FALLING BODIES. 



taken his name. Att- 

 wood's machine consists 

 essentially of a wheel 

 R, about six inches 

 in diameter, over the 

 grooved edge of which 

 are balanced two equal 

 weights, suspended by 

 along silk thread, which 

 is both light and strong. 

 The axle of this wheel 

 is supported upon the 

 circumferences of four 

 friction wheels, r, r, r, r, 

 for greater delicacy oi 

 motion. As the thread 

 is so light that its 

 weight may be disre- 

 garded, it is evident 

 that the weights will be 

 in equilibrium whatever 

 their position. 



This apparatus is sup- 

 ported upon a wooden 

 pillar, seven or eight feet 

 high. The silk cord 

 carrying K, one of the 

 weights, passes in front 

 of a graduated rod 

 which carries a movable 

 ring B, and a movable 

 platform A. At the top 

 of the pillar is a plate n, 



