32 AUTOBIOGRAPHY. [Ch. IL 



From my marriage, January 29, 1839, and residence in Upper 

 Gower Street, to our leaving London and settling at Down, 

 September 14, 1842. 



[After speaking of his happy married life, and of his 

 children, he continues :] 



During the three years and eight months whilst we resided 

 in London, I did less scientific work, though I worked as hard 

 as I possibly could, than during any other equal length of time 

 in my life. This was owing to frequently recurring un- 

 wellness, and to one long and serious illness. The greater 

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

 work on Coral Beefs, which I had begun before my mar 

 and of which the last proof-sheet was corrected on May 6th, 

 1842. This book, though a small one, cost mo twenty months 

 of hard work, as I had to read every work on the islands of 

 the Pacific and to consult many chaits. 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 inter- 

 mittent elevation of the land, together with denudation 

 and the deposition of sediment. This necessarily led mo 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. { I 

 also continued to superintend the publication of the Zoology of 

 the Voyage of the Beagle. Nor did I ever intermit collecting 

 facts bearing on the origin of species ; and I could sometimes 

 do this when I could do nothing else from illness. 



In the summer of 1842 I was stronger than I had been for 

 some time, and took a little tour by myself in North Wales, 

 for the sake of observing the effects of the old glaciers which 



* Geolog. Soc. Proc. iii. 1842. t Gtolog. Trans, v. 1840. 



X Geclog. Soc, Proc, ii. 1838. 



