ACKNOWLEDGEMENTS.

In the present report, your Committee has embodied recommendations from the reports of the Institute's Committee on Matthiessen's Standard, and on Magnetic Units, from the recent reports of the British Board of Trade Committee, and from the suggestions of Dr. Silvanus P. Thompson to Dr. Elisha Gray, in reference to the Congress.

Respectfully submitted,

(Signed)

CARL HERING, Chairman,
WM. A. ANTHONY,

New York, December 28th, 1892.

A. E. KENNELLY.

By a resolution adopted at the meeting of the General Congress Committee of the American Institute of Electrical Engineers, December 28th, the following proposed subjects, suggested by a Sub-Committee of the British Royal Commission for the Chicago Exhibition, were ordered to be published with this report:

Subjects on some of which it is proposed that short and suggestive special papers might be read by specially selected members.

Comparison between procedure in different countries.

Methods of avoiding electrical interference and risks to person and property.

Units of magnetic quantities and mode of embodying them in concrete standards.

The adoption of the name henry" for the unit of self and mutual induction.

Adoption of the "kilowatt

power.

instead of the "horse power" as the unit of

International nomenclature for describing phenomena of alternate currents and of electro-magnetic waves.

National and nunicipal testing laboratories.

Materials for standards of electric resistance.

Points of difference of the electrical vocabulary used in different countries. The direct conversion of the energy of fuel into electric energy.

Comparison of the various methods employed for the electric transmission of

power.

The cost of insulation in relation to high pressure for the electric transmission of power.

Comparison of the economies of the various systems of electric distribution. Alternate current motors.

The behavior of transformers when supplying power to alternate current motors.

The construction of condensers for alternate current purposes.

The measurement of power in polyphase currents.

Direct coupled and non-direct coupled dynamos.

The use of equalizing dynamos in a three and a five-wire system.

The use of accumulators in central stations.

The proportions between output of dynamos and the weight of copper and iron employed in their construction.

Electric traction.

Application of electric power in mining.

The adoption of a uniform method of distinguishing positive and negative mains.

Electric supply meters-American, British, Continental.

Criterion of sensibility of galvanometers.

Commercial instruments for measurement of electric quantities.

The relation between the voltage of the arc and the quality and composition of the carbons,

The aging of glow lamps.

The electric working of metals.

The use of electric and magnetic tests for ascertaining the mechanical properties of metals and alloys.

The best material and mode of erection of lightning conductors in the light of recent researches in electric discharges.

The prospecting for iron by magnetic surveys.

International telegraphy.

Fast-speed and long-distance telegraphy.

The use of batteries or other generators for telegraphy.

Telegraphic lines-land and sea.

Harmonic telegraphy.

Writing telegraphs.

Long distance telephony.

The possibility of providing telephonic communication without wires. Application of electric signaling to the working of railways (alarms, time, etc.), and to naval and military purposes.

Magnetic separators.

The use of electricity in engraving and in art reproductions.

[SUPPLEMENT TO REPORT OF THE SUB-COMMITTEE ON PROVISIONAL PROGRAMME FOR THE INTERNATIONAL ELECTRICAL CONGRESS OF 1893.]

APPENDIX I.

BRIEF SUMMARY OF THE UNITS, TERMS, SYMBOLS AND DEFINITIONS ADOPTED BY PREVIOUS ELECTRICAL CONGRESSES.

The Paris Congress of 1881 adopted, on September 21st, 1881, the following:

The fundamental units: centimetre, mass of a gramme and the second, for electrical measurements. The practical units, ohm and volt, defined in terms of the absolute units. The ampere defined by the volt and the ohm. The coulomb defined by the ampere and the second. The farad defined by the coulomb and the volt. It also resolved that the ohm be represented by a column of mercury of one square millimetre cross-section at 0° C., and of such a length, to be determined by an international commission, that its resistance be equal to the ohm.

The Paris Conference of 1884 adopted, on May 3d, 1884, the following:

The legal ohm of 106 centimetres. The ampere defined in terms of the absolute units. The volt defined by this ampere and the legal ohm. The unit of light defined as the quantity of light emitted perpendicularly from a square centimetre of platinum at the temperature of its solidification.1

At the Philadelphia Conference, in 1884, it was proposed to adopt the "watt," but, from the official records, this term does not appear to have been formally adopted.

The Paris Congress of 1889 adopted, on August 31, 1889, the following:

The joule defined in terms of the absolute units, and in terms of the ampere, ohm and second. The watt in terms of the absolute units, and also in terms of the joule and second. The bougiedecimale defined as the twentieth part of the absolute standard

1. The name "violle." sometimes applied to this standard of light, was not adopted by this Conference, but came into use subsequently. It does not ap ear to have been formally adopted by any international congress. This standard is equal to about 2.08 carcels, or, approximately, to 20 English candles.

2. The bougie-decimale is a close approximation to the English standard candle, as also to one-tenth part of a carcel.

of light adopted by the conference of 1884. The quadrant as the practical unit of induction, defined in centimetres. This congress also defined the following terms:-The period of an alternating current is the duration of one complete oscillation. The frequency is the number of periods per second. The mean intensity of an alternating current is defined by the relation

The effective intensity is the square root of the mean square of the intensity of the current. The effective E. M. F. is the square root of the mean square of the E. M. F. The apparent resistance is the factor by which the effective intensity must be multiplied to give the effective E. M. F. The positive pole of an accumulator is the one which is connected to the positive pole of a dynamo during the charge, and is the positive pole during the discharge. The term interurban is to apply to all telephonic communication between two subscribers or public stations belonging to different groups. The metallic circuit was adopted for urban telephone circuits and for interurban lines.

The Frankfort Congress of 1891 adopted, on September 12, 1891, the following:

Physical quantities shall be represented in italics. Units shall be represented in Roman_type. Physical constants and angles shall be represented by Greek letters. The practical electrical units shall be represented by their initial letters in Roman capitals as follows:-Ampere by A, coulomb by C, farad by F, volt by V, joule by J, ohm by O, watt by W.

The proposition made by Mr. Hospitalier,' to establish an international system of notation, abbreviations and symbols was referred to a committee, to report at the next congress.

1. See Appendix IV.

APPENDIX II.

The following is taken from the Report of the Committee of the American Institute of Electrical Engineers, on “Units and Standards.".

LIST OF NEW UNITS PRACTICALLY NEEDED FOR CONVENIENCE IN DEALING WITH MAGNETIC CIRCUITS.

1st Magneto-Motive Force, and Difference of Magnetic Potential. Simple Definition.-The analogue in a magnetic circuit of voltage in an electric circuit.

Strict definition. The magneto-motive force in a magnetic circuit is 47 multiplied by the flow of current linked with that circuit.

The magneto-motive force between two points connected by a line, is the line integral of magnetic force along that line. Electro magnetic dimensional formula, L M T-1.

1

The absolute unit of M. M. F. is Xunit current of one turn.

1

Απ

The practical unit is X ampere of one turn, or one-tenth

Απ

of the absolute unit-i. e., 0.0796 ampere-turn gives the unit. The prefix kilo would perhaps be occasionally used for practical applications.

2d. Magnetic Flux.

Simple definition. Total number of lines of force or total field.

Strict Definition.-The magnetic flux through a surface bounded by a closed curve, is the surface integral of magnetic induction taken over the bounded surface, and when produced by a current is also equal to the line integral of the vector potential of the current taken round the boundary.

The uniform and unit time rate of change in flux through a closed magnetic circuit, establishes unit electro-motive force in the circuit.

Electro-magnetic dimensional formula, MT.

The absolute unit is one c. G. s. line of induction.

The practical unit is 108 c. G. s. lines.

Fluxes range in present practical work from 100 to 100,000,000 C. G. s. lines, and the working units would perhaps prefix milli- and micro-.

3d. Magnetic Intensity, or induction density.

Simple Definition.- Flux per sq. cm.

Strict Definition.-The induction density at a point within an element of surface is the surface differential of the flux at that point.