326 



ON THE COXSERVATION OF FORCE. 



which, being raised to the tops of mountains by meteoro- 

 logical processes, returns in streams from them. The 

 gravity of water we use as moving force, the most direct 

 application being in what are called overshot wheels, one 

 of which is represented in Fig. 38. Along the circumfer- 

 ence of such a wheel are a series of buckets, which act as 



Fig. 38. 



receptacles for the water, and, on the side turned to the 

 observer, have the tops uppermost , on the opposite side 

 the tops of the buckets are upside-down. The water flows 

 at M into the buckets of the front of the wheel, and at 

 P', %vhere the mouth begins to incline downwards, it flows 

 out. The buckets on the circumference are filled on the 



