nd selectors, however,
the connector is required to make a double selection under the guidance
of the subscriber. The first selector makes a single selection of a
group under the guidance of the subscriber and then an automatic
selection in that group not controlled by the subscriber. So it is with
the second selector. The connector, however, makes a selection of a
group of ten under the guidance of the subscriber and then, again under
the guidance of the subscriber, it picks out a particular one of that
group.

The connector also has other functions in relation to the ringing of
the called subscriber and the giving of a busy signal to the calling
subscriber in case the line wanted is found busy. It has still other
functions in that the talking current, which is finally supplied to
connected subscribers, is supplied through paths furnished by it.

_Location of the Connectors._ Connectors are the only ones of the
selecting switches that are in any sense individual to the subscribers'
lines. None of them is individual to a subscriber's line, but it may be
said that a group of ten connectors is individual to a group of one
hundred subscribers' lines. Since each group of one hundred lines has a
group of connectors of its own and since each one hundred lines also has
a line-switch unit of its own, and since the lines of this group must be
multipled through the bank contacts of the connectors of this individual
group and through the bank contacts of the line switches of this
particular unit, it follows that on account of the wiring problems
involved there is good reason for mounting the connectors in close
proximity to the line switches representing the same group of lines.
Some help in the grasping of this thought may result if it be remembered
that the line switch is, so to speak, the point of entry of a call and
that the connector is the point of exit, and, in order to reduce the
amount of wiring and to economize space, the point of exit and the point
of entry are made as close together as possible.

The relative locations and grouping of the line switches and connectors
are clearly shown in Fig. 395, which is a rear view of the same
line-switch unit that was illustrated in Figs. 387 and 388.

[Illustration: GAS ENGINE AND POWER BOARD Citizens' Telephone Co.,
Racine, Wis. _The Dean Electric Co._]

=Operation of the Connector.= The circuits of the connector are shown in
Fig. 396. In addition to the features that have b