Our magazine has over ten thousand subscribers.
It is not practicable to connect each subscriber directly to all the others, hence a system of exchanges has been adopted.
When a subscriber called (by turning the handle of his magneto- 'generator), the shutter of the annunciator associated with his line dropped.
Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.
A subscriber desiring a connexion pressed the key and communicated his own number and that of the wanted subscriber to the operator in attendance on the call-wire.
Then, when the connexion was made, the originating subscriber rang up the other.