The Water of Artesian Wells—Hewitt. 125 



[Papers.] 



]. THE WATER OF ARTESIAN WELLS; ITS (QUALITY AND THE POSSI- 

 BILITY OF ITS BECOMING A SOURCE OF SUPPLY IN MINNE- 

 SOTA. — C. iV. Heivitt. 



1 1. THE GEOLOGICAL CONDITIONS WHICH CONTROL ARTESIAN WELL 

 BORING IN SOUTHEASTERN MINNESOTA.— C W. Hall. 



I. 



[abstract.] 



The speaker presented the analyses of thirty-two artesian or 

 drilled well waters, made in the laboratory of the State Board of 

 Health of Minnesota under his direction, and presented a brief 

 study of their history, quantity and composition, as bearing upon 

 the question of such water for domestic water supply. He pre- 

 ferred the term "drilled" wells, as implying the essential fact that 

 the water supply was obtained from beneath one or more strata of 

 soil or rock, impermeable to surface water, and, therefore, com- 

 paratively free from the dangers of surface wells, or even deep 

 wells not so protected. It will be seen, too, that the question of 

 depth is not of so much importance as that of character of soil or 

 rock penetrated. The 'Mrive well" is excluded from this list, as 

 not fulfilling the conditions, i. e. supply below impenetrable strata 

 of soil or rock, and wells so tubed as to prevent the entrance of 

 surface water to the supply. As to tubing, he advised the iron 

 pipe, thoroughly coated with asphaltum inside and outside, or 

 coated with black oxide of iron by one of the several processes 

 used for that purpose. Galvanized iron was condemned as al- 

 most always imperfectly made, and as adding salts of zinc to the 

 water. The so-called kalamein pipe was also objected to as not 

 proved to be safe. 



The plain wrought iron pipe is safe and good. The iron 

 ( ompounds which it adds to the water are harmless and may serve 

 a good ])urpose (in pipes not directly connected with pumps) by 

 precipitating the part or whole of organic matter. To prevent 

 surface water trickling down through the bore, outside the pipe, 

 into the water supply, tamping around the pipe after it is in place 

 with pure clay or water cement, should be carefully done, and the 

 pipes ^hould come well above the ground. 



