594 



SCIENCE. 



[N. S. Vol. II. No. 44. 



pages, illustrated by over 300 pictures, besides 

 a number of folding panoramas, not paged. It 

 contains fifteen chajjters, of which the first four 

 ('The Valley of the Colorado,' 'Mesas and 

 Buttes,' ' Mountains and Plateaus,' 'Cliffs and 

 Terraces') constitute an introduction in the 

 form of a general description of the region 

 traversed by Colorado River. Seven chapters 

 are devoted to the itinerary of the memorable 

 exploration of the canyon in 1869 ; four chap- 

 ters contain the itinerary of the supplementary 

 explorations in 1870 ; and the final chapter is a 

 summary description of the canyon. The in- 

 troductory and concluding chapters are based 

 on present knoAvledge of the geography, geol- 

 ogy, meteorology and ethnology of the region ; 

 the itineraries are also brought up to date, 

 where there is need, by explanatory paragraphs, 

 and while they are in part reprinted from offi- 

 cial and other reports they are enriched by ex- 

 tracts from the original journals not hitherto 

 published. 



The vallej' of the Colorado extends from near 

 Yellowstone Park to the Gulf of California, and 

 from the deserts of the Great Basin to the Rocky 

 Mountain front ; it is one of the five principal 

 river basins of the United States and bordering 

 territory. It comprises the low-lying desert 

 plains of the far Southwest, the western slope 

 of the main continental divide and the rugged 

 ranges beyond, together with the vast system of 

 plateaus and mesas lying between mountain and 

 desert. In much of this region the ' great stone 

 book ' in which the history of the earth is re- 

 corded lies open, and the broad expanse of its 

 rocky pages is the paradise of the geologist ; 

 throughout much of the region, too, geologic 

 process is so rapid as to catch the eye of the 

 wayfarer and impress the lessons of dynamic 

 geology. Here it was that Powell perceived 

 the signigcance of the baselevel, and thereby 

 planted the germ of geomorjjhy — the ' New Ge- 

 ology,' by which the field of the science has 

 been doubled ; here, too, he discovered that the 

 high mountain is the young mountain, and that 

 the crust of the earth is responsive to the trans- 

 fer of load ; here, also, other comprehensive 

 generalizations were made whereby the science 

 of the earth was stimulated and raised to a 

 higher plane. Other American geologists, as 



well as Powell, have gained inspiration in this 

 fortunately conditioned field. Gilbert's con- 

 cepts became masterly as he traversed the rocky 

 tables and rested in the shadow of the cliffs of 

 the Colorado country, and his memoir on the 

 Henry mountain is still the model geologic 

 monograph; Button's magnificent generaliza- 

 tions, of which some are even yet hardly grasped 

 by his contemporaries and followers, were for- 

 mulated in the same inspiring field ; there it 

 was, too, that Holmes developed the genius un- 

 der which art and earth-science were joined, 

 and his portraiture of plateau and mesa and of 

 clitr and canyon (reproduced in part in the 

 present work) remains a model ; it was in the 

 depths of the same canyon that Walcott coordi- 

 nated paleontology and stratigraphy more per- 

 fectly than before, and shaped the ideas now 

 bearing fruit in the policy of the federal survey. 

 Through these students and others the in- 

 fluence of the field was spread over the country 

 and world. Thus the valley of the Colorado is 

 classic ground for the geologist ; and with re- 

 spect to physical geology at least, no other part 

 of the earth has contributed so much to the 

 body of the science. 



This is the region which is appreciatively yet 

 succinctly described by its original explorer 

 and most philosophic student in the introduc- 

 tory chapters of his book. The description is at 

 the same time sufficiently popular to be followed 

 by the layman, and sufficiently profound to set 

 forth the i^rinciples of the science in consider- 

 able fullness ; and the chapters accordingly 

 serve the double purpose of depicting the salient 

 features of an interesting region in attractive 

 word painting, and of popularizing newly es- 

 tablished principles. Perhaps this part of the 

 book might have been made more useful to 

 students by pointing out the extent to which 

 the principles weve developed in the field de- 

 scribed ; but this is only one of the examples, 

 in which the book abouuds, of the elevation of 

 well considered facts and principles above the 

 ego. 



The valley of the Colorado is hardly less 

 notable in its aboriginal population than in its 

 geologic features. Within its confines the primi- 

 tive Shoshoni, embracing the 'Diggers' of early 

 explorers, the warlike Apache, the peaceful 



