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Anonymous

"Watch and Clock Escapements A Complete Study in Theory and Practice of the Lever, Cylinder and Chronometer Escapements, Together with a Brief Account of the Origin and Evolution of the Escapement in Horology"

Now, the quick movement of the pallet and
fork may make the hand mark more or less of an arc on the index than one
of ten degrees, as the grasp may slip on the pallet staff; but the arc
indicated by the slow movement in unlocking will be correct.
[Illustration: Fig. 75]
By taking a piece of sharpened pegwood and placing the point in the slot
of the fork, we can test the fork to see if the drop takes place much
before the lever rests against the opposite bank. As we have previously
stated, the drop from the pallet should not take place until the lever
_almost_ rests on the banking pin. What the reader should impress on his
mind is that the lever should pass through about one and a half degrees
arc to unlock, and the remainder (eight and a half degrees) of the ten
degrees are to be devoted to impulse. But, understand, if the impulse
angle is only seven and a half degrees, and the jewel pin acts in
accordance with the rules previously given, do not alter the pallet
until you know for certain you will gain by it.


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