Nikola Tesla U.S. Patent 1,119,732 - Apparatus for Transmitting Electrical Energy Patent Wrapper Page 72

768 Per & Apart of the improvements which form the subject of this specification, the transmitting circuit, in its general features, is identical with that described and claimed in my original patents Nos. 645,576 and 649,621. The circuit comprises a coil A which is in close inductive relation with a primary C, and one end of which is connected to a ground-plate E, while its other end is led through a separate self-induction coil B and a metallic cylinder B' to the terminal D. the connection to the latter should always be made at, or near the center, in order to secure a symmetrical distribution of the current, as otherwise, when the frequency is very high and the flow of large volume, the performance of the apparatus might be impaired. The primary C may be excited in any desired manner, from a suitable source of currents G, which may be an alternator or condenser, the important requirement being that the resonant condition is established, that is to say, that the terminal D is charged to the maximum pressure developed in the circuit, as I have specified in my original patents before referred to. The adjustments should be made with perticular care when the transmitter 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 resonanting circuit as E A B B Dimmense electrical activities, measured by tens and even hundreds of thousands of horse-power, and in such a case, if the points of maximun pressure should be shifted below the terminal D, elong coil B, a ball of fire might break out and destroy the support F or anything else in the way. For the better appreciation of the nature of this danger it should be stated, that the destructive action may take place with inconceivable violence. This will cease to be surprising when it is 74 a (5) ^ 371-70