THE CENTURY'S PROGRESS IN GEOLOGY 



They are found not merely on the Jura, but on number- 

 less 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 supposititious Deluge. Brong- 



THE RESULTS OF EROSION BY WIND 



niartand Cuvierand Buckland and their contemporaries 

 appeared to have no difficulty in conceiving that masses 

 of granite weighing hundreds of tons had been swept 

 by this current scores or hundreds of miles from their 

 source. But of course the uniformitarian faith permit- 

 ted 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 



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