18401881] EARTH-MOVEMENTS 135 



been not heated, then of course there would be a great differ- Letter 488 

 ence whether the rivet-holes entered the water high or low, 

 so that there was greater or less pressure of gravity. How to 

 close my volcanic rivet-holes I don't know. 



I do not know whether you will understand what I am 

 driving at, and it will not signify much whether you do 

 or not. I remember in old days (I may mention the subject 

 as we are on it) often wishing I could get you to look 

 at continental elevations as the phenomenon, and volcanic 

 outbursts and tilting up of mountain chains as connected, but 

 quite secondary, phenomena. I became deeply impressed 

 with the truth of this view in S. America, and I do not think 

 you hold it, or if so make it clear : the same explanation, 

 whatever it may be, which will account for the whole coast of 

 Chili rising, will and must apply to the volcanic action of the 

 Cordillera, though modified no doubt by the liquefied rock 

 coming to the surface and reaching water, and so [being] 

 rendered explosive. To me it appears that this ought to be 

 borne in mind in your present subject of discussion. I have 

 written at too great length ; and have amused myself if I 

 have done you no good so farewell. 



To C. Lyell. Letter 489 



Down, July 5th [1856]. 



I am very much obliged for your long letter, which has 

 interested me much ; but before coming to the volcanic 

 cosmogony I must say that I cannot gather your verdict as 

 judge and jury (and not as advocate) on the continental 

 extensions of late authors, 1 which I must grapple with, and 

 which as yet strikes me as quite unphilosophical, inasmuch as 

 such extensions must be applied to every oceanic island, if to 

 any one, as to Madeira ; and this I cannot admit, seeing that 

 the skeletons, at least, of our continents are ancient, arid 

 seeing the geological nature of the oceanic islands themselves. 

 Do aid me with your judgment : if I could honestly admit 

 these great [extensions], they would do me good service. 



With respect to active volcanic areas being rising areas, 

 which looks so pretty on the coral maps, I have formerly felt 

 " uncomfortable " on exactly the same grounds with you, 



1 See Life and Letters, II., p. 74 ; Letter to Lyell, June 25th, 1856 : 

 also letters in the sections of the present work devoted to Evolution and 

 Geographical Distribution. 



