178 



FERGUSON'S LECTURES. 



LECT. Water may be raised by means of a stream A L 



X-^V^K^ turning a wheel C D E, according to the order of the 



The 



Persian 



wheel. 



letters, with buckets a, a, a, a t &c. hung upon the 

 wheel by strong pins b, b, b, b, &c. fixed in the side of 

 the rim : but the wheel must be made as high as the 

 water is intended to be raised above the level of that 

 part of the stream in which the wheel is placed. As 

 the wheel turns, the buckets on the right-hand go down 

 into the water, and are thereby filled, and go up full on 

 the left-hand, until they come to the top at K ; where 

 they strike against the end n of the fixed trough M, and 

 are thereby overset, and empty the water into (he 

 trough ; from which it may be conveyed in pipes to the 

 place which it is designed for : and, as each bucket gels 

 over the trough, it falls into a perpendicular position 



