Wind Power for Irrigation 



317 



Table showing computed amount of water lifted 10 feet high during consecutive 

 10- day periods for one full year, expressed in acre-inches 



Keferring to the table, it will be seen that the smallest 

 amount of water pumped in any 10 days was 9.87 acre-inches, 

 this occurring between July 28 and August 7, at a time when 

 most water is needed. In this period there were 7 full days 

 when no water was pumped, all the water being raised during 

 3 days of the period. 



The mean amount of water pumped during the 100 days 

 from May 29 to September 6 was 24.5 acre -inches per 10 days, 

 and as this is the season in the United States when most water 

 is needed for irrigation, the figure may be taken as representing 

 the capacity of such a pumping system. That is to say, such a 

 plant is able to supply 10 inches of water to 24.5 acres during 

 100 days when the lift is 10 feet, and to 12.25 acres where the 

 lift is 20 feet. If the crop irrigated demands 20 inches of water 

 in. 100 days, then the area which could be supplied under a 

 10-foot lift would be only 12.25 acres, and under a 20-foot lift 

 only 6.12 acres. It must be understood, however, that these 

 results are possible only under conditions of no loss between the 

 pump and the land to which the water is applied. 



From theoretical considerations and the above data, it 

 appears probable that for different sizes of wheels and for dif- 

 ferent lifts, but under otherwise similar conditions, areas may 

 be irrigated as given in the table below. 



