the basement to the upper floors or between
floors elsewhere must be provided for in a way that will not be wasteful
of space, and arrangements must be made for supporting the cables in
their vertical runs. In the aggregate their weight may be great, and
furthermore each individual cable must be so supported that its sheath
will not be subject to undue strain. Another factor which must be
considered in vertical cable runs is the guarding against such runs
forming natural flues through which flames or heated gases would pass,
in the event of even an unimportant fire at their lower ends.

=Arrangement of Apparatus in Small Manual Offices.= Where a
common-battery multiple switchboard equipment is used, at least three
principal rooms should be provided--one for the multiple switchboard
proper; one for the terminal and power apparatus, including the
distributing frames, racks, and power machinery; and the third for the
storage battery. These should adjoin each other for purposes of
convenience and of economy in wiring.

[Illustration: Fig. 418. Typical Small Office Floor Plan]

_Floor Plans for Small Manual Offices._ As was pointed out, there are
several plans of disposing of the main and intermediate distributing
frames and the line and cut-off relay racks. The one most practiced is
to mount the relay rack alongside the main and intermediate distributing
frame in the terminal room. A typical floor plan of such an arrangement
for a small office, employing as a maximum five sections of multiple
switchboards, is shown in Fig. 418. This is an ideal arrangement well
adapted for a rectangular floor space and on that account may often be
put into effect. It should be noted that the switchboard grows from left
to right, and that alternative arrangements are shown for disposing of
those sections beyond the second. The cable turning section through
which the multiple and answering jacks are led to the terminal frames is
placed as close as possible to the terminal frames. This results in a
considerable saving in cable. An interesting feature of this floor plan
is the arrangement of unitary sections of main and intermediate frames
and relay racks, representing recent practice of the Western Electric
Company. The iron work of the three racks is built in sections and these
are structurally connected across so that the first section of the main
frame, the intermediate frame, and the relay rack form one unit, the
structural iron work whi