306 Improvements for diminishing Friction in Clocks. 



cated to the pendulum through these inclined planes by two- 

 arms fixed on the verge, which come into contact with them, 

 and unlock one on each vibration of the pendulum. Thus, 

 suppose a momentum to have been given by the inclined 

 plane on the right ; at the same timelhat this takes place, 

 the wheel moves forward and raises the inclined plane on 

 the lett, and the pendulum, having performed its oscilla- 

 tion to the left, receives a momentum from the inclined 

 plane to compensate for the loss of power which would take 

 place during the ensuing vibration to the right, and so on 

 alternately. The advantage in this model consists, I con- 

 ceive, in diminishing the friction in the acting part of the 

 pallets, in giving a regular certain momentum, independent 

 of any variation which may occur in the wheel-work, or on 

 the acting part of the pallets, except during the short time 

 of unlocking. 



The second description, being a free pendulum without 

 a verge, is as follows :. — The swing wheel must be on the 

 outside of the back plate. The pallets are fonned like a 

 pair of tongs, and are a fixture to the clock. There is a 

 spring fixed in the upper part of the tongs, which keeps 

 tliem extended against the points of the adjusting screws. 

 The points of the tongs are pallets with n^clined planes, 

 and have lockings as the one above described. The tongs 

 are made to spring from the point by which the pendulum 

 is suspended, and, by altering the adjusting screws, a pro per 

 tension may be given to the spring part of the pallets ; but 

 they must be sufficiently under the influence of the main 

 power. I think the main power should be about one-third 

 more than is necessary to raise the inclined plane, so as to 

 allow for an increase of friction which may take place in 

 the wheel -work. There must be a cross-piece fixed to the 

 pendulum, which must come into contact with two pins 

 that are fixed in the inclined planes of the pallets, so as to 

 unlock one on each vibration of the pendulum. Suppose 

 the pendulum to be put in motion, and to have unlocked 

 the inclined plane on the right ; the wheel moves forward, 

 and raises the inclined plane on the left, at which time the 

 pendulum receives a momentum from the spring pallet on 

 the right, and, after performing its excursion to the left, 

 receives a momentum as on the nght, and so on alternately. 

 The advantage of th,i3 escapement over that above described 

 is, that it avoids the friction of the verge and detent pivots, 

 and during a part of the vibration the pendulum is disen- 

 gaged, so that it is a free pendulum. 1 have no doubt that 



the 



