oach which its inner side occupied, and the measurement
can then be taken with the gauge. If care is used in the selection of a
broach, that it be as nearly perfect in round and taper as possible, by a
little experiment you can soon ascertain just what part of the length of
the broach corresponds to one degree on the gauge and by a repetition of
the experiment the broach can then be divided accurately, by very minute
rings turned with a fine-pointed graver, into sections, each representing
one degree, or 1/2500 of an inch, and the measurement will thus be
simplified greatly.

[Illustration: _Fig. 13._]

As before stated, much depends upon the condition of your gravers and the
manner of using them. It is of the utmost importance that they be kept
sharp, and as soon as they begin to show the slightest sign of losing
their keenness, you should sharpen them. The proper shape for balance
pivots was shown in Fig. 4. Now let us examine into the best positions
for holding the gravers. In Fig. 13 two ways of holding the graver are
shown, _A_ representing the right and _B_ representing the wrong way. If
the graver is applied to the work as shown at _A_, it will cut a clean
shaving, while if applied as shown at _B_ it will simply scrape the side
of the pivot and ruin the point of the graver without materially
forwarding the work. Again, the holding of the graver as indicated at _A_
has its advantages, because the force of the cut is towards the hand
holding it, and should it catch from any cause the jar of the obstruction
will be conveyed immediately to the hand, and it will naturally give and
no harm will be done. If, on the other hand, the graver should meet with
an obstruction while held in the position indicated at _B_, the force of
the cut will be in the direction of the arrow, downward and toward the
rest, and the rest being unlike the hand, or rather being rigid, it
cannot give, and the result is that the work, or graver, or both, are
ruined. In Fig. 14 two other methods of holding the graver are shown. The
general roughing out of a staff should be done with the graver held about
as shown at _A_, Fig. 13; but in finishing, the graver should be held so
that the cut is made diagonally, as indicated at _A_, Fig. 14. It is
rather dificult to explain in print just how the graver should be held,
but a little experiment will suffice to teach the proper position. The
best indication that a graver is doing its work properly, is the