ESCAPEMENT. 



Fig 5. 



between two teeth at the other side, the upper of which coming 

 against it the motion of the wheel is again arrested. 



The wheel, therefore, 

 is thus made to revolve 

 on its axis, E, not with 

 a continuous motion, as 

 would be the case if it 

 were impelled by the 

 weight or mainspring, 

 without the interference 

 of any obstacle, but 

 with an intermitting 

 motion. It moves by 

 starts, being stopped 

 alternately by one pallet 

 or the other coming in 

 the way of its teeth. 



When the pendulum, 

 and therefore the an- 

 chor, is at the extreme 

 right of its play, the 

 pallet, m, having en- J 

 tered between two teeth, 

 a tooth rests against its 

 lower side, the wheel is 

 arrested, and the pallet, 

 m', is quite disengaged 

 from, and clear of, the 

 teeth of the wheel. 

 When in swinging to 

 the left the arm D B becomes vertical, the tooth of the wheel on the 

 left has just escaped from the pallet, m, and the wheel being 

 liberated, has just commenced to be moved* by the force of the 

 weight or mainspring. But at the same moment the pallet, m', 

 enters between the teeth of the wheel on the right, and when the 

 anchor has arrived at the extreme left of its play, the tooth of the 

 wheel, which is above the pallet, m', will have fallen upon it, so 

 that the motion will again be arrested. 



Thus it appears, that during the first half of the swing from 

 right to left, the motion of the wheel is arrested by the pallet, m, 

 and during the remaining half of the swing the wheel moves, but 

 is arrested the moment the swing is completed. 



In like manner it may be shown, that during the first half 

 of the swing from left to right, the motion of the wheel is 

 arrested by the pallet, w', that it is liberated and moves during 



15 



