gly
increased or decreased as the pressure exceeds or falls below
this. In the latter case the power may be increased by using a
smaller pulley. Fig. 1 is the motor with one side removed, showing
the paddle-wheel in position; Fig. 2 is an end view; Fig. 3 shows
one of the paddles, and Fig. 4 shows the method of shaping the
paddles. To make the frame, several lengths of scantling 3 in.
wide by 1 in. thick (preferably of hard wood) are required. Cut
two of them 4 ft. long, to form the main supports of the frame,
AA, Fig. 1 ; another, 2 ft. 6 in. long, for the top, B, Fig. 1;
another, 26 in. long, to form the slanting part, C, Fig. 1; and
another, D, approximately 1 ft., according to the slant given C.
After nailing these together as shown in the illustration, nail
two short strips on each side of the outlet, as at E, to keep the
frame from spreading.

Cut two pieces 30 in. long. Lay these on the sides of the frame
with their center lines along the line FF, which is 15 in. from
the outside top of the frame. They are shown in Fig. 2 at GG. Do
not fasten these boards now, but mark their position on the frame.
Two short boards 1 in. wide

[Illustration: Detail of Homemade Waterwheel]

by 1 in. thick (HH, Fig. 2) and another 1 in. by 1-1/2 in. (I,
Fig. 2) form a substantial base.

Cut the wheel from sheet iron 1/16 in. thick, 24 in. in diameter.
This can be done roughly with hammer and chisel and then smoothed
up on an emery wheel, after which cut 24 radial slots 3/4 in. deep
on its circumference by means of a hacksaw. On each side of the
wheel at the center fasten a rectangular piece of 1/4-in. iron 3
by 4 in. and secure it to the wheel by means of four rivets; after
which drill a 5/8 in. hole through the exact center of the wheel.

Cut 24 pieces of 1/32-in. iron, 1-1/2 by 2-1/2 in. These are the
paddles. Shape them by placing one end over a section of 1-in.
pipe, and hammer bowl shaped with the peen of a hammer, as shown
in Fig. 4. Then cut them into the shape shown in Fig. 3 and bend
the tapered end in along the lines JJ, after which place them in
the slots of the wheel and bend the sides over to clamp the wheel.
Drill 1/8-in. holes through the wheel and sides of the paddles and
rivet paddles in place. Next secure a 5/8-in. steel shaft 12 in.
long to the wheel about 8 in. from one end by means of a key. This
is done by cutting a groove in the shaft and a corresponding
groove in the wheel and fitting in a piece of me