144 IRRIGATION FARMING. 



some berries, vegetables, and other small stuff may be 

 raised, it generally takes too much work and time to 

 water a large area of them in that way. 



The farmer who sees a severe drouth broken by a 

 three hours' flow of water hardly understands that 

 every acre of his farm has received in an inch of irri- 

 gation no less than loo tons of water, or loo acres has 

 had 10,000 tons of water poured over it. The quan- 

 tity of water on a single acre by such irrigation will 

 be not less than 130 cubic yards. A little wetting of 

 this character places more than 1,000 tons in twenty- 

 four hours on every acre, or 100,000 tons on a 100- 

 acre farm. Now an average irrigation requires a five- 

 inch layer of water over an entire field, while some 

 crops, oats for instance, often demand a solid covering 

 of ten inches. When using windmill irrigation in a 

 small way it may be well to roughly approximate an 

 acre of garden or orchard as requiring 1,000 barrels of 

 water for an ordinary wetting, but in this the greatest 

 economy is necessary, and it is best to apply the water 

 by the rill or row method. The following figures will 

 give an idea of the amount of water necessary to prop- 

 erly irrigate a definite area of land in a humid climate, 

 such as that of the central and eastern states : There 

 are 6,272,640 square inches to an acre. One inch of 

 water or a stream one inch wide and one inch deep, 

 flowing at a rate of four miles an hour, will give 6,082,- 

 560 inches in twenty-four hours. Such a stream will 

 therefore cover nearly an acre one inch deep in twenty- 

 four hours. This would require about 25,920 gallons 

 or 823 barrels of water. 



Advantage of Large Heads. — A full head of 



