196 PRACTICAL IRRIGATION. 



gained thereby. Elaborate tests in actual practice have shown that 

 the water will seep out in the same length of time a radius of ten feet 

 from a valve buried in the ground, or from a mere post hole three 

 inches in diameter, or from a hole that is one foot in diameter, or 

 from one that is two feet in diameter. This may seem a strange state- 

 ment, yet if we will consider that the contents of a circle twenty feet 

 in diameter contains 314 square feet, and that by making a hole two 

 feet in diameter, we would only take away 3.14 feet, or "about one 

 per cent of the soil within the larger circle, it is apparent that little 

 is saved in point of time by making a large hole to be filled up 

 with extraneous and perhaps expensive material. 



As the cost of such a system as is recommended above would be 

 about $100 per acre, it still puts the system beyond the reach of most 

 of the ranchers, although the annual saving would be about 15 per 

 cent on this Investment in labor, etc., without any reference to saving 

 the water. It is also impracticable where the water is distributed m 

 open ditches, as it requires some little pressure in order to distribute 

 the water through an inch pipe. Other means less expensive were 

 therefor<^ tried, one of which has been quite successful. This system is 

 calleci. INTER-IRRIGATION. 



It consists in distributing the water above ground but in disseminat- 

 ing it below the surface. This is done by means of holes the width of 

 an ordinary shovel dug to the depth of from lo to 24 inches, accord- 

 ing to the nature of the soil, in the center of each square formed by 

 four trees. On ground that is level or nearly so, a single furrow is 

 run down a little to the side of these holes; a furrow at right angles 

 from that furrow is dug to run in and fill up the hole, which is kept 

 full during the period of irrigation. The water then passes on down 

 the furrows and into the next hole, and so on to the last hole in the 

 orchard. Where the water can be run down diagonally through an 

 orchard, or if the orchard is set quincunx, there need be but one fur- 

 row in every other row. Where the ground is rolling, or on side hills, 

 it will be necessary to have wooden or other troughs or a system of 

 movable pipes to keep the ground from washing, and it Is always best 

 to have troughs or pipes. The troughs in use at Lenapuente are made 

 from wooden strips 1x2 nailed on 1x3, making a V-shaped trough. No 

 joists are required as a single length is run from hole to hole. The 

 cost of such troughs is about J18 per acre where they run on the 

 squares, or |12 per acre where they are run every other row diagonal- 

 ly. The pipes used at Lenapuente, where the water is delivered under 



