esigns can be wrought out after the
start is once made. A good way to figure the price on the grate is
to add up the costs of the parts and charge about 12 cents per
hour for the work.

** How to Make a Water Wheel [374]

Considerable power can be developed with an overshot water wheel
erected as in Fig. 1. This wheel is made with blocks of wood cut
out in sections as indicated by the lines, so as to form the
circle properly. The wheel can be

[Illustration: Overshot and Undershot Wheels]

about 24 in. in diameter to produce results and about 10 in. wide.
Get some tin cans and attach them around the wheel as shown. Bore
the wheel center out and put on the grooved wood wheel, P, and a
rope for driving, R. This rope runs to a wooden frame in the
manner illustrated. The water is carried in a sluice affair, N, to
the fall, O, where the water dippers are struck by the volume and
from 2 to 4 hp. will be produced with this size of wheel if there
is sufficient flow of water. This power can be used for running
two or three sewing machines, fans, fret-saws, and the like.
Another form of water wheel is shown in Fig. 2. This is driven by
an underflow of current. This type of wheel can be made on lines
similar to the other, only that the paddles are of wood and extend
outward as shown. The wheel is supported in a bearing on the piece
S. A belt, T, communicates the power to the wheel V and from here
the power is carried to any desired point.

** How To Build An Imitation Street Car Line [374]

An imitation street car line may sound like a big undertaking,
but, in fact, it is one of the easiest things a boy can construct,
does not take much time and the expense is not great. A boy who
lives on a farm can find many fine places to run such a line, and
one in town can have a line between the house and the barn, if
they are some distance apart.

Often all the boards and blocks required can be had for helping a
carpenter clear away the rubbish around a new building. Wheels and
parts of old bicycles, which can be used in so many ways, can be
found at a junk shop at very low prices, wheels in good repair are
not expensive. For the car for the street car line try to find a
set of wheels having axles, but if you cannot find such, make
shafts of hard wood, about 3 in. by 2-1/2 in. and by means of a
jackknife turn, or shave down the ends to receive the hub bearings
of the wheels. Fasten the wheel hubs securely over the ends of