An observant workman
will, after a little practice, be able to determine this matter.
We will next take up the double roller and fork action, and also
consider in many ways the effect of less angles of action than ten
degrees. This matter now seems of more importance, from the fact that we
are desirous to impress on our readers that _there is no valid reason
for adopting ten degrees of fork and roller action with the table
roller, except that about this number of degrees of action are required
to secure a reliable safety action_. With the double roller, as low as
six degrees fork and pallet action can be safely employed. In fork and
pallet actions below six degrees of angular motion, side-shake in pivot
holes becomes a dangerous factor, as will be explained further on. It is
perfectly comprehending the action of the lever escapement and then
being able to remedy defects, that constitute the master workman.
HOW TO MEASURE THE ANGULAR MOTION OF AN ESCAPE WHEEL.
[Illustration: Fig.
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