e offices equipped with manual
switchboards, we have chosen the Chelsea office of the New York
Telephone Company as an excellent example of modern practice.

[Illustration: Fig. 422. Floor Plan, Operating Room, Chelsea Office, New
York City]

The ground plan of the building is U-shaped, in order to provide the
necessary light over the rather large floor areas. The plan of the
operating floor--the sixth floor of the building--is shown in Fig. 422.
As will be seen, this constitutes a single operating room, the _A_-board
being located in the right wing and the _B_-board in the left. The point
from which both boards grow is near the center of the front of the
building, the boards coming together at this point in a common cable
turning section. The disposal of the various desks for the manager,
chief operator, and monitors is indicated. Those switchboard sections
which are shown in full lines are the ones at present installed, the
provision for growth being indicated in dotted lines.

[Illustration: Fig. 423. Terminal Room and Operators' Quarters, Chelsea
Office, New York City]

The fifth floor is devoted to the terminal room and operators' quarters,
the terminal room occupying the left-hand wing and the major portion of
the front of the building, and the operators' quarters the right-hand
wing. The line and the trunk cables come up from the basement of the
building at the extreme left, being supported directly on the outside
wall of the building. Arriving at the fifth floor, they turn
horizontally and are led under a false flooring provided with trap
doors, to the protector side of the main frame. The disposal of the
cables between the various frames will be more readily understood by
reference to the following photographs.

A general view of a portion of the _A_-board of the Chelsea office is
shown in Fig. 424, this view being taken from a point in the left-hand
wing looking toward the front. In Fig. 425 is shown a closer view of a
smaller portion of the board. Fig. 426 gives an excellent idea of the
rear of this switchboard and of the disposal of the cables and wires.
The main mass of cables at the top are those of the multiple.
Immediately below these may be seen the outgoing trunk cables. The forms
of the answering-jack cables lie below these and are not so readily
seen, but the cables leading from these forms are led down to the runway
at the bottom of the sections, and thence along the length of the board
to the