Nikola Tesla and His Works - On the Occassion of the Eightieth Anniversary Page 34

in medicine as “diathermy” and “Darsonvalization.” In addition, Tesla’s numerous experiments showed that they could be used for a very economical electric lighting system. Carbon filament bulbs consumed a lot of energy at that time. Tesla’s work influenced the development of the light bulb industry, demonstrating how new progress could be achieved in this direction. Tesla also conducted many electrochemical experiments and built various devices to produce ozone and nitrogen compounds from the air for fertilizer production through electrical means. Later, a new industry developed based on these experiments in this regard. His experiments also proved to be of unusual importance for generating high voltages. Before Tesla, electricians produced voltages of only a few thousand volts, while Tesla, in the mentioned lectures, produced voltages of several hundred thousand volts. In his radio station in Colorado in 1899, he produced even millions of volts. Generating such enormous voltages was possible only after extensive research into the best methods of insulating conductors and equipment because this field of scientific research was unexplored at that time. It was in its infancy. It was known that oil was a good insulator and could be useful for building transformers. However, Tesla scientifically examined the role of oil as an insulator for transformer windings at very high voltages and made the discovery that oil as an insulator has good properties only if it is thoroughly boiled, and all air bubbles are removed. If even the smallest bubble remains unnoticed, it can lead to negative results and harmful consequences. Tesla presented the results of this discovery in the mentioned lectures. Various luminous phenomena showed that different laws apply to high-frequency currents than to ordinary currents. Tesla discovered the so-called skin effect, which consists of these currents flowing on the surface of the conductor. As a practical result, new conductor constructions followed. Tesla used cylindrical conductors and braided wire to minimize losses in current conduction. Impedance phenomena also revealed new insights. However, the most significant revelation for both science and practical application in radio technology was the discovery that Tesla’s high-frequency currents did not require a supply and return wire. Experiments showed that the energy of such currents could be transmitted without a return wire. Tesla attached a wire to one end of the transformer, raising it high into the air and insulating it at the top, placing various bulbs and evacuated tubes at the upper part. When he activated the transformer, he found that the bulbs and tubes lit up. Bulbs and tubes illuminated even without any contact with the wire. This phenomenon led Tesla to the idea of creating open electrical circuits for transmitting electrical energy without wires.