Page:Physical Geography of the Sea and its Meteorology.djvu/36

10 the vast amount of vapour there drained off, while other whirlpools and currents, such as the gigantic Gulf Stream, come to preform 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 perpetual 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. Icebergs.—"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 mountains 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 600 feet, and extending 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 contrivances 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 the poles; even under the torrid 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 latitudes reaches some intermediate point of congelation betwixt one