... and a false alarm wouldbe raised. The open and the close circuits were therefore equally objectionable. Thenext method suggested was that which was usually called the balanced current system. It was this :-if a wire (Fig. 9) extended along the train as before, and a battery were placed at one end, one pole...

...W H PREECE © Thomas Telford and ICE 1867 LONDON & SOUTH WESTERN RAILWAY COMMUNICATION PASSENGERS DRIVERS GUARDS BELLS SIGNALS ELECTRICITY ELECTRICAL ELECTRIC ALARMS SYSTEMS TRAINS RAILWAYS SAFETY CARRIAGES ROLLING STOCK ROPES 80 COMMUNICATION IN TRAINS...