of "Alternating Currents and Alternating-Current Machinery."

MICHAEL IDVORSKY PUPIN, A.B., Sc.D., Ph.D.

Professor of Electro-Mechanics, Columbia University, New York.
Author of "Propagation of Long Electric Waves," and "Wave-Transmission over Non-Uniform Cables and Long-Distance Air Lines."

FRANK BALDWIN JEWETT, A.B., Ph.D.

Transmission and Protection Engineer, with American Telephone & Telegraph Co.
Author of "Modern Telephone Cable," "Effect of Pressure on Insulation Resistance."

ARTHUR CROTCH

Formerly Lecturer on Telegraphy and Telephony at the Municipal Technical Schools, Norwich, Eng.
Author of "Telegraphy and Telephony."

JAMES ERSKINE-MURRAY, D.Sc.

Fellow of the Royal Society of Edinburgh; Member of the Institution of Electrical Engineers.
Author of "A Handbook of Wireless Telegraphy."

A. H. McMILLAN, A.B., LL.B.

Author of "Telephone Law, A Manual on the Organization and Operation of Telephone Companies."

WILLIAM ESTY, S.B., M.A.

Head of Department of Electrical Engineering, Lehigh University.
Joint Author of "The Elements of Electrical Engineering."

GEORGE W. WILDER, Ph.D.

Formerly Professor of Telephone Engineering, Armour Institute of Technology.
Author of "Telephone Principles and Practice," "Simultaneous Telegraphy and Telephony," etc.

WILLIAM L. HOOPER, Ph.D.

Head of Department of Electrical Engineering, Tufts College.
Joint Author of "Electrical Problems for Engineering Students."

DAVID S. HULFISH

Technical Editor, The Nickelodeon; Telephone and Motion-Picture Expert; Solicitor of Patents.
Author of "How to Read Telephone Circuit Diagrams."

J. A. FLEMING, M.A., D.Sc. (Lond.), F.R.S.

Professor of Electrical Engineering in University College, London; Late Fellow and Scholar of St. John's College, Cambridge; Fellow of University College, London.
Author of "The Alternate-Current Transformer," "Radiotelegraphy and Radiotelephony," "Principles of Electric Wave Telegraphy," "Cantor Lectures on Electrical Oscillations and Electric Waves," "Hertzian Wave Wireless Telegraphy," etc.

F. A. C. PERRINE, A.M., D.Sc.

Consulting Engineer; Formerly President, Stanley Electric Manufacturing Company; Formerly Professor of Electrical Engineering, Leland Stanford, Jr. University.
Author of "Conductors for Electrical Distribution."

A. FREDERICK COLLINS

Editor, College Wireless Bulletin.
Author of "Wireless Telegraphy, Its History, Theory and Practice," "Manual of Wireless Telegraphy," "Design and Construction of Induction Coils," etc.

SCHUYLER S. WHEELER, D.Sc.

President, Crocker-Wheeler Co.; Past-President, American Institute of Electrical Engineers.
Joint Author of "Management of Electrical Machinery."

CHARLES PROTEUS STEINMETZ

Consulting Engineer, with the General Electric Co.; Professor of Electrical Engineering, Union College.
Author of "The Theory and Calculation of Alternating-Current Phenomena," "Theoretical Elements of Electrical Engineering," etc.

GEORGE W. PATTERSON, S.B., Ph.D.

Head of Department of Electrical Engineering, University of Michigan.
Joint Author of "Electrical Measurements."

WILLIAM MAVER, Jr.

Ex-Electrician Baltimore and Ohio Telegraph Company; Member of the American Institute of Electrical Engineers.
Author of "American Telegraphy and Encyclopedia of the Telegraph," "Wireless Telegraphy."

JOHN PRICE JACKSON, M.E.

Professor of Electrical Engineering, Pennsylvania State College.
Joint Author of "Alternating Currents and Alternating-Current Machinery."

AUGUSTUS TREADWELL, Jr., E.E.

Associate Member, American Institute of Electrical Engineers.
Author of "The Storage Battery, A Practical Treatise on Secondary Batteries."

EDWIN J. HOUSTON, Ph.D.

Professor of Physics, Franklin Institute, Pennsylvania; Joint Inventor of Thomson-Houston System