It is quite likely that the celt itself was simply a development of the wedge.
In the modern chisel, all the grinding is done on one side.

This constitutes the essential feature of the chisel, namely, that the back of the blade is kept perfectly flat and the face is ground to a bevel.
Blades vary in width from 1/16 inch to 2 inches.

Next to the blade on the end of which is the cutting edge, is the shank, Fig.65.Next, as in socketed chisels, there is the socket to receive the handle, or, in tanged chisels, a shoulder and four-sided tang which is driven into the handle, which is bound at its lower end by a ferrule.

The handle is usually made of apple wood.
[Illustration: Fig.65.

Firmer-Chisel.] The most familiar form is the _firmer-chisel_, Fig.