INGENIOUS ATTEMPTS AT SOLUTION OF A DIFFICULT PROBLEM.
Much ingenuity to a worthy end, but of little practical value, is displayed in these various attempts at the solution of a very difficult problem. In Fig. 159 we have a mechanism combining two escape wheels engaging each other in gear; of the two wheels, R R', one alone is driven directly by the train, the other being turned in the opposite direction by its comrade. Both are furnished with pins c c', which act alternately upon the pallets P P' disposed in the same plane upon the verge V and pivoted between the wheels. Our drawing represents the escapement at the moment when the pin C' delivers its impulse, and this having been accomplished, the locking takes place upon the pin C of the other wheel upon the pallet P'. Another system of two escape wheels is shown in Fig. 160, but in this case the two wheels R R are driven in a like direction by the last wheel A of the train. The operation of the escapement is the same as in Fig. 159.
In Fig. 161 we have a departure from the road ordinarily pursued. Here we see an escapement combining two levers, invented by the Chevalier de Béthune and applied by M. Thiout, master-horologist, at Paris in 1727. P P' are the two levers or pallets separately pivoted. Upon the axis V, of the lever P, is fixed a fork which communicates the motion to the pendulum. The two levers are intimately connected by the two arms B B', of which the former carries an adjusting screw, a well-conceived addition for regulating the opening between the pallets. The counter-weight C compels constant contact between the arms B B'. The function is always the same, the recoil and the impulsion operate upon the two pallets simultaneously. This escapement enjoyed a certain degree of success, having been employed by a number of horologists who modified it in various ways.