IRRIGATION AND DRAINAGE 155 



time of free lands is past. During the nineteenth century, a 

 continent was to be had for the asking. When anyone in 

 America wanted a farm, all he had to do was to go out to the 

 West and settle on one. Those opportunities are gone, 

 never to return. The land is definitely limited in quantity 

 and in productivity. We must, therefore, make the very 

 best use of it, reclaim it if possible where it lies waste, and put 

 it into the highest possible state of productivity. This is the 

 great problem which the American farmer faces today. In 

 the solution of this, irrigation and drainage play a large part. 

 255. Horticulture and irrigation go hand in hand. Many 

 of the finest fruit regions of America have been made possible 

 by artificial application of water to land. Deserts have been 

 reclaimed and waste places made to blossom and bear fruit by 

 the magic of the irrigation ditch. But the real problems 

 lie yet ahead. In no type of farming is there such imperative 

 need of intelligence and forethought, for the difficulties are 

 many, and they must be met and solved. The student who is 

 considering these problems no wean be assured that he is grap- 

 pling with questions worthy of a lifetime of thoughtful study. 



EXERCISES 



EXERCISE I. Constructing Cippoletti weir, and measuring stream flow. 



Materials. One-inch board six inches wide and about three feet long; 

 saw; pencil; ruler; level; wooden peg one foot long. 



Procedure. For this exercise use any small stream in the neighbor- 

 hood. If no natural stream is available, produce an artificial one by 

 turning on the garden hydrant. The size of the weir constructed 

 will be determined by the size of the stream available for measurement. 



In accordance with description given in the body of the text, construct 

 a Cippoletti weir. Set this board in a furrow in such a way that it will 

 act as a dam, causing the watej to flow over the crest of the weir. Drive 

 a peg in the furrow on the upper side of the weir to such a depth in the 

 ground that the top of the peg is level with the crest of the weir. Turn 

 water down the furrow and allow it to flow (but at not too great speed) 

 over the crest of the weir. The peg should be so located that it is 

 covered by the water impounded by this miniature dam. After the 



