e pallet. We name the point so
established the point _r_. The outer angle of this pallet is located at
the intersection of the radial line _A b_ with the line _B i_; said
intersection we name the point _v_. Draw a line from the point _v_ to
the point _r_, and we define the impulse face of the entrance pallet;
and the angular motion obtained from it as relates to the pallet staff
embraces six degrees.

Measured on the arc _l_, the entire ten degrees of angular motion is as
follows: Two and a half degrees from the impulse face of the tooth, and
indicated between the lines _B h_ and _B f_; one and a half degrees lock
between the lines _B f'_ and _B i_; six degrees impulse from pallet
face, entrance between the lines _B i_ and _B j_.

A DEPARTURE FROM FORMER PRACTICES.

Grossmann and Britten, in all their delineations of the club-tooth
escapement, show the exit pallet as disengaged. To vary from this
beaten track we will draw our exit pallet as locked. There are other
reasons which prompt us to do this, one of which is, pupils are apt to
fall into a rut and only learn to do things a certain way, and that way
just as they are instructed.

To illustrate, the writer has met several students of the lever
escapement who could make drawings of either club or ratchet-tooth
escapement with the lock on the entrance pallet; but when required to
draw a pallet as illustrated at Fig. 23, could not do it correctly.
Occasionally one could do it, but the instances were rare. A still
greater poser was to request them to delineate a pallet and tooth when
the action of escaping was one-half or one-third performed; and it is
easy to understand that only by such studies the master workman can
thoroughly comprehend the complications involved in the club-tooth lever
escapement.

AN APT ILLUSTRATION.

As an illustration: Two draughtsmen, employed by two competing watch
factories, each designs a club-tooth escapement. We will further suppose
the trains and mainspring power used by each concern to be precisely
alike. But in practice the escapement of the watches made by one factory
would "set," that is, if you stopped the balance dead still, with the
pin in the fork, the watch would not start of itself; while the
escapement designed by the other draughtsman would not "set"--stop the
balance dead as often as you choose, the watch would start of itself.
Yet even to experienced workmen the escape wheels and pallets _looked_
exactly alike. O