Then all the telephone wires of a certain district converge at a central station, and each pair of wires is connected with its own particular switch at the switchboard of the station.

That is simple enough; but when you come to consider that every subscriber must be so connected that he can be put into communication with every other subscriber, not only in his own section but also with every subscriber throughout the city, it will be seen that the switchboard at central is as marvellous as it is complicated.

The operators sit before the switchboard in high swivel chairs in a long row, with their backs to the centre of the room.

We came upon twelve soldier-operators sitting before portable switchboards with metal transmitters clamped upon their heads, giving and taking messages to and from all the corners and crannies of the mid-battle-front.

As Mr. Carty himself puts it: The little switchboards of that day were a good deal like the automobiles of some years agoone was likely to spend more time under the switchboard than, sitting at it!