788 EXPERIMENT STATION RECORD. 



cost, ease and rapidity of construction, and its adaptability to a wide range 

 of conditions and locations. In rock-fill dams the greater part of the struc- 

 ture consists of loose rock dumped into place and rendered impervious by the 

 use of earth, lumber, concrete, or steel, the size of the dam and the ultimate 

 cost of obtaining and placing the materials determining which is preferable 

 in each case. The mass and weight of the rocks provide the necessary stability 

 against water pressure and overturning and sliding tendencies. 



Shallow pumping for irrigation in the West, W. L. Wilder (Mid-Continent, 

 5 (1912), No. 7, pp. Ui-n, figs. 7). — This general discussion of shallow irriga- 

 tion pumping in the West indicates that the best sources of cheap power on the 

 farm at the present time are the gasoline engine and the electx'ic motor. To 

 these are considered due the success of shallow irrigation pumping. Several 

 forms of pumps and water-lifting devices in present use are described. 



Irrigation by pumping in western Kansas, F. D. Cobuen (Topeka, Kans., 

 1912, pp. 12, figs. 3). — ^The author discusses the possibilities presented by irri- 

 gation pumping in western Kansas, describing several private pumping plants in 

 use which give satisfaction and showing that whenever irrigation by pumping 

 from deep bored or artesian wells may be done to supplement rainfall it will 

 bring about great increases in crops. 



A new method of subirrigation (Texas Farm Co-operator, 35 (1912), No. 35, 

 pp. 1, 2). — A description is given of a subirrigation system in Texas in which 

 the water is distributed by concrete pipe, the main pipe; 4 in. in diameter, run- 

 ning the length of a field and feeding 2-in. lateral pipes which are laid at 

 intervals of 33 ft. At intervals of 3 ft. small holes are made in the tops of the 

 lateral pipe in which are inserted small plugs with pin hole end openings. 

 Concrete caps are placed over these plugs, leaving just enough space to allow 

 the water coming through the plug to percolate from under the cap and into 

 the soil. It is claimed that a well with a capacity of only 40 gal. per minute 

 furnishes sufficient water to iri-igate 20 acres, using a 4i-in. working barrel 

 pump driven by a 2-horsepower engine. The advantages presented by this 

 system are the great savings of land and water. 



Overhead irrigation in the citrus grove (Pacific Rural Press, 8ft (1912), No. 

 2, p. 28.) — A system of overhead irrigation is described in which galvanized iron 

 pipe lines are run underground through every alternate row of trees, and stand 

 pipes 15 ft. high are raised through every fourth tree, the water being dis- 

 tributed through rotary sprinklers. The head pipe is 4 in. in diameter and is 

 tapped by 17 rows of 1^ in. pipe, which reduces to 1} in. toward the center and 

 to 1 in. along the lower third. The branch pipes to individual trees are | in. 

 and the stand pipes | in. The pumping is done by electricity and the cost of 

 the system was about $150 per acre. 



Super-elevation of water surface in passing around curves at high veloci- 

 ties (Engin. and Contract., 38 (1912). No. 1, p. 2J,, figs. 2).— A mathematical 

 discussion is given providing for a raise in the outside walls of irrigation canal 

 curves to prevent loss of water due to superelevation. 



[Duty of water], W. W. McLaughlin (Mid-Continent, 5 (1912), No. 5, pp. 

 25, 26, fig. 1). — This is a general discussion of the meaning of the duty of 

 water, presenting the opinion that this should be based entirely upon the 

 economic productive power of the water, including net return on money in- 

 vested, labor and equipment required, and the marketable qualities of the crop 

 produced, rather than on the amount of water required to produce a certain 

 quantity of crop, and thus distinguishing between primitive methods and 

 modern scientific methods of irrigation. 



Notes on irrigation in Cape Colony, J. Mullie (Bui. Agr. Congo Beige, 

 3 (1912), No. 2, pp. 257-290, pi. 1, figs. 25).— A general discussion of the 



