326 LIFE AT DOWN. ALTAT. 33-45. 



" Full of detailed observations, this work still remains the 

 best authority on the general geological structure of most of 

 the regions it describes. At the time it was written the 

 'crater of elevation theory,' though opposed by Constant 

 Prevost, Scrope, and Lyell, was generally accepted, at least on 

 the Continent. Darwin, however, could not receive it as a valid 

 explanation of the facts ; and though he did not share the view 

 of its chief opponents, but ventured to propose a hypothesis 

 of his own, the observations impartially made and described 

 by him in this volume must be regarded as having contributed 

 towards the final solution of the difficulty." Professor Geikie 

 continues (p. 21) : " He is one of the earliest writers to recog- 

 nize the magnitude of the denudation to which even recent 

 geological accumulations have been subjected. One of the 

 most impressive lessons to be learnt from his account of 

 ' Volcanic Islands ' is the prodigious extent to which they 

 have been denuded. . . . He was disposed to attribute more 

 of this work to the sea than most geologists would now 

 admit ; but he lived himself to modify his original views, 

 and on this subject his latest utterances are quite abreast of 

 the time." 



An extract from a letter of my father's to Lyell shows his 

 estimate of his own work. " You have pleased me much by 

 saying that you intend looking through my * Volcanic Islands ' : 

 it cost me eighteen months ! ! ! and I have heard of very few 

 who have read it. Now I shall feel, whatever little (and little 

 it is) there is confirmatory of old work, or new, will work its 

 effect and not be lost" 



The third of his geological books, ' Geological Observations 

 on South America,' may be mentioned here, although it was 

 not published until 1846. " In this work the author embodied 

 all the materials collected by him for the illustration of South 

 American Geology, save some which had been published 

 elsewhere. One of the most important features of the book 

 was the evidence which it brought forward to prove the slow 



