228 THE PRINCIPLES OF SOIL MANAGEMENT 



foot per second through a growing season of ninety 

 days, is sufficient to irrigate one hundred acres. This 

 is sufficient to cover the area 21.3 inches deep, and is 

 equivalent to a little over seven inches per month. 

 (See pages 135 and 137.) 



The miner's inch varies in value in different sections. 

 It is most commonly defined as the amount of water 

 which will flow from an opening one inch square under 

 a pressure-head of six inches above the top of the orifice, 

 during a year, and is considered sufficient to irrigate 

 from 5 to 10 acres. It is equivalent to about 1.5 cubic 

 feet per minute, or 21.6 inches over 10 acres in a season, 

 which, it will be observed, is practically the same appli- 

 cation as one second-foot, as stated above. 



102. Methods of applying water. In his book on 

 Irrigation and Drainage, King makes the following- 

 cogent statement with reference to the application of 

 water in irrigation practice. "When water has been 

 provided for irrigation, and brought to the field, where 

 it is to be applied, the steps which still remain to be 

 taken are far the most important in the whole enter- 

 prise, not excepting those of engineering, however 

 great, which may have been necessary in providing 

 a water-supply that shall be constant, ample and moder- 

 ate in cost; for failure in the application of water to the 

 crop means utter ruin for all that has gone before." 



"To handle water on a given field so that it shall be 

 applied at the right time, in the right amount, without 

 injuring the crop, requires an intimate acquaintance 

 with the conditions, good judgment, close observation, 

 skillful manipulation, and patience after the field has 



