inmen call this number when arriving at sidings or wherever they may
need to do so.

Another method of installing a telephone system upon electric railways
is as follows: Instead of instruments being mounted in booths or on
poles along the line, portable telephone sets are carried on the cars
and jacks are located at regular intervals along the right-of-way on the
poles. The crew of the car wishing to get in touch with the central
office or the dispatcher, plugs into one of these jacks and uses the
portable telephone set. At indoor stations, in offices or buildings
belonging to the railroad, the regular magneto sets may be employed, as
in the first case outlined.

On electric railway systems where the traffic is heavy, the train or car
movements may be handled by a dispatcher just as on the steam railroad.
There is usually one difference, however. On a steam road, the operators
who give the train crews their orders and manipulate the semaphore
signals are located at regular intervals in the different waystations.
No such operators are usually found on electric railways, except,
perhaps, at very important points, and, therefore, it is necessary for
the dispatcher to be able to signal cars at any point and to get into
communication with the crews of these cars. He does this by means of
semaphores operated by telephone selectors over the telephone line. The
telephone circuit may be equipped with any number of selectors desired,
and the dispatcher can operate any particular one without operating any
other one on the circuit. Each selector, when operated, closes a pair of
contacts. This completes a local circuit which throws the semaphore arm
to the "danger" position, at the same time giving the dispatcher a
distinctive buzz in his ear, which informs him that the arm has actually
moved to this position. He can get this signal only by the operation of
the arm.

Each semaphore is located adjacent to a telephone booth in which is also
placed the restoring lever, by means of which the semaphore is set in
the "clear" position by the crew of the car which has been signaled. The
wall-type telephone set is usually employed for this class of service,
but if desired, desk stands or any of the various transmitter arms may
be used.

It is necessary for the crew of the car which first approaches a
semaphore set at "danger," to get out, communicate with the dispatcher,
and restore the signal to the "clear" position. The dispatcher can