Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 44

658 Sub. Afhen, X F each other that they are practically simultaneous, so far as the operation of such relays as R1 and R2 is concerned. Evidently, however, it is not necessary to employ two or more receiving circuits, but a single circuit may be used also at the receiving station constructed and arranged like the transmitting circuits or systems illustrated in Figs. 3, 4 and 5, in which case the corresponding disks, as D3 D4 D5, at the sending, will be driven in synchronism with those at the receiving stations as far as may be necessary to secure the desired result. But whatever the ra ture of the specific devices employed, it will be seen that the fundamental idea in my invention is the operation of a receiver by the conjoint or resultant effect of two or more circuits, each tuned to respond exclusively to waves, impulses or vitrations of a certain kind or class produced either simultaneously or successively by a suitable transmitter. It will be seen from a consideration of the nature of the method hereinbefore described, that the invention is applicable not only in the special manner described, in which the transmission of the impulses is effected through natural media, but for the transmission of energy for any purpose and whatever the ne ditun through which the impulses are conveyed. What I claim is: 1. In a system for the transmission of electrical energy, the combination with means for producing two or more distinctive kinds of disturbances or impulses, of receiving circuits, each tuned to respond to the waves or impulses of one kind only, and a receiving device dependent for operation upon the conjoint action of the several receiving circuits, as set forth. -10