INVENTORS
length of signalling wires. ln the installation as laid down at present two miles was the maximum hauling distance, and the signalling covered the same length. If the roads were longer the system could be lengthened, (d) A noticeable reduction in the cost of battery upkeep effected through the reduction from the high value often used to the three or four volts required by the relay. (e) With the adoption of this system all danger of explosion was eliminated. (f) The apparatus was of the simplest possible description. It required no special maintenance and involved no special wiring. (g) Suitable glands were provided to the box for leading in armoured or any other form of cable which it would be desired to employ.