Discussion, pp. 1196-1212, by Messrs. W. I. Slichter, A. E. Averett, Elmer A. Sperry, and H. C. Specht.

Relation between effectiveness of concatenation and magnitude of speed range. Description of several compensated Cascade sets.

A. Miller Gray

THE HEATING OF INDUCTION MOTORS

Vol. xxviii-1909, pp. 527-553

Theoretical and experimental investigation of heating of induction motors when starting and while running, showing its effect upon design. Data on thermal conductivity, convection and radiation which are of general value in design of electric machinery. Discussion, pp. 554-558, by Mr. David Hoock.

A TRIGONOMETRIC METHOD FOR THE SOLUTION OF ALTERNATING-
CURRENT PROBLEMS

Harold Pender

Vol. xxvii-1908, pp. 1397-1424 Development of a short method for solving alternating-current problems with examples of its application to single-phase and three-phase transmission lines, transformer and induction motors. Tables of reactance capacity, resistance and drop factors for use in such calculations. Discussion, pp. 1424-1427, by Messrs. Comfort A. Adams, W. A. Del Mar and L. W. Rosenthal.

Magnitude of errors involved by this method when applied to transmission line calculations.

REDUCTION IN CAPACITY OF POLYPHASE MOTORS DUE TO UNBALANCING
IN VOLTAGE

8. B. Charters, Jr., and W. A. Hillebrand
Vol. xxviii-1909, pp. 559-575
Experimental study of the effect of unbalanced e. m. f. and phase shift
on output of induction and synchronous motors.

Discussion, pp. 576-586, by Messrs. R. E. Hellmund, A. E. Averett, A. M. Dudley, John C. Parker, Charles P. Steinmetz, Charles F. Scott, H. L. Wallau, S. B. Charters, Jr., I. E. Hanssen, and W. E. Hillebrand.

Vol. xxviii-1909, pp. 587-598

THE CURRENT LOCUS OF THE SINGLE-PHASE INDUCTION MOTOR A. S. Langsdorf Theoretical discussion of a method of calculating the exact secondary current locus for single-phase induction motors.

Discussion, pp. 599-600, by Messrs. V. Karapetoff and A. S. Langsdorf. Teaching the theory of the single-phase induction motor.

MULTI-SPEED INDUCTION MOTORS

Vol. xxviii-1909, pp. 601-609

H. G. Reist & H. Maxwell Theoretical discussion of methods of varying speeds of induction motors by changing the number of poles, the change of poles being accomplished

by regrouping the coils, by use of independent windings and by concatenation. Actual tests.

Discussion, pp. 610-614, by Messrs. H. C. Specht, A. M. Dudley, Charles P. Steinmetz, E. F. W. Alexanderson, A. E. Averett, and H. G. Reist. General discussion of limitations of these methods of speed variation, and additional data on internal concatenation.

FUNCTION OF FLY-WHEELS IN CONNECTION WITH ELECTRICALLY
OPERATED ROLLING MILLS

H. C. Specht

Vol. xxviii-1909, pp. 869-878 Theoretical analysis of the performance of induction motor rolling mill drive with varying amounts of fly-wheel effect. Numerical examples chosen to indicate the most economical combination for driving a given plate and rail mill.

Discussion, incorporated with that of Mr. R. Tschentscher's paper on "Electric Power Problems in Steel Plants."

THE REQUIREMENTS FOR AN INDUCTION MOTOR FROM THE USER'S
POINT OF VIEW
Walter B. Nye

Vol. xxix--1910, pp. 147-149
Brief mention of some of the conditions which must be met in the
design of coils, bearings, shafts, pulleys and controllers so as to improve
continuity of service and facilitate repairs.
Discussion (including that of paper by Mr. Dugald C. Jackson on "The
Applicability of Electrical Power to Industrial Establishments;" Mr.
Charles T. Main's paper on "Central Stations Versus Isolated Plants for
Textile Mills;" Mr. R. S. Hale's paper on "The Supply of Electrical
Power for Industrial Establishments from Central Stations," and Mr.
G. H. Stickney's paper on "Illumination for Industrial Plants"), pp. 150-
182, by Messrs. J. C. Parker, Charles B. Burleigh, Norman T. Wilcox,
H. B. Emerson, N. W. Dalton, H. W. Peck, R. D. DeWolf, Albert L.
Pearson, H. D. James, C. A. Graves, J. H. Gardiner, and H. D. Jackson.

General discussion of the relative advantages and disadvantages of central stations and private plant energy supply, together with figures and experience from actual practice. Brief description of decentralized system of electrical energy production in which moderate size non-condensing turbo-electric stations supply both electricity and steam to consumers, the stations being interconnected both by the electric and the steam distribution systems.

INTERACTION OF FLY-WHEELS AND MOTORS WHEN DRIVING ROLL
TRAINS BY INDUCTION MOTORS

F. G. Gasche

Vol. xxix-1910, pp. 1385-1402 General discussion of the application of fly-wheels to roll mill drive, followed by mathematical analysis of the forces acting in an induction motor fly-wheel set when coupled to a roll train, with a full mathematical development of the equations.

Discussion, pp. 1403-1414, by Messrs. C. P. Steinmetz, C. F. Scott, Gano Dunn, Selby Haar, W. W. Crawford, and F. G. Gasche.

Short-cut methods of calculating the performance of fly-wheel induction motor drive for roll trains.

D. ALTERNATING-CURRENT COMMUTATOR MACHINES

A STUDY OF THE HEYLAND MACHINE AS MOTOR AND GENERATOR Comfort A. Adams

Vol. xxi-1903, pp. 519-568 Outline of development of alternating-current commutator motor leading up to the Heyland machine. Principle and theory of operation of the Heyland motor. Tests of the performance characteristics of the machine as a motor, and as shunt and compound generator. Bibliography.

SPEED-TORQUE CHARACTERISTICS OF THE SINGLE-PHASE REPULSION MOTOR Walter I. Slichter Vol. xxiii-1904, pp. 1-7

Observed and calculated performance characteristics of single-phase repulsion motor for railway service compared with direct-current series

motor.

Discussion, incorporated with that of paper by Charles P. Steinmetz on "The Alternating-Current Railway Motor."

Charles P. Steinmetz

THE ALTERNATING-CURRENT RAILWAY MOTOR

Vol. xxiii-1904, pp. 9-25

Brief account of early work with compensated series commutator single-phase motor. Design data given for motors built by Eickemeyer and actual performance characteristics of this motor compared with calculated performance of repulsion motor. Analytical theory of singlephase repulsion motor.

Discussion (including that of paper by Walter I. Slichter on "SpeedTorque Characteristics of the Single-Phase Repulsion Motor"), pp. 26-81, by Messrs. B. G. Lamme, A. S. McAllister, B. J. Arnold, Charles P. Steinmetz, P. M. Lincoln, W. I. Slichter, Ralph D. Mershon, A. H. Armstrong, Robert Lundell, O. S. Lyford, Jr., H. A. Wagner, Charles F. Scott, B. A. Behrend, W. S. Franklin, Dugald C. Jackson, and V. Karapetoff.

Theory of operation of compensated series and repulsion motors treated analytically and graphically. Observed performance characteristics of repulsion motor as motor and generator.

REPULSION INDUCTION MOTOR

Maurice Milch

Vol. xxv-1906, pp. 269-290 Theory and performance characteristics of a commutator single-phase induction motor that starts as a repulsion motor.

Discussion, pp. 291-294, by Messrs. C. P. Steinmetz, D. C. Jackson and G. Percy Cole.

Some requirements of cotton mill drive.

B. G. Lamme

THE SINGLE-PHASE COMMUTATOR TYPE MOTOR

Vol. xxvii-1908, pp. 137-156 Brief discussion of certain features in the design of compensated singlephase series motors for railway service; covering effects of magnetic induction and frequency in commutation and torque; decrease of effective air gap; effect of power-factor on overload torque, etc. No discussion.

THE VECTOR DIAGRAM OF THE COMPENSATED SINGLE-PHASE
ALTERNATING-CURRENT MOTOR

W. I. Slichter

Vol. xxvi-1907, pp. 1527-1532

Physical theory and development of the diagram.
Discussion, p. 1533, by Mr. V. Karapetoff.
Effect of saturation on vector diagram.

E. F. Alexanderson

A SINGLE-PHASE RAILWAY MOTOR

Vol. xxvii-1908, pp. 1-17 Classification of single-phase railway motors, followed by theoretical analysis of the performance characteristic of a series-repulsion motor. Discussion, pp. 18-42, by Messrs. L. B. Stillwell, B. G. Lamme, W. B. Potter, O. S. Lyford, Jr., W. I. Slichter, S. N. Kintner, Charles P. Steinmetz, W. S. Murray, E. F. Alexanderson, and Elmer A. Sperry. General remarks on the relative merits of series-repulsion and compensated series motors, with considerable data on the actual performance of the compensated series motor as to power-factor, commutation, brush wear, etc.

A SKETCH OF THE THEORY OF THE ADJUSTABLE SPEED SINGLE-PHASE
SHUNT INDUCTION MOTOR

F. Creedy

Vol. xxviii-1909, pp. 475-516 Theoretical discussion of methods of varying the speed of single-phase shunt repulsion motors, with results of tests.

Discussion, incorporated with that of paper by E. F. W. Alexanderson on "Repulsion Motor with Variable Speed Shunt Characteristics."

REPULSION MOTOR WITH VARIABLE SPEED SHUNT CHARACTERISTICS E. F. W. Alexanderson Vol. xxviii-1909, pp. 511-521 Theoretical discussion of method of speed control for a single-phase shunt repulsion motor.

Discussion, pp. 522-526, including discussion of F. Creedy's paper on "Adjustable Speed Single-Phase Shunt Induction Motors," by Messrs. V. Karapetoff, E. F. W. Alexanderson and F. Creedy.

Further remarks on the methods of speed variation of shunt repulsion motors, together with test data.

ON THE SPACE ECONOMY OF THE SINGLE-PHASE SERIES MOTOR William S. Franklin and Stanley S. Seyfert

Vol. xxix-1910, pp. 23-40

Theory and tests of a balanced choke coil arrangement for preventing excessive short-circuit currents due to pulsating flux; also description of a proposed single-phase commutator motor with external armature and commutator intended to give improved utilization of space.

Discussion, pp. 41-53, by Messrs. S. M. Kintner, E. H. Anderson, E. F. W. Alexanderson, S. S. Seyfert, L. B. Stillwell, and W. S. Franklin. Detailed criticism of the external armature type motor tending to show its impracticability. Brief mention of other methods of improving space economy. Weight and space factors from actual practice.

E. CONVERTERS AND MOTOR-GENERATORS

THE INDUCTION MOTOR AND THE ROTARY CONVERTER AND THEIR RELATION TO THE TRANSMISSION SYSTEM

Chas. F. Scott

Vol. xviii-1901, pp. 371-382 Detailed comparison of induction and synchronous motors as to construction, performance characteristics and operation. General discussion of synchronous converters, induction motor-generators and synchronous motor-generators, bringing out their relation to the generator.

Discussion, incorporated with that of paper by E. W. Rice, Jr., on “The Control of High-Voltage Systems of Large Power."

Ernst J. Berg

ELECTRIC RAILWAY APPARATUS

Vol. xviii-1901, pp. 603-630

Discussion of the characteristics and limitations of generators, converters, motor-generators and motors for different kinds of electric railway service. Extended consideration of the relative merits of directcurrent series, and polyphase induction motors in a given numerical instance, comparing performance, efficiency and cost.

Discussion (including that of paper by Albert H. Armstrong on "Notes on Modern Electric Railway Practice"), pp. 631-666, by Messrs. Paul Janet, Chas. P. Steinmetz, G. Gillon, Chas. Janisch, Bion J. Arnold, C. O. Mailloux, E. P. Roberts, L. B. Stillwell, A. H. Pott, C. F. Scott, P. K. Stern, H. C. Spaulding, F. S. Holmes, Ernst J. Berg, A. H. Armstrong, and N. C. Sawers.

General remarks on the stability of the induction motor for traction purposes.