HOW TO SET A FORK AND ROLLER ACTION RIGHT.

As previously stated, frequently the true place to begin to set a lever
escapement right is with the roller and fork. But to do this properly we
should know when such fork and roller action is right and safe in all
respects. We will see on analysis of the actions involved that there are
three important actions in the fork and roller functions: (_a_) The fork
imparting perfect impulse through the jewel pin to the balance. (_b_)
Proper unlocking action. (_c_) Safety action. The last function is in
most instances sadly neglected and, we regret to add, by a large
majority of even practical workmen it is very imperfectly understood. In
most American watches we have ample opportunity afforded to inspect the
pallet action, but the fork and roller action is placed so that rigid
inspection is next to impossible.

The Vacheron concern of Swiss manufacturers were acute enough to see the
importance of such inspection, and proceeded to cut a circular opening
in the lower plate, which permitted, on the removal of the dial, a
careful scrutiny of the action of the roller and fork. While writing on
this topic we would suggest the importance not only of knowing how to
draw a correct fork and roller action, but letting the workman who
desires to be _au fait_ in escapements delineate and study the action of
a faulty fork and roller action--say one in which the fork, although of
the proper form, is too short, or what at first glance would appear to
amount to the same thing, a roller too small.

Drawings help wonderfully in reasoning out not only correct actions, but
also faulty ones, and our readers are earnestly advised to make such
faulty drawings in several stages of action. By this course they will