[Illustration: _Fig. 16._]

For grinding, bell-metal or soft iron slips are desirable, and the
grinding is effected by means of oil stone powder and oil. Two slips of
metal similar in shape to A and B, Fig. 16, are easily made, and will be
found very useful. A is for square pivots, etc., while B is used for
conical pivots. These slips should be dressed with a dead smooth file,
the filing to be done crosswise, to hold the oil stone powder and oil.
During the operation of grinding, the lathe should be run at a high speed
and the slips applied to the work lightly, squarely and carefully. The
polishing is effected by means of diamantine and alcohol. After the work
is brought to a smooth gray surface, slips of boxwood of the shape shown
in Fig. 16 should be substituted for the metal slips. Oil stone slips are
sometimes used in lieu of metal ones, but they soon get out of shape and
are troublesome to care for on this account. All things considered, there
is nothing better for polishing than a slip or file made of agate, say
one inch long, one-quarter inch wide and one-eighth inch thick. A slip of
this kind can be obtained from any lapidary, and after grinding with
emery and water until the surface has a very fine grain, it should be
mounted by fastening with cement into a brass socket and this is then
inserted into a small wooden handle, as shown in Fig. 17. The agate slip
should be ground to about the shape of B, Fig. 16, so that one side can
be used for square corners and the other for conical pivots. The final
polish can soon be imparted by means of a small boxwood slip, or
flattened peg-wood, and diamantine and alcohol. Never try to bring out
the final polish until you are satisfied that all graver marks have been
ground out, otherwise you will simply have to go all over the work again.

[Illustration: _Fig. 17._]

When the staff is finished from the lower pivot to the seat of the
balance, the upper part should be roughed out nearly to size and then cut
off preparatory to finishing the top part.

Attention was previously called to the fact that the majority of
watchmakers prefer to finish all the lower portion of the staff first,
notwithstanding the fact that there are numerous advantages to be gained
by proceeding to first finish up the upper portion. We have now reached
the point where the wax chuck must be used, and perhaps these advantages
may be now more clearly defined. In order that the two procedures may be
m