.33 mm. By using 3deg. of a
lifting angle on the teeth, the distance from the heel of the tooth to
the pallet center will be .4691 mm.; by allowing .1 mm. between wheel
and pallet and .15 mm. for stock on the pallets we find we will have a
pallet arbor as follows: .4691 - (.1 + .15) x 2 = .4382 mm. It would not
be practicable to make anything smaller.

[Illustration: Fig. 3.]

It behooves us now to see that while a narrow pallet is advisable a very
wide tooth is not; yet these two are inseparable. Here is another case
for a compromise, as, unquestionably the pallets ought to be planted on
the tangents. There is no difficulty about it in the English lever, and
we have shown in our example that a judiciously planned club tooth
escapement of medium size can be made with the center distance properly
planted.

[Illustration: Fig. 4.]

When considering the center distance we must of necessity consider the
widths of teeth and pallets and their lifting angles. We are now at a
point in which no watchmaker of intelligence would indicate one certain
division for these parts and claim it to be "the best." It is always
those who do not thoroughly understand a subject who are the first to
make such claims. We will, however, give our opinion within certain
limits. The angle to be divided for tooth and pallet is 10 1/2deg. Let us
divide it by 2, which would be the most natural thing to do, and examine
the problem. We will have 5 1/4deg. each for width of tooth and pallet. We
_must_ have a smaller lifting angle on the tooth than on the pallet, but
the wider the tooth the greater should its lifting angle be. It would
not be mechanical to make the tooth wide and the lifting angle small, as
the lifting plane on the pallets would be too steep on account of being
narrow. A lifting angle on the tooth which would be _exactly_ suitable
for a given circular, would be _too great_ for a given equidistant
pallet. It follows, therefore, taking 5 1/4deg. as a width for the
tooth, that while we could employ it in a fair sized escapement with
equidistant pallets, we could not do so with circular pallets and still
have the latter pitched on the tangents. We see the majority of
escapements made with narrower teeth than pallets, and for a very good
reason.

In the example previously given, the 3deg. lift on the tooth is well
adapted for a width of 4 1/2deg., which would require a pallet 6deg. in
width. The tooth, therefore, would be 3/4 the width of