r may be
applied to the former. There is one curious invention which has been
applied to driers only (Pat. 322,762--W.H. Tolhurst). See Fig. 25. A
convex shaft-supporting step resting on a concave supporting base,
with the center of its arc of concavity at the center of the upper
universal joint, has been employed, and its movements controlled by
springs, but the step was apt to be forced from its support. The
drawing shows the improvement on this, which is to give the
shaft-supporting step a less radius of curvature.

[Illustration: Fig. 25.]

An interesting form of drier has its own motor, a little steam engine,
attached to the frame of the machine. See Fig 24. This of course
demands fixed bearings. The engine is very small. One size used is 3"x4".
When a higher velocity of basket is required, we have the arrangement
in Fig. 26.

[Illustration: Fig. 26.]

MOTORS.--This naturally introduces the subject of motive power. We may
have the engine direct acting as above, or the power may be brought on
by belting. Fig. 27 shows a drier with pulley for belting. Fig. 28
(W.H. Tolhurst) shows a very common arrangement of belting and also the
fast and loose pulleys. When the heaviest part of the engine is so far
from the vertical shaft as to overhang the casing on one side, there is
apt to be an objectionable tremor. To remedy this, it is suggested to
put these heavy parts as near the shaft as possible. It has been
suggested also to use the Westinghouse type of engine, although the
type shown in Fig. 24 works faultlessly in practice.

[Illustration: Fig. 27.]

One plan (Pat. 346,030), designed to combine the advantages of a direct
acting motor and an oscillating shaft, mounts the whole machine, motor
and all, on a rocking frame. The spindle is of course in fixed bearings
in the frame. However, the plan is not practical.

[Illustration: Fig. 28.]

In driers the direct acting engine has many advantages over the belt.
The atmosphere is always very moist about a whizzer, and there are
frequently injurious fumes. The belt will be alternately dry and wet,
stretched and limp, and wears out rapidly and is liable to sever. In
all machines in which the shaft oscillates, if the center of
oscillation does not lie in the central plane of the belt, the tension
of the latter is not uniform. This affects badly both the belt and the
running. A reference to the various figures will show the best position
for the pulley.

The greatest