Nikola Tesla

Tesla was born in 1856 in the village of Smiljan, in the Austrian Empire, now Croatia, and trained as an engineer in Graz and Prague. He worked for Continental Edison’s Paris office and then, in 1884, moved to New York to work for Edison’s own manufacturing arm, the Edison Machine Works.

Every motor of the day worked the same way: current had to be switched into the spinning part through a ring of metal contacts called a commutator, and the brushes riding on it sparked, wore down and needed constant service. Tesla patented a different idea on 1 May 1888 — feed two or more alternating currents, out of step with each other, into a fixed set of coils, and the magnetic field itself rotates, with nothing to switch and no brushes to spark or wear. He read the design to the American Institute of Electrical Engineers two weeks later.

George Westinghouse bought the patents that same year, paying Tesla a lump sum and a royalty of two dollars and fifty cents for every horsepower of motor capacity sold. After the Panic of 1893 hit Westinghouse hard, while the company was also paying to build the huge generating station at Niagara Falls, Tesla let the royalty go rather than see the patents sold off to someone else; Westinghouse’s own annual report for 1897 records a single payment of $216,600 to Tesla in its place — a fraction of what years of royalties on a system that came to power much of the country would likely have paid him.

The motor wired into this board is not his motor. It runs on direct current from a single battery, switched into the spinning part by a commutator and a pair of brushes — the very mechanism Tesla’s induction motor did away with, since his ran on alternating current and needed no brushes at all. What carries over is the idea underneath both: a current makes a magnetic field, and a field pushes on a magnet. His field rotated on its own, from AC alone; this motor needs a propeller’s drag to show the fact his design was also built on — that a spinning motor is a generator too, pushing back against whatever drives it.