Nikola Tesla Patents
lub. a nary obstacles do not materially interfere with the transmis-7 sion 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 necessarily following from the use of long and heavy conductors enclosing large areas have made his method, up to the present time, obviously impracticable for use over very great distances. 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. This mode of transmission offers most of the advantages of the preceding method, and, as it is much cheapèr and as the energy of the impulses diminishes still less rapidly with the distance, it is far more practicable. But, nevertheless, 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. It is important to observe that, in all the methods which have been mentioned, the receiving circuit or instrument must be maintained in a definite position with respect to the transmitting apparatus, and this often imposes great limita tions and disadvantages upon the use of the apparatus. 3 This page retyped from microfilm for better readability - Ed.] 413
