Disturbance of the Crust of the Earth, " 



will, however, render it impossible that the climate of the tem- 

 perate zone should become what it was formerly. At any 

 rate, the exposure of so greatly extended a surface to the 

 agency of the atmosphere will very much retard the restora- 

 tion, and radiation must also have increased with the extent 

 of surface. Hence it is probable that we cannot look for any 

 great improvement of climate, unless atmospheric influence 

 shall, by some great change, be reduced. 



If I have not erred in the assumptions I have made, we 

 have thus a catastrophe sufficiently sudden to have enveloped 

 living creatures in a material which would preserve their 

 bodies for- ages if floated to the Arctic Regions ; or leave their 

 remains in a region colder now than it was when they lived. 

 Thus may the valley of the Rhone have been filled with ice, 

 and boulders transported from the Alps to the Jura, and 

 centres of dispersion have been formed. We may find also the 

 origin of the older diluvium, while preparation was made for 

 subsequent floods that have left various and, in some in- 

 stances, apparently anomalous traces behind them. Agassiz 

 may also be furnished with means to support his original in- 

 ference, with this only variation, that he supposed the ice to 

 have been formed before the mountains were raised, while I 

 have supposed them first raised and then covered with ice. 



The Society will now have perceived that I have modified 

 my opinions respecting the glacier theory considerably. But 

 if I had not found what I regard at present as a somewhat 

 plausible hypothesis respecting the means by which an icy co- 

 vering would be produced geologically, I should still have been 

 in greater doubt than I am in now. While, however, I admit 

 more fully the operations of ice, I do not give up the notion 

 that the phenomena of the surface require for their explana- 

 tion the joint action of fluid and of solid water. 



