Round about Asheville. 297 



rapidly become canons, and the revived phase will retreat up 

 stream in the same manner that the canons of youth extended 

 back into the first uplifted mass. If the area of soft rocks be 

 bounded by a considerable mass of very hard rocks, it is con- 

 ceivable that a second phase of age, a base level, might creep 

 over the valley while yet the summits of the first old age re- 

 mained unattacked, and should perchance revival succeed revival 

 the record of the last uplift might be read in sharp cut channels 

 of the great rivers, while the forms of each preceding phase led 

 like steps to the still surviving domes of that earliest old age. 



Is there aught in these speculations to fit our facts? 1 think 

 there is. We have seen that our mountains and valleys are the 

 result of differential degradation, and that this is not only broadly 

 true but true in detail also. This is evidence that streams have 

 been long at work adjusting their channels, they have passed 

 through the period of maturity. 



We have climbed to the summits of the Unakas and found 

 them composed of rocks as hard as those from which the pinnacle 

 of the Matterhorn is chiseled ; but we see them gently sloping, as. 

 a plain. These summits are very, very old. 



We have recognized that dissected plain, the level of the 

 Asheville amphitheatre, now 2,400 feet above the sea ; it was a, 

 surface produced by subaerial erosion, and as such it is evidence 

 of the fact that the French Broad River, and such of its tributa- 

 ries as drain this area, at one time completed their work upon it,, 

 reached a base level. That they should have accomplished thi& 

 the level of discharge of the sculpturing streams must have been 

 constant during a long period, a condition which implies either 

 that the fall from the Asheville plain to the ocean was then much, 

 less than it now is, or that through local causes the French Broad, 

 was held by a natural dam, where it cuts the Unaka chain. 



If we should find that other rivers of this region have carved, 

 the forms of age upon the surfaces of their intermontane valleys, 

 and there is now some evidence of this kind at hand, then we 

 must appeal to the moi'e general cause of base-levelling and 

 accept the conclusion that the land stood lower in relation to the 

 ocean than it now does. Furthermore, we have traversed the 

 ravines which the streams have cut in this ancient plain and we 

 may note on the accompanying atlas sheet that the branches ex- 

 tend back into every part of -it ; the ravines themselves prove 

 that the level of discharge has been lowered, the streams have 



