evented by
the breaking of the shaving as it hits against the cutter or its cap.
Hence the advantage of bending up and breaking or partly breaking the
shaving as soon as possible after it is cut. This shows why the cap is
set close to the edge of the cutter. Another reason is that it thereby
stiffens the cutter and prevents "chattering." If a thick shaving be
desired the cap has to be set farther back. In a smooth-plane 1/32
inch is enough, in a jack-plane 1/8 inch is often desirable. The
following are the planes in common use:

The _jack-plane_, Fig. 102, 14" to 15" long, is the one used where a
considerable amount of material is to be taken off to bring a piece of
wood to size, and therefore the outline of the cutting edge instead of
being straight is slightly curved or "crowned" so that in planing the
surface of a board it makes a series of shallow grooves, the ridges
of which must afterward be smoothed off by another plane. Also for
beginners whose hands are not strong it is sometimes wise to grind the
cutter with some "crown", in order to take off narrow shavings, which
require less strength. For school use, where the jack-plane is used
for all purposes, the cutter is usually ground almost straight and
only the corners rounded as in the smooth-plane and the fore-plane.[5]

[Footnote 5: In whetting a plane-bit, a slight crown may be given
it by rubbing a bit harder at the ends of the edge than in the
middle. Strop in the same way as a chisel (p. 59).]

The _fore-plane_, 22" to 26" long, and the _jointer_, 28" to 30" long,
are large planes, similar to the jack-plane, except that the cutting
edge is straight. They are used for straightening and smoothing long
pieces.

The _smooth-plane_, 5-1/2" to 10" long, is a short plane, similar to
the jack-plane, except that the cutting edge is straight. It is used
for smoothing.

These four planes, the jack-plane, the fore-plane, the jointer, and
the smooth-plane, are essentially alike, and directions for the use of
one apply to all.

There are two chief adjustments in the Bailey iron plane: the brass
set-screw, see 8 in Fig. 101, which regulates the depth of the cut,
and the lever, 9, which moves the cutter sidewise so that it may be
made to cut evenly. The skilful worker keeps constant watch of these
adjustments. It is well to form the habit of always sighting along
the sole before beginning to plane, in order to see that the cutter
projects properly, Fig.