Nikola Tesla Patents
382 in the former case, and, there being no difficulty in energizing powerfully the transmitting circuit a receiver can be easily operated at a distance of several miles. Furthermore, the circuits are readily synchronized, and ordinary obstacles do not materially interfere with the transmission of the impulses. But the rapid diminution of the energy of the impulses as the distances become very considerable, which is enormously enhanced by the generation of wasteful currents in the earth, the great expense and other disadvantages ne cessarily following from the use of long and heavy conductors enclosing large areas have made this method, up to the present time, obviously impracticable for use over very great distances. Still another way, which has also been known for 15 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 1 This mode of made to act upon a sensitive receiver. transmission offers most of the advantages of the preceding method, and, as it is much cheaper and as the 2 energy of the impulses diminishes still less rapidly with the distance, it is far more practicable. But, hevertheless, in the manner in which it has been heretofore experimented with, and with the devices so far used in connection with it, it has been capable only of a very limited range of application. Sub. a: out 2 -3-.
