In this device the emery-wheel is driven by belt power as follows.
It is manufactured into wheels, in structure like the emery-wheel, and serves the same purpose.
The emery-wheel and gear pinion d are fast together, and a pin passes through and holds g and h together.
On the end of the emery-wheel spindle is a feed lever, by means of which the emery-wheel may be fed along the lathe centre.
Now an emery-wheel will take a cut whose fineness is simply limited by the wear of the wheel in the length of the cut.
After the design has been cut on the emery-wheel all its rough edges are smoothed off on a stone of much finer grain.
Now, let us substitute for the emery-wheel another wheel of the same size made of vulcanized rubber, glass or resin.
The heat that has been developed is the measure of the mechanical energy that I have used against the emery-wheel.