But the difference of potential at the receiver end of the line is

that is; the drop of potential in the line will be

that means that, while a continuous current will experience a loss of potential of 12.85 volts per line wire, and from the impedance of the line a difference of potential of 19.27 volts per line wire is calculated, we find in this particular case a rise of potential of 10.4 volts per line wire, so that the difference of potential is rising along the line instead of decreasing, and that by not less than 20.8 volts.

In this case at an E. M. F. of 500 volts produced in the generator, an E. M. F. of 598.7 volts will appear at the generator terminals, and 619.5 at the receiver terminals.'

The conclusion that we derive herefrom is, that it is not permissible to calculate the drop of potential in an alternating circuit by multiplying the resistance drop by the impedance factor. The difference of potential between the ends of the line will indeed be equal to the current times impedance. The losses of potential in the line, however, will usually be less than the difference of potential between the ends of the line, and may even be negative; that is, the potential may rise in the line.

This is due to the difference of phase between the line impedance and the impedances of the other part of the circuit, as explained in the paper. I considered it advisable, however, to dwell upon this more particularly, since the mistake is made frequently, to calculate the drop of potential in an alternating current line from resistance, impedance factor and current. In reality the drop of potential in one part of an alternating circuit, depends not only upon the constants of this part of the circuit, but upon the conditions of the other parts of the circuit also, and may, therefore, at the same current strength vary enormously with different conditions of load.

Now a few words more on a question of terminology. Perusing the literature of the last years on this subject, we find everywhere the endeavor to establish a suitable name for quantities

like

2πη Ι or

1 2πη Κ

1. It needs not to be remarked that if the generator contains iron, due to the variable permeability of iron the numerical values will, in practice, be found more or less modified.

It is of the dimension "speed or "resistance," is expressed in ohms, and defined by

E. M. F. at right angles to current

current

This quantity and the true or ohmic resistance are the catheti of a rectangle with the impedance as hypothenuse.

Kennelly names it "inductance-speed" (the factor 2 n being an angular velocity).

This name, however, does not apply well to

1 2πη Κ

About two years ago I proposed the name "inductance" for this quantity, so that impedance should be the resultant of resis tance and inductance, as components. Unfortunately the name “inductance" has now been applied to what we called before the "coefficient of self-induction: S. P. Thompson in the new edition of his book has adopted the name "inductance" for 2 π πn L also.

The name "inductive resistance" has been used by Fleming and others. This name, however, has been applied also as synonymous with "impedance." "Ohmic inductance" has been proposed, but all these double names are too inconvenient to be of much practical value. Decidedly the best name would be "inductance," the more so as the constant L is so little used in practice that the ponderous name "coefficient of self-induction will hardly cause any inconvenience.

Lynn, Mass., April, 1893.

[REPLY TO MR. STEINMETZ, COMMUNICATED BY THE AUTHOR.] Concerning Mr. Steinmetz's remarks, one in particular is of such practical importance that it will not probably suffer by emphasis or repetition. Mr. Steinmetz points out that when a circuit is composed of an alternator, supply conductor, and load, each having its individual impedance, their vector sum will generally be less than their arithmetical sum. Consequently if the generator delivers 1,100 volts at its terminals, and the drop in the supply wires allowing for the impedance factor is 100 volts (50 on each conductor, as might be indicated by a voltmeter connected between the far and near ends of one wire), the voltage at the transformer terminals would be never less, but usually more than 1,000 volts, particularly if condensers are in circuit at the receiving end, and its exact value would depend upon all the impedances in the circuit. It is therefore essential to observe that all the tabular impedance factors given in the paper as applying to sinusoidal currents, or augmented impedance formulas applying to non-sinusoidal currents, accurately yield the drop in the con

ductors so long as the static capacity in those conductors is negligible. The voltage of delivery at the distant end will always be greater than the difference between this drop and the voltage of supply at the near end, unless it happens that the impedances of the load and of the conductor have the same vector, or time con stant. But unless condensers are added to the receiving end of the line, this variation of the actual voltage of delivery from the difference between line drop and voltage of supply, is generally small at full load on practical alternating transformer circuits. In other words the time constant of the ordinary supply wires does not differ materially from the apparent time constant of the transformers when loaded, although obviously this statement cannot be depended upon too far.

AMERICAN INSTITUTE OF ELECTRICAL

ENGINEERS.

ANNUAL MEETING.

NEW YORK CITY, May 16th, 1893. The meeting was called to order at 4.20 P. M. by the President, Mr. Frank J. Sprague, who announced that the first business would be the appointment of tellers to count the ballots for officers.

THE PRESIDENT:-I will appoint Messrs. T. C. Martin and George A. Hamilton, tellers, and they will proceed at once to the counting of the ballots which are in the possession of the Secretary.

MR. THOMAS D. LOCKWOOD: -In view of the fact that the procedure of election is a new one upon this occasion, and also that the rule governing our procedure is rather long and easily forgotten, I suggest that the Secretary be instructed to read the new rule before the tellers proceed to their work, or, as an alternative, that a copy of the rule be given to the tellers that they may refer to the same while proceeding with their work. I will make that as a motion.

[The motion was seconded.]

MR. PHELPS: I hope Mr. Lockwood will be content with having a copy of the rule given to the tellers.

THE PRESIDENT:-It is hardly necessary to put the motion. A copy of the rule will be handed to the tellers.

MR. JAMES HAMBLET:-In view of the great work which will be required of the tellers, I would make a motion, if it is in order, that the number of tellers be increased to five in order to facilitate the work.

THE PRESIDENT:-The rule states that there shall be only two tellers.

THE SECRETARY:-I should say it would be perfectly in order for those tellers to have clerks to assist them.

MR. HAMBLET:-I was not aware of that rule. the suggestion in view of the great work entailed.

I merely made

THE SECRETARY:-I have the ballots here with a list of the membership corrected to the first of May, and in order to facilitate this work, the ballots have been arranged in packages which are numbered from one up-about fifteen packages in all. The ballots will be found in alphabetical order to correspond with the list. The ballots are at the disposal of the tellers.

THE PRESIDENT:-The tellers will at once assume their duties. THE SECRETARY:-I would like to suggest, in the first place, that the tellers are to count the ballots in the meeting room and we shall have to pass on the point whether the place they are going to is the meeting room or not. They have disappeared from view.

MR. PHELPS:-Let us call them back.

THE PRESIDENT:-I appoint Mr. Phelps a committee of one to recall the tellers for instructions.

[Mr. Phelps went after the tellers, who returned.]

THE PRESIDENT-I take it that the front room might be used by the tellers.

[The tellers proceeded with the counting of the ballots in the front room.]

THE SECRETARY:-I have the report of the Council and the Treasurer printed.

MR. PHELPS-Are these reports to be read? Or are they to be considered as read? It has been the invariable custom, on financial reports being presented, to appoint a committee, usually of two, to audit the Treasurer's report, and I hope that that procedure will be taken to-day.

The Secretary read the following reports:

AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS.

REPORT OF COUNCIL FOR THE YEAR ENDING APRIL 30TH, 1893.

In compliance with the requirements of the Rules, the Council submits to the Annual Meeting a report of the work of the Institute during the past year.

Ten meetings of the Council have been held at which the average attendance has been 8, the highest number present at a meeting having been 14, and the lowest 5, which was at the June meeting held in Chicago.

At the meeting held May 17th, 1892, upon recommendation of a Special Committee, Lord Kelvin, Dr. Werner von Siemens, and Cyrus W. Field were elected to honorary membership.

In accordance with the announcement at the last Annual Meeting, the 9th General Meeting of the Institute was held at Chicago on June 6th, 7th and 8th. The meeting was very fully attended, especially by Western members, while the Eastern States were also well represented. The general result was entirely satisfactory. Eight other meetings have been held in New York City. At these various meetings 30 papers and reports were read and discussed, and have since been printed and distributed to the members. The volume of the TRANSACTIONS for 1892 contained 858 pages and was one-third larger than that of the previous year.