Nikola Tesla Patents
a 2 1 "Another method consists in passing a current through a circuit, preferably one enclosing a very large area, inducing thereby in a similar circuit situated at a distance, another current, and affecting by the same, in any convenient way, a receiving device. ("Still another way, which has also been known for many years, is to pass, in any suitable manner, a current through a portion of the ground, as by connecting to two points of the same, preferably at a considerable distance from each other, the two terminals of a generator, and to energize by a part of the current diffused through the earth, a distant circuit which is similarly arranged and grounded at two points widely apart and which is made to act upon a sensitive receiver. "These various methods have their limitations, one especially, which is common to all, being that the receiving circuit or instrument must be maintained in a definite position with respect to the transmitting apparatus, which often imposes great disadvantages upon the use of the apparatus. "In several applications filed by me and patents granted to me, I have disclosed other methods of accomplishing results of this nature which may be briefly described as follows: "In one system the potential of a point or region of the earth is varied by imparting to it intermittent or alternating electrifications through one of the terminals of a suitable source of electrical disturbances, which, to heighten the effect, has its other terminal connected to an insulated body, preferably of large sur-2This page retyped from microfilm for better readability - Ed.] 373
