3/6 Artesian Wells in North and South Dakota. 



acres, the usual area of a homestead. Allowing a depth of twelve 

 inches of water for this use during the growing season, the year's 

 supply of water from a well flowing loo gallons per minute is 

 required, without allowance being made for leakage or evapora- 

 tion from the reservoir. The Devil's lake well would therefore 

 irrigate only 64 acres, and the Jamestown well, flowing 375 gal- 

 lons per minute will water less than a section one mile square. 

 But each of these wells cost about $7,000, to which must be 

 added the cost of the construction of reservoirs and irrigating 

 ditches, placing the expense of such water supply far beyond its 

 prospective value for ordinary agriculture. 



An important objection, however, against the use of this 

 water for irrigation seems to lie in its dissolved alkaline and saline 

 matter, which must be left in the soil. After continued use in 

 irrigation during many years the residuum from this water would 

 quite certainly prove injurious to crops, so that the land would 

 become worthless. Such results have attended irrigation with 

 only very slightly alkaline water on the alluvial plains of the 

 arid northwestern provinces of India. The proportion of sulphate 

 of soda in streams flowing down from the Himalayan range and 

 in canals taking water from them varies from 9 to 43 parts in a 

 million, and the proportion of common salt is from 0.23 to 15 

 parts; yet under the dry climate of northwestern India the nat- 

 ural evaporation of so nearly pure water, and its use in irriga- 

 tion have caused extensive tracts of land formerly productive to 

 become barren.* 



The analysis of the water of the Jamestown well, which, 

 doubtless closely resembles that of all the wells obtaining their 

 supply from the Dakota sandstone, is given by Prof. James A. 

 Dodge, as follows: 



Analysis of the mineral matter in the water of the artesian well at 

 Jamestoivn, North Dakota. 



Parts per Million. Grains per Gallon. 



Silica 35.7 2 0823 



Alumina... 3.5 .2041 



Carbonate of iron 2.2 .1283 



Carbonate of lime 188 10.6743 



Sulphate of lime 249 14.5241 



Sulphate of mag^nesia 154.2 8.9944 



Sulphate of soda 1139.4 66.3602 



Sulphate of potash 81.5 4.7523 



Chloride of sodium 369.1 21.5296 



Phosphates Traces. 



* Medlicott and Blanford, Manual of the Geology of India, pp. 413-415. 



