10 PHYSICAL GEOGllAPnY OF THE SEA, AND ITS METEOROLOGY. 



tlio vast amount of vapour tlicro drained off, wliilc other whirl- 

 pools and currents, such as the gigantic Gulf Stream, come 

 to jierform their part in the same stupendous drama. The waters 

 of this vast ocean river are, to the north of the- tropic, greatly 

 warmer than those around; the climate of every country it 

 approaches is improved by it, and the Laplander is enabled by 

 its means to live and cultivate his barley in a latitude which, 

 everywhere else throughout the world, is condemned to per- 

 petual sterility. There are other laws which the great sea 

 obeys which peculiarly adapt it as the vehicle of interchange 

 of heat and cold betwixt those regions where either exists in 

 excess. 



31. Iceb&rgs. — " In obedience to these laws water warmer than 

 ice attacks the basis and saps the foundations of the icebergs — 

 themselves gigantic glaciers, which have fallen from the moun- 

 tains into the sea, or which have grown to their present size 

 in the shelter of bays and estuaries, and by accumulations from 

 above. Once forced from their anchorage, the first storm that 

 arises drifts them to sea, where the beautiful law which renders 

 ice lighter than the warmest water, enables it to float, and drifts 

 southward a vast magazine of cold to cool the tepid water which 

 bears it along — the evaporation at the equator causing a deficit, 

 the melting and accumulation of the ice in the frigid zone giving 

 rise to an excess of accumulation, which tends, along with the 

 action of the air and other causes, to institute and maintain the 

 transporting current. These stupendous masses, which have been 

 seen at sea in the form of church spires, and gothic towers, and 

 minarets, rising to the height of from 300 to COO feet, and ex- 

 tending over an area of not less than six square miles, the masses 

 above water being only one-tenth of the whole, are often to be 

 found within the tropics. 



32. Mountain ranges. — "But these, though among the most 

 regular and magnificent, are but a small number of the con- 

 trivances by which the vast and beneficent ends of nature are 

 brought about. Ascent from the surface of the earth produces 

 the same change, in point of climate, as an approach to tlie poles ; 

 even under the ton-id zone mountains reach the line of perpetual 

 congelation at nearly a third less altitude than the extreme 

 elevation which they sometimes attain. At the poles snow is 

 perpetual on the ground, and at the different intervening lati- 

 tudes reaches some intermediate point of congelation betwixt one 



