Toe.
18.

Heel.
19.

Throat.
20.

Thumb piece, or clamp lever, or cam.
[Footnote 4: The numbers and names in italics are those given in Stanley's Catalog, No.34.Some of these names, as "plane-iron," are survivals from the days of the wooden plane and are obviously unsuitable now.] There are various principles involved in the action of the plane.

The effect of the flat sole is to regulate the cut of the cutter.