310 CLIMATIC CHANGES IN THE PRAIRIE REGION. 



Great Sahara, and mark what the French government and Mehemet Ali have ef- 

 fected by the agency of man in reclaiming those reaches of drifty sands, we may 

 predict equal possibilities for the Llano Estacado with its elements of fertility. 



Over twenty millions of trees have been planted in the deserts of the Nile 

 and their productive area extended wonderfully, and immense date groves, within 

 the last twenty years, have sprung up at intervals on the Great Sahara, irrigated 

 by artesian wells and surrounded by thrifty plantations. 



General Emory, describing the Moro Valley, says: f"The plains were 

 strewn with brick-dust, colored lava, scoria and slag ; the hills to the left capped 

 with white, granular quartz. The plains are almost destitute of vegetation ; the 

 hills bear a stunted growth of pinon and red cedar." 



This valley is now one of the richest wheat-producing regions of New Mex- 

 ico, and when the writer visited it ten years ago, its thriving villages and fine 

 farms presented a curious contrast to the desolate picture drawn as above in 1846. 



In the report of the Geological Surveys of the Territories,* Professor Cyrus 

 Thomas in his investigations of the agricultural possibilities of the regions included 

 in the surveys, says: "In calculating the probable development of the same, it 

 is necessary to lay aside to a great extent all our ideas of agriculture based upon 

 experience in the States. For, not only are the physical aspects of this portion 

 of the West so different from the eastern half of our country as to strike the most 

 superficial observer, but the climate is almost completely reversed, the thermo- 

 metric and hygrometric conditions bearing no such relations to vegetation and agri- 

 culture here as there. Hence, the criteria by which we judge the fertility and 

 productiveness of the soil and its adaptation to given products (except, perhaps, 

 the strictly chemical tests) do not hold good here. The pale appearance of the 

 soil, the barren look and stunted growth of a spot, are by no means conclusive 

 evidences of its sterility, for the application of water may show it to be rich in 

 vegetative force." Professor Thomas hints at the incorrectness of the earlier of- 

 ficial reports on the subject of the Great Plains (as plainly asserted by myself), 

 " that the primitive explorers condemned, in too hasty and general terms, the 

 possibilities of that whole region to the uses of man, dwelling upon its desolate- 

 ness and sterility in most emphatic terms." 



Let us turn once more to some of the historic facts connected with the dis- 

 boscation of a country and the alleged meteorological effects of thus disrobing a 

 region of its timber. 



M. Becquerel, of the French Institute, an unquestionable authority, says: 

 "The effects of disboscation on the sources and quantities of living water which 

 irrigate a country are of the most important consideration, and hence require 

 serious attention. The difficulty in verifying these effects is the greater, inasmuch 

 as it is impossible to say a priori, whether a forest or portion of a forest, destined 

 to be cleared away, contributes to supply such or such a source, such or such a 

 river. Springs are owing in general to the infiltration of rain-water in a previous 

 formation, through which this water sinks until it meets with an impervious stra- 



t Reconnoissances in New Mexico and California, 1846. * F. V. Hayden, U. S. Geologist, Report of 1870. 



* 



