Nikola Tesla Patents
JLJUJ TJ DUULJ LI LJDE) LILILOODU sub a' of current, or with a receiving instrument, as the case may be. In inductive relation to said coils in each instrumant is a flat spirally wound coil B, or B¹, one terminal of which is shown as connected to a ground plate C, whilə the other, which leads from the center, is adapted to be connected to a suitable terminal which is generally maintained at an elovation in the air. The coils B, B¹ are contained in insulating receptacles D of the kind ordinarily used to contain liquefied air or other gas, and in the drawing a quantity of such liquid is shown in each receptacle sufficient to entirely surround and cover the coils B, B¹. It will be understood that the temperature of a liquefied gas under such conditions will be very low, and so long as its coil B or B' is immersed therein, it will be kept at a uniformly low temperature. I do not, of course, intend to limit my self to this specific means of artificial cooling, as others may be employed. I have found it possible, by taking advantage of the facts abovepointed out and of the means described, to secure a rise of electrical pressure in an excited circuit very many times greater than hasheretofore been practicable, it and this result makes feasible, among other things, to greatly extend the distance of transmission and to excludo much more effectively effects tending to interfere with the signals than has been possible by the means here to fore known. Having now described my invention, what I claim is: -5503
