The file should cut in the direction of the set.

The angle of the cutting edge is determined by the horizontal inclination of the file to the blade; the angle of the point is determined by the perpendicular inclination of the file to the blade.
Finally the sides of the teeth are rubbed lightly with a slipstone to remove the wire edge.

It should always be remembered that a saw is an edge tool, and its edges are as liable to injury as any edges.
PLANES.
The _plane_ is a modified chisel.

The chief difference in action between a chisel and a plane in paring is this: the back of the chisel lies close down on the surface of the wood that is cut, and acts as a guide; whereas, in the plane, the cutter is elevated at an angle away from the surface of the wood, and only its cutting edge touches the wood, and it is held and guided mechanically by the plane mechanism.
In other words, a plane is a chisel firmly held in a device which raises the cutter at an angle from the work, regulates the depth of the cut, and favors the cutting rather than the splitting action.
An illustration of a chisel converted into a plane is the adjustable _chisel-gage_, Fig.

99.
[Illustration: Fig.99.Adjustable Chisel-Gage.] [Illustration: Fig.100.Wooden Bench-Plane.] [Illustration: Fig.101.Section of Jack Plane.] The plane has developed as follows: it was first a chisel held in a block of wood.