Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 7

IMPROVEMENTS IN SYSTEMS OF SIGNALLING. BE IT KNOWN THAT I, NIKOLA TESLA, of the Borough of Manhattan, in the City, County and State of New York, have invented. certain new and useful improvements in Systems of Signalling, of which the following is a specification; In certain systems, for transmitting intelligible messages, or governing the movements and operations of distant automatons, electrical impulses or disturbances, produced by suitable apparatus, are conveyed through the natural media to a receiving circuit, capable of responding to the impulses and thereby effecting the control of other appliances. Generally a special device, highly sensitive, is connected to the receiving circuit which, in order to render it still more susceptible, and also to reduce the liability of its being affected by extraneous disturbances, is carefully synchronized with the transmitter. By a scientific design of the sending and receiving circuits and other apparatus, and skillful adjustment of the same, these objects may be in a measure attained, but in long experience I have found that notwithstanding all constructive advantages and experimental resources, this method is in many cases inadequate. Thus, while I have succeeded in so operating, selectively, under certain favorable conditions, more than one hundred receivers, in most cases it is practicable to work successfully but a few, the number rapidly diminishing as, either cwing to great distance or other cause, the energy available in the synchronized circuits is small, and therefore Cancelled per subspec -1621