242 Of the gathering of W veels,

ces, the following proportions will an- iwer to every caſe.

As the half height of the wheel is to the fourtly part of the intended gather, ío make the length of the arm to the diſtance ſought.

This proportion may be thus demon-

ſtrated from fig. 9g.

Let abcd repreſent the under ſide

of an axle, ne fr a line drawn along

the middle of it, n o the diſtance ſet for-

ward at one out head, and ro the dif

tance ſet forward at the other.. Then, ſince the centre line of the axle muſt correſpond with the centre line of the buſhes, and the face of the wheel cuts theſe lines at right angles, if the centres of the out heads were continued in the

ſtraight line in n and r, the face of the

wheels

0 7A