I am an electrical engineer, inventor and futurist. My engineering work on the induction motor and the polyphase system helped design the modern alternating current (AC) electricity supply.
In 1906 I demonstrated a bladeless turbine at 16,000 rpm; in 1910–1911 several of my bladeless turbine engines were tested at 100–5,000 hp at the Waterside Power Station in New York.
In March 1901 J. P. Morgan put $150,000 into my plan for transatlantic wireless transmission in return for 51% of the resulting patents; I built the Wardenclyffe facility at Shoreham, New York, until the project halted in 1905.
In 1899 I set up an experimental station at Colorado Springs to study how low-pressure air conducts and to run much larger coils than my New York lab allowed, then published the findings in The Century Magazine in June 1900.
In 1898 I publicly demonstrated a coherer-based radio-controlled boat, my "telautomaton", at an electrical exhibition in Madison Square Garden, and offered it to the U.S. military as a radio-controlled torpedo.
From 1894 I researched "invisible" radiant energy after noticing damaged film; in March 1896 I built a high-energy single-terminal vacuum tube powered by the Tesla coil and recorded the hazards of working with it.
Westinghouse branded its polyphase AC system the "Tesla Polyphase System" and won the bid to light the 1893 Chicago fair, showing the public that AC was safe, reliable and efficient at scale.
In 1893 Edward Dean Adams asked me to assess every competing system for transmitting power from Niagara Falls. I advised two-phase AC; the contract went to Westinghouse on that advice.
In 1893, speaking in St. Louis, at the Franklin Institute and to the National Electric Light Association, I told audiences that a system like mine could send signals or even power through the Earth to any distance.
I obtained around 300 patents worldwide — at least 278 known, in 26 countries — and received the Elliott Cresson Medal (1894), the AIEE Edison Medal (1916) and the John Scott Medal (1934).
After 1890 I used high AC voltages from my Tesla coil to transmit power by inductive and capacitive coupling, and lit Geissler tubes and incandescent bulbs from across a stage in public demonstrations.
In 1889, repeating Hertz's experiments, I found high-frequency current overheated a Ruhmkorff coil. I replaced its insulation with an air gap and a movable iron core, and patented the result in 1891.
In July 1888 my backers negotiated a licence of my polyphase motor and transformer designs to George Westinghouse for $60,000 in cash and stock plus $2.50 per AC horsepower. In 1891 I released the company from that royalty to keep it championing the motor.
