ill be recalled by reference to Fig. 348
that the line lamp and the answering jack were permanently associated
with the line and cut-off relays, such mutations of arrangement as were
possible at the intermediate distributing frame serving only to vary the
connection between the multiple of a line and one of the various groups
of apparatus consisting of an answering jack and line lamp and
associated relays. In the Kellogg arrangement, Fig. 353, the line and
cut-off relays, instead of being permanently associated with the
answering jack and line lamp, are permanently associated with the
multiple jacks, no changes, of which the intermediate or main frames are
capable, being able to alter the relation between a group of multiple
jacks and its associated line and cut-off relays. In this Kellogg
arrangement the intermediate distributing frame may only alter the
connection of an answering jack and line lamp with the multiple and its
permanently associated relays. The pilot and night alarm arrangements of
Fig. 353 should be obvious from the description already given of other
similar systems.

[Illustration: Fig. 353. Kellogg Two-Wire Line Circuit]

=Dean Multiple Board.= In Fig. 354 are shown the circuits of the
multiple switchboard of the Dean Electric Company. The subscriber's
station equipment shown at Station _A_ and Station _B_ will be
recognized as the Wheatstone-bridge circuit of the Dean Company.

_Line Circuit._ The line circuit is easily understood in view of what
has been said concerning the Western Electric line circuit, the line
relay _1_ being single wound and between the live side of the battery
and the ring side of the line. The cut-off relay _2_ is operated
whenever a plug is inserted in a jack and serves to sever the connection
of the line with the normal line signaling apparatus.

_Cord Circuit._ The cord circuit is of the four-relay type, but employs
three conductors instead of two, as in the two-wire system. The relay
_3_, being in series between the battery and the sleeve contact on the
plug, is energized whenever a plug is inserted in the jack, its winding
being placed in series with the cut-off relay of the line with which the
plug is connected. This completes the circuit through the associated
supervisory lamp unless the relay _4_ is energized, the local lamp
circuit being controlled by the back contact of relay _4_ and the front
contact of relay _3_. It is through the two windings of the relay _4_