Nikola Tesla Patents
will take place in the same. In order to magnify the electrical movement in the secondary as much as possible, its inductive connection with the primary A should not be a very intimate one, as in ordinary transformers, but should be loose, so as to permit free oscillation. The spiral form of coil C secures this advantage, while at the same time the turns near the primary A are subjected to a strong inductive action and develop a high initial electromotive force. These adjustments and relations being carefully completed, and other constructive features indi1 cated rigorously observed, the electrical movement produced in the secondary system by the inductive action of the will primary A be enormously magnified, the increase being directly proportionate to the inductance and frequency, and inversely to the resistance of the secondary system. I have found it practicable to produce in this manner an electrical movement thousands of times greater than the initial, that is, the one impressed upon the secondary by the primary A, and I have thus reached rates of flow of electrical energy in the system ECE measuring many tens of thousands of horse-power. Such immense movements of electricity give rise to a variety of novel and striking phenomena, one of which is that already referred to. The powerful electrical oscillations in the system E' C E, being communicated to the ground, cause corresponding vibrations to be propagated to distant parts of the globe, whence they are reflected and, by interference with the outgoing vibrations, produce stationary waves, the crests and hollows of which lie in concentric circles, relatively to which the -7This page retyped from microfilm for better readability - Ed.] 525
