DESEET OF ICE. 35 



rivers are only frozen to a depth of eight or ten feet. As soon 

 as the first warm days of spring appear, the thawed surface- 

 waters gather under the ice-cover, raise it with irresistible force, 

 and, bursting the bonds with which it enthralled the current, 

 bear its fragments along to the river's mouth, where they are 

 soon dispersed over the ocean. 



In a short time all is life and activity in the liberated waters. 

 Millions upon millions of worms, mollusks, insects, and reptiles 

 awaken from their winter lethargy, the sweet-water fishes emerge 

 from the mud in which they lay plunged in torpor, and from the 

 sea other legions come pouring in to trust their eggs to the warmer 

 stream. All this would not have been possible, all this activity 

 and enjoyment could never have existed, if the weight of ice had 

 been superior to that of water. 



Then also the Arctic and Antarctic seas would have been 

 converted into solid masses, which the sun would have been as 

 incapable to melt as he is unable completely to liquefy the 

 glaciers of the Alps. In consequence of the cold radiating from 

 their surface, these vast oceans of ice would have encroached 

 upon a great part of the temperate zones, and, by preventing 

 that beneficial system of maritime currents through which a 

 considerable portion of tropical heat is transported into the 

 higher latitudes, would have still further contributed to extend 

 the domains of perpetual winter. And, finally, the exhalations 

 of the tropical ocean which now regularly return to its bosom, 

 would have accumulated in such vast masses in the colder 

 regions, that in all probability the fountains of the sea would 

 have been finally exhausted of the greater part of their waters, 

 and the dry land converted into an arid waste. So much is 

 certain, that at best but a small portion of the globe would have 

 been a fit habitation for man, who, thus confined to a narrow 

 space and plunged in barbarism, could never have fulfilled the 

 higher objects of his existence. 



Thus the physical laws on which the circulation and the 

 migrations of the waters over the surface of the globe depend, 

 have all been made to harmonise with the wants of animal life, 

 or the higher requirements of the human race ; thus they all 

 contribute to extend the domains of organic nature. 



The meteorological phenomena are but exceptionally or locally 



destructive ; their general effect is constantly beneficial. Vast 



D 2 



