452 IRRIGATION FARMING. 



for individual consumers, and the combination is now 

 using a special type of centrifugal pump adapted to 

 low lift and high speed — chara<5leristics which make it 

 possible to direc5lly connedl the pumps to standard 

 high-speed indudlion motors. Twenty-five pumping 

 plants are operated under this system, each delivering 

 from 1,400 to 2,000 gallons a minute, and it may be 

 said in a very liberal sense that the investment has 

 been fully justified by the service performed during 

 the most drouthy conditions. The average cost of 

 each battery was $3,500. Each station consists of 

 four wells in a line sunk to a depth of from 80 to 1 30 

 feet through strata of alluvial loam, clay, and water- 

 bearing sand. The wells are cased with galvanized 

 iron pipe thirteen inches in diameter No. 16 gauge, 

 perforated with vertical slits opened about a sixteenth 

 of an inch. 



The casing was landed in clay, perforating all the 

 sand below a depth of thirty feet. The shoe on the 

 starter was somewhat larger than the casing, and by 

 means of a small supplementary sand pipe sunk to the 

 first water the sand encountered by the large casing 

 was inclosed in a layer of coarse sand which, while 

 effecflually excluding the flow of fine sand, offered lit- 

 tle obstrudlion to the water entering the casing. Sur- 

 face water was encountered at a depth of from ten to 

 fifteen feet, and, as a rule, a flow of three to four cubic 

 feet a second was secured when the thickness of the 

 water-sand was from twenty to thirty feet. In this 

 kind of work much depends on the care and skill exer- 

 cised in sinking the wells, securing a proper landing, 

 and adapting the perforations to the quality of sand 



