Review of Recent Geological Literature. 'ilh 
After a brief treatment of the geology of the water-bearing strata, 
with numerous cross-sections, he gives a detailed account of the wells 
by counties. Here are furnished figured sections of 133 wells, which 
afford an easy means of learning the character of the formations pene- 
trated. 
In discussing the sources of the water, the limits of the basin and the 
cause of decline of pressure toward the south and east, he agrees with 
other geologists. 
Concerning the amount of the waters, he comes to a more hopeful 
conclusion than some others of the government survey who expressed 
themselves a few years ago. He thinks the areas of exposed permeable 
beds in Montana, Wyoming and Dakota connected with the supply may 
aggregate nearly 14,000 square miles, and says: "The present outflow of 
the wells can be but a small proportion of the intake of the beds at 
their outcrop at the very lowest estimates. This is quite clearly shown 
by the exceedingly slight influence in pressure that the wells have upon 
one another in areas where there are many wells quite near together." 
"It has been claimed by some persons that the pressure and yields of 
many wells are decreasing, but of this- 1 can find no definite evidence 
that would indicate diminution in the water supply." "I see no reason 
why the artesian waters should not be produced in sufficient volume to 
supply all local needs of the usual kind and irrigate in a moderate way 
all lands to which their head will carry them. I believe there are no 
grounds for fear that the water will give out or prove inadequate for 
every need."' 
The availibility of the waters for irrigation is stated strongly. "There 
are now nearly 100 farms on which artesian waters are used for irriga- 
tion on a greater or less scale, not counting many gardens and several 
trial areas. In most cases the results have been so satisfactory that 
much interest and enthusiasm has been aroused." "It can not be 
claimed that all the artesian waters of the region will prove acceptable 
for irrigation, but it does appear probable that waters unfit for this use 
will be found to be very unusual." 
An interesting account of the methods and results of such irrigation 
in South Dakota is given, with several tine illustrations. 
In closing, two practical suggestions are given, one on the use of ar- 
tesian water for power and another on the conditions and management 
of artesian wells. 
The report consists of about 90 pages of text with numerous diagrams 
and illustrations and 9 well devised maps. 
Some of the points specially novel or notable are the following: 
The mapping and description of ten small artesian basins deriving 
their waters from the sands under the glacial drift. The main basin 
which has been referred to in most cases is from the Dakota sandstone, 
and possibly some older formations. 
Another is the mapping of the floor of the artesian basin, or of "bed- 
rock" under the Dakota sandstone. This has never been attempted 
before, and data are too few and too uncertain to do it satisfactorily ; 
