7 'E L li J • 1 ■/'/•; 11 7^ / 7 !■: I< h'.X C 'I I A NCli S \ 'S I 'K M 



52 5 



subscriber circuit description. Many other items are included in the 

 cord circuit by means of which the operator may expedite the setting 

 up and removing of coniu'ctions. Among these items is the busy test. 

 When an operator is about to complete a call to a station it is necessary 

 that she know that the station is free to receive the call. To ascertain 

 this a means is provided so that she may make a (ij) busy test on the 

 sleeve of the jack associated with that subscriber line and, if the 

 station is busy, a position light will be lit. If no light is received the 

 operator will plug into the jack and complete the connection. 



Multiple appearances of the jacks and lamps associated with 

 subscriber lines and inter-toll trunks are provided so that a number of 



ANSWER 



^ 



: 



OPERATOR'S 

 SET 



1_ i. 



k^V\.^ 



±1 



X 



1 



lit sil f^ 



CALL 



60 

 INTERRUPTIONS 

 PER 

 MINUTE 



Fig. 13^ — Typical cord circuit. 



operators may be available to answer a call from a station or an 

 inter-toll trunk. If more than one operator answers it is necessary 

 that they be aware of that fact, and that the first operator shall take 

 and complete the call. A circuit is provided to indicate this. 



Facilities are provided to split the cord, that is, to enable the 

 operator to communicate in one direction without the communication 

 being recorded in the other direction. Ringing is accomplished in a 

 manner similar to that used in telephone practice, the No. 1 

 switchboard using manual start machine ringing and the smaller 

 No. 3.4 switchboard using manual ringing. While the cord is 

 connected to one line and the operator is attempting to complete 

 the connection to another line, the first line is held closed in order not 

 to mar transmission. 



