which the two cords meet at C, where another peg may be driven in, will be
the line at right angles to B-A.

[Illustration: Right Angle of Camp Square]

Measuring Device

The illustrations opposite show a device by which a camp, baseball
grounds, running track, tennis court or any distance may be quickly and
accurately measured. The first thing to do is to get an inch board and cut
a round disc (a) about 12 inches in diameter. Cut two of them and tack
them together. The diagram "b" is easier to cut out and will serve the
purpose just as well. When the two are temporarily tacked together, bore a
hole through the centre for the axle. The eight spokes should be of light
material and not too pointed or they will sink in the ground and prevent
accuracy. The spokes are tacked on one disc as shown in "c" and then the
other disc is nailed on the outside.

[Illustration: A Measuring Device]

Paint the end of one spoke red, so that you can count it every time it
comes around. By having the points that touch the ground exactly 9 inches
apart, one revolution of the wheel will measure six feet. For an axle use
a small piece of broom handle, and for a handle use a long light pole. By
varying the length of the spokes you can make the wheel measure any
desired distance.

Wall Tent

The line of the camp having been laid out, the next thing is the erection