70 AUTOBIOGRAPHY. 



time, when I could do anything, was devoted to my 

 work on ' Coral Reefs/ which I had begun before 

 my marriage, and of which the last proof-sheet was 

 corrected on May 6th, 1842. This book, though a 

 small one, cost me twenty months of hard work, as 

 I had to read every work on the islands of the Pacific 

 and to consult many charts. It was thought highly of 

 by scientific men, and the theory therein given is, 

 I think, now well established. 



No other work of mine was begun in so deductive 

 a spirit as this, for the whole theory was thought out 

 on the west coast of South America, before I had seen 

 a true coral reef. I had therefore only to verify and 

 extend my views by a careful examination of living 

 reefs. But it should be observed that I had during 

 the two previous years been incessantly attending to 

 the effects on the shores of South America of the 

 intermittent elevation of the land, together with 

 denudation and the deposition of sediment. This 

 necessarily led me to reflect much on the effects of 

 subsidence, and it was easy to replace in imagination 

 the continued deposition of sediment by the upward 

 growth of corals. To do this was to form my theory 

 of the formation of barrier-reefs and atolls. 



Besides my work on coral-reefs, during my residence 

 in London, I read before the Geological Society 

 papers on the Erratic Boulders of South America,* on 

 Earthquakes,! and on the Formation by the Agency of 

 Earth-worms of Mould.J I also continued to superin- 



* l Geolog. Soc. Proc.' iii. 1842. f Geolog. Trans.' v. 1840. 



% ' Geolog. Soc. Proc.' ii. 1838. 



