44 



IRRIGATION. 



a thin sheet flowing over a smoothed surface, or as a 

 number of small streams, flowing in a network of courses 

 over the surface, or in regular channels between the drills 

 or rows of plants. The ground may be laid out upon 

 various plans, as the method of cultivation adopted 

 require. A plan (see fig. 10), adapted for a crop 



i 



Fig. 10. ABBANGEMENT FOB HILLS OB DEILLS. 



cultivated in hills or drills, each drill forming its own 

 furrow of distribution in which the water may flow, is as 

 follows : A supply canal, seen at a, ft, is made at the 

 highest part of the ground, with several short canals con- 

 necting it with a distributing canal, c, d. From this 

 distributing canal the water flows into the furrows, shown 

 by the fine lines. The field is watered in sections by 

 closing the canal at any desired place, as at e, f, with a 

 sheet-iron plate or wooden gate, shown at fig. 11, in 



