Review of Recent Geological Literature. 49 
like a careful and detailed account of the contents of this volume. We 
can only dwell on a few points which will illustrate the nature, meth- 
ods, and progress of the plans adopted for irrigating the arid region of 
the west. Mr. Hinton says (page 19) : 
"In the past seven years the actual area of reclamation by irrigation- 
cultivation has increased from about 5,000,000 to at least 8,500,000 acres. 
By the time of the opening of the Columbian World's Fair, the United 
States may expect the cultivation by means of irrigation of at least 17,- 
000,000 acres of land that within the last decade have been declared by 
learned authority to be wholly irreclaimable, worthless for agriculture, 
useless for tree-planting, and hardly tit for even the grazing of scraggy 
sheep and the broad-horned steer." 
"The removal of the alkali from the land is one of the first require- 
ments. This is to be accomplished by underdrainage wherever the soil 
allows it. To Hood the land till underdrains laid reasonable distances 
apart shall have run for some time will end the trouble, not only for the 
time being, but for centuries, provided only that solid beds of the alkali 
salts do not underlie it. But this is the rare exception." 
In those parts of the arid region which can be irrigated the streams 
flow underground. These subterranean rivers exist in other parts of 
the country, but where water is abundant no effort is made to trace 
them. The Rio Santa Cruz in Arizona is an example of these. In the 
upper part of its course the stream is of varying width and depth, ac- 
cording to the season. Lower down it disappears altogether, but its 
course is marked by mesquite trees to a width of from 500 to 2,000 feet. 
The gravel of the valley has been tested at Tucson to a depth of 52 feet, 
and is estimated to carry 370,000 irrigating inches every twenty-four 
hours (page ?•">). 
The various devices by which the hidden water is brought to light are 
explained. Of course when a pump is required, as is often the case, the 
work is expensive. Hut in those parts where the water is truly artesian, 
or even where it rises to the surface, little or no expense attends getting 
it except the sinking of the well. 
The report of Col. Xettleton consists of a rapid survey along eleven 
lines across the country on the Platte and the Arkansas rivers and in 
the valley of the Loup, with an examination of the existing wells, in 
order to ascertain the probability of getting water by boring. Some 
curious statements are given regarding the so-called blowing wells. 
which in certain states of the weather emit a blast of air and in others 
suck air down the bofe. On one of these he tells us that a brass whistle 
has been set which announces a coming storm with a note audible a 
quarter of a mile from the well. 
Col. Nettleton made some attempt to ascertain the rate of How of the 
underground water, but without success. He is. however, inclined to 
accept the figures of the French engfi rs and set it down at about one 
mile in the year or fourteen feet per daj . 
One of the strongest flows mentioned is in Beadle county, South Da- 
kota. At !i<io feet water was reached with pressure sufficient lo furnish 
