250 IRRIGATION. 



tween the rows will serve for the irrigation of the crop. 

 For other crops that are sown broadcast, the furrows may 

 be made by rollers, figs. 96 and 97, which press the ground 

 into regular corrugations as soon as the seed is sown, and 

 harrowed. 



It may be well to notice in this place the exaggerated 

 and erroneous ideas of some writers upon the subject of 

 irrigation, who do much injury by misleading public 

 opinion upon some vital points. For instance in a paper 

 upon this subject, published in the Report of the Depart- 

 ment of Agriculture for 1871, it is declared, " that with 

 very few exceptions, every foot of land lying in Colorado 

 and Kansas, between the base of the Kocky Mountains 

 and Kansas City on the 

 Missouri river, is sus- 

 ceptible of irrigation." 

 It is true that it is sus- 

 ceptible of irrigation if 

 the necessary water can Fig ^.^^^ ON A HILL _ SU)E . 

 be found by this too 



sanguine and mis-informed writer. But the water is not 

 there, and in fact but a very small portion of the territory 

 can ever be brought under irrigation with the existing sup- 

 ply. As an example, the Arkansas valley may be considered. 

 The nearest crest of the water-shed, on the north side of 

 this river, is 45 miles distant ; on the south it is much 

 more distant. If we calculate a territory only 90 miles 

 wide, and 500 miles long, depending upon this river, it 

 would contain 28,800,000 acres, requiring at one cubic 

 foot per second per 100 acres, 288,000 cubic feet per 

 second. To supply this there would be required a river 

 nearly 2 miles wide and 10 feet deep, flowing 2 miles an 

 hour, with no allowance for loss by evaporation and per- 

 colation. The Arkansas is not one-fifth of this capacity, 

 and could not supply one-tenth of the territory. What 

 then becomes of the rest of the territory which is without 



