apement with eight and one-half degrees of pallet action and
equidistant locking faces. It is, of course, understood the escape wheel
is to be drawn ten inches in diameter, and that the degree arcs shown in
Fig. 1 will be used.

We commence by carefully placing on the drawing-board a sheet of paper
about fifteen inches square, and then vertically through the center
draw the line _a' a''_. At some convenient position on this line is
established the point _a_, which represents the center of the escape
wheel. In this drawing it is not important that the entire escape wheel
be shown, inasmuch as we have really to do with but a little over sixty
degrees of the periphery of the escape wheel. With the dividers
carefully set at five inches, from _a_, as a center, we sweep the arc
_n n_, and from the intersection of the perpendicular line _a' a''_ with
the arc _n_ we lay off on each side thirty degrees from the brass degree
arc, and through the points thus established are drawn the radial lines
_a b'_ and _a d'_.

[Illustration: Fig. 18]

The point on the arc _n_ where it intersects with the line _b'_ is
termed the point _b_. At the intersection of the radial line _a d'_ is
established the point _d_. We take ten and one-half degrees in the
dividers, and from the point _b_ establish the point _c_, which embraces
the arc of the escape wheel which is utilized by the pallet action.
Through the point _b_ the line _h' h_ is drawn at right angles to the
line _a b'_. The line _j j'_ is also drawn at right angles to the line
_a d'_ through the point _d_. We now have an intersection of the lines
just drawn in common with the line _a a'_ at the point _g_, said point
indicating the center of the pallet action.

The dividers are now set to embrace the space between the points _b_ and
_g_ on the line _h' h_, and the arc _f f_ is swept; which, in proof of
the accuracy of the work, intersects the arc _n_ at the point _d_. This
arc coincides with the locking faces of both pallets. To lay out the
entrance pallet, the dividers are set to five inches, and from _g_ as a
center the short arc _o o_ is swept. On this arc one degree is laid off
below the line _h' h_, and the line _g i_ drawn. The space embraced
between the lines _h_ and _i_ on the arc _f_ represents the locking face
of the entrance pallet, and the point formed at the intersection of the
line _g i_ with the arc _f_ is called the point _p_. To give the proper
lock to the face of the