36 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



submarine waters of the intertropical ocean ; or ^Ylletller it be owing 

 to all of these influences together that these waters are kept on 

 the surface, suffice it to say, we do know that they go into the 

 Caribbean Sea (§ 103) as a surface current. On their passage to 

 and through it, they intermingle with the fresh waters that are 

 emptied into the sea fi^om the Amazon, the Orinoco, and the Mis- 

 sissippi, and from the clouds, and the rivers of the coasts round 

 about. An immense volume of fresh v\^ater is supplied from these 

 sources. It tends to make the sea- water, that the trade-winds have 

 been playing upon and dri\dng along, less briny, warmer, and 

 lighter : for the waters of these large intertropical streams are 

 warmer than sea-water. This admixture of fresh water still leaves 

 the Grulf Stream a brine stronger than that of the extratropical sea 

 generally, but not quite so strong (§ 102) as that of the trade-wind 

 regions. 



107. The dynamics of the sea confess the power of the winds in 

 Currents created by thoso tromendous cmTeuts which storms are some- 

 ^*''™'- times kno^^ai to create; and that even the gentle 

 trade-mnds may have influence and effect upon the cm-rents of the 

 sea has not been denied (§ 82). But the effect of moderate winds, 

 as the trades are, is to cause what may be called the drift of the 

 sea rather than a cmTent. Drift is confined to surface waters, and 

 the trade- winds of the Atlantic may assist in creatmg the Grulf 

 Stream by driftmg the waters which have supplied them ytiHi vapour 

 towards the Caribbean Sea. But admit never so much of the water 

 which the trade-winds have played upon to be drifted into the Carib- 

 bean Sea, what should make it flow thence with the Gulf Stream to 

 the shores of Em'ope ? It is because there is room for it there ; and 

 there is room for it because of the difference in the specific gra^dty of 

 sea-water in an intertropical sea on one side, as compared v*ith the spe- 

 cific gravity of water in northern seas and frozen oceans on the other. 



108. The dynamical forces which are expressed by the Gulf 

 ?h^atS'^foni/°the ^^^6^^ i^ay "^th as much propriety be said to reside 

 Gulf Stream to be in tlioso northom waters as in the West India seas ; 



found in the differ- p -t -i l^ r^ •^ ^ o T 



ence as to specific lor ou ouc Side WO liavc the Caribbean bea, and 

 piS'and'po^'r' wa-' ^^"^ 0^ Mcxico, mth their waters of brine ; on the 

 ^ers. other, the Great Polar basin, the Baltic, and the 



North Sea, the two latter with waters that are but little more than 

 brackish.* In one set of these sea-basins the water is heavy ; in 



The Polar basin has a known water area of 3,000,000 square miles, and an 

 unexplored area, including land and water, of 1,500,000 square miles. Whether 



