A HISTORY OF SCIENCE 



pold von Buch, who contended that the mountains had 

 sprung up like veritable jacks-in-the-box. Von Buch, 

 whom his friend and fellow-pupil Von Humboldt con- 

 sidered the foremost geologist of the time, died in 

 1853, still firm in his early faith that the erratic bowl- 

 ders found high on the Jura had been hurled there, like 

 cannon-balls, across the valley of Geneva by the sudden 

 upheaval of a neighboring mountain- range. 



AGASSIZ AND THE GLACIAL THEORY 



The bowlders whose presence on the crags of the 

 Jura the old German accounted for in a manner so 

 theatrical had long been a source of contention among 

 geologists. They are found not merely on the Jura, but 

 on numberless other mountains in all north- temperate 

 latitudes, and often far out in the open country, as 

 many a farmer who has broken his plough against them 

 might testify. The early geologists accounted for 

 them, as for nearly everything else, with their suppo- 

 sititious Deluge. Brongniart and Cuvier and Buck- 

 land and their contemporaries appeared to have no 

 difficulty in conceiving that masses of granite weigh- 

 ing hundreds of tons had been swept by this current 

 scores or hundreds of miles from their source. But, 

 of course, the uniformitarian faith permitted no such 

 explanation, nor could it countenance the projection 

 idea; so Lyell was bound to find some other means of 

 transportation for the puzzling erratics. 



The only available medium was ice, but, fortunately, 

 this one seemed quite sufficient. Icebergs, said Lyell, 

 are observed to carry all manner of debris, and deposit 

 it in the sea-bottoms. Present land surfaces have often 



144 



