29G Prof. A. C. Ramsay on the Erosion 



sketch, and in all probability will remain so till their governments 

 authorize more general and uniform painstaking surveys. When 

 this is done, and when all the faults and curvatures possible are 

 actually laid down, and when geological sections on a true scale 

 have been run across the Alps, it will then be possible to reason 

 with precision on the denudation of the mountains; and it 

 will be found (what is well known now) that before the present 

 surface of the valleys saw the light, vast piles of strata, as in 

 Wales, have been removed by denudation, and the valleys were 

 formed long after the latest important disturbances of the strata 

 took place. - 



And now to prove that 1 also respect authority, let me quote 

 from books of immortal repute; and surely those who reverence 

 authority most, will not disdain that of Hutton and Playfair. 

 What say the father of physical geology and his great disciple ? 

 "If," says Hutton, reasoning on this subject, "the valley was 

 made for the rain by any other natural cause, either we should 

 tell by what means this work had been performed, or all reason- 

 ing on the subject is at end, and fancy substituted in its place. 

 If, again, the river be considered as the means employed by 

 nature in making this valley, then all the solid parts between 

 the bounding mountains must have been removed." Again, 

 reasoning on the weathering and erosion that originated the py- 

 ramids on and around Mont Blanc, he observes, " It is true, 

 indeed, that geologists have everywhere imagined to themselves 

 great events, or powerful causes, by which these changes in the 

 earth should be brought about in a short space of time ; but they 

 are under a double deception ; first, with regard to time, which 

 is unlimited*, whereas they want to explain appearances by a cause 

 acting in a limited time; secondly, with regard to operation, 

 their supposition of a great debacle is altogether incompetent for 

 the end required." Again, arguing on the approximately hori- 

 zontal gneissic strata of the neighbourhood of Monte Rosa, he 

 shows that the great isolated peaks have been separated by " the 

 greatest degradation, in being wasted by the hand of time. . . . 

 Here," he says, " is nothing but a truth that may almost every- 

 where be perceived " if we had only faculties to perceive it. 



Again, reasoning on strata that correspond on opposite sides 

 of valleys, Playfair, in the Huttonian Illustrations, says, " there is 

 no man, however little addicted to geological speculations, who 

 does not immediately acknowledge that the mountain was once 

 continued quite across the place in which the river now flows ; 

 andjif he ventures to reason concerning the cause of so wonder- 

 ful a change, he ascribes it [in the modern fashion] to some 

 great convulsion of nature, which has torn the mountain asunder 

 * In the original, "limited.". This is an evident misprint. 



