Nikola Tesla U.S. Patent 1,119,732 - Apparatus for Transmitting Electrical Energy Patent Wrapper Page 69

18. Fig. 1 is a sectional view of a free terminal and the upper portion of its support; fig. 2, 3 and 4 are sectional view of devices modified in details, and fig. 5 is a view in elevation and part section of an improved free terminal and circuit of large surface with supporting structure and generating apparatus. Referring to Fig. 1, a designates a hood or shell of conducting material of spherical form with an opening on the lower side, and b an insulating support which passes through this opening and fits into a metallic socket g secured to the inner, surface of the hood. The conductor e, conveying the high potential charges to this terminal, is led into it through the same opening and connected to its inner or under side. Then, for convenience, the wire is connected to the outer side of the shell, it should pcint towards the center of the latter, as otherwise the density might be great at the connection and the streamers breaking out there might limit the performance of the apparatus. The terminal, of course, need not be entirely of metal, the only requirement being that its outer surface be conducting, and that it be supported at points of low electric density. In this manner the leakage of the current along the post b is obviated, while owing to the uniformly large radius of curvature of the outer surface which should be smooth and, if possible, polished the breaking out of the charge into the air is prevented. Thus a considerable quantity of electricity may be accumulated on a single shell, notwithstanding its small linear dimensions and capacity. The wire should be heavily insulated, for it will be charged to a much greater density than the terminal, (3) 71 67 371 765