Nikola Tesla U.S. Patent 649,621 - Apparatus for Transmission of Electrical Energy Patent Wrapper Page 9

206 necessarily implies that the capacity and inductance in each of the circuits have such values as to secure the most perfect condition of synchronism with the impressed oscillations. qi When the source of current G, is in operation and produces rapidly pulsating or oscillating currents. in the circuit of coil C, corresponding induced rrents of very much higher potential are generated in the secondary coil A, and, since the potential in the same gradually increases with the number of turns towards the center and the difference of potential between the adjacent turns is comparatively small, a very high potential, impracticable with ordinary coils, may be successively obtained. As the main object for which the apparatus is designed is to produce a current of excessively-high potential, this object is facilitated by using a primary current of very considerable frequency, but the frequency of the currents is in a large measure arbitrary, for if the potential be sufficiently high and the terminals of the coils be maintained at the proper elevation where the atmosphere is rarefied, the stratum of air will serve as a conducting medium for the current produced and the latter will be transmitted through the air with, it may be, even less resistance than through an ordinary conductor. As to the elevation of the terminals D D! it is obvious. that this is a matter which will be determined by a number of things, as by the amount and quality of the 4