4OO Telephone Systems of the Continent of Europe 



at one end, and at the other furnished with pole pieces P. The 

 primary and secondary circuits are of the same resistance, 170 

 ohms, and are equally divided between the two bobbins. An 

 armature, F, hangs from the support s, and is adjusted to make 

 contact normally with one of two stops, c c 1 , which closes the 

 circuit of the local battery and the relay R, the armature of which 

 is kept attracted against the dead stop D until a magneto current 

 traversing the coils of the translator sets the armature F oscillating 



between its stops. The relay 

 armature being momentarily 

 liberated between the oscilla- 

 tions, touches its second stop 

 D 1 , and closes another local 

 circuit through a battery and 

 an indicator of ordinary type, 

 which consequently falls. The 

 terminals A 1 to A 4 are for the 

 trunk and subscribers' lines, R ' 

 for the relay, and K for the in- 

 dicator local circuits (see also 

 fig. 142). This plan is essen- 

 tially the same as that indicated 

 in the author's original trans- 

 lator patent of 1881. Fig. 142 

 shows the connection of the 

 translators with the trunk sec- 

 tion of the multiple board. 

 One translator circuit is joined 

 to the wires of the trunk ; the 

 other, on the single-cord plan, 

 to a double-conductor cord and plug. On inserting this latter 

 in the spring-jack of the local wire, translation between the 

 two lines is effected. The double-conductor cord is provided 

 with two switches, A and B, for ringing and speaking respec- 

 tively. The ring-off drop c is worked by the translator as 

 described, but as it is only wanted after a connection has been 

 put through, two springs, F, are provided which keep apart so 

 long as the plug is in its idle position, but which touch and loop 



FIG. 142 



