HYDRAULICS. 



437 



which ring, the water is delivered from the upper open 

 ends of the screw-tubes, and falls into the open box N. 

 The lower end of the axle K turns on a gudgeon, in 

 the water in N; and the spiral tubes in that axle take 

 up the water from N, and deliver it into such another 

 box under the top of K ; on which there may be such 

 another wheel as /, to turn a third axle by such a wheel 



upon it. And in this manner, water may be raised 



to any given height, when there is a stream sufficient for 

 that purpose to act on the broad float boards of the 

 first wheel. 



A quadruple Pump-mill for raising Water. 



This engine is represented thus : In which A B C D 

 is a wheel, turned by water according to the order of 



the letters. On the horizontal axis are four small wheels, 

 toothed almost half round : and the parts of their edges 



