Work on Glacial Questions 365 



in the question ever afterwards, and he says "my error has been 

 a good lesson to me never to trust in science to the principle of 

 exclusion 1 ." 



Although Darwin had not realised in 18.38 that large parts of the 

 British Islands had been occupied by great glaciers, he had by no 

 means failed while in South America to recognise the importance of 

 ice-action. His observations, as recorded in his Journal, on glaciers 

 coming down to the sea-level, on the west coast of South America, 

 in a latitude corresponding to a much lower one than that of the 

 British Islands, profoundly interested geologists ; and the same work 

 contains many valuable notes on the boulders and unstratified beds in 

 South America in which they were included. 



But in 1840 Agassiz read his startling paper on the evidence of 

 the former existence of glaciers in the British Islands, and this was 

 followed by Buckland's memoir on the same subject. On April 14, 

 1841, Darwin contributed to the Geological Society his important 

 paper On the Distribution of Erratic Boulders and the Contem- 

 poraneous Unstratified Deposits of South America, a paper full of 

 suggestiveness for those studying the glacial deposits of this country. 

 It was published in the Transactions in 1842. 



The description of traces of glacial action in North Wales, by 

 Buckland, appears to have greatly excited the interest of Darwin. 

 With Sedgwick he had, in 1831, worked at the stratigraphy of that 

 district, but neither of them had noticed the very interesting surface 

 features 2 . Darwin was able to make a journey to North Wales in 

 June, 1842 (alas! it was his last effort in field-geology) and as a result 

 he published his most able and convincing paper on the subject in 

 the September number of the Philosophical Magazine for 1842. 

 Thus the mystery of the bell-stone was at last solved and Darwin, 

 writing many years afterwards, said " I felt the keenest delight when 

 I first read of the action of icebergs in transporting boulders, and 

 I gloried in the progress of Geology 3 ." To the Geographical Journal 

 he had sent in 1839 a note "On a Rock seen on an Iceberg in 

 16° S. Latitude." For the subject of ice-action, indeed, Darwin 

 retained the greatest interest to the end of his life 4 . 



In 1846, Darwin read two papers to the Geological Society 

 On the dust which falls on vessels in the Atlantic, and On the 

 Geology of the Falkland Islands ; in 1848 he contributed a note 

 on the transport of boulders from lower to higher levels ; and in 

 1862 another note on the thickness of the Pampean formation, as 

 shown by recent borings at Buenos Ayres. An account of the 

 British Fossil Lepadidae read in 1850, was withdrawn by him. 



i M. L. n. pp. 171—93. 8 L. L. i. p. 58. 



3 L. L. i. p. 41. * M. L. n. pp. 148—71. 



