MOTION OF GLAC1EKS. 7ft 



Although a river generally has its source in mountainous 

 regions, it must be remembered that all the waters that descend 

 upon the territory of which it forms the lowest level, gradually 

 find their way into its current. Thus, the monarch of all 

 streams, the Amazon Eiver, is the natural drain of a territory 

 thirty times larger than England. Thousands of rivulets and 

 brooks, fed by the waters which descend from the slopes of 

 thousands of glens and valleys, or filter through the vast forest- 

 plains that rise but a few feet above their surface, all contribute 

 to swell the majesty of its current. Its sources are in reality 

 wherever, on that vast extent of land, water descends and drains 

 into any one of its innumerable affluents. When we hear that 

 on an average the river of the Amazons alone restores every 

 minute half a million of tons of water to the ocean, and then 

 consider the countless number of streams all alike active, that 

 are scattered over the globe, we may form a faint idea of the 

 vast quantity of vapours which are constantly rising from the 

 deep, and of the magnitude of these silent operations of nature. 

 Yet such is the immensity of ocean, that supposing all the waters 

 it constantly loses, never to return again into its bosom, it 

 would require thousands of years of evaporation to exhaust the 

 immensity of its reservoirs! 



It might be supposed that the waters which congeal on the 

 sides of mountains covered with perennial snow, or fill 

 Alpine valleys in the form of glaciers, were eternally fixed on 

 earth — but there also we are deceived by delusive appearances 

 of immobility. Every year the glacier slowly but restlessly 

 makes a step forwards into the valley, and while its lower end 

 dissolves, new supplies of snow constantly feed it from above. 

 It has been calculated by Agassiz that the ice masses of the 

 Aar glacier require 133 years to perform their descent from its 

 summit to its inferior extremity — a distance of ten miles — so 

 that their sojourn in that chilled valley far surpasses that of the 

 oldest patriarch of the mountains. How great must be their 

 delight when they at last are liberated from the spell which so 

 long enchained them, and freely bound along on their way to 

 Ocean! How they must shudder at the idea of once more 

 returning to their desolate prison, and long for the perpetual 

 warmth of spicy groves and tropical gardens ! 



In the colder regions of the earth, in Greenland or Spitz- 



