ed, as carborundum,
emery, and so on. Sandpaper comes in various grades of coarseness from
No. 00 (the finest) to No. 3, indicated on the back of each sheet. For
ordinary purposes No. 00 and No. 1 are sufficient. Sandpaper sheets
may readily be torn by placing the sanded side down, one-half of
the sheet projecting over the square edge of the bench. With a quick
downward motion the projecting portion easily parts. Or it may be torn
straight by laying the sandpaper on a bench, sand side down, holding
the teeth of a back-saw along the line to be torn. In this case, the
smooth surface of the sandpaper would be against the saw.

[Illustration: Fig. 154. Sharpening a Cabinet-Scraper: 2nd Step,
Whetting.]

[Illustration: Fig. 155. Sharpening a Cabinet-Scraper: 3rd Step,
Removing the Wire-Edge.]

Sandpaper should never be used to scrape and scrub work into shape,
but only to obtain an extra smoothness. Nor ordinarily should it be
used on a piece of wood until all the work with cutting tools is done,
for the fine particles of sand remaining in the wood dull the edge of
the tool. Sometimes in a piece of cross-grained wood rough places will
be discovered by sandpapering. The surface should then be wiped free
of sand and scraped before using a cutting tool again. In order to
avoid cross scratches, work should be "sanded" with the grain, even if
this takes much trouble. For flat surfaces, and to touch off edges,
it is best to wrap the sandpaper over a rectangular block of wood,
of which the corners are slightly rounded, or it may be fitted over
special shapes of wood for specially shaped surfaces. The objection
to using the thumb or fingers instead of a block, is that the soft
portions of the wood are cut down faster than the hard portions,
whereas the use of a block tends to keep the surface even.

[Illustration: Fig. 156. Sharpening a Cabinet-Scraper: 4th Step,
Turning the Edge.]

_Steel wool_ is made by turning off fine shavings from the edges of
a number of thin discs of steel, held together in a lathe. There
are various grades of coarseness, from No. 00 to No. 3. Its uses
are manifold: as a substitute for sandpaper, especially on curved
surfaces, to clean up paint, and to rub down shellac to an "egg-shell"
finish. Like sandpaper it should not be used till all the work with
cutting tools is done. It can be manipulated until utterly worn out.

5. POUNDING TOOLS.

The _hammer_ consists of two distinct parts, the head an