) board structures; (3) panel structures; (4) framed structures. A
few illustrations of each class are given below.

(1) SIMPLE OR UNJOINED PIECES

Of these there are a number that are advantageous for the learning of
tool processes; at the same time they give opportunity for expression
in design, and when finished are of use.

Examples are: key-boards, chiseling-boards, bread-boards,
sleeve-boards, ironing-boards, coat- and skirt-hangers, and gouged
trays. Some of these are so simple as to include hardly any process
but planing, directions for which are given above, p. 72.

[Illustration: Fig. 270. Pen-Tray.]

Where there is more than one process involved, the order of procedure
is of importance. In general, a safe rule to follow in each case is
to plane up the piece true and square, or, in technical language, to
"true" it up. At least as many of its surfaces should be trued as are
necessary for the "lay out." Where the piece is to be rectangular
all the surfaces should be true; where some of the surfaces are to be
curved it is unnecessary and a waste of time to square them first. For
example, in making a gouged tray with curved outline, Fig. 270, the
working face, the working edge, and the thickness should all be true
before the plan is laid out. Then, after the outline is drawn, the
trough may be gouged, the outline cut with turning-saw, chisel, and
spokeshave, and the edges molded with the gouge or chisel. If there is
incised decoration it should be cut before the molding is cut, so that
while being incised, the piece will lie flat without tipping.

These simple pieces, as well as others, are often embellished by
_chamfering_. A chamfer is a surface produced by cutting away an
arris. It differs from a bevel in that a bevel inclines all the way
to the next arris, while a chamfer makes a new arris, Fig. 271. A thru
chamfer extends the whole length or width of a piece, while a stop
chamfer extends only part way. For the laying out of a chamfer see p.
115.

[Illustration: Fig. 271. Difference Between Chamfer and Bevel.]

Thru chamfering is best done with a plane, Fig. 272. For this purpose
the piece may be held in the bench-vise and the plane tipped to the
proper angle, or the piece may be held in a handscrew which in turn is
held in the vise as in Fig. 175, p. 102. The chamfers with the grain
should be planed before those across the grain.

[Illustration: Fig. 272. Thru Chamfering.]

In chamfering a four-