COUESE OF THE aULF-STREAM. 65 



rapid than the Mississippi or the Amazon, and its volume a thousand 

 times greater." Such is the epic language in which Maury's fine 

 V\"ork commences.* 



After having made the tour of the Caribbean Sea and the Grulf of 

 Mexico in six months, after having driven back upon the shores of 

 Alabama the muddy waters of the Mississippi which border its dark 

 Line waves, the Gulf-stream follows the northern coasts of Cuba, 

 then turns the southern point of Florida, and penetrates the strait 

 which separates the American continent from the islands and banks 

 of Bahama. Swelled by the mass of w^ater which the great equator- 

 ial current sends directly through the straits of the archipelago, and 

 above all by the old channel of Bahama, the Gulf-stream flows 

 straight to the north, pressing through the ocean like a river nearly 

 37 miles wide, and of an average depth of 200 fathoms. Its speed 

 is great, evon equalling that of the principal rivers of the world, 

 being sometimes from about 4 J to 5 miles an hour ; but usually 

 it is about 3 ^ miles. The mass of water discharged by the current 

 may, therefore, be estimated at nearly 45 millions of cubic yards 

 per second, that is to say, at 2000 times the mean* discharge of 

 the Mississippi ; and yet it was to the outflow of this North American 

 river that many geographers formerly attributed the existence of the 

 Gulf- stream ! When winds from the south, the west, or even the 

 north-west, and the movement of the tides, favour the progress of this 

 current, it rolls toward the Atlantic in much greater volume than 

 usual. But on the other hand, when retarded by tempests that blow 

 from the north-east, it pours a much smaller quantity of water into 

 the ocean. When thus checked, it swells, rises, spreads with fury over 

 the low lands that border it, ravages vast tracts, and causes whole 

 islands to disappear. At its embouchure into the ocean, this marine 

 river resembles those streams which flow through continents^ it erodes 

 on the one side, while it deposits alluvium on the other. And doubt- 

 less the Bahama islands, which are scattered through the sea to the 

 east of the Gulf- stream, and the Ke7/s or rocks developed on the north 

 in a long range, rest on a foundation of submarine banks formed in 

 part by the deposits of this grand river, f 



On emerging from the strait of Bernini the Gulf-stream expands 

 and spreads over the Atlantic, but at the same time its depth becomes 

 proportionately less considerable. Whilst the strata of cold water 



* Fhysical Geography of the Sea, p. 23. 



t Agassiz. R. Thomassy, Bulletin de la Societe de Geographie, Novembre, 1860. See 

 below, the chapter entitled, Earth and its Fauna. 



F 



