Nikola Tesla U.S. Patent 1,119,732 - Apparatus for Transmitting Electrical Energy Patent Wrapper Page 16

712 smaller Per B 11 4 protruding more or less beyond the others (in which case they may be of larger curvature) so that, should the pressure rise to a value, beyond which it is not desired to go, the powerful discharge may dart out there and lose itself harmlessly in the air. Such a plate, performing a function similar to that of a safety valve on a high pressure reservoir, is indicated at v. Still further extending the principles underlying my invention, special reference is made to coil B and conductor B'. The latter is in the form of a cylinder with smooth or polished surface of a radius much larger than that of the half spherical elements pp, and widens out at the bottom into a hood a4, which should be slotted to avoid loss by eddy currents and the purpose of which will be clear from the foregoing. The coil B is wound on a frame or drum Dl of insulating material, with its turns close together. I have/ namely, discovered that when so wound the effect of the small curvature of the wire itself is overcome and the coil behaves as a conductor of large radius o curvature, corresponding to that of the drum." This feature is of considerable practical importance and is applicable not only in this special instance, but generally. For example, such plates as p of terminal D, though preferably of large curvature themselves, need not be necessarily so, for provided only that the individual plates or elements of a high potential conductor or terminal are arranged in proximity to each other and with their outer boundaries along an ideal symmetrical enveloping surface of large curvature, the advantages of the invention will be more or less fully realized. of A 371-24 13