lint.

[Illustration: Fig. 333. Plug-Seat Switch]

[Illustration: Fig. 334. Order-Wire Arrangement]

=Methods of Handling Transfers.= One way of giving the number of the
called subscriber to the second operator in a transfer system is to
have that operator listen in on the circuit after it is continued to her
position and receive the number either from the first operator or from
the subscriber. Receiving it from the first operator has the
disadvantage of compelling the first operator to wait on the circuit
until the second operator responds; receiving it from the subscriber has
the disadvantage of sometimes being annoying to him. This, however, is
to be preferred to the loss of time on the part of the originating
operator that is entailed by the first method. A better way than either
of these is to provide between the various operators working in a
transfer system, a so-called _order-wire_ system. An order wire, as
ordinarily arranged, is a circuit terminating at one end permanently in
the head receiver of an operator, and terminating at the other end in a
push button which, when depressed, will connect the telephone set of the
operator at that end with the order wire. The operator at the
push-button end of the order wire may, therefore, at will, communicate
with the other operator in spite of anything that the other operator may
do. An order-wire system suitable for transfer switchboards consists in
an order wire leading from each operator's receiver to a push button at
each of the other operator's positions, so that every operator has it
within her power to depress a key or button and establish communication
with a corresponding operator. When, therefore, an operator in a
transfer system answers a call that must be completed through a transfer
circuit, she establishes connection with that transfer circuit and then
informs the operator at the other end of that circuit by order wire of
the number of the trunk and the number of the subscriber with which that
trunk is to be connected. Fig. 334 shows a system of order-wire buttons
by means of which each operator may connect her telephone set with that
of every other operator in the room, the number in this case being
confined to three. Assuming that each pair of wires leading from the
lower portion of this figure terminates respectively in the operator's
talking apparatus of the three respective operators, then it is obvious
that operator No. 1, by depressing button No