192 
IOWA ACADEMY OF SCIENCE 
free mingling of the waters of these sandstones with those of the 
upper layers. These questions, however, demand farther study 
than I have been able to give them before they can be settled. 
Whatever may be the character of the unmixed waters from dif- 
frent strata there can be no doubt about the actual quality of water 
obtained by the driller when he has penetrated the deep lying sand- 
stones in different localities. In the following tables no absolute 
accuracy can be claimed regarding the identity of the lowest strata 
penetrated in some of the drillings, though in most cases there can 
be no reasonable doubt, according to Dr. Norton, from whose report 
they are mostly taken. They show the increasing mineralization 
from north to south, and from east to west. 
Table one shows the increase in mineralization of deep well 
waters as we go west through the second tier of counties from the 
northern boundary, from Waukon to Hull. As may be seen there is 
practical constancy till we pass Emmetsburg, but at Sanborn and 
Hull the solids increase about five times. 
Table (2) represents waters from wells in the fourth tier of 
counties south, beginning at Dubuque and ending at Sioux City. 
At Dubuque the large number of wells show about the same amount 
of solids and a fair average is taken. There is an apparent irreg- 
ularity in the solids at Webster City, which may be explained from 
the fact that the water was taken from a gas drilling, which was 
probably never properly cased. 
Table (3) shows wells in the sixth tier of counties beginning 
at Clinton. It will be observed that the results are in general the 
same as in tables (1) and (2), save that the transition from light 
to heavy waters occurs farther east. The varying amounts of sol- 
ids in the Grinnell wells will be referred to later. South of tne 
sixth tier of counties deep wells are few and afford no series from 
east to west. 
If we change the direction and pass from north to south the same 
general results are obtained. Table (4) begins at Lansing and 
follows along or near the Mississippi river. The transition may be 
assumed to occur at Davenport since Wilton is at a considerable 
distance from the river. 
Table (5) represents a chain of wells beginning at Calmar, ex- 
tending south and slightly west to Centerville. The transition, 
which is less sharp, though this may be accidental, occurs at 
Amanaon, about the same parallel as Davenport. 
Table (6) represents wells from Mason City on the north to Des 
Moines. It is probable that the Nevada well is too shallow to be 
