152 Telephone Systems of the Continent of Europe 



board, on which all the subscribers' lines are multipled, for the 

 calling subscriber. The junction lines are divided into 500 out- 

 going and 500 in-coming, the subscribers' lines being multipled 

 also on the junction tables. When a calling subscriber wants a 

 client on another switch-room, the local operator advises the 

 junction girl, who obtains the connection from the other switch- 

 room and completes it through the caller's repeat jack. When a 

 demand comes from another switch -room the junction operator 

 can, of course, satisfy it herself. Junction lines must not be 

 occupied longer than ten minutes for one connection if other 

 subscribers are waiting. At the expiry of that time the talkers 



EARTH 



FIG. 38 



are invited to cease, and if they do not comply are summarily 

 disconnected. Special sections are provided for the accommoda- 

 tion of 150 public telephone stations, and for the theatrophone 

 lines to the Opera-Comique and Louis-le-Grand. The trunk 

 switching is somewhat complicated by the special appliances 

 necessary for the systems of simultaneous telephony and telegraphy 

 so much used in France. Three systems are employed Van 

 Rysselberghe's, Cailho's, and Picard's. The first is too well known 

 to require description. The second is a modification of the plan 

 generally associated in this country with the name of Mr. Frank 

 Jacob, although M. Cailho is understood to claim that he described 



