Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 12

626 Cancelled سجل systems e s'd and Es²d arranged and connected in the same manner and synchronized with the systems at the sending station, so as to respond each exclusively to one of the vibrations of the transmitting apparatus. The same rules of adjustment are obviously obserted in the receiving circuits, care being furthermore taken that the synchronizing is effected when all apparatus is connected to the circuits and placed in position, as any change will generally more or less modify the vibration. Each of the 1 receiving coils, and s², is shunted by a local circuit con1 1 2 taining, respectively, sensitive devices a, a, batteries , b², adjustable resistances r, r², and sensitive relays R¹, 2 2 all joined in series, as shown. The connections and the general arrangement of the various instruments are not essential 1 and may be varied in many ways /The sensitive devices a and 2 may be minute air-gaps, or they may be any of the well2 1 known contrivances suitable for such purposes. The relays R¹, R² have armatures 1, 1, which are connected by a wire , and when attracted, establish electrical contacts at and ², thus closing a circuit containing a battery b3, an adjustable R 2 9 2 resistance r and a relay R³./From the above description it > 3 will be readily seen, that the relay R will be operated only 2 1 when both contacts, and c, are closed. The two vibrations at the sending station may be controlled in any suitable rammer,as, for instance, by opening or closing the circuit of the scurce S, electrical vibrations being sent out, simultaneously or in rapid succession, as may be desired, at each closure of the circuit. The two receiving -6