Nikola Tesla U.S. Patent 723,188 - Method of Signaling Patent Wrapper Page 9

566 in proximity to them. Adjustable inductances L1 and L2 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 s¹ s², and are joined in series through inductances 1¹ 12, conductor F, condensers c¹ and c², brushholders and B2 and a toothed disk D, which is connected to the ground plate E and conductor F, as shown, two independent primary circuits being thus formed. The condensers c¹ 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 B and B2 are capable of angular and, if necessary, also of lateral adjustment, so that any desired order of succession or any difference of phase may be obtained between the discrarges occurring in the two primary circuits. The condensers being energized from a suitable source S, preferably of high potential, and the disk D being rotated, its projections or teeth 2 coming at periodically recurring intervals in very close proximity to or, as the case may be, in contact with conducting rods or brushes n n, cause the condensers to be discharged in rapid succession through their respective circuits. In this manner the two secondary systems, D¹ S¹ E and D2 S2 E, are set in vibration and oscillate freely, each at its proper rate for a certain interval of time at every discharge. The two vibrations are impressed upon the ground through the plate F, and spread to a distance, reaching the receiving station, which has two similar circuits or systems e s dl and es²², arranged and connected in the -5