200 



IRRIGATION. 



the water must be led downwards from the furrow in a 

 thin sheet or in numerous trickling streams, which may 

 be made to cover the intervals between the furrows. 

 There will be, however, some instances, and in time, after 

 the best of the irrigable lands have been occupied, the 

 majority of the tracts left will be of this character, in 

 which the surface will offer more than usual difficulties 

 in the way of preparation for irrigation. These tracts 

 referred to are hilly lands, or so called foot hills ; high 

 prairie lands or bluffs bordering the more tractable river 



Fig. 88. IMPROVEMENT OF A HILL-SIDE. 



bottoms and valleys. The surfaces of such lands are in 

 general cut up with hollows, ravines, gulleys, and similar 

 irregularities of a somewhat miniature character, but 

 which nevertheless offer obstacles to the passage of water 

 channels ; or there may be aprupt declines and rounded 

 protuberances, which will require modifying to some ex 

 tent. By some system of preparation all such lands may 

 be brought under irrigation, and a few typical cases are 



Fig. 89. MANNER OP FILLING A GULLET. 



here referred to with the requisite treatment. A profile 

 of a hill too steep in one portion to be irrigated, is repre 

 sented by the dotted lines in fig. 88. The rounded out 

 line, a, I, c, offers an obstruction to both water furrows 

 and the passage of men or animals. By cutting away 

 the projecting portion at b 3 and depositing it in the bot- 



