Nikola Tesla U.S. Patent 1,119,732 - Apparatus for Transmitting Electrical Energy Patent Wrapper Page 36

732 dition is established when the apparatus is at work, that is to say, that the terminal D is charged to the maximum pressure developed in the circuit, The adjustment should be made with particular care when the apparatus is one of great power, not only on account of economy, but also in order to avoid danger. I have shown that it is practicable to produce in a resonating circuit as E A B B D an irmens e electrical movement, measured by rates of tens and even hundreds of thousands of horse power, and in such a case, if the points of maximum pressure should be shifted below the terminal D, say along coil B, a ball of fire may break out and destroy the support F or anything else in the way. To increase the safety, I provide on a convenient place, preferably on terminal D, one or more elements or plates of somewhat smaller curvature, so that, when a certain maximum. pressure is reached, beyond which it is not desired to go, the powerful current 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 . Still further extending the principles underlying my invention, special reference is made to coil Band conductor B'. The latter is in the form of a cylinder with smooth or polished surface and preferably of a radius much larger than that of the half-pherical elements 22, 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 tre foregoing. The coil B is wound on a drum Dl, which should be of still larger radias, and its turns are packed closely 3717 ما3