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CALIFORNIA FRUITS: HOW TO GROW THEM 



per day; 0.02 cubic foot per second, 1.2 cubic feet per minute, 72 

 cubic feet per hour. One acre-inch of water (that is, 1 inch in 

 depth over an acre of surface) equals 27,152 gallons, or 3,630 

 cubic feet, and 1 miner's inch will supply this quantity in about 

 50.4 hours. Thus a simple calculation shows that a little stream 

 of 5 miner's inches will supply enough water to cover an acre 2.3 

 inches deep in about 23 hours a fair amount for one irrigation 

 of soil of average character if it has not been allowed to become 

 too dry before the application. In fact this is an average amount 

 actually used for an irrigation of shallow-rooted plants like most 

 field and garden crops. 



Weir Measurement. The term "weir" is not always understood 

 by those who use it. The term can properly be used only for 

 structures designed to allow the water to flow over the crest with 

 a considerable fall on the down-stream side. There are a large 



Weir box in operation showing post from which to measure depth of stream. 



number of forms of weirs, taking their names from the shape of 

 the weir notch, or the form of crest. The triangular weir has a 

 V-shaped notch. The rectangular weir has a horizontal crest with 

 vertical sides. Both of these forms of weir are good, when used 

 by the expert irrigator or engineer who understands the principles 

 and factors which enter into their calculations. In order to avoid 

 the variable factors which enter into the calculations for the flow 



