Fig. 37
(Fig. 10 of Specification 18,644/97).—Another mode of sending a jerk from a spark gap at j into a badly insulated cable or other conductor, which is connected at the other end to a Coherer, the circuit being completed inductively through the air by means of the areas p, p1. The dotted lines s represent the switch connection of [Fig. 33].
38
(Fig. 13 of Specification 18,644/97).—Another method of signalling through a pair of imperfect conductors, such as gas and water pipes i, without the above elevated inductive connection.
Fig. 39
(Fig. 3 of Specification 29,069/97).—Diagram of Coherer connection to Syntonic Collector, with capacity shunt for telegraphic instrument.
(4) No. 29,069, 1897. In this patent various methods of connecting up the shunting condenser, whose object it is to transmit all jerks undiluted to the coherer, are shown, all adapted to work with a syntonic resonator ([Fig. 39]). There is also shown a complete switch ([Fig. 40]) for effecting the transition from “sending” to “receiving,” exposing the coherer to the full effect of the distant radiator, and completely protecting and isolating it from its home radiator; the switch being so arranged that signalling is impossible unless the home coherer is protected. A rotating commutator is also shown, whose object is to expose the coherer to the full influence of a receiver, especially of a non-syntonic receiver or simple collector, without its being shunted or otherwise interfered with by the telegraphic apparatus; to which, however, immediately afterwards the rotating commutator connects it, and then effects the tapping back.