DEVELOPMENT OF THE EARTH'S SURFACE 



that is, sinking of the ocean bottoms not only caused 

 water to accumulate there, but by straightening the curve 

 of the earth-crust pressed against the continents on each 

 side, pushing up their edges and crumpling them into 

 coast ranges, and thus determining the typical form of 

 continents, viz., that of interior continental basins with 

 coast-range rims. He worked out the whole theory of 

 mountain-range formation from this point of view ; and 

 if American geologists have been especially active and 

 successful in developing the theory of the formation of 

 mountain ranges, it is because Dana led the way. It is 

 easy to see, therefore, why he was so intensely interested 

 in the sinking of the mid-Pacific bottom, as indicated by 

 the coral reefs. This sinking had its correlative in the 

 elevation of the western side of the American continents, 

 north and south, and especially in the ridging up of their 

 margins into the great mountains on that side. 



In the above statements (i and 2) I believe I have 

 given substantially Dana's views, although perhaps modi- 

 fied a little by suggestions of my own mind ; but we go 

 on. 



3. It is evident that from this general point of view 

 the same causes which originated continents and ocean 

 basins, by continuing to act, would increase the size and 

 height of the former and the depth of the latter, and 

 therefore the places of continents and oceans must have 

 remained substantially the same. Dana, therefore, was 

 the originator of the idea of the substantial permanence 

 of the places of these greatest inequalities of the earth's 

 surface. The previous school, which may be called the 

 school of Lyell, took an entirely different view. The 

 gradual evolution of the earth as a unit and of the organic 

 kingdom as a whole was imperfectly, if at all, conceived 

 by the Lyellian school, for Darwin was not yet. Fossils 

 were ' ' medals of creation ' ' means of determining strata ; 

 the oscillations of the earth's crust were irregular and 

 17 257 



