Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 39

JLJ T Sub. Spec. ressure developed therein coincide with the elevated terminals D1 D2. The two systems may have electrical oscillations impressed upon them in any desired manner, converiently by energizing them through primarie's Pl and P2, placed in proximity to them. Adjustable inductances L1 and 12 are preferably included in the primary circuits chiefly for the purpose of regulating the rate of the primary oscillations. In the drawing these primaries Pl and P2 surround the coils sl S2, and are joihed in series through inductances L¹ L2, conductor F, condensers Cl and C2, brush holders B1 ard B2 and a toothed disk D, which is connected to the conductor F and, if desired, also to the ground plate E, as shown, two independent primary circuits being thus forised. The condensers Cl and C2 are of such capacity and the inductances L1 and L2 are so adjusted that each primary is in close resonance with its secondary system, as I have explained in other patents granted to me. The brush holders B1 and 32 are capable independently of angulàr and, if necessary, also of lateral adjustment, so that any desired order of succession or any difference of time interval between the discharges occurring in the two primary circuits may be obtained. The condensers being energized from a suitable source S, preferably of high potential, and the disk D being rotated, its projections or teeth p 2, coming at periodically recurring intervals in very close proximity to pr, as the case may be, in contact with conducting rods or trushes nn, cause the condensers to be discharged in rapid succession through their respective circuits. In this manner the two secondary systems, Dl S1 E and D2 S2 E, are set in vibration 653