124 



IRRIGATION. 



are submerged in the stream, fig. 56. By offering a little 

 obstruction to the stream, to increase the rapidity of the 

 current where the natural velocity is not sufficient, the 

 wheel is set in motion and revolved. Water buckets are 

 fixed to the circumference of the wheel, in such a position 

 that the direction of their longitudinal axle is 45 degrees 

 from that of the axle of the wheel. The buckets are 



Fig. 56. THE &quot;NORIA&quot; OB WATEB WHEEL. 



partly filled as they pass through the water, and are dis 

 charged as the wheel brings them round to an inverted 

 position, into a wooden trough placed alongside of the 

 wheel. From this trough the water is conveyed to the 

 distributing channels. Water may be raised by this rough 

 and ready process, in the cheapest manner, to a hight of 

 ten or twelve feet, requiring no attention and working 

 by day and night so long as the stream flows. Another 

 method by which a small portion of the water may be 

 raised is applicable to brooks of moderately small volume, 



