in connection with the signal
transmitter controller.

Secondary Connector:--This switch contains in its cylinder bank of
contacts the multiple points of one hundred subscribers' lines and its
function is to connect the conductors of the called line to the
conductors of the connective division. This is accomplished by adjusting
the register to correspond to the value of the tens digit of the line
desired and by adjusting the cylinder brushes to correspond to the value
of the units digit of the line. The switch is controlled by the rotary
switch in connection with the signal-transmitter controller.

=Operation.= A brief description of the progress of a call from its
institution to the complete connection and subsequent disconnection
begins with the adjustment of the dial indicators of the telephone set
and the turning of the crank of the signal transmitter one revolution.
This act, performed by the calling subscriber, connects one of the line
conductors to earth. Immediately the decimal indicator associated with
the section in which the calling line terminates is energized and starts
the division starter. The division starter instantly starts the rotary
switch of an idle division. The rotary switch now starts the
decimal-register controller and connects to it the decimal register of
the primary connector of the division selected.

All of the above acts in the central office occur practically
simultaneously. The impulses generated by the controller are effective
upon the decimal register of the started division and, therefore, adjust
that register to a position corresponding to the tens value of the
calling line.

The rotary switch now disconnects the tens register and starts the
cylinder brushes of the primary connector which automatically stop when
they encounter the calling line. At this instant the cut-off relay of
the line is energized and the decimal indicator is released. The call
now is clear of all sectional apparatus and another call may come
through immediately, being assigned in charge of another idle division.

The total time in which any call is in charge of the sectional
apparatus, _i. e._, the total time from the grounding of the line
conductor at the sub-station until the line has been connected with by
the primary connector of some division of that section and the sectional
apparatus has been released by the operation of the cut-off relay,
approximates two-fifths of a second.

The next operation i