phosphorus glass used by optical instrument makers which is intensely
hard, and if colored ruby-red makes a beautiful pallet jewel, which will
afford as much service as if real stones were used; they are no cheaper
than carnelian pallets, but much richer looking. The prettiest cap for
the balance is one of those foilback stones in imitation of a rose-cut
diamond.

[Illustration: Fig. 30]

[Illustration: Fig. 31]

In turning the staffs it is the best plan to use double centers, but a
piece of Stubs steel wire that will go into a No. 40 wire chuck, will
answer; in case such wire is used, a brass collet must be provided. This
will be understood by inspecting Fig. 30, where _L_ represents the Stubs
wire and _B N_ the brass collet, with the balance seat shown at _k_. The
escape-wheel arbor and pallet staff can be made in the same way. The
lower end of the escape wheel pivot is made about ¼" long, so that a
short piece of brass wire can be screwed upon it, as shown in Fig. 31,
where _h_ represents the pivot, _A_ the lower plate, and the dotted line
at _p_ the brass piece screwed on the end of the pivot. This piece _p_
is simply a short bit of brass wire with a female screw tapped into the
end, which screws on to the pivot. An arm is attached to _p_, as shown
at _T_. The idea is, the pieces _T p_ act like a lathe dog to convey the
power from one of the pivots of an old eight-day spring clock movement,
which is secured by screws to the lower side of the main plate _A_. The
plan is illustrated at Fig. 32, where _l_ represents pivot of the
eight-day clock employed to run the model. Counting the escape-wheel
pivot of the clock as one, we take the third pivot from this in the
clock train, placing the movement so this point comes opposite the