nchronous clocks. When the dispatcher wishes to put through a call, he
throws the keys of all the stations that he desires and then operates a
starting key. The bells at all these stations are rung by one operation.

The dispatcher's sending equipment of the Cummings-Wray system is shown
in Fig. 480, and the waystation selector in Fig. 481. It is necessary
with this system for the clocks at all stations to be wound every eight
days.

[Illustration: Fig. 481. Cummings-Wray Selector]

In the dispatcher's master sender the clock-work mechanism operates a
contact arm which shows on the face of the sender in Fig. 480. There is
one contact for every station on the line. The clock at this office and
the clocks at all the waystation offices start together, and it is by
this means that the stations are signaled, as will be described later,
when the detailed operation of the circuits is taken up.

=Telephone Equipment.= Of no less importance than the selective devices
is the telephone apparatus. That which is here illustrated is the
product of the Western Electric Company, to whom we are indebted for all
the illustrations in this chapter.

_Dispatcher's Transmitter._ The dispatcher, in most cases, uses the
chest transmitter similar to that employed by switchboard operators in
every-day service. He is connected at all times to the telephone
circuit, and for this reason equipment easy for him to wear is
essential. In very noisy locations he is equipped with a double head
receiver. On account of the dispatcher being connected across the line
permanently and of his being required to talk a large part of the time,
there is a severe drain on the transmitter battery. For this reason
storage batteries are generally used.

[Illustration: Fig. 482. Waystation Desk Telephone]

_Waystation Telephones._ At the waystations various types of telephone
equipment may be used. Perhaps the most common is the familiar desk
stand shown in Fig. 482, which, for railroad service, is arranged with a
special hook-switch lever for use with a head receiver.

Often some of the familiar swinging-arm telephone supports are used, in
connection with head receivers, but certain special types developed
particularly for railway use are advantageous, because in many cases the
operator who handles train orders is located in a tower where he must
also attend to the interlocking signals, and for such service it is
necessary for him to be able to get away from th