190 



PRACTICAL IRRIGATION. 



Proposed table for the measurement of irrigation water: 



1 Myria-inch- 10 Kilo-inches 10,000 inches 



1 Kilo-inch 10 Hecto-inches 1,000 inches 



1 Hecto-inch 10 Deka-inches 100 inches 



1 Deka-inch 10 inches 10 inches 



1 Inch 10 Deci-inches 1 inch 



1 Deci-inch 10 Centi-inches 1-10 inch 



1 Centi-inch 10 Milli-inches 1-100 inch 



1 Milli-inch 1-1000 inch 



TABLES OF EQUIVALENTS. 



1 Myria-inch 

 1 Kilo-inch 

 1 Hecto-inch 

 1 Deka-inch 

 1 inch 

 1 Deci-inch 

 1 Centi-inch 

 1 Milli-inch 



129,000,000 



12,960,000 



1,296,000 



129,600 



12,960 



1,296 



gallons 

 gallons 

 gallons 

 gallons 

 gallons 

 gallons 

 129.60 gallons 

 12,96 gallons 



Water Is contained in the soil in three different states, as: 



1. Hydroscopic water. 



2. Capillary water, and 



3. Water of percolation. 



Hydroscopic water is that which is not perceptible to the senses, 

 but is appreciated by a loss or gain of weight in the soil which ac- 

 quires or is deprived of it. 



Capillary water is that which is held in the fine pores of the sc'i 

 by the surface attraction of its particles. 



Water of percolation is that which fills the interstices in thi» soil 

 and would percolate through or filter out from the soil. 



An acre of ground contains 43,460 square feet; allow 100 pounds 

 per cubic foot of dry soil, we would have 4,356,000 pounds evpry foot 

 in depth. Let us make a reasonable assumption as to the reservoir 

 capacity of our soils. They will hold as hydroscopic and capilliary 

 water about 20 per cent, of their weight. Assuming that our soils 

 are only wet to a depth of ten feet in the rainy season, we would 

 have 8,712,000 pounds of water stored in each acre of ground, or more 

 than ten times the amount of water necessary to raise 20,000 pounds 

 of oranges per acre, if all the water was available, which it is not. 



Professor King has estimated that it takes to raise different crops, 

 such as hay, barley, clover, etc., from 300 to 500 tons of water to 

 make one ton of dry matter. My investigations lead me to think 

 that it takes much less to raise fruit, about 200 tons of water to raise 



