26 AUTOBIOGRAPHY. [ch. ii. 



gor, and Capel Curig. This tour was of decided use in 

 teaching me a little how to make out the geology of a coun- 

 try. Sedgwick often sent me on a line parallel to his, tell- 

 ing me to bring back specimens of the rocks and to mark 

 the stratification on a map. I have little doubt that he did 

 this for my good, as I was too ignorant to have aided him. 

 On this tour I had a striking instance how easy it is to over- 

 look phenomena, however conspicuous, before they have been 

 observed by any one. We spent many hours in Cwm Idwal, 

 examining all the rocks with extreme care, as Sedgwick was 

 anxious to find fossils in them ; but neither of us saw a trace 

 of the wonderful glacial phenomena all around us ; we did 

 not notice the plainly scored rocks, the perched boulders, 

 the lateral and terminal moraines. Yet these phenomena 

 are so conspicuous that, as I declared in a paper published 

 many years afterwards in the Philosophical Magazine* a 

 house burnt down by fire did not tell its story more plainly 

 than did this valley. If it had still been filled by a glacier, 

 the phenomena would have been less distinct than they 

 now are. 



At Capel Curig I left Sedgwick and went in a straight 

 line by compass and map across the mountains to Bar- 

 mouth, never following any track unless it coincided with 

 my course. I thus came on some strange wild places, and 

 enjoyed much this manner of travelling. I visited Bar- 

 mouth to see some Cambridge friends who were reading 

 there, and thence returned to Shrewsbury and to Maer for 

 shooting; for at that time I should have thought myself 

 mad to give up the first days of partridge-shooting for ge- 

 ology or any other science. 



Voyage of the ' Beagle ' : from December 27, 1831, to 



October 2, 1836. 



On returning home from my short geological tour in 

 North Wales, I found a letter from Henslow, informing me 

 that Captain Fitz-Roy was willing to give up part of his 

 own cabin to any young man who would volunteer to go 

 with him without pay as naturalist to the Voyage of the 

 Beagle. I have given, as I believe, in my MS. Journal an 

 account of all the circumstances which then occurred ; I 

 will here only say that I was instantly eager to accept the 



* Philosophical Magazine, 1842. 



