low red, and shaped with as little hammering as possible; it may then
be allowed to cool slowly, when it may be filed or ground to give it
the required form. It may now be hardened by heating it to a cherry
red and plunging it straight down into clean cool (not too cold)
water. It should then be polished on two of its sides, when the temper
may be drawn in the flame of an alcohol lamp or Bunsen gas burner; or,
if these are not convenient, a heated bar of iron may be used instead,
the tool being placed in contact with it until the required color
appears. This for tools to be used in turning steel, iron, and brass
may be a straw color. For turning wood it may be softer. The main
point to be observed in tempering a tool is to have it as hard as
possible without danger of its being broken while in use. By a little
experiment the amateur will be able to suit the temper of his tools to
the work in hand.

In the engraving accompanying the present article a number of hand
turning tools are shown, also a few tools for the slide rest. These
tools are familiar to machinists and may be well known to many
amateurs; but we give them for the benefit of those who are
unacquainted with them and for the sake of completeness in this series
of articles.

[Illustration: TURNING TOOLS.]

Fig. 1 is the ordinary diamond tool, made from a square bar of steel
ground diagonally so as to give it two similar cutting edges. This
tool is perhaps more generally useful than any of the others. The
manner of using it is shown in Fig. 23; it is placed on the tool rest
and dexterously moved on the rest as a pivot, causing the point to
travel in a circular path along the metal in the lathe. Of course only