equipment, and also
that by making changes in the jumper wires on the intermediate frame,
any given answering jack and line lamp with its associated line cut-off
relay may be associated with any set of multiple jacks.

_Pilot Signals._ In a portion of the circuit leading from the battery
that is common to a group of line lamps is the winding of the pilot
relay, which is common to this group of line lamps. This controls, as
already described, the circuit of the pilot lamp common to the same
group of line lamps. In addition, a night-bell circuit is sometimes
provided, this usually being in the form of an ordinary polarized
ringer, the circuit of which is controlled by a night-bell relay common
to the entire office. Normally, this relay is shunted out of the circuit
of the common portion of the lead to the pilot relay contacts by the key
_8_, but when the key _8_ is opened all current that is fed to the pilot
lamps passes through the night-bell relay, and thus, whenever any pilot
lamp is lighted, the night-bell relay will attract its armature and thus
close the circuit of the calling generator through the night bell.

A study of this figure will make clear to the student how the portions
of the circuit that are individual to the line are associated with such
things as the battery, that are common to the entire office, and such as
the pilot relay and lamp, that are common to a group of lines
terminating in one position.

_Modified Relay Windings._ In some cases, the line relay instead of
being double wound, as shown, is made with a single winding, this
winding being normally included between the ring side of the cut-off
relay and the battery, the tip side of the cut-off relay being run
direct to ground. The present practice of the Western Electric Company
is towards the double-wound relay, however, and that is considered
standard in all of their large No. 1 multiple boards, except where the
customer, owing to special reasons, demands a single wound relay on the
ring side of the line. The prime reason for the two-winding line relay
is the lessened click in the calling-subscriber's receiver which occurs
when the operator answers. All line relays prior to 1902 were
single-wound, but after that they were made double and used some turns
of resistance wire to limit the normal calling current.

_Relay Mounting._ In the standard No. 1 relay board of the Western
Electric Company and, in fact, in nearly all common-battery multiple