224 



PNEUMATICS. 



Wind may be applied to various purposes, such as 

 Fig- 183. sawing wood by the aid 



of a circular saw, turn- 

 ing grindstones, and 

 particularly in pumping 

 water. One of the best 

 contrivances for pump- 

 ing is represented by 

 Fig. 183, where A is 

 the circular wind-mill, 

 with a number of sails 

 set obliquely to the di- 

 rection of the wind, and 

 always kept facing it 

 by means of the vane, B. 

 The crank of the wind- 

 mill, during its revo- 

 lutions, works the pump-rod, I, and raises the water 

 from the well beneath. In whatever direction the wind 

 may blow, the pump will continue working. The 

 pump-rod, to work steadily, must be immediately un- 

 der the iron rod on which the vane turns. If the di- 

 ameter of the wind-mill is four feet, it will set the 

 pump in motion even with a light breeze, and with a 

 brisk wind will perform the labor of a man. Such a 

 machine will pump the water needed by a large herd 

 of cattle, and it may be placed on the top of a barn, 

 with a covering, to which may be given the architec- 

 tural effect of a tower or cupola, as shown in Fig. 184, 

 opposite. 



A more compact machine, but of more complex con- 

 struction, is shown in Fig. 185, opposite, where the up- 



Wind-mill for pumping water on farms : 

 A, wind-mill ; B,vane; \, pump-rod. 



