OF WATER-MILLS 



79 



LECTJ. 



LECTURE IV. 



(F OTLLS, CRANES, WHEEL-CARRIAGES, AND THE 

 ENGINE FOR DRIVING PILES. 



As these engines are so universally useful, it would be A common 

 ridiculous to make any apology for describing them.* 



In a common breast-mill, where the fall of water may 

 be about ten feet, A A 

 is the great wheel, 

 which is generally about 

 17 or 18 feet in diame- 

 ter, reckoned from the 

 outermost edge of any 

 loat-board at a to that 

 of its opposite fleat at b 

 To this wheel the water 

 is conveyed through a 

 channel, and by falling 

 upon the wheel, turns it 

 round. 



On the axis B B of this wheel, and within the mill 

 house, is a wheel D, about 8 or 9 feet diameter, having 

 61 co^s, which turn a trundle E containing ten upright 

 staves or rounds ; and when these are the number of 

 cogs and rounds, the trundle will make 6 ^ revolutions 

 for one revolution of the wheel. 



The trundle is fixed upon a strong iron axis called 

 the spindle, the lower end of which turns in a brass 

 foot, fixed at F, in the horizontal beam S T called the 

 bridge-tree ; and the upper part of the spindle turns in 

 a wooden bush fixed into the nether millstone, which 



Note, 36. The various modes of applying water as a prime mover 

 n mechanics will be fully examined at the end of this Lecture. 



