apparatus, or, as called in this system,
"divisions," are common to a section and are employed in a manner
similar to the connecting cords of a manual switchboard. The number of
these divisions provided for each section is, therefore, determined by
the number of simultaneous connections resulting from calls originating
in the section. It has been the custom in building this apparatus to
provide each section with seven divisions or connective elements.

The line apparatus comprises one relay, having a single winding, and two
pairs of contacts operated by its armature. This device is substantially
the well known cut-off relay almost universally employed in
common-battery systems. The fixed multiple contacts of the lines in the
switching banks of the connecting apparatus are considered as pertaining
to the various pieces of apparatus on which they are found rather than
to their respective lines. A good idea may be obtained of the
arrangement of the sectional and divisional apparatus by referring to
Fig. 404, which is one unit of a thousand-line equipment. The apparatus
in the vertical row at the extreme left of the illustration is the
sectional apparatus, while the remaining seven vertical rows of
apparatus are the divisions.

_The Section._ The sectional apparatus for each unit consists of three
separate devices called for convenience a _decimal indicator_, a
_division starter_, and a _decimal-register controller_. All of these
devices are normally motionless when idle. The energization of the
decimal indicator, in response to the inauguration of a call at a
subscriber's station, results immediately in an action of the division
starter which starts a division to connect with the line calling. It
results also in the starting of the decimal-register controller, the
remaining unit of sectional apparatus.

It is thus seen that upon the starting of a call by a subscriber, all
of the sectional apparatus belonging to his one hundred lines
immediately becomes active, the division starter acting to start a
division, the decimal indicator becoming energized to indicate the tens
group in which the call has appeared, and the decimal-register
controller becoming active to adjust the decimal register of the
division assigned by the division starter. The division starter having
assigned a division for the exclusive use of this particular call,
passes to a position from which it may start a similar idle division
when the next call is