ews of Tongueing and
Grooving Planes.]

In description Fig. 125 is similar to Fig. 124. The steel skate runs in
the groove and supports the cutting blade similar to that in the plough
plane, and provided a grooving plane of this type is of suitable width it
may be used for making grooves for loose tongues. There is on the market
a metal plane which is specially designed with handles at both ends.
This plane carries a grooving iron on one side and a tongueing iron on
the other side; thus with one plane both the tongue and the groove can be
worked.

[Illustration: Fig. 126.--Tongueing Shoulders of Tenons.]

Fig. 126 shows the method of tongueing the shoulders of tenons as used in
thick timber which is to be veneered on the face. A temporary piece of
wood (A) is put between the tenon cheek and the saw, thus forming a guide
for the latter. After cutting one saw kerf a thicker piece is made and a
second saw kerf cut; the waste between the saw kerfs is now removed with
an 1/8 in. chisel and this completes the groove. A tongue of this type
acts as an extra tenon and prevents the joint from "lipping" (becoming
uneven) on the face side.

THE MORTISE AND TENON JOINT

A mortise and tenon joint is the method of joining timber by working a
solid rectangular projection in the one piece and cutting a corresponding
cavity to receive it in the adjoining piece. The projection is called the
tenon, and the cavity the mortise. Joints of this type are secured in
various ways. Small wedges, wooden dowels, metal dowel pins, glue and
paint are frequently used, and prior to the introduction of glue we have
examples of Egyptian furniture in which the mortise and tenon joints were
united by a composition of cheese.

[Illustration: Fig. 127.--Barefaced Tenon Joint.]

[Illustration: Fig. 128.--Stub Tenon.]

BAREFACED TENONS.--Fig. 127 illustrates the joint in its simplest form
and shows a tenon having only one shoulder. This is called a barefaced
tenon, and it will be noticed that the portion which carries the mortise
is thicker than the rail on which the tenon is cut. The joint is
therefore level (or flush as it is called) on one side only, and it
should never be used at the corner of a frame. It is a useful interior
joint for framing that has to be covered on the back side with
matchboarding, and allows the work to finish level at the back when the
boarding has been applied (see plan, Fig. 127).

STUB OR STUMP TENON (Fig. 128; a