a variety of other
structural forms, but principally with such as are used in heavy
building work, and in cases where neither fish plates nor scarfing will
answer the purpose.

[Illustration: _Fig. 293. Spur Tenon._]

[Illustration: _Fig. 294. Saddle Joints._]

BRIDLE JOINTS.--This is a form of joint where permanency is not desired,
and where it is necessary to readily seat or unseat the vertical timber.
It is also obvious that the socket for the upright is of such a
character that it will not weaken it to any great extent.

SPUR TENON.--This tenon can be used in many places where the regular one
is not available. This, like the preceding, is used where the parts are
desired to be detachable, and the second form is one which is used in
many structures.

SADDLE JOINT.--This is still another manner in which a quickly
detachable joint can be constructed. The saddle may be mounted on the
main base, or cut into the base piece. An infinite variety of forms of
saddles are made, most of them being used in dock work, and for framing
of that character where large timbers are used, as in the building of
coal chutes, and the like.

[Illustration: _Fig. 295. Joggle Joints._]

[Illustration: _Fig. 296. Framing Joints._]

JOGGLE JOINT.--This joint is used almost exclusively for brace work
where great weight must be supported. The brace has a tenon, and the
end must also be so arranged that it will have a direct bearing against
the upright, which it braces and supports, or it may have two faces, as
in the second figure, which is an exceedingly strong construction.

[Illustration: _Fig. 297. Heel Joints._]

[Illustration: _Fig. 298. Stub Tenon._]

FRAMING JOINTS.--These are the simplest form in which two members are
secured together. They are used almost wholly in rafter work, and have
very few modifications. The depth of the cut, for the toe of the rafter,
depends on the load to be carried, and also on the distance the end of
the rafter is from the end of the horizontal member on which the rafter
rests.

HEEL JOINTS.--This is by far the most secure of the framing type of
joints. This, if properly made, is much better than the construction
shown in the previous illustration, but the difficulty is to make the
rafter fit into the recesses properly. This is no excuse for failure to
use, but it is on account of inability to make close fits that is
accountable for lack of use. It will be seen that in case one of the
heels res