sitions where the top or
bottom edge of the work meets the eye, and where, if the rail were
allowed to run through, the end grain would appear unsightly.

[Illustration: Fig. 74.--Mitre Bridle Joint.]

[Illustration: Fig. 75.--Mirror Frame with Bridle Joints.]

Fig. 78 is a so-called bridle-joint at the corner of a frame. This is
also called an "Open slot mortise and tenon joint," a good strong,
serviceable joint which can be used instead of the closed mortise and
tenon type, its advantage being that less labour is required in the
making. (See also Fig. 169.)

Fig. 79 is an "Oblique angle bridle joint," used in similar positions to
the above, but when the two pieces meet at an acute angle at the end of a
frame.

Fig. 80 shows the application of the bridle joint to a roof truss. Two
sketches are shown at the joining of the tie beam and the principal
rafter. The joint _a_ is the type generally used. (See also Fig. 71 for
the joints in a queen post roof.)

[Illustration: Fig. 76.--Oblique Bridle Joint.]

[Illustration: Fig. 77.--Stopped Bridle Joint.]

[Illustration: Fig. 78.--Bridle Joint at Corner of Frame.]

[Illustration: Fig. 79.--Oblique Angle Bridle Joint.]

[Illustration: Fig. 80.--Application of Bridle Joint to Roof Truss.]

SETTING OUT AND MARKING.--It is a safe rule, when setting out a bridle
joint, to divide the thickness of the timber into three equal parts. This
will leave the timber on each side of the tongue equal to the thickness
of the tongue, thus giving uniform strength to the joint. The bridle
joint is chiefly used for connecting the internal parts of wooden frames.
It is stronger than the halving joint, and, owing to its peculiar
construction, requires little in the way of pegs, screws or nails to
secure it in position. Fig. 81 illustrates the joint, both open and
closed.

To understand the method of setting out and marking, glance at the
sketch, Fig. 81. It is not necessary that the bridle piece A be the same
width as the cross piece B; but it must be remembered when setting out
the joint with the marking knife or pencil that the width marked W on
piece B must be equal to the width W on the piece A. The timber should be
fairly accurately sawn or planed to the same thickness, and all edges
should be square and true.

The wood is placed upon the bench, and the joint marked out by using a
marking knife or penknife blade and the try square. A knife blade is much
better than a pencil, as t