33^ HEROES OF SCIENCE. 



distance, could have been produced by the sea, but 

 not finding any remains of marine animals, or 

 evidence of such action as the ice would produce in 

 rounding and watervvearing stone, he began to 

 examine the influence of glaciers in wearing rocks 

 and carrying the rubbish down with them. He was 

 of course aware that there had been an age of cold 

 in Switzerland, corresponding to the glacial epoch 

 of Europe to the north, and he was therefore 

 prepared to find some proofs of the former great 

 extension of glaciers beyond their present limits. 

 He was disposed to believe that the Alps were 

 higher than they now are in that age of cold. In 

 order to account for the former action of ice and the 

 production of huge moraines, in comparison with 

 which those now found at the glacier foot are 

 pigmies, Lyell wrote : " In the glacial period, when 

 the weight of ice was enormously greater, when in 

 the region of the Alps there was so little melting, 

 when glaciers at present only ten, fifteen, and 

 twenty miles long, and from three hundred to one 

 thousand feet deep, were fifty to one hundred, and 

 even one hundred and fifty miles long, and four 

 thousand feet deep (and if there is any truth at all 

 in the generally received theory of the old Swiss 

 glaciers, such must have been their gigantic dimen- 

 sions), one may readily grant that the pressure and 

 friction were so much in excess of what we now see 

 as to explain the contrast between the ice work 

 done in the olden times, and that accomplished in 

 our own days, to say nothing of the probably dis- 



