To define the remainder of the form of our escape-wheel tooth we will next delineate the heel.
The escape-wheel arbor and pallet staff can be made in the same way.
From A as a center, through the point n we sweep the arc k, and on this line we locate the points of the escape-wheel teeth.
The next straight tooth of the escape-wheel is now resting against the roller e, and the same operation again takes place.
This last arc defines the addendum of the escape-wheel teeth.
A is the escape-wheel, B the escape-wheel teeth, C the roller let on the verge, or axis of the balance.
Our advice is to use the smaller one if it does not require the escape-wheel teeth to be "dressed," that is, made smaller.
But the pressure of the escape-wheel against the detent, and the consequent friction, prevent the pendulum from acting freely.
It is to be borne in mind that at the point f is located the extreme point of an escape-wheel tooth.
The energy thus stored helps the wheel to revolve the other way during the locking of a tooth of the escape-wheel.