FARM IRRIGATION 247 



streams. There are over 200,000 acres in Cal- 

 ifornia irrigated from wells, the lift in many cases 

 being over 200 feet. 



Windmills. The most common source of power 

 for moving water is the windmill. When small 

 areas are to be irrigated, and it is not necessary to 

 raise the water over 25 feet, a windmill can often 

 be used to advantage. It is first necessary to be 

 assured of sufficient wind during the growing 

 season. Fortunately, the arid and semi-arid prai- 

 ries and valleys of the West are usually windy. 

 In the East, especially in a hilly country, it is some- 

 times necessary to secure an exposed site for the 

 windmill, as a tower 70 to 90 feet high, above hills, 

 trees and other obstructions. The windmill should 

 be able to utilise all the power in winds of from 8 

 to 30 miles an hour, according to the size of the 

 machinery. For the best service it should have 

 two pumps, one of smaller capacity than the other, 

 and should be so adjusted that each may be used 

 alone, or both together, according to the strength of 

 the wind. Small, rapid windmills, having wheels 

 8 to 12 feet in diameter are usually considered most 

 economical. According to the Office of Experi- 

 ment Stations a good windmill will irrigate from 

 | to 7 acres of land at a cost of .75 to $6 per acre. 

 But there are many crude, home-made windmills 

 that do fairly good work, costing from $5 to $25, 

 being made of old mowing machines, dry goods 

 boxes and bale wire. These have enabled many a 

 poor settler to get a start the first few years. 



The water may be drawn from a well, stream, 

 pond or lake. In many parts of the arid region 

 water may be struck from 20 to 50 feet deep and 

 an unfailing well secured, from which water may 

 be raised for irrigation. But it is absolutely 



