82 IRRIGATION FARMING. 



baking. There is nothing so good in the long run for 

 building ditch laterals as the common plow and scraper. 

 Make the ditch bottom as wide as the scraper even for 

 the small laterals, if they are to be permanent. The 

 first plowing should be at least three times as wide as 

 the finished ditch, .so the earth may be thoroughly 

 broken up and no smooth or grass-covered surface left 

 for the bank to rest upon. On a side-hill the plowing 

 should extend well down the lower side. Under an 

 extensive canal system a water consumer's land may 

 lie a mile or two distant from the main ditch. In a 

 case of this kind the laterals must be of a permanent 

 character. This work may require as much skill and 

 judgment as the constru<5lion of the canal itself, and 

 should be well done. When the ditch is completed let 

 a very little water in for the first few days and shut it 

 off every afternoon. The high embankments will settle 

 and are reasonably sure to crack, and the earth must 

 then be tamped into the cracks. The ends of flumes 

 will need tamping and puddling. The coarse gravel in 

 the banks will leak like a sieve and will require many 

 a shovelful of fine earth to fill up the interstices. In a 

 few weeks, however, all will be settled in place. 



In laying out a supply lateral leading from the 

 main canal it is important to have it large enough to 

 carry at least double the average amount of water it 

 will contain. The water supply will vary greatly in a 

 season, and it is a matter of much importance to be 

 ready to use all the water available. In construdling 

 such a watercourse it is a good plan to throw out four 

 furrows with a sixteen-inch plow — two each way. 

 Then throw out and defepen the lateral with a round- 



