Nikola Tesla U.S. Patent 645,576 - System of Transmission of Electrical Energy Patent Wrapper Page 43

1 by hundreds of thousands and even millions of volts, and in pursuing investigation with such apparatus I have discovered certain hitherto unknown but highly important and useful facts. Among these, and bearing directly upon the subject of my present application are the following:- First, that with electrical pressures of the magnitude herein contemplated the ordinary atmosphere becomes, in a measure, capable of serving as a conducting medium for the transmission of electrical energy; Second, that the conductivity of the air increases so materially with the increase of electrical pressure and degree of rarefaction that it becomes possible to transmit through even moderately rarefied strata of the atmosphere electrical energy up to practically any amount and to any distance. My preser ana atat ad.. to based upon these discoveries, consists then in producing at one point an electrical pressure of such character as to cause a current to traverse the air intermediate to the point of generation and a distant point at which the energy is received and utilized. In order to attain this result it is necessary to employ an apparatus capable of generating electrical pressures vastly in excess of any heretofore used and to lead the current to a terminal at an elevation where the rarefied atmosphere is capable of conducting freely the particular current produced; then, at a distant point where the energy is to be utilized, to maintain à terminal at or about the same elevation to receive the current, -2Legibility of line at center of page same as on microfilm - Ed.] 161