The Inventions, Researches and Writings of Nikola Tesla

...to join a company intended to manufacture and sell an arc lighting system based on some of his inventions in that branch of the field. With unceasing diligence, he brought the system to perfection and saw it placed on the market. The thing that most occupied his time and thoughts throughout this period, however, was his earlier discovery of the rotating field principle for alternating current work, and its application in motors that have now become known throughout the world.

Strong as his convictions on the subject were at the time, he stood very much alone, for alternating current had no well-recognized place. Few electrical engineers had ever used it, and the majority were entirely unfamiliar with its value or even its essential features. Even Mr. Tesla himself did not learn how to construct alternating current apparatus of fair efficiency until after protracted effort and experimentation. That he had accomplished his purpose, however, was shown by the tests of Prof. Anthony, conducted in the winter of 1887–8, when Tesla motors, in the hands of that distinguished expert, achieved an efficiency equal to that of direct current motors. Nothing now stood in the way of the commercial development and introduction of such motors, except that they had to be designed to operate on the existing circuits in this country, which were all of high frequency.

The first full publication of his work in this direction—outside of his patents—was a paper read before the American Institute of Electrical Engineers in New York in May 1888 (read at the suggestion of Prof. Anthony and the present writer). There, he exhibited motors that had been in operation long before, and with which his belief that brushes and commutators could be dispensed with was triumphantly proven correct. The section of this volume devoted to Mr. Tesla’s inventions in the utilization of polyphase currents will show how thoroughly he had mastered the fundamental idea from the outset and applied it in the greatest variety of ways.

Having noted for years the many advantages obtainable with alternating currents, Mr. Tesla was naturally led to experiment with them at higher potentials Voltage. and higher frequencies than were common or approved. Ever pressing forward to determine, even in the slightest degree, the outlines of the unknown, he...