THE SEA AND THE ATMOSPHERE . 9 



thus established, constantly carrying away the heat from the tomcl 

 toward the icy regions, and, there becoming cold by contact with 

 the ice, they carry back their gelid freight to refresh the torrid zone. 



29. "Did the earth, as was long beheved, stand still while the 

 Of iiiiiraai rotation, gun circlcd aroimd it, we should have had directly 

 from north and south two sets of meridional currents blowing at 

 the sm-face of the earth toward the equator ; in the upper regions 

 we should have had them flowing back again to the place whence 

 they came. On the other hand, were the heating and cooling in- 

 fluences just referred to to cease, and the earth to fail in impressing 

 its own motion on the atmosphere, we should have a fmious hurri- 

 cano rushing round the globe at the rate of 1000 miles an hour — 

 tornadoes of ten times the speed of the most violent now knowTi to 

 us, sweeping everything before them. A combination of the two 

 iniluences, modified by the friction of the earth, which tends to draw 

 the au' after it, gives us the trade-winds, wdiich, at the speed of 

 from ten to twenty miles an hour, sw^ep round the equatorial region 

 of the globe unceasingly. 



30. " Impressed v,'ith the motion of the air, constantly sweeping 

 Currents. its surfkce iu ouc dircctiou, and obeying the same 



laws of motion, the great sea itself would be excited into currents 

 similar to those of the air, were it not walled in by continents and 

 subjected to other control. As it is, there are constant cmTents 

 flowing fi'om the torrid toward the frigid zone to supply the vast 

 amount of vapour there drained ofi", v^'hile other w^hirlpools and 

 cmTents, such as the gigantic Gulf Stream, come to perform 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 

 vv'orld, 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 w^here either 

 exists in excess. 



31. " In obedience to these laws water warmer than ice attacks 

 Icebergs. the basis and saps the foundations of the icebergs — 



themselves gigantic glaciers, which have faUen from the mountains 

 into the sea, or which have gro\ATi 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 



