The spur wheel is 12 feet diameter, 24 inches face, and contains 96 teeth.
Having obtained the arcs d, e, f, the curves may be marked thereon as for a spur wheel.
To the spur wheel 3, a bevel wheel 4, is fixed, with which the other also revolves loose upon a stud.
This can be done in this way: attach a spur wheel to the back of the face plate.
In the latter case, the small one is the pinion, and the larger one the spur wheel.