if that key set is still acting to
control the sending of impulses to the automatic switches, it may be
said to be busy, and it is not selected by this preliminary selecting
apparatus in response to an incoming call. As soon, however, as the
necessary impulses have been taken from the key set by the automatic
apparatus, that key set is released and is again ready to receive a
call. In this way the calls come before each operator only as that
operator is able and ready to receive them.

=Setting up a Connection.= As soon as the key-set lamp lights, in
response to such an incoming call, the operator presses a listening
button, receives the number from the subscriber, and depresses the
corresponding number buttons on that key set, thereby determining the
numbers in each of the series of impulses to be sent to the selector and
the connector switches to make the desired connection. The operator
repeats this number to the calling subscriber as she sets it up, and
then presses the starting button, whereupon her work is done so far as
that call is concerned. If, upon repeating the call to the subscriber,
the operator finds that she is in error, she may change the number set
up at any time before she has pressed the starting button.

=Building up a Connection.= The keys so set up determine the number of
impulses that will be transmitted by the impulse-sending machine to the
selector and the connector switches. These switches, impelled by these
impulses, establish the connection if the line called for is not already
connected to. If a party-line station is called for, the proper station
on it will be selectively rung as determined by the party-line key
depressed by the operator. If the line is found busy, the connector
switch refuses to make the connection and places a busy-back signal on
the calling line.

=Speed in Handling Calls.= This necessarily brief outline gives an idea
only of the more striking features of the automanual system. A study of
the rapidity with which calls may be handled in actual practice shows
remarkable results as compared with manual methods of operating. The
operators set up the number keys corresponding to a called number with
the same rapidity that the keys of a typewriter are pressed in spelling
a word. In fact, even greater speed is possible, since it is noticed
that the operators frequently will depress all of the keys of a number
at once, as by a single striking movement of the fingers. The rap