n inserting in the lathe and
bringing it in contact with a piece of fine emery paper or cloth.

[Illustration: _Fig. 2._]

I draw the temper in the following manner: Place some fine brass filings
in a boiling-out cup or bluing pan and lay the blank upon these filings,
holding the pan over the flame of an alcohol lamp until the blank assumes
a dark purple color, which it will reach when the heat gets to about 500 deg.
F. This I consider the right hardness for a balance staff, as it is not
too hard to work well under the graver nor too soft for the pivots. At
this degree of hardness steel will assume an exquisite polish if properly
treated. Another method of tempering is to place the staff on a piece of
sheet iron or copper (say 1 inch wide by 4 long), having previously bent
it into a small angle, for the reception of the staff, as shown in Fig.
3. This piece of metal, when nicely fitted into a file handle, will
answer all the purposes of the bluing pan and presents quite a neat
appearance. Having placed the blank in the angle, lay on it a piece of
yellow wax about the size of a bean, and heat it over your lamp until the
wax takes fire and burns. Blow out the flame and allow the staff to cool,
and it will be found to be of about the right hardness.

[Illustration: _Fig. 3._]

We have now arrived at an important station in staff making, a junction,
we may term it, where many lines branch off from the main road. At this
particular spot is where authorities differ. I have no hesitation in
saying that at this particular point the split chuck should be removed
from the lathe head and carefully placed in the chuck box and the cement
chuck put in its place. I believe that all of the remaining work upon a
staff should be executed while it is held in a cement chuck. On the other
hand I have seen good workmen who turned and finished all the lower part
of a staff while in a split chuck, cut it off and turned and finished the
upper part in a cement chuck. All I have got to say is that they had more
confidence in the truth of their chucks than I have in mine. I have even
read of watchmakers who made the entire staff in a split chuck, but I
must confess I am somewhat curious to examine a staff made in that way,
and must have the privilege of examining it before I will admit that a
true staff can be so made.

We will suppose that the workman has a moderately true chuck, and that he
prefers to turn and finish all the lower portions i