PREFACE.

...and discussions, and makes note of all his inventions known so far, particularly those relating to polyphase motors Motors that use multiple alternating currents with different phases to create a rotating magnetic field. and the effects achieved with currents of high potential high voltage and high frequency. It is evident that Mr. Tesla has constantly pushed forward, rarely pausing for even a moment to work out the detailed applications of the new principles he has explained, even when those uses were immediately obvious to him. Whenever possible, his own words have been used.

It should also be noted that this volume is published with Mr. Tesla’s authorization and approval, and that permission was obtained to republish the papers he presented to various technical societies in America and Europe. Mr. Tesla has kindly assisted the author by reviewing the proof sheets for the sections covering his most recent research. The work has also benefited from a careful revision by the author’s friend and editorial colleague, Mr. Joseph Wetzler, who reviewed all the proofs.

DECEMBER, 1893.

original: T. C. M. refers to Thomas Commerford Martin, a prominent Irish-American electrical engineer and editor.