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CALIFORNIA FRUITS: HOW TO GROW THEM 



moved backward and forward until the water is all passing through 

 the slot, the water being kept up to the top of the board, or 4 inches 

 above the center of the opening. The length of the opening measures 

 the number of miner's inches of water flowing through. If the flow 

 is too great to pass through the opening 1 inch wide, the opening 

 may be made wider, the water still to be kept 4 inches above the 

 center of the opening. The laws of several States provide that in 

 devices for measuring water for sale by the miner's inch the opening 

 shall be 6 inches high and shall be provided with a slide as shown 

 in the picture. The number of miner's inches then discharged is 

 equal to the number of square inches in the opening. The assump- 

 tion made that the discharge is proportional to the size of the open- 

 ing is not true, but the error in measuring small quantities is not 

 great enough to be taken into consideration. By converting the 

 results of measurements in miner's inches to gallons, cubic feet, or 

 some other familiar unit, it may be determined how long it will take 



Measuring miner's inches in a small stream or ditch. 



the stream to fill a reservoir or cover a given field with the neces- 

 sary depth of water. This unit is readily convertible into cubic feet 

 or gallons or acre-inches of water, according to the time the 

 water flows. 



The following data will be helpful in computations : One miner's 

 inch, as described above, equals 0.1496 gallons per second, 8,976 gal- 

 lons per minute, 538.56 gallons per hour, 12,925.44 gallons per day ; 

 0.02 cubic feet 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. 



