COTTONWOOB AND JACKSON COUNTIES. 513 



Material resources. ; 



Iodine, bromine and phosphoric acid, absent Test with potassium permanganate showed 

 2.6 parts oxygen consumed by organic matter per 1,000,000 water. Hardness, 22 degrees. The 

 water is notable for excessive hardness, due to sulphate of lime and carbonates of lime and 

 magnesia, 



Travertine. Small deposits of travertine, or calcareous tufa, made by springs that issue 

 from the drift, often called "petrified moss" from its having incrusted moss and leaves, thereby 

 preserving their forms, occur in Jackson county on the east side of the ravine of a creek near the 

 center of section 26, Petersburg; and on the southeast side of a creek near the center of section 

 15, Des Moines, about two miles northwest from Jackson and some 50 feet above the Des Moines 

 river. 



MATERIAL RESOURCES. 



Agriculture must be the chief industry and source of wealth to Cotton- 

 wood and Jackson counties. Their soil, their narrow belts of timber beside 

 rivers and lakes, the natural pasturage and plough-land of their broad ex- 

 panse of prairie, have been treated of on a former page of this report. 

 Items to be noticed here are water-powers, building stone, lime, bricks, 

 and peat. 



Water-powers. The only water-power used in Cottonwood county is 

 that of the Windom mills, on the Des Moines river, owned by Collins & 

 Drake; head, nine feet; three run of stone; a large flouring mill. 



Another excellent water-power is available on this river a mile below 

 Talcott lake, where a dam may be built which would make this lake a res- 

 ervoir, raising it three or four feet. 



In Jackson county the Des Moines river supplies three powers, all used 

 by flouring mills. These are the Brown brothers' mill, in section 28, Bel- 

 mont, having a head of about nine feet; the Des Moines Valley mills, owned 

 by E. P. Skinner, in section 10, Des Moines, three miles northwest from 

 Jackson, with a head of about eight feet; and the Jackson mills, at Jack- 

 son, owned by J. W. Hunter, with head of nine feet and three run of stone. 



Building stone. The Potsdam quartzyte of northern Cottonwood county 

 has been somewhat quarried, as already mentioned, in sections 23 and 25, 

 Selma, in section 8, Delton, and in section 6, Dale. Owing to the very hard 

 and gritty nature of this rock and its tendency to rhomboidal fracture, it 

 supplies only rough blocks, seldom of large dimensions, yet quite suitable 

 for common foundations and walls, and for the masonry of culverts and 

 small bridges. 



Lime. Boulders of magnesian limestone, gathered from the drift, are 

 burned for lime by Lars Rasmusson, in section 11, Des Moines, about two 



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