000 standard weights, and the

inspection and testing involved in the jiurchase of more than 1,000,000

electric lamps, and 2,000,000 barrels of cement, the check testing of

imported sugars, the analysis and testing of Government supplies,

and of the structural materials used on Federal buildings. These are examiDles of the character of the work, of which a fuller account is given later in this report, the limits of which would be exceeded if

the work of the year were reported with the fullness needed for its

proper presentation. The results of much of the work will be found

in the 41 publications of the Bureau issued during the year. The

following report briefly summarizes the work by divisions.

ELECTRICITY.

In the Electrical Division researches have been carried on to maintain the electrical standards, to fix them more accurately, and also

to improve methods of electrical measurement and of testing. During the past year much testing was done for the Government and the

public to determine whether instruments and materials conform to

specifications, and what types of instruments are best suited to given

purposes, to ascertain the riierits of new designs, and to obtain

accurate calibrations of instruments for use in important tests or in

the measurement of large quantities of electric power.

Work has been continued on the mercury ohms and standard cells

in order to make these concrete standards of electric resistance and

electromotive force still more trustworthy. The investigation of the

silver voltameter as a standard instrument for the precise measure- ment of electric current has been completed and will shortly be published. The investigation of the absolute measurement of electric

current by a cui*rent balance has been completed and published.

These fundamental I'esearches in electrical science have been con- ducted Avith a thoroughness which marks an important advance in

electrical measurements.

Investigations have been made upon the properties of electric con- densers and upon the dielectric constant, absorption, and resistivity

of a number of crystals, resulting, among other things, in the discovery of a substance, fluorite, which shows no absorption. For several

years the effect of light upon insiilators has been under investigation,

and during the past year the work has been extended to include the

effect of humidity. The large amount of valuable information upon

this subject thus obtained will soon be published.
6 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

PRECISION RESISTANCE MEASUREMENTS.

The precision resistance measurements have included the investiga - tion of the methods and apparatus used in electric resistance measure- ments; the design, investigation, and construction of resistance standards; the determination of the electrical properties of conductors;

and the testing of resistance standards, bridges, precision rheostats,

potentiometers, etc. Each year a number of the 1-ohm resistance standards of the

sealed type are sent abroad for measurement in the national standards laboratories of England, France, and Germany, as recom- mended by a subcommittee of the International Committee on Electrical Units and Standards. These measurements show that the units

of resistance now in use in these national laboratories agree in value

to within 2 or 3 parts in 100,000—a degree of accuracy 10 times

greater than that obtainable prior to the development at the Bureau

of the sealed type.

The investigation of the resistance material therlo, to which refer- ence was made in the report of last year, has been continued. In

addition to continuing the record of changes in the resistance of the

older standards, additional standards have been constructed. So

far the results of the investigation seem to show that, as a material

for use in the construction of precision resistance standards, therlo

is somewhat bett-er than manganin.

The new apparatus designed by the Bureau for testing potentiometers has been carefully tested, found well adapted for the purpose,

and is now in regular use. The theory of the corrections to potentiometers has been worked out and different methods for determining the

corrections studied.

During the year the constants of a number of moving-coil galvanometers were determined for the purpose of finding the relative

suitability of the different instruments to the work in which they are used and to see to what extent the behavior of such galvanometers

IS in accordance with the theory. The measurements made show that,

for well constructed instruments, all the constants can be determined

with fair accuracy from the data given by five independent measurements, and that their behavior is in good agreement with the theory.

ELECTRICAL MEASURING INSTRUMENTS.

The number of electrical measuring instruments tested during the

year was greater than in any preceding year, tests of current transformers and break-down tests of insulating materials being very

much in excess of previous years. Several exhaustive tests of instruments were made for the makers in order to show where improve-
BEPOET OF DIEECTOB OF BUREAU OF STANDAEDS. 7

ments were necessary or desirable. Exhaustive comparative tests of

American direct-current watt-hour meters were begun during the year,

and considerable progress was made. A new and important method

of testing current and potential transformers was developed. New

apparatus has been designed and constructed to measure time in the

testing of watt-hour meters. This replaces the chronograph and stop

watch, as it is quicker and more convenient than the former and more

accurate than the latter.

MAGNETISM.

Magnetic properties of 58 samples of steel were determined during

the year—20 involved total core losses, 21 normal induction and

hysteresis determinations, and 17 special tests. These special tests indicate the changing requirements of the users of steels for electrical apparatus. While unusual now, they will undoubtedly have

to be met more frequently in the future. Considerable time has,

therefore, been spent in devising methods and apparatus for making

such tests. Methods and apparatus have been modified so that

specimens which are much larger or smaller than the standard sizes can now be tested. Upon such measurements depend largely the

improved efficiency of electrical apparatus.

Measurements of permeability at very low inductions and very high

frequencies, such as are common in telephony, have been made. Methods for such work need still further development and have been

investigated to some extent during the year.

For the regular testing for total losses in transformer and armature

steels, the tendency is toward the use of higher inductions than heretofore. Additional difficulties are thus introduced owing to a number

of conditions such as the variation of the form factor of the alternator

with the higher magnetizing currents needed. Effort is being made

to meet these new conditions satisfactorily.

The Bureau has loaned a number of standard magnetic test bars

to various educational institutions for the purpose of checking up

their permeameters. In this way it is planned to secure gTeater uniformity in magnetic measurements.

The cooperation between the Bureau and the committee on the

magnetic testing of iron and steel of the American Society for Testing Materials still continues. This cooperation in the consideration

of specifications and in the carrying on of experimental work, prevents needless duplication of Avork. The standards committee of the

American Institiite of Electrical Engineers has also agreed to co- operate in this work.

The investigation on the correlation of the magnetic and mechanical properties of commercial steels with a view to discovering some

simple magnetic test which may replace some of the mechanical
8 EEPOBT OF DIEECTOE OF BUEEAU OF STANDAEDS.

tests and thus avoid the destruction of the material under examination is still in progress. A large amount of data has been collected,

and in every case investigated there haA'e been magnetic diiferences

between specimens which had mechanical differences. Without

generalizing from the results already obtained, it may be stated that

the outlook is very promising. For example, in a certain grade of

steel such as is used in springs and tools, the magnetic tests showed

whether or not it had received the proper heat treatment to give it the desirable mechanical properties.

If the material is not satisfactoiy, the same magnetic test shows

whether the defect is in the nature of too great brittleness or too

little mechanical strength. Another test on this same material will

show whether it has been subjected to local strains beyond the elastic

limit. In another case a steel rail which had broken in sexwice and

in which the microscope showed the presence of transverse fissures,

had a decidedly lower permeability than a similar rail of the same

composition which had never been in service and which showed no

such transverse fissures. Defects in certain low carbon steel bars

have been produced in various ways, e. g., by bending, nicking,

stretching, drilling holes, etc., and in every case the good and the

defective material have shown characteristic differences.

This work has been carried on with only a limited number of

small specimens and by laboratory methods. As this field is almost

entirely neAv, it will be necessary to carry on these preliminary investigations with hundreds of samples, including all the materials

that are used in practice. In case the complete investigation fulfills

the promise of the part already done, no reason is apparent why

the same or similar methods may not be applied to the commercial

sizes, e. g., full-length steel rails.

INVESTIGATIONS IN ELECTKOLYSIS.

The investigations in the field and in the laboratory of the serious

effects of electric currents upon underground structures, piping, etc.. have been continued throughout the year. Eesults already obtained

relating to the effects of electric currents on concrete have been compiled, and will soon be ready for publication. This report treats of

(1) the nature and causes of the phenomena which arise from the

passage of electric currents through both reenforced and nonre- enforced concrete; (2) the condition under which damage to concrete

structures by stray currents may occur in practice, and the extent to

which trouble may be expected under practical conditions; and (3)

precautions that may be taken for minimizing damage from this

source in both new and old structures.

The field work relating to the subject of electrolysis of underground

structures generally has been continued along the lines previously
EEPOET OF DIRECTOR OF BUREAU OF STANDARDS. 9

folloAved. In this connection a careful study of electrolysis conditions in a number of cities is being made, in some of Avhich the

problem of electrolysis is a serious one, Avhile in others comparatively little trouble has been experienced. A detailed study is being made of all the factors entering into the electrolysis situation

in each of these places, and a careful study of all possible methods of

mitigation is being carried on with the view of pointing out certain

principles of general application that may be of material assistance to

electric railway companies and others in securing the maximum of

protection at a minimum costPHOTOMETRY.

The two sections of this Avoi'k are (1) flame standards, the calibration of photometric instruments, the testing of illuminants, and

problems in illuminating engineering; and (2) the preparation and

calibrating of incandescent electric standards (carbon and tungsten) and of color screens, maintenance of the primary photometric

units, and the inspection and life testing of lamps for the Government. The direct relation of light measurement to human wellbeing makes the work in photometry of special interest and importance.

The work upon flame standards consisted largelj^ in the calibration

of pentane lamps to be used as standards in testing the gas supplied

in various cities. The previous investigations of the Bureau have

shown the necessity of such calibration, and the publication of this

fact through the proceedings of the American Gas Institute, as well

as through the Bureau's circulars and correspondence with inspectors of gas and other officials, has led to a great increase in the number of such standard lamps sent to the Bureau for test. The number

certified during the past year exceeds the total of all previous years

combined. Each lamp tested usually serves as the standard by

which the illuminating power of the gas supply of a city is judged.

The importance of this work is evident, since b}^ such standardization

t]ie quality of gaslight is maintained.

The experience of the Bureau has made it a recognized authority on the construction and operation of pentane standard lamps. The

effects of varied construction and operation of pentane lamps have

been carefully studied. Many additional details and related questions still need investigation, e. g., to determine the effects (1) of

variations in construction (in order to specify more exactly the

dimensions of those parts which may affect its value), (2) of sur- rounding screens, (3) of variation in the proportions of air and

pentane supplied to the burner. It would also be desirable to further

verify the results already obtained in regard to the effects of atmos73089—13 2
10 KEPORT OF DIRECTOR OP BUREAU OF STANDARDS.

pheiic conditions on the lamps and, at the same time, to extend the

investigation by obtaining gTeater variations in those conditions, and

by making comparative measurements on other flames, especially on

the kinds of burners which are used in the testing of gas.

A great variety of problems in illuminating engineering has arisen

during the year^ several of which occujoied considerable time and

included tests of lighting installations as well as the illuminants

themselves.

For commercial companies tests have been made of the efficiency,

light distribution, and life of luminous arcs, and of the intensity

and distribution of light from a number of inverted gas lamps.

The Bureau has been called on for advice as to the improvement

of the lighting of the Civil Service building and the economical

lighting of the post office building at Baltimore. The latter was

taken up by the President's Commission on Economy and Efficiency

as a typical case of the lighting of public buildings.

During the year the field work of the investigation on the condition

of commercial weights and measures throughout the country was

practically concluded with inspections in Oklahoma, Louisiana, Alabama, Kentucky, Indiana, Colorado, New Jersey, and New York.

The interest in the preliminary reports of the investigation continued,

and a number of these were issued in typewritten form where there

was immediate need of them, as in States where legislation was

introduced, etc. The hearty cooperation of the State and local officers

greatly enhanced the value of the results obtained, and their influ- ence upon local conditions was in many cases prompt and effective.

The reports on the cities inspected throughout the country are now

practically completed and will soon be ready for the printer. When

issued it is expected that a majority of the States which have not yet

passed satisfactory legislation will be convinced of the necessity of

so doing by the conditions revealed in these reports, and it is probable

that many will take action at the following sessions of their legislatures. In this investigation startling irregularities were found in

trade measures, as indicated by the brief summary of the apparatus

tested during the year.

WEIGHTS AND MEASURES.

Number of tests. Percentage.

Tested.

Correct. Incorrect. Total. Correct. Incorrect.

Scales Weights

Dry measures. .

Liquid measures

639

994

357

242

511

184

357

95

1,150

1,182 694

337

55.57 84.09

51.44

71.81

44.43

15.91 48.56

28. 19
KEPOBT OF DIRECTOR OF BUREAU OF STANDARDS. 11

Cogent reasons for the urgency of this subject are apparent when

it is remembered that the neglect of inspection gives the dishonest

dealer a distinct advantage over the honest dealer and the con- sumer is helpless, since the standards are in the possession of the

Government. This investigation is fundamental and its effect will

be far-reaching upon the weights and measures of daily trade, benefiting alike the consumer and the honest merchant.

The Bureau has assisted in the framing of local legislation, and

technical assistance was also rendered, both by correspondence and

personal work, by members of the Bureau staff to the States which

have recently passed such legislation in establishing inspection departments.

Revision of the State and National laws on weights and measures

was completed during the year, and included all of the recently

enacted laws on the subject. The compilation practically represents the status of weights and measures in the United States at the

present date, and should be of great value to both National and

State governments in the consideration of future legislation.

The Seventh Annual Conference on the Weights and Measures of

the United States, held at the Bureau on February 15 and 16, 1912,

proved, both in numbers and in results accomj)lished, to be by far

the most successful held since the inauguration of the meetings in

1905. In all, 98 persons attended, 25 States were represented, Avhile

51 city and county Aveights and measures officials took part in the

proceedings.

An unprecedented number of old sets of State standards were submitted for test, as well as a considerable amount of new equipment.

This was largely on account of the interest manifested in the question

of correct weights and measures and the interest of the States in

revising their laws on the subject. While this testing of standards

taxed the facilities of the Bureau to the utmost, the work was completed promptly. The standards tested were those of Connecticut,

Indiana, Arizona, Minnesota, Montana, Nevada, New Jersey, Pennsylvania, Vermont, and Wisconsin, besides those of a number of

municipalities.

Early in the year a thorough investigation of the fine-mesh sieves

used in testing cement were made for the purpose of preparing revised

specifications for Portland cement, which were put into effect by Executive order on April 12, 1912. The old specifications were found

impractical and their application in actual testing resulted in the

rejection of practically all sieves submitted. New sieve specifications

were prepared in cooperation with the manufacturers and users, utilizing the new data gathered by the Bureau during the past four

3'^ears, and they have already had a beneficial effect upon the manufacture of cement sieves.
12 BEPOET OF DIRECTOR OF BUREAU OF STANDARDS.

The thermal expansion TTork has made substantial progress, and

the Bureau is now prepared to determine the expansivity of brass

from room temperature up to about 700° C.

A systematic investigation of the expansivity of materials should

be begun. In the case of many substances no data appear to have

been published, and in almost all instances a revision of existing data

is desirable. Pure metals, analyzed alloys, and various industrial

materials shovild be examined over as wide a temperature range as

possible. The investigation should inquire into thermal hysteresis,

the effects of such heat treatment as hardening and annealing, the

behavior in the neighborhood of critical regions, changes in dimensions with humidit}', the effects of such mechanical treatment as rolling, hammering, drawing into wires, prolonged vibrations, etc. The third edition of Circular No. 2 on " Metal Tapes " was completely revised and enlarged to cover all Bureau tests involving meas- urements of length and area, including thermal expansion. In addition to the usual specifications and fee schedules, information was

inserted concerning units and standards, conditions influencing the

dimensions of bodies, etc. MASS.

The material for a new circular on the testing of masses was prepared during the year. This comprises instructions as to the use, care, adjustment, and test of standard weights, and information and

tables for use in precision work when the observed weighings were

reduced either to vacuo or to some standard pressure. Tolerances for

the weights submitted to the Bureau were established, as well as for

commercial or trade weights for which there was urgent demand.

Advance sheets of the circular were furnished for criticism to the

various manufacturers concerned and valuable suggestions were

received.

V0LU3IE.

A marked improvement in American-made volumetric glassware

and hydrometers submitted for test during the past year is noted, the

apparatus now submitted being equal, and in some respects superior,

to the best grades of similar apparatus of European manufacture.

This is in sharp contrast with the condition which prevailed at the

time the Bureau Avas established, and is one of the best examples of

the value of rigid specifications coupled with facilities for ascertaining whether the apj)aratus purchased on specifications conforms

thereto. Practicallj'^ all volumetric apparatus and hydrometers used

in the Government laboratories are now ordered on Bureau specifications, and university and private laboratories are using them with

increasing frequency.
KEPOKT OF DIBECIOK OF BUEEAU OF STANDAKDS. 13

BAROMETRY.

Aneroid barometers are instruments of great importance to sur- veyors, explorers, aviators, and in scientific investigations. The Bureau has undertaken the thorough study of these instruments, which

are used to measure the atmospheric pressure and from this to ascer- tain the altitude above or below sea level. The investigation, which

included the intercomparison of a large collection of aneroid barometers representing twelve different makers, was completed during the

year. The results show to what extent the errors of an aneroid are physically inherent and to what extent they may be avoided by suitable tests. In the investigation four kinds of tests were made,

namely, mechanical, temperature, atmospheric, and air-pump tests. The mechanical tests consisted (1) in determining for each aneroid

the probable error of a single pointer reading as affected by parallax,

tapping, etc., and (2) in calibrating the pressure and altitude scales

of typical aneroids.

The temperature tests consisted chiefly in taking aneroids out doors

on a very cold winter night and later heating in a receiver surrounded

by hot water, with the conclusion that in good instruments thermal

errors are negligible compared with other errors, and therefore need

not be seriously considered until more is done to eliminate mechanical and elastic errors. In the free atmosphere tests, 25,000 observations were taken in

order to keep track of the history of each aneroid in the interim between successive air-pump tests, to ascertain to what extent it is fair

to pass judgment on an aneroid from observations on the fluctuations

of its correction from day to day, and to detect secular changes.

The air-pump tests were, however, the most important, and also

the most laborious, as it was necessary to hold the aneroids for 24

hours at the lowest pressure in order to observe the creeping effect

due to imperfect elasticity. This determination of the creep appears

to be the crucial point in ascertaining the quality of an aneroid.

As a sequel to the foregoing investigation the development of

standard specifications for the purchase of aneroids has been imdertaken at the joint request of other branches of the Government service

and of manufacturers. The final results of the Bureau's work in this

field can not fail to be of great value in improving the design, manufacture, and use of these important instruments.

Special apparatus was constructed to test mercurial barometers,

and especially to stud}? several sources of error peculiar to them. To

obtain the necessary range of pressure for testing high-altitude mercurial barometers, the receiver Avas constructed for operating the

verniers and cistern screws through air-tight containers. Finally

a routine method was put into practice for carrying out the necessary
14 EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS.

manipulation, observation, recording, and computing so as to secure

the greatest accuracy in the least time.

NEW WORK IN WEIGHTS AND MEASURES.

An investigation of variations in spring scales was commenced to

determine the possible errors of certain types, especially when subjected to temperature changes, with the end in view of establishing

tolerances for this type of scale. The manufacturers of spring scales

showed much interest in this investigation and several submitted

compensating devices designed to correct defects noted by the Bureau.

This investigation should be extended to springs in general, and

should include a systematic study of their elasticity, temperature

coefficient, durability, and other properties, as affected by the composition of the steel and the heat treatment of the material of which

they are made. Spring scales, on account of their convenience, are more largely used in this country than in any other country in the

world, and any improvement in their action would be of general

concern.

It is proposed to undertake the investigation and testing of railroad, elevator, and other scales used in weighing commodities for interstate shipment, and for this purpose to purchase a standard test car equipment and a standard scales of sufficient capacity. This will

necessitate a special appropriation. A number of the railroads have

already efficient inspection departments, and others are establishing

them, but there are a number of roads that have practically no supervision of their track scales, which are defective in design and incorrect in their indications.

Since approximately $2,200,000,000 are derived from freight, practically all of which is weighed upon some form of railroad scales, it

is of the greatest importance that the scales be correct. At the present

time controversies continually arise between the railroads and shippers, owing to lack of confidence as to the correctness of weighings

and it is believed these controversies will in a large measure bt

obviated if the correctness of the scales is assured.

Certain industries, such as the grain industry, maintain their own

weighmasters and scales in the more important grain markets, but the

average shipper is without the means to check his weights and is compelled to pay charges determined by weighing on scales over which

neither he nor the Government has at present any supervision. Most

of the commodities are shipped from one State to another, and even

if the States should establish inspection services to cover railroad

scales a number of questions would arise that could only be settled

by the Federal Government. The equipment proposed would enable

the Bureau to cooperate with the State authorities, and also to

standardize their apparatus for them.
KEPOET OF DIRECTOR OF BUREAU OF STANDARDS. 15

THERMOMETRY, PYROMETRY, AND HEAT MEASUREMENTS.

The work of testing in all the sections of this division has increased

ver}^ greatly in the last two years. It has been possible to meet

these demands only at the expense of progress on several important

' investigations that are fundamental to the work of this division.

THERMOMETRY.

The thermometers tested in this division during the year number

I7j866, made up as follows : 81 Beckmann and calorimetric thermometers graduated to 0.01° or 0.02° and used in work of the highest

precision, 254 ordinary calorimetric thermometers used in determining the heating values of fuels, 9 primary standard Baudin thermometers used to define the standard scale of temperatures, 2

liquid-in-glass thermometers for measuring very low temperatures,

1,060 ordinary mercurial thermometers, and 16,460 clinical thermometers used by the medical profession. In addition there were

tested in this section 7 electrical resistance thermometers, 1 thermocouple, and 1 compound differential thermocouple.

Work has been continued whenever opportunity would permit on

the standardization of a number of primary standard mercurial

thermometers in the range of 100° to 500° C.

A theoretical and experimental investigation of the effects of

thermometric lag on temperature measurements was completed during the year and is now in press. A paper on the corrections for the

emergent stem of mercurial thermometers was published during the

year.

Through the courtesy of Drs. Day and Sosman an opportunity

was afforded to compare several platinum resistance thermometers

with their nitrogen gas thermometer up to 630° C. It is hoped that

this and similar work will, in the near future, lead to international

agreement as to the standard scale of temperature to be used by the

several national laboratories.

CALORIMETRY.

An important work of the Bureau is the determination of standard

heats of combustion and especially the standardization of the instruments and materials used in such work. During the year this division furnished 168 standard combustion samples of sugar, naphthalene, and benzoic acid, used by chemists and engineers to standardize

the calorimeters and to check the accuracy of the methods used in

determinations of the heating value of fuels.

Special tests made in this section included the test of a gas caloruiieter for a public-service commission, the determination of the specific
16 EEPOET OF DIRECTOK OF BUP.FAU OF STANDAKDS.

heats of two special distillates, the determination of the heats of

combustion of a special engine oil, and of an oil gas by-product for

manufacturing concerns. Considerable work has been done during the year on the investigation of various forms of calorimeters used in the industrial testing

of the heating values of gases. In view of the increasing importance

of the heating value in legal requirements for the sale of gas, this

investigation promises results of immediate practical importance.

Some work was also done on the determination of the specific heat

of copper in the temperature range within which this constant should

be known with the highest accuracy for calorimetric purposes.

PYROMETRY.

The tests carried out in this section include 6 platinum resistance

thermometers, 41 platinum alloj'^, and 21 base-metal thermocouples,

26 pyrometer galvanometers, 8 optical and radiation pyrometers, 53

determinations of the melting points of metals, alloys, slags, etc., an increase of about 60 'per cent over that of the preceding year.

Considerable work was done on the radiation from surfaces of

steel at high temperatures with a view to furnishing data to users of radiation p3a'ometers. which would enable them to reduce observations with these instruments to true temperatures. This investigation

is being extended to the radiation from nickel and other metals.

An investigation was completed during the year on the melting

points of 54 samples of fire clay, bauxite, silica, magnesia, and chromite bricks. Work is in progress on the melting points of pure re- fractory oxides such as magnesia, lime, etc. It has been found

that some of these materials have much higher melting points than

has been supposed.

A paper on the present status of the temperature scale was communicated to the recent International Congress in Applied Chemistry.

Circular No. 36 was compiled and issued during the year, giving

a summary of our present knowledge of the melting points of the

elements.

A committee of the International Photometric Commission has

expressed the desirability of having experiments carried out on a primary standard of light along the lines suggested by two members

of this division in a paper published some years ago in the technical

press.

A number of industrial plants have very complete temperature

measurino- installations. It is most desirable that convenient means

be afforded these plants which would enable them to check the accu- racy of the pyrometers from time to time, in much the same way
KEPORT OP DIRECTOR OF BUREAU OF STANDARDS. 17

that the Bureau has enabled users of calorimeters to check the results

of their tests by furnishing standard combustion samples. This can

be done by furnishing standard melting-point samples, consisting

of a series of metals and salts of accurately known melting points.

The necessary assistance should be provided as soon as possible to

enable the Bureau to furnish such standard samples.

The measurement and control of high temf)eratures is receiving

rapidly increasing attention in many industrial lines, and an important part of the work of this division consists in furnishing information bearing on these questions. Our laboratories are visited

almost daily hj engineers and technical men interested in temperature problems.

METALLURGY AND SrETALLOGRAPHY.

The tests carried out in this section include the determination of

the heating and cooling curves of 6 samples of steel and 11 metallographic tests. A paper on the work on metallurgy was recently

published in the technical press by a member of this division. Work

was continued throughout the year on the factors influencing the

recalescent points in pure iron and in iron alloys, and on the methods

of determining heating and cooling curves.

MISCELLANEOUS.

Other tests carried out in this division were as follows: 18 special

tests, such as the freezing and absorption tests of bricks, heat tests of miscellaneous materials, etc.; flash-point and viscosity tests of

85 samples of lubricating oils.

Two papers were published in the Bulletin during the year by a member of this division on a method of computing the constant of

Planck's equation for the radiation of a black body and on the steam

turbine expansion line on the Mollier diagram.

OPTICS.

SPECTROSCOPY AND APPLIED OPTICS.

In connection with the investigati(;n of conducting gases as photometric standards, a set of 40 helium tubes prepared as primary

candlepower standards of light in accordance with the results of

previous work were measured up. The results showed that the proposed standard has the requisite reproducibility. A comparative

test of sources suitable for photographic spectrophotometry led to

the adoption of the condensed tungsten spark in air, operated on a

10,000-volt transformer as the best. Tubes of improved design

filled with pure gases have been supplied various optical laboratories

73089—13 3
18 EEPOET OF DIRECTOE OF BUEEAU OF STANDAEDS.

as light sources. The demand for these tubes is rapidly increasing.

Various spectroscopic tests of chemicals have been made and an investigation of the spectra of acetj'lene and methane is under way.

A large number of optical instruments and accessories have been

tested during the year along the lines laid down in Circular No. 27,

which appeared early in the year. These tests include the determination of the residual aberrations, focal length, and apertvire of photographic objectiA'es of all kinds, small telescope objectives, microscope

objectives and oculars; and the field covered magnification, light loss

and definition of telescopes, reading microscoj)es and projection apparatus. The radii of curvature of numerous lens surfaces and test pieces have been determined. Applications for determinations of

shutter speed have been received.

Investigations carried on include a comparative determination of

the properties of a series of wide-angle objectives and considerable

work on high speed and process lenses. Methods of determining

abei-rations have been devised and developed until the list is practically complete. Tests of photogTajDhic test charts have been made

and new ones devised suitable for rough, rapid tests. A study of the

limits of tolerance in the errors of various classes of objectives is under way. A precise rapid method of determining shutter speed

has been devised.

Man}^ determinations of refractive indices have been made during

the 3^ear. These include very precise (6-place) determination of

standard test liquids and glasses, certification of the standard plates

used b}^ chemists to check the scales of direct reading refractometers,

the determination of index and dispersions of optical glasses, precise determinations of egg albumen (age test) for the Department of

Agriculture, and numerous rough determinations (l-place) of various oils, solutions, and crystals.

A large spectrometer of the highest obtainable precision and a set of prisms for reference standards have been added to the equipment.

Several direct reading refractometers have been tested and certified.

An investigation of commercial refractometers with a view to improvement in sensibilit,y and precision is under waj.

The precise measurement of color has received a great deal of

attention during the past 5i'ear. An absolute color analyzer, giving

anatyses directly in terms of wave lengths of the dominant hue and

the per cent white impurity, was devised and is now in use. A large number of card and glass reference standards of color

have been standardized and certified. Standardization of the ref- erence standards used in the purchase and sale of cotton oil is under

way. Work is planned on the methods of color analysis and standardization of the colors of textiles, papers, tobaccos, butter, dyes,

liquors, etc.
EEPOET OF DIRECTOR OF BUREAU OF STANDARDS. 19

An extended series of comparisons of direct midda}^ sunlight Avith

the light of the acetylene flame have shown that the former is a satisfactory constant working standard as Avell as an ideal white light.

Using such sunlight as standard white, the variations in the colors

of various sources with temperature or total radiation are beinginvestigated.

A great many absorbing screens of various kinds have been tested

•during the year. A comparative test of photographic ray filters

for the Government indicated those Avhich sacrifice least of the active

desirable light and yet possess the desirable absorption of blue and

red. The efficiency of the photographic safe lights for use with

different kinds of plates has been determined. Numerous absorption glasses for protecting the eye from injurious ultra violet radiation and absorbing a minimum of visible light have been investigated

with the result that American-made glasses are now available which

are more efficient than the best imported ones. The reflecting and diffusing powers of various surfaces and transmission screens, now receiving so much attention by illuminating

engineers, have been investigated. A new, rapid, and precise instrument for determining reflecting poAver has been perfected, used

in our testing, and made available to the public. Another instrument has been devised and used in determining the distribution of

the reflected and transmitted light. A number of determinations of

reflecting power have been made on materials sent in for test. Data on the injurious effects of ultra violet light in various illuminants have been sought by the public and have been supplied as far

fis available. A preliminary investigation of this subject has been

carried out with the cooperation of the Treasury Department, and

a more detailed investigation planned.

The fundamental principles and methods, of colorimetry depend

upon the sensibility of the human eye to differences in wave lengths

and purity, and similarly those of photometry to differences in

brightness. These sensibilities are being investigated by new and

improved methods and valuable data are being obtained.

POLARIMETRY.

Work in connection with the standardization of sugar analysis by

means of the polariscope test has been carried on by the section of

polarimetry for the Customs Service and the public. During the past

year the control of sugar analysis at the various ports of entry

by check analyses of samples transmitted daily has been continued.

The efficiency of the method continues to show itself by the constantly increasing accuracy of the analytical results obtained at the

ports of entry. The new type of adjustable saccharimeter as devel-
20 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

oped at the Bureau has been introduced into the Customs Service

iind a still higher accuracy is anticipated. Many quai-tz plates used

in the daily control of the saccharimeter haA'e been tested and certified for the Treasury Department and for the public.

The determination of the hundred per cent point of sugar-testinginstruments is one of the fundamental problems of polarimetry. Aii

investigation for the purpose of determining this important constant

has been under way since the organization of this section and is now

practically completed. The investigation of the hundred per cent

point of the saccharimeter has developed the fact that an important

error exists in the accepted value of this fundamental constant. To

eliminate all uncertainty this investigation will be continued.

The preparation and distribution of standard sugar samples of

sufficiently high purity to be used to test saccharimeters and calorimeters has been continued, and by a careful study a greater certainty

of analj^sis has been attained.

A most fundamental problem in j^olarimetry as well as optics in

general at the present time is the production of monochromatic light

of considerable intensit}^ Considerable time has been devoted to

this subject in the polarimetric laboratory, and within the year an

instrument has been perfected which apj^ears to solve this important

problem.

During the year a temporary constant temperature room has been

installed, permitting the extension of the Avork into a number of

new fields. Several new researches have been started, and the work

of preparing pure sugar from a wide range of sources has been

carried on. Owing to the amount of vacuum Avork incident to the work of this

section, a neAV vacuum pump has been designed and perfected, Avhich

not only produces the highest A'acua Avith great rapidit}', but does

it for the first time without the aid of an auxiliary air pump. These

features have an important bearing on the constantly increasing use of high A^acua in the arts and sciences.

KADIOMETKT.

Work has progressed on the radiation constants of the so-called

" black body " (a uniformly heated inclosure). This concerns standfird radiation of energy and the divergence of various sources from

such standard radiation, a problem Avhich underlies the theory of

pyrometry, photometry, and spectroscopy.

The " blackness " of the radiator Avas speciall}^ studied bv nine

series of spectral energy curves obtained with tAvo porcelain tube

furnaces. Energy curves were obtained from the Avhite porcelain

tubes; then similar curves were obtained at the same temperatures

when the inner walls of these tubes were painted Avith chromium
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 21

oxide, with cobalt oxide, or combinations of these two oxides. In

all, 91 energy curves were obtained using different j)risms, different

ijdjustments of^the same prism, different water cooled shutters, and

different thermocouples.

A new paper entitled " Instruments and Methods of Radiometry "

is now ready for publication. The paper contains information for

the specialist as well as for the beginner, and was prepared in re- sponse to numerous requests by both types of inquirers for information upon this subject. No authoritative or complete treatise on

racliometry is available.

Until recently psychologists have been using light stimuli without

knowing their mechanical equivalent. All such work must, therefore, be repeated ; and now they are confronted with such difficulties as (1) lack of training in radiometry, (2) lack of simple instruments which are sufficiently sensitive to measure light stimuli, and

(3) lack of standard of radiation. Surface thermopiles of bismuth

and silver were constructed and tested (likewise the light filters

which absorb all the infra-i-ed) to meet the needs of this class of

investigators.

A new paper entitled " Selective Emission of Various Substances "

has been prepared for publication concerning (1) the radiation constants of platinum, (2) the emission spectrum of neon and helium,

(3) the emissi^dty of different parts of the acetylene flame, (4) the

variation of emissivity with thickness of the radiating layer, oxides,

(5) standard spectral eiiei'gy curves, and (6) light filters Avhich absorb all the infra-red. The investigation of the radiation constants

of platiniun proves a far more extensive research than might be

suspected. The results, obtained confirm the previous researches in

this series, showing that the metals have no radiation constants.

The maximum emission of neon radiation lies in the visible (red^

spectrum, which does not obtain in other gases.

Further data on the Nernst glower and tungsten were prepared

for publication in '• Selective Emission of Yarious Substances IV;

Standard Spectral Energy Curves." A new quartz mercury vapor

lamp has just been prepared for producing intense spectral lines,

with which it is intended to find the absorption in the short focus

spectrometer to be used in this investigation.

In an interesting radiometric investigation of the manner of

production and the quality of the light emitted by fireflies two

noteworthy facts were ascertained—^(1) the maximum of the light

emission is different in different species, not an optical illusion as was supposed, and (2) the temperature of the luminous organs is

higher than that of the adjacent nonluminous segments. The study

of the physics of light production in such insects may yield results

of great practical utility.
22 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The recent purchase of one of Abbot's standard silver-disk pyrheliometers will enable the Bureau to compare its measurements of

radiation in absolute measure Avith the Abbot prftnary standard.

A primary standard similar to Abbot's in type but different in

design will be constructed and a small dividing engine for cutting

surface bolometers was recently constructed in the instrument shop.

Several surface bolometers were acquired, making it possible to

intercompare this type of the Bureau's instruments with those of

other makers. The utility of the Callendar radiobalance as an

absolute standard was investigated and found wanting.

An investigation of much technical importance is the determination of the diffuse reflecting power of various substances for different spectral regions, e. g., 0.6u,, l.Oix, 4.4[;., 9.0\)., 3.0;ji, etc. The

radiometer consists of a surface thermopile of 22 elements in a space of 11 millimeters, the total width being 5 millimeters. Numerous substances have been examined, including various kinds of

lampblack, platinum black, green leaves, building material, cloth

pigments, etc. As the Bureau is a final court of appeal when physical constants are in dispute, it can not consistently or authoritatively use data for the accuracy of which it can not vouch. An excellent

illustration of this point is the question of the diffuse reflecting

power of lampblack, and of pigments in general, which investigation

is now nearing completion in this Bureau. New and apparently

accurate data were published elsewhere, the results of which gave an

" apparent reflecting power from two to three times the " true

'"

value.

IN TERFEEOMETRY.

The determination of 10 wave lengths of lieon has been published.

The values obtained are thought to be accurate to 1 part in 5,000,000, or better, and will be useful spectroscopic standards.

Attention has been given to elaborating definite methods for the use of the neon wave lengths in interferometry. Extensive tables

have been prepared to facilitate the determination of the order of

interference. It is expected that the neon lamp Avill be of great

value in future work in interferometry.

Experiments have been made in tlie preparation of iridium mirrors by kathode disintegration, and some very good mirrors prepared for laboratory use. A modification of the original kathode

method has been devised and used with some success in the preparation of very thin mirrors.

The determination of expansion coefHcients by interferential

methods has been put upon a Avorking basis. Three coefficients

have been determined for the Coast and Geodetic Survey. Attention has and is still being given to improving the methods for determination of expansion coefficients.
KEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 23

CHEMISTRY.

The research work of the Chemical Division has resulted during

the year in the preparation of papers upon the following subjects:

The determination of manganese in vanadium and chrome-vanadium

steels ; the determination of chromium and its separation from vana- dium in steels; a rapid method for the determination of vanadium

in steels, ores, etc., based on its quantitative inclusion by the phosphomolybdate precipitate; a new method for the determination of

vanadium—and explanation; the reduction of vanadic acid in con- centrated sulphuric acid solution by hydrogen dioxide and by persulphates; the hydrolysis of sodium oxalate and its influence upon

the test for neutrality ; the standardization of potassium permanganate solution by sodium oxalate; the determination of manganese

as sulphate and by the sodium bismuthate method ; the use of benzoic

acid as an aciclimetric standard; an improved extraction apparatus;

a new apparatus for vacuum sublimation; preliminary report on the

quality of platinum laboratory utensils; errors in the determination

of moisture in coal ; a modified form of stability test for smokeless

powder and similar materials ; the evaporation test of mineral lubricating and transformer oils. The researches now in progress include: Methods of analysis of

phosphate rock, with special reference to the determination of

alumina; action of lubricating oils; methods of direct determination

of rubber; exact determination of physical constants of pure alcohol

(a work necessitated by the wide use of alcohol as a solvent) ; methods of testing and analyzing illuminating gas; causes and

effects of electrolysis on concrete; the investigation of waterproofing

materials; the effect of atmospheric conditions of roofing terne

plates; the exposure tests of 125 paints made from systematic combinations of 13 primary pigments; effects of water emersion upon

paints for metal surface. The determination of the atomic weight

of bromine is about completed and will be published in the fall. During the year 1,091 samples of standard analyzed materials were

distributed for check testing the accuracy of technical analyses. New

standard samples of three special steels were prepared during the

year. Standard samples of chrome-tungsten steel are now under

analysis by a corps of chemists of acknowledged repute and skill m

such analyses, and will shortly be issued in the regular series. Special difficulties were met in the preparation of the standard cast brass

samples which it is expected will soon be overcome. It is gratifying

to report that one of the prominent chemical manufacturers has suc- ceeded in manufacturing on a large scale highly pure sodium oxalate,

which the Bureau has established as a standard for oxidimetry in

volumetric analysis.
24 EEPOET OF DIRECTOK OF BUBEAU OF STANDABDS.

Members of the Chemical Division liave cooperated in the revision

of the methods of coal analj^sis and the determination of water in

coal and other fuels and minerals.

In the determination of the properties of materials the following

classes of materials were investigated: Irons end steels, metals and

alloys and other iron and steel, coated metals, cements, asphalt, felts,

etc., linseed oil, oil driers, j)aints and paint materials, varnishes,

lubricating oils, sealing wax, rubber, papers, ]Drinting inks, wool, flax

packing asbestos, insulating tape—a total of about 8,613 materials

analyzed and certified.

ENGINEERING INSTRUMENTS.

The testing of engineering instruments during the year consisted

chiefly in the rating of water-current meters for the Geological Survey, Keclamation Service, for a State Water Supply Commission,

and for State universities. The instruments calibrated included 20i

stream meters, 37 pressure gauges. 10 anemometers, 4 water meters,

2 fire extinguishers, 2 steam-engine indicators. 1 ship speedometer,

and 1 tachometer. A new type of fire extinguisher was also tested

and reported upon to the Treasury Department.

At the request of the Secretary of the Treasury an extended tesc of portable vacuum cleaning machines was undertaken for the Office

of the Supervising Architect of the Treasury Department. Twentytwo machines submitted by 16 ditfeient manufacturers were tested.

Methods of measuring the air were investigated and new apparatus

was desigTied. Electrical efficiency curves were plotted, as well as curves showing the relation of vacuum maintained to volume of air

moved, and an extended sweeping test was made to obtain a rating

for the machines as cleaners. Suggested changes Avere made in the

specifications of the Treasury Department for portable vacuum

cleaners. A detailed report of the tests was made to the Treasury

Department.

An investigation of methods of testing water-current meters in

different countries resulted in the development of designs for a test- ing tank to be installed at the Bureau. The tank will be of the

straight-away type, about 400 feet in length, and specially adapted

to testing anemometers as well as water-current meters. This equipment Avill enable the Bureau to investigate these important instruments and greatly facilitate their testing.

ENGINEERING, STRUCTURAL, AND MISCELLANEOUS MATERIALS.

JIETALS.

Installation of the two Emery machines has been in progress for

the past fiscal year and the smaller machine of the two, having a capacity of 230,000 pounds for loads of tension and compression.
KEPOET OP DIRECTOE OF BUREAU OP STANDARDS. 25

has been erected and preliminary tests made upon it. The larger

Emery machine, of 2,300,000 pounds capacity, has been installed so far as the main machine parts are concerned and the Bureau is now

awaiting the delivery of the weighing mechanism which will complete the installation. An accumulator system has been provided

for use in the joint operation of these two machines, consisting of

three independent accumulators, one of which is compound. This

equipment is located in, the Washington laboratory of the Bureau.

At Pittsburgh a new building has been completed for housing the

several machines located at the laboratory. The 10,000,000-pound

Olsen testing machine has been erected and tests upon it are now

being made. This machine is located in the new^ building and all of the testing machines have been grouped in the same room. Increased machine facilities have been i^rovided for the fabrication of

special tools and equipment and preparation of specimens for test purposes.

Both laboratories have been called upon as heretofore to make investigative tests and tests for acceptance of current supplies for different departments of the Government. The Bureau has also been

called upon by engineering societies to conduct investigative tests. Arrangements are being made to conduct such tests in cooperation

with several of the technical societies.

Specifically, the laboratories have been engaged on strain measure- ments of bridges, buildings, and also the lock gates, emergency dams,

and walls of the Panama Canal. Compression tests of structural

members have been arranged for in cooperation with committees of

the American Society of Civil Engineers and the American Railway

Engineering Association. Current work has included an inquiry

into the properties of railway material and the contributory causes

of railway accidents. The work on railway material has been con- ducted at the request of the Interstate Commerce Commission, while

the work at the Isthmus has been in cooperation with that of the

Isthmian Canal Commission. The Bureau has also been called upon

to aid the War Department and the ISTavy Department in regard to

the structural state of steel fo-rgings.

In addition to the work on metal testing the Bureau is engaged

on inquiries of strength of woods intended for dry-dock purposes on

behalf of the Isthmian Canal Commission. This inaugurates a line

of work which will embrace an inquiry into the properties of the

different native North American woods and those which are found

in the insular possessions of the country.

CEMENT.

Cement testing.—A total of 19,365 samples of cement were tested

at the Washington, Pittsburgh, and Northampton laboratories during
26 KEPOET OP DIRECTOR OF BUREAU OP STANDARDS.

the year, representing in Government purchases over 2,000,000 barrels of Portland cement. Physical tests were made on the samples

to determine their specific gravity, fineness of grinding, time of set- ting, soundness in air, water, and steam, and tensile strength.

Practically all of the tests were made for the Government departments, each laboratory inspecting and testing the cement purchased

in its particular field. Samples of the cement used in the construction of Federal buildings throughout the country and miscellaneous

samples received from the Government departments and the public

were tested, and the testing and supervision of sampling and shipments at the milt for the Government departments were made in con- nection with the testing in the Washington laboratory. The Pittsburgh laboratory supervised similar work in connection with purchases made in the vicinity of Pittsburgh. At the Pittsburgh branch

the routine cement testing is done for the United States Army Engineers in connection with the erection of dams along the Ohio River.

Shipments have also been made to several of the dry docks along the

Atlantic coast, erected under the supervision of the Navy Department. The cement for the Isthmian Canal was tested at Northampton. The decrease in shipments to the Canal Zone caused a falling off in the work at Northampton by 20 per cent as compared

with the preceding year. The work of the Washington and Pittsburgh laboratories increased about 50 per cent.

Cement specifications.—A conference of Government engineers of

the various departments was held at the Bureau of Standards for the.

purpose of unifying the specifications for Portland cement used by

the United States Government. A specification was developed which

was unanimously adopted by this conference on February 13, 1912.

Conferences were also held with committees of the national engineering societies, and substantial agreement was reached on all but a few points. On April 30, 1912, the President issued an Executive

order requiring that the new specifications be used in all purchases

of cement. The Government thus obtains a product of assured quality

and at a saving owing to definite requirements and greater competition in bidding. The standardization of product also benefits the

public consumer. It is hoped complete uniformity of specification

may soon be attained for the entire industry for both the Government

and the public.

Investigations upon cement and concrete.—Investigative work in

the cement section is being carried on to obtain information in regard

to the constitution of Portland cement, and how the physical properties are changed by differences in the composition and consequent

differences in the constitution. For this purpose there has been

erected at Pittsburgh a 2 by 20 foot rotary kiln with the necessary
KEPOET OF DIRECIOK OF BUREAU OF STANDARDS. 27

grinding apparatus. Ther© has also been established in this connection a petrographic laboratory, and, in addition to the usual chemical

and physical tests of the cement manufactured, a complete petrographic analysis is made. The subject of the hydration of cement is

also being taken up in this line. The kiln is also used for makingburnings of raw materials submitted by the general public for a nominal fee.

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

and concretes was continued, and an exposure station Avas established on Government property at Charleston, S. C, to continue the work

started at Atlantic City, N. J. A technologic paper, now in press,

gives the preliminary results of the laboratory and field investigations. The completed results of the investigation on the effect of

alkali salts on cement are included in this publication.

A field and laboratory investigation of the permeability to water

of structural materials is in progress. The results are urgentlj' needed

by the Government as well as the public in the design of structures

where impermeability or protection against dampness are a necessity.

The work involves both laboratory and field tests. An investigation of the volumetric changes which take j)lace in

concrete structures owing to temperature variation in the hardening

of concrete is being made to determine the necessity of expansion or

contraction joints or the causes of cracking in concrete structures.

Reference marks are placed on structures which can be measured

from time to time and volumetric changes noted.

It is proposed that the testing of cement include an exposure of the

cement to high-pressure steam. The value of such a test as a means

of indicating the structural quality of cement is under investigation

by the Bureau. The effects of heat, moisture, and pressure are being

separately investigated.

PITTSBURGH BRAKCH OF THE BUREAU.

The Pittsburgh branch of the Bureau of Standards is located on the

grounds of the Pittsburgh storage and supply depot of the United

States Army, and occupies the Army building (known as No. 10),

a brick kiln house erected since the ceramic work was started at Pittsburgh, and a new building just erected by the Bureau to contain the

large testing machines. Building No. 10, approximately 44 by 210

feet and 45 feet high, contains two floors, each floor being divided into

offices and small laboratories. On the second floor are located the

chemical laboratory, ceramic laboratories, the main lime laboratory,

the library, the petrographic laboratory, and general offices. The

first floor is divided into larger rooms for the heavier machines re-
28 REPORT OF DIRECTOR OF BUREAU OP STANDARDS.

quired in the work. Here the main laboratorj^ of the ceramic section

occupies the front of the building. On this floor is located the laboratory for the physical testing of cement and concrete, as well as the

machine shop, the carpenter shop, and two rooms for the storage of

material.

The kilii house is a one-storj^ brick fireproof building 30 by 80 feet

and 20 feet high. The larger part is occupied by kilns of the ceramic

department and includes two down-draft natural-gas fired kilns—one

30 by 36 inches and one 32 hy 40 inches; also a 20-inch circular kiln

and furnace for testing fire brick under loads, as well as two small

carbon resistance furnaces for determining the softening points of

clays, bricks, and porcelains. The smaller section of the kiln house

contains the 2 by 20 foot rotary kiln for cement burning, as well as the crusher, hammer, and ball mills for grinding the raw mix and

cement clinker.

The new building is approximately 45 by 90 feet and 60 feet high,

with an engine and boiler room and a section connecting it with building No. 10. The latter section is divided into two stories, the upper

being used as oiiices and the lower as a storage room for the machine

shop, which it adjoins. The main building houses one 100,000, two

200,000, one 600,000, and one 10,000,000 pound testing machines—all

of the Olsen type—as well as several smaller machines used for various purposes. In order to handle the large specimens for the larger

machines a 20-ton crane is provided, the gantry of which is sufficiently

high (40 feet) to clear the top of the large testing machines. This

also extends about 40 feet beyond the north side of the building, en- abling the crane to pass out of the building and over a railroad siding

and pick up large specimens directly from the cars.

CERAMICS.

With the rapidly increasing cost of wood as a building material,

with the growing demand for fireproof construction, for more satisfactory sanitary conditions, for permanent roads throughout the

country, for a more artistic architecture, and for the development of

the American clay industries to replace the large importation, the

subject of clays and clay products becomes an important one in our

present civilization. The many technical problems connected with

the utilization of clays, and the testing of their products, have ren- dered it advisable to provide facilities for work along these lines,

especially since the Government is a large user of ceramic structural

materials. This has been done at the Pittsburgh laboratories, where

the necessary machines for the grinding, preparing, and molding of

clays are available, together with ample kiln space for reaching any
KEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 29

desired temperature. Electric furnaces for the determination of the

higher softening- points of silicates, and all apparatus for the physical

and chemical study of silicate mixtures, are provided. Use is also

being made of the testing machines of the Pittsburgh branch for the

determination of compressive and tensile strength, etc. Many tests are being made of ceramic materials for the various Government

bureaus, such as the Supervising Architect of the Treasury, the

Isthmian Canal Commission, the Keclamation Service, and the

Geological Survey, as well as for a number of State surveys.

Among the researches now being carried on are the following

The influence of time upon the rate of vitrification, the viscosity

of porcelain bodies, the behavior of clay refractories, the crushing

strength of burnt claj' as related to porosity, the production of hightemperature porcelain, the dehydration of clays, the development of

vesicular structure in clays due to overfiring. and a study of paving

bricks in connection with their wear in actual use.

LIME.

Although lime is one of our oldest building materials, no attempt

has been made until very recently to standardize its quality. The

tendency to found modern building codes upon an exact basis has

shown that standard specifications for lime are needed. The demand

comes especially from the various cities and from the National Lime

Manufacturers' Association.

In attempting to satisfy this demand a series of tests have been

devised by which limes can be compared Avith regard to the folloAving properties: Chemical analysis, plasticitj^ (or spreading quality),

carrying capacity, color, waste (the proportion of lumps of hard

material which must be screened out before the lime can be used),

yield (the volume of standard paste obtained by slaking unit weight

of lime), hardness, crushing strength, tensile strength, and shrinkage.

The applicability of these tests has been determined b}^ trying them

out on a large number of representative samples of all kinds of lime

and hydrated lime, and they are now available to the general public

for a nominal fee.

Research work is being carried out to determine whether the above

tests cover all of the important properties of lime, and whether they can be improved by being made more nearly scientifically exact without sacrificing practical applicability.

It has also been found necessary to investigate the influence of the

processes upon the properties of the material. Moreover, it would

be inadvisable to demand a certain quality of lime without due re- gard to its commercial production and application. The discoAery
30 REPORT OF DIRECTOK OF BUREAU OF STANDARDS.

of new uses for lime, or the study of the adaptability of different

kinds of lime to different uses, should be of benefit to the industry as a whole.

The Bureau is at present cooperating with the National Lime

Manufacturers' Association and the American Society for Testing

Materials to formulate standard specifications for lime.

PAPER AND TEXTILES.

The Bureau tested during the year 2,046 samples of paper of all grades used by the Government. In addition to the routine work of

the paper-testing laboratory, considerable work has been done in the

process of installing additional equipment for the production of

standard paper samples. This equipment will soon be ready for use. Some preliminary work has been done toward making permanent

standard slides of different paper-making fibers. Analine colors were

chosen to match the color given to the fiber by the zinc-chlorideiodine-potassiuni-iodide stain. Sufficient investigation has been car- ried through to encourage hope in the successful outcome of these

investigations.

The textile laboratorj^ is now in a position to make all physical and

chemical tests on raw and unspun fibers, yarns, twines, and fabrics.

The Bureau has investigated the effect of moisture on the tensile

strength of yarns of all kinds, also the leng-th of test specimens for

tensile strength tests. A large number of scouring tests on raw wool

were made to determine the percentage of grease present, the amount

of moisture contained, and the regain; samples being secured from

manufacturers in different parts of the country.

The Bureau has also begun the standardization of fabrics, yarns,

and twines by the foundation of standard specifications for use in

the various Government departments. These specifications are drawn

up from actual samples obtained from the various Government

bureaus. During the year 514 different textile samples were tested

and certified.

RUBBER AND MISCELLANEOUS MATERIALS.

During the past fiscal year, the Avork of the miscellaneous laboratory has comprised the testing of the physical properties of miscellaneous materials, such as mechanical rubber goods, leather, metals,

packings, etc., for the various Government departments; investigations of the physical properties of rubber, and the development of

special testing machines and improved methods of testing.

The large quantities of mechanical rubber goods received for test from the Isthmian Canal Commission and the General Supply Com-
EEPOKT OF DIRECTOR OF BUREAU OF STANDARDS. 31

niittee made it necessary to devise means for facilitating and expediting the work. A number of special testing machines have been

designed and are now in operation, thus greatly increasing the capacity of the laboratory.

The materials tested during the past fiscal year include rubber hose,

rubber dredging sleeves, gaskets, rubber valves, packing (rubber,

asbestos, flax), rubber belting, rubber bands, leather belting, iron and

steel, brass and bronze, insulated wire, rawhide belt lacing, brushes,

linoleum, steel punches, fiber board, insulating tape, sash cord, brass

valves, metal tape, paper fasteners, stitching wire, sheet metal, gal-

\'anized conduit, and condenser tube—in all, a total of 993 different

samples.

The following investigations are now being conducted: (1) A

study of the properties of elastic rubber bands and the development

of an accelerated test for determining their life and efficiency''; (2) a studj^ of the x^roperties of leather belting and methods of testing

with a view to the improvement of present specifications; and (3) a study of the aging properties of various rubber compounds such as are used in the manufacture of mechanical rubber goods, and the

development of an accelerated test to determine the life of such compounds.

Several manufacturers of rubber goods have rendered material

assistance in these investigations by furnishing the necessary rubber

compounds for test. It is hoped that in the near future it will be

possible to install an experimental, mixing plant at the Bureau

in order that every stage of the work may be directly under our

supervision.

THE OFFICE.

LIBRARY.

The number of accessioned volumes in the Bureau library is now

9,340; 284 periodicals, 189 of which are by exchange, are currently' re- ceived here and at Pittsburgh. The extra copies of copyrighted

Ijooks relating to the Bureau's work have been transferred from the

Library of Congress to the Bureau, as in the previous year. More

than 1,000 volumes have been thus transferred, covering all copyright deposits previous to the current year.

PUBLICATIONS.

During the past year 41 new publications Avere issued by the

Bureau, as follows: Scientific papers, 2G; technologic papers, 9; circulars, 3 ; miscellaneous, 3. The circulars related to " Copper Wire
32 EEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

Tables." " State and Municipal Eegnlations for the Quality. Distribution, and Testing of Illuminating Gas,'' and " United States Government Specifications for Portland Cement." The miscellaneous publications were : " The Sixth Annual Conference on the Weights and

Measxires of the United States," " State and National Laws Concerning the Weights and Measures of the United States," and a descriptive

pamphlet concerning the organization and work of the Bureau of

Standards.

PERS0^^NEL.

During the fiscal year 1912. the personnel consisted of 192 persons

employed in statutory positions and about 80 upon si:)ecial research

and investigajtion specially authorized by Congress. The statutory

positions were classified as follows

Scientific.—1 chief physicist, 1 chief chemist, 2 associate chemists,

2 physicists. 12 associate physicists, 32 assistant physicists, 7 assistant

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

and 3 laboratory helj^ers ; total, 125.

Office.—Secretary, 1 storekeeper, 1 librarian, 14 clerks, 1 packer

and shipper, 6 messenger boys ; total, 23.

Operation of plant.—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 Avoodworkers, 1 draftsman, 1 glass blower; total, 13.

SUMMARY or 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

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

folloAvs.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 33

Nmnhcr and raJiie of tests completed, fiscal year ended June 30, 1912.

For Government. For public. Total. Nature of test. Number. Value. Number. Value. Number. Value.

Length 405 .$1,008.65 207 $356. 35 612 $1,365.00 Mass 2, 230 1,245. 35 945 566. 15 3, 175 1,811.50 Capacity 8,302 3,420.41 933 568. 75 9' 235 3^989. 16 Temperature 3,513 1,563.50 11,-584 3, 727. 44 15^097 5^290. 94 Hydrometry 2,002 1,867.25 173 220. 50 2,175 2, 087. 75 Miscellaneous 6 7. 00 12 20.70 18 27. 70 Optical 1,289 1,.373. 10 49 162.00 1,338 1.535.10

Electrical 269 794. 10 336 2,041.40 605 2,835.50 Photometry ' 4,503 11,635.50 386 1,338.50 4,889 12,974.00

9,367 58,062.30 921 1,775.89 10,288 59,838. 19 Physical and mechanical tests: Engineerinf; (miscellaneous) 1,112 1,736.50 13 42.00 1,125 1,778.50 Eufjineering instruments 223 1,064.00 32 144. 50 255 1,208. 50 Structural materials 21,658 39,508. 00 111 565. 75 21,769 40,073.81 Paper and textiles 2,571 2,990.50 44 76.75 2, 615 3,067.25

Total 57,450 126, 276. 22 15, 746 11,606. 68 73, 196 137,882. 90

' In addition, the Bureau inspected 1,199,974 incandescent lamps at various factories for other depart- ments of the Government, the fees for which would amount to $11,724.47 additional.

2 4,317 of these tests, amounting to .$41,239, were chemical tests made on structural materials. The receipts for tests were as follows

:

Total receipts, 1912 $12. 690. 34

Received prior to July 1, 1911, for tests completed iu fiscal year 1912 $353. 12

Outstanding fees 28.00

Refunds 15.00

39G. 12

13. OSG. 46

Uecei\ ed for tests completed, fiscal year 1911 378. 53

Received for tests in progress at close of fiscal year 1912 1, 101. 25

1, 479. 78

Fees for tests completed, fiscal year 1912 11, 606. 68

FINANCIAL STATEMENT.

The following statement shows the amount and object of each

ap^oropriation provided for the Bureau for the fiscal year 1912, the

disbursement during the year, the amount of unfilled and unpaid

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

iit the close of business June 30, 1912

:

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

.$214,554. 43 41,455.75 22,075.19

2,574. 52

13. 138. 43

68, 167. 90 15,000.00

25,635.71 22,049.52

69,875.04

.$9,535.36

10, 436. 33 3.321.24

336. 19 1,843.35

10, 320. 57

8,350.00

4,340.14

1,703.96 114,427.06

.$12,250. 21

135. 42

306. 34 89.29

18. 22 39.03

24. 15 1.156. 52

15,697. 90

Equipment 52,027.50

25,702.77 3,000.00

15.000. 00

78,-533.50 23,350. 00 30,000.00

25,000.00

200,000. 00

Grounds

Investigating elTects of electric currents

Tcsling structural materials

resting of structural materials of the United States

I'osting machines

resting machine at Pittsburgh, Pa. (continued).

.

Lalioraforv

Total 688,953. 77 494,526.49 164,710.20 29.717.08
34 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

The following statement shows the condition of the approjjriations for the two preceding fiscal years at the close of business June

oO, 1912

Appropriation.

1910 1911

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

Liability. Balance.

Salaries SI 65, 280. 00

40, 000. 00

17,500. 00 3,000.00

$160,461.01

45, 771. 06

17,271.91 2,963.63

$4,818.99

120. 41

11.14

36. 37

$201 , 440. 00

46, 000.00

20, 042. 37

3, 000. 00

15,000.00

.«189, 552. 27 42,405.10

19,968.62

2, 785. 57

14,859.28

$11,887. 73

68. 35

69.88

214. 43

108.82

Equipment

General ex- penses Grounds

$108. 53

216. 95

$3,526. 55

3.87

Investigat i n g

effOL-ts of electric currents 31.90 Gaslight standards 10, 000. 00 9,955. )0 10. 00 34. 90 Testing struc- tural materials Weights and

measures

55,109.10

10,000.00

54,921.81

9,081.89

187. 29

10,000.00 918. U

4,000. 00

7, 629. 90 4,000.00 2,370.10 Freight tiiick.

Total 255, 780. 00 248, 0.52. 61 335. 48 7,391.91 3.50,591.47 333, .574. 54 3, 562. 32 13,454.61

Respectfully,

S. W. Stratton, Director.

To Hon. Charles Nagel,

Secretary of Comm,erce and Labor.

o


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