lanes are still
common, Fig. 100. Finally there appeared the iron plane, Fig. 101,
with it various mechanical adjustments. The following are the parts of
the Bailey iron plane:[4]

1. Cutter, or bit, or blade, or _plane-iron_.
2. Cap, or _plane-iron cap_, or curling iron.
3. Cutter screw, or _plane-iron Screw_.
4. Clamp, or _lever cap_, or wedge.
5. Clamp screw, or _cap screw_.
6. _Frog_.
7. _Y Adjustment_.
8. Brass set screw, or _brass adjusting nut_.
9. Lever (for _lateral adjustment_).
10. _Frog screw_.
11. _Handle_.
12. _Knob_.
13. _Handle bolt and nut_.
14. Knob screw, or _Knob bolt and nut_.
15. _Handle screw_.
16. _Bottom_, or sole.
17. 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. If the
surface be uneven, the cutter will not cut at all, or but little, in
passing over low places, since the toe and heel of the sole will then
be resting on higher places; but when the cutter reaches a high place
a shaving will be taken off. Hence it follows that the longer the
plane, the straighter will be the surface produced. The length of the
plane used is determined by the length of the wood to be planed, and
the degree of straightness desired.

The part of the sole directly in front of the cutter presses firmly
down on the wood and so prevents the shaving from splitting far in
advance of the edge. It follows that the narrowness of the mouth in
a plane is an important factor in the production of smooth surfaces.
This can be regulated by adjusting the toe in the block-plane, and by
moving the frog in the jack- and smooth-planes.

A recent improvement in jack-, smooth-, and fore-planes consists of
an adjustable frog, by means of which the throat can be narrowed
or widened at will by means of a set-screw in the rear of the frog
without removing the clamp and cutter. It is made by Sargent
and Company. The Stanley "Bed Rock" plane has a similar but less
convenient device.

[Illustration: Fig. 102. Sighting Along the Sole of Jack-Plane.]

The splitting of the wood in advance of the edge is also pr