88 SURVEY UNDER OFFICE OF WORKS CHAP, in 



thanks for one of the very best papers I ever read, believe me, 

 very truly yours, CHA. LYELL. 



ii HARLEY STREET, 8M October 1846. 



When I inferred that the denuded dome of the Wealden had 

 lost some 2000 [feet] and upwards of thickness of strata removed, 

 I also assumed that it was shaved off by the ocean when rising, and 

 had never constituted hills 4000 to 5000 feet high. So I think of 

 your denuded tracts. They were never suffered to attain an Alpine 

 elevation. 



To the foregoing letter Ramsay sent the following 



reply : 



BALA, \^th October 1846. 



MY DEAR SIR We have been so busy in the field 

 (Sir Henry only having left us to-day) that I have not 

 previously had time fully to consider your letter. 



In the beginning you refer to what I have written 

 about the Mendip Hills as a type of certain denudations 

 in the following words : First, the disturbance of the 

 beds of the Palaeozoic rocks ; second, the denudation 

 of several thousand feet of the same beds. Yet it seems 

 to me, on reading other passages of your paper, that 

 you cannot mean this ; for your ideas of denudation 

 acting contemporaneously with subterranean move 

 ments, whether of upheaval or depression, agree with 

 those which I published in 1831 in my Principles; the 

 gradual action of the ocean acting concurrently with 

 movements of the land, etc. etc. Now, as you adopt 

 these views, I cannot comprehend how you can dis 

 pense with indefinite geological time for your denuda 

 tion in the case I allude to, etc. etc. 



In this argument I think you have partially mis 

 understood me, partly because, in my anxiety to be 

 concise, I have not sufficiently entered into detail ; and 

 again perhaps from not bearing in mind that my 

 reasonings are not intended for universal generalisa- 



