Nikola Tesla Books
Tesla's last great work was wireless telegraphy, telemechanics, and other branches of radio engineering. Tesla was the first to conceive the idea of using high-frequency currents for the wireless transmission of signals and energy over great distances. He employed the connection that we today call the "antenna-ground" system. As early as 1892, Tesla conducted experiments in the wireless transmission of energy and signals, which in 1893 was confirmed by S. A. Popov, whom the Russians regard as the founder of wireless telegraphy, as an eyewitness. With his apparatus, Tesla in 1897 carried out the transmission of signals over a distance of 35 kilometers, and in 1899 his transmitting station in Colorado, situated at an altitude of about 2,000 meters, could be heard at a distance of 1,000 kilometers around. At that station in Colorado, Tesla spent about two years. There he conducted experiments with high voltages reaching 12 million volts. Tesla believed that it would be possible to transmit wirelessly not only signals but energy in general, which could be used to power machines, airplanes, and the like.
Concerning his experiments in Colorado, Tesla published only a brief report. He was not accustomed to keeping a written journal of his laboratory work, relying instead on his phenomenal memory. Thus, no written documents exist regarding his work in Colorado, and a large part of his observations there remains forever unknown to us.
In 1898, in the harbor of New York, Tesla demonstrated before the patent commission that he could control a boat by wireless means.
After that, on Long Island, he built a tower 57 meters high, which had at its top a hemisphere 20 meters in diameter, but he did not complete it, and in 1905 he abandoned it entirely.
