EARTH SCIENCES IN NINETEENTH CENTURY 679 



Nowhere is the orderhness of geological changes better attested 

 than in the forms of ridge and valley seen today in various examples, 

 young and old, of wasting mountain ranges themselves, and in the 

 systematic adjustment that is attained by the drainage lines with 

 respect to the structures on which they work. Here, indeed, is 

 cumulative testimony for uniformitarianism ; for nothing but the 

 long persistence of ordinary processes can account for these marvelous 

 commonplaces. So wonderful is the organization of these land and 

 water forms in physiographic maturity and old age, so perfect is their' 

 systematic interdependence, that one must grudge the monopoly of 

 the term "organism" for plants and animals, to the exclusion of well- 

 organized forms of land and water. By good fortune, "evolution" is 

 a term of broader meaning; we may share its use with the biologists; 

 and we are glad to replace the violent revolutions of our predecessors 

 with the quiet processes that evolution suggests. 



It is the assurance of orderly continuity that binds the past to the 

 present in the endless sequence of events, and shows us that geography 

 is only today's issue of a perpetual journal, whose complete files 

 constitute geology. He must be a geographer of the old school who 

 would now maintain that his subject, in content and treatment, 

 really belongs outside of the geological curriculum. It may, on the 

 other hand, be justly contended that the whole of earth science is 

 made up of geographic sheets— until today, paleogeographic, if you 

 like — all horizontally stratified with respect to the vertical time line. 

 In every sheet we find news of the relation of earth and life, of environ- 

 ing control and organic response, of physiography and ontography. 

 Every httle item of news here pubhshed is worthy of close attention. 

 The reader may examine all sorts of items on a single sheet and 

 consider their temporary, areal distribution, and so acquire the geo- 

 graphic view; or he may examine the changing items of certain areas, 

 following their chronological sequence in successive sheets, and so 

 acquire the geological view; but it would be unfortunate if, in so 

 doing, he did not perceive the interchangeable relations of these two 

 methods of investigation. 



There is, to my understanding, a great profit that has been gained 

 from conceiving the whole body of our science in the way thus sug- 

 gested. Branches such as meteorology and terrestrial magnetism, 



