d now appears
as shown at Fig. 175, with the addition of a handle shown at _G G'_. It
is evident that we can allow the pivot _s_ to protrude from the sleeve
_F_ any portion of its length, and regulate such protrusion by the screw
_t_. To employ this tool for getting the proper length to which to cut
the pivot _y_, Fig. 171, we remove the lower cap jewel to the cylinder
pivot and, holding, the movement in the left hand, pass the pivot _s_,
Fig. 175, up through the hole jewel, regulate the length by turning the
sleeve _F_ until the arm of the escape wheel _I_, Fig. 176, will just
turn free over it. Now the length of the pivot _s_, which protrudes
beyond the sleeve _F_, coincides with the length to which we must cut
the pivot _y_, Fig. 171. To hold a cylinder for reducing the length of
the pivot _y_, we hold said pivot in a pair of thin-edged cutting
pliers, as shown at Fig. 177, where _N N'_ represent the jaws of a pair
of cutting pliers and _y_ the pivot to be cut. The measurement is made
by putting the pivot _s_ between the jaws _N N'_ as they hold the pivot.
The cutting is done by simply filing back the pivot until of the right
length.

TURNING THE PIVOTS.

We have now the pivot _y_ of the proper length, and what remains to be
done is to turn it to the right size. We do not think it advisable to
try to use a split chuck, although we have seen workmen drive the shell
_A A'''_ out of the collet _D_ and then turn up the pivots _y z_ in said
wire chuck. To our judgment there is but one chuck for turning pivots,
and this is the cement chuck provided with all American lathes. Many
workmen object to a cement chuck, but we think no man should lay claim
to the name of watchmaker until he masters the mystery of the cement
chuck. It is not such a very difficult matter, and the skill once
acquired would not be parted with cheaply. One thing has served to put
the wax or cement chuck into disfavor, and that is the abominable stuff
sold by some material houses for lathe cement. The original cement, made
and patented by James Bottum for his cement chuck, was made up of a
rather complicated mixture; but all the substances really demanded in
such cement are ultramarine blue and a good quality of shellac. These
ingredients are compounded in the proportion of 8 parts of shellac and 1
part of ultramarine--all by weight.

HOW TO USE A CEMENT CHUCK.

The shellac is melted in an iron vessel, and the ultramarine added and
stirred to i