Page:Lippincotts Monthly Magazine-61.pdf/90

Rh cost. Still in some fashion the geologists and engineers did scramble over six hundred and ﬁfty-eight thousand square miles of country, making, as they say, “only a preliminary survey;” yet the results of that inquiry revolutionized the opinions which had been theretofore held upon the relative importance of the underground ﬂows to the redemption of the sterile surfaces above them and to the reduction of a climate parched with excess of drouth to a degree of agreeable salubrity.

It was found that nearly the whole of the district explored was underlaid with sheets of water; not one sheet, nor two, but often three sheets, imposed one above the other, intercalated with strata of impervious rock. In writing his report upon this discovery, as the phenomenon exists in Nebraska, Professor Hicks of that State said, “The underﬂow along the incline bodies of porous rocks is undoubtedly a more important source of moisture than are all the rivers which enter the State.”

Though the inquiry was not pushed farther west than the eastern foot-hills of the Rocky Mountains, yet from data gathered and observations made in this ﬁeld, from the reports of geologists and engineers in the employ of the States which spread over the area untouched by the scientists at Washington, from records of well-borings therein, and from such observation as I have been able personally to make, it is possible to view the phreatic permeation of the entire arid country with an eye somewhat to the system of its arrangement, its potential future development, and the place it will hold as a contributing source of the conversion to industrial uses of such lands of the region as are susceptible of being brought under subjection through the agency of applied moisture.

In its widest scope, the arid region of the United States comprises half the territory of the entire country; for to so great an extent must irrigation be employed either as a primary or a secondary factor in the cultivation of crops. From about the 96th to the 99th meridian there is a strip of about two hundred and ﬁfty miles in breadth which Major J. W. Powell calls the “sub-humid” tract. Within it there is an annual precipitation sufficient to insure crops, but the precipitation is so disproportionately bestowed, and at such irregular intervals throughout the year, that the seasons of successful farming are interspersed with long and disastrous droughts; reliance, therefore, upon moisture directly falling from the clouds is extremely hazardous, and, unsupplemented by waters from stream distribution, it is not generally reposed.

But west of the 99th and east of the 121st meridian, throughout the whole breadth of the country, from Canada to Mexico, there is a district in which nothing needing moisture greater than that required by the artemisia or the cactus can be planted and grown. It is a region aggregating about one million three hundred and forty thousand square miles, a territory larger than Arabia, as large as and not more arid than the combined areas of Persia and India, with their united populations of two hundred and ﬁfty millions of human souls.

Saving the eastern boundary of this domain, its topographical character is extremely broken. Upon the east a vast ﬂank of gently sloping plains incline from vertebrae of mountains and move swiftly on into the valley of the Mississippi; to the west it is a mere jumble of steeps