Fig. 2.
Fig. 3.Fig. 4.Fig. 5.
A glance at [figs. 3, 4, and 5] will show the arrangement of such instruments upon a telegraphic circuit, designed to enable a number of telegraphic despatches to be transmitted simultaneously along the same wire. The transmitters and receivers that are numbered alike have the same pitch or rate of vibration. Thus the reed of T´ is in unison with the reeds T´ and R´ at all the stations upon the circuit, so that a telegraphic despatch sent by the manipulation of the key K´ at the station shown in [fig. 3] will be received upon the receiving instruments K´ at all the other stations upon the circuit. Without going into details, I shall merely say that the great defects of this plan of multiple telegraphy were found to consist, firstly, in the fact that the receiving operators were required to possess a good musical ear in order to discriminate the signals; and secondly, that the signals could only pass in one direction along the line (so that two wires would be necessary in order to complete communication in both directions). The first objection was got over by employing the device which I term a “vibratory circuit-breaker,” shown in the next diagram, whereby musical signals can be automatically recorded.
Fig. 6.