138 
IOWA ACADEMY OP SCIENCE 
a depth of 2,054 feet. The following are four analyses of its water made at 
intervals of about one year. 
Date of Analysis. 
Total Solids. 
Sept. 18, 1905 
Sept. 9, 1906 
Nov. 26-, 1907 
Sept. 9, 1908. 
1,228 
1,637 
1,930 
2,594 
The content of mineral matter has steadily increased during the four years, 
and it seems very likely that this is due to the gradual deterioration of the 
casing due to corrosion. 
The want of efficiency and durability in the casings is one of the chief weak 
points in the deep well as a source of water supply. Not only do casings rust 
through, but in many instances they do not reach sufficient depths to shut out 
hard water and to prevent caving of shale. The town of Grinnell has lost one 
well and the capacity of another in quality and quantity has been’ greatly 
diminished by the caving of shale at the depth of about 1,700 feet or just above 
the St. Peter. At the present time well number (4) is being drilled and has 
reached a depth of 1,850 feet. The plans and contract regarding casing are so 
unusual, and are likely to be of such importance that a mention of them seems 
desirable. 
As is well known cast iron far excels wrought iron in its resistance to the 
corrosive action of air and water. Of course, the mild steel which has so 
largely replaced wrought tubing on account of its cheapness is still far inferior 
to wrought iron in durability. Having had experience with both soft steel and 
wrought iron tubing the Grinnell authorities contracted for a casing of cast 
iron in well number (4) to reach to a depth of 1,700 feet. If this experiment 
succeeds it ought to be of much interest from both, the practical and scientific 
standpoints. There are few if any deep wells near the center of the state from 
which the waters above the great sandstone layers are entirely excluded. No 
one now certainly knows what these sandstones are capable of yielding in this 
region in either the quality or the quantity of water. In the Grinnell wells 
as they have hitherto been cased, very considerable quantities of hard water 
have been received from the limestone layers below the casings at depths from 
1,200 to 1,600 feet. If the water supply of the new well should prove abundant 
and should have a mineral content anywhere near as low as the water from 
the same strata fifty miles to the northeast, it ought to encourage more deep 
wells in this region, and even the extension of the region of artesian wells 
farther to the south and west. In any event the successful putting down of 
this casing will demonstrate the practicability of cast iron for this purpose, 
and the opportunity of thus very greatly increasing the durability of the casing 
and the life of the deep well. 
Iowa waters from whatever source are notably harder than those from cor- 
responding sources in the states farther east. The wafers of Lake Michigan 
and of the great lakes generally contain about 130 parts of solid matter per 
million; lakes and rivers farther to the east contain smaller amounts, even to 
less than half as much. On the other hand the softest of Iowa river, lake and 
well waters contain about twice that amount; that is, about 260 parts per 
million. There are few well waters of this degree of freedom from mineral 
matter. Excepting a few wells the great majority vary from 350 to 10,000 
