s on the top of the bench, Fig. 169. When the vise is likely
to be twisted out of square by the insertion of a piece of wood at one
end of it, it is well to insert another piece of equal thickness at
the other end of the vise to keep it square, as in Fig. 120, p. 82. In
this case, (Fig. 120,) the extra piece also supports the piece being
worked upon.

[Illustration: Fig. 170. Saw-Horse.]

The vise is also of great use in carrying on many other processes, but
a good workman does not use it to the exclusion of the saw-horse and
bench-hook.

Horses are of great use both for the rough sawing of material and in
supporting large pieces during the process of construction. The common
form is shown in Fig. 170, but a more convenient form for sawing has
an open top, as in Fig. 171.

[Illustration: Fig. 171. Saw-Horse.]

The _picture-frame-vise_, Fig. 172, is a very convenient tool for
making mitered joints, as in picture-frames. The vise holds two sides
firmly so that after gluing they may be either nailed together or a
spline inserted in a saw cut previously made. See Fig. 268, No. 55, p.
181. If the last joint in a picture-frame does not quite match, a kerf
may be sawn at the junction of the two pieces, which can then be drawn
close together.

[Illustration: Fig. 172. Picture-Frame-Vise.]

_Handscrews_, Fig. 173, consist of four parts, the shoulder jaw and
the screw jaw, made of maple, and the end spindle and the middle
spindle, made of hickory. The parts when broken can be bought
separately. Handscrews vary in size from those with jaws four inches
long to those with jaws twenty-two inches long. The best kind are
oiled so that glue will not adhere to them. In adjusting the jaws, if
the handle of the middle spindle is held in one hand, and the handle
of the end spindle in the other hand, and both are revolved together,
the jaws may be closed or opened evenly, Fig. 174. In use care must
be taken to keep the jaws parallel, in order to obtain the greatest
pressure and to prevent the spindles from being broken. It is always
important to have the jaws press on the work evenly. To secure
this, the middle spindle should be tightened first, and then the end
spindle. Handscrews are convenient for a great variety of uses, as
clamping up glued pieces, holding pieces together temporarily for
boring, Fig. 247, p. 153, holding work at any desired angle in the
vise, as for chamfering or beveling, Fig. 175, etc.

[Illustration: Fig.