546 THE GLACIAL LAKE AGASSIZ. 



and on a small scale the water of artesian wells in this valley has been 

 applied to patches of garden vegetables and other crops near dwellings. 



Will it be profitable, on a larger scale, to store the water of artesian 

 wells in reservoirs for use in the season of growing crops, and especially 

 during severe droughts! To this inquiry we may reply by computing the 

 amount of water needed for imgating a given space, as a quarter-section of 

 160 acres, the usual area of a homestead. Allowing a depth of 12 inches 

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

 from a well flowing 100 gallons per minute is required, without allowance 

 being" made for leakage or evaporation from the reservoir. The Devils 

 Lake well would, tlierefore, iri'igate only 64 acres, and the Jamestown 

 well, flowing 375 gallons per minute, will water less than a section 1 mile 

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

 the cost of the construction of reservoirs and imgating ditches, placing the 

 expense of such water supply far beyond its prospective value for oitlinary 

 agricultm'e. 



Unusual difficulties were encountered in boring these wells, which are 

 the deepest, excepting only the well at Highmore, in the list on page 530. 

 With the experience now acquired, they might probably be bored for half 

 as great expense; and shallower wells, from 600 to 1,000 feet deep, as at 

 Yanliton, Woonsocket, and Aberdeen, may be bored and piped at a cost 

 ranging from $800 to $1,500. The still shallower artesian wells in the 

 drift of the Red River Valley, varying in depth from 35 feet to 250 or 300 

 feet, cost from $50 to $200 or $300. Each of these wells could supply 

 water sufficient for the irrigation of a few acres, and those having the most 

 copious flow would irrigate 50 acres or more if their water were stored in 

 reservoirs for use only during the summer. 



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 during many years, the 

 residuum from the water would quite cei'tainly prove injurious to crops, so 

 that the land would become worthless. Such results have attended irriga- 

 tion with only very slightly saline water on the alluvial plains of the arid 

 northwestern provinces of India. The proportion of sulphate of soda in 



