This is accomplished by making the needle revolve in a
vertical instead of a horizontal plane. The only adjustment
necessary is that of leveling, which is accomplished by turning
the thumbscrew shown at A, Fig. 1, until the hand points to zero
on the scale.
First make a support, Fig. 2, by bending a piece of sheet brass to
the shape indicated and tapping for the screws CC. These should
have hollow ends, as shown, for the purpose of receiving the
pivoted axle which supports the hand. The core, Fig. 3, is made of
iron. It is 1 in. long, 1/4 in. wide and 1/8 in. thick. At a point
a little above the center, drill a hole as shown at H, and through
this hole drive a piece of knitting-needle about 1/2 in. long, or
long enough to reach between the two screws shown in Fig. 2. The
ends of this small axle should be ground pointed and should turn
easily in the cavities, as the sensitiveness of the instrument
depends on the ease with which this axle turns.
After assembling the core as shown in Fig. 4, it should be filed a
little at one end until it assumes the position indicated. The
pointer or hand, Fig.
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