For twisting tests we need a special handle (see Fig. 164), which is
slipped on to the pivot and transmits the twist to L through a pin pressing
on the back of the lever. The stirrup is made out of strip iron, bent to
shape and drilled near the ends for the grip spindle. To the bottom is
screwed and soldered a brass or iron plate, into the underside of which the
pin is driven.
[Illustration: FIG. 164.--Handle for twisting test.]
To prevent the handle bending over, solder round the pivot hole 3/4 inch of
brass tubing, fitting the pivot closely.
Tests.--Grip tests should be made with each hand separately. The
baseboard should lie flat on a table or other convenient support, and be
steadied, but not pushed, by the hand not gripping.
Twisting tests may be made inwards with the right hand, and back-handedly
with the left. The apparatus is stood on edge, square to the performer,
resting on the horns of A and a support near the balance.
Finger tests are made by placing the thumb on the front face of B, and two
fingers on the farther side of the lever, one to the left and the other to
the right of the tail of the balance.
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