Nikola Tesla Books
circumstances; he had to do hard physical labor - digging ditches, carrying out various repairs, and other odd jobs - in order to earn a living. Before long he also parted ways with that company, and in 1887 he founded the "Tesla Electric Company," which placed at his disposal a laboratory and other resources, so that on October 12, 1887, he was able to file the basic patent for his polyphase motor. The patent was granted to him on May 1, 1888.
Soon some prominent experts became interested in his inventions and quickly recognized the enormous significance of Tesla's discovery. Particularly strong interest was shown by Westinghouse, an industrialist from Pittsburgh, who, among other things, manufactured well-known air-brakes for railroads and was also engaged in building direct-current power stations. Since Tesla had no intention of exploiting his inventions himself, he sold the patent rights to Westinghouse for one million dollars, and for each horsepower of his generator produced he was to receive one dollar as a royalty. This agreement was valid for fifteen years, that is, for the duration of the patent rights.
On May 16, 1888, Tesla delivered his famous lecture on his motor at the American Institute of Electrical Engineers, which made an enormous impression on the professional public of the time. At that lecture he demonstrated motors that had an efficiency of 60 percent. In the following year Professor Anthony carried out thorough tests which proved that the motors - further improved by Tesla in the meantime - achieved efficiencies of 90 to 95 percent. Tesla worked for Westinghouse in Pittsburgh until 1890. After that he returned to New York and threw himself into the study of new problems.
