HOW TO SET A JEWEL PIN AS IT SHOULD BE.
Many workmen have a mortal terror of setting a jewel pin and seem to
fancy that they must have a specially-devised instrument for
accomplishing this end. Most American watches have the hole for the
jewel pin "a world too wide" for it, and we have heard repeated
complaints from this cause. Probably the original object of this
accommodating sort of hole was to favor or obviate faults of pallet
action. Let us suppose, for illustration, that we have a roller with the
usual style of hole for a jewel pin which will take almost anything from
the size of a No. 12 sewing needle up to a round French clock pallet.
[Illustration: Fig. 65]
We are restricted as regards the proper size of jewel pin by the width
of the slot in the fork. Selecting a jewel which just fits the fork, we
can set it as regards its relation to the staff so it will cause the
pitch circle of the jewel pin to coincide with either of dotted circles
_a_ or _a'_, Fig. 65.
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