boards, of other than the
smallest sizes, to employ some form of ringing generator, either a
power-driven generator or a pole changer driven by battery current for
furnishing ringing current without effort on the part of the operator.

[Illustration: Fig. 301. Dean Two-Position Switchboard]

Switchboards as shown in Figs. 294 and 295, are called single-position
switchboards because they afford room for a single operator.
Ordinarily for this class of work a single operator may handle from
one to two hundred lines, although of course this depends on the
amount of traffic on the line, and this, in turn, depends on the
character of the subscribers served, and also on the average number of
stations on a line. Another single-position switchboard is shown in
Figs. 299 and 300, being a front and rear view of the simple magneto
switchboard of the Western Electric Company, which is provided with
the target signals of that company rather than the usual form of drop.

Where a switchboard must accommodate more lines than can be handled by
a single operator, the cabinet is made wider so as to afford room for
more than one operator to be seated before it. Sometimes this is
accomplished by building the cabinet wider, or by putting two such
switchboard sections as are shown in Figs. 294 or 299 side by side. A
two-position switchboard section is shown in front and rear views in
Figs. 301 and 302.

[Illustration: Fig. 302. Rear View of Dean Two-Position Switchboard]

_Sectional Switchboards._ The problem of providing for growth in a
switchboard is very much the same as that which confronts one in
buying a bookcase for his library. The Western Electric Company has
met this problem, for very small rural exchanges, in much the same way
that the sectional bookcase manufacturers have provided for the
possible increase in bookcase capacity. Like the sectional bookcase,
this sectional switchboard may start with the smallest of equipment--a
single sectional unit--and may be added to vertically as the
requirements increase, the original equipment being usable in its more
extended surroundings.

[Illustration: Fig. 303. Sectional Switchboard--Wall Type]

This line of switchboards is illustrated in Figs. 303 to 306. The
beginning may be made with either a wall type or an upright type of
switchboard, the former being mounted on brackets secured to the wall,
and the latter on a table. A good idea of the wall type is shown in
Fig. 303. Three di