LATERAL EDDIES. 85 



CHAPTER X. 



LATERAL EDDIES. — RENNELL's CURRENT. — COUNTER-CURRENT IN THE SEA OF THE 

 ANTILLES. — EQUILIBRIUM OF THE WATERS IN THE BALTIC, THE BOSPHORUS, AT 

 THE ENTRANCES TO THE MEDITERRANEAN AND THE RED SEA. — EXCHANGE OF 

 WATER AND SALT BETWEEN THE SEAS. 



None of those great currents, which wind through the oceanic basins, 

 show in their exterior contours the same sinuosities as the seas through 

 which they flow. "While most of the shores present a succession of 

 promontories and gulfs, the currents stretch in long regular curves, 

 which in their vast sweep indicate but generally the form of the 

 depression which contains them. Every considerable gulf, which is 

 separated from the ocean by any projecting land, remains outside 

 the whirlpool of waters, unless it should be in the very axis of the 

 current, like the sea of the Antilles. Yet even in those parts, which 

 do not share in the general circulation, the waters do not remain 

 perfectly stationary. They also have their circulatory system, and it 

 is from the great maritime current that each secondary eddy receives 

 its impulsion. 



A remarkable example of these currents of the secondary order 

 is presented on the west of Europe in the semicircular basin 

 formed by the coasts of Spain, France, England, and Ireland. A 

 portion of the waters of the Gulf-stream coming from the north and 

 north-west strikes the coasts of Galicia and the Asturias; it turns 

 east towards the extremity of the Gulf of Gascony, flows along 

 the shore of the Landes, then that of Saintonge, Poitou, Bretagne, 

 and returning in a north-west and west direction, forms a sort of 

 liquid barrier across the Channel. To the south of Cape Clear 

 this oceanic river, known under the name of Rennell's current, 

 after the English savant who discovered its existence, finallj^ enters 

 the Gulf- stream, and returns to the south with the waters of the 

 ocean. Thus a complete circuit is made around the basin, analo- 

 gous to that which occurs in each of the great oceans of the world. 

 PtennelPs current, in its turn, coasting at a greater or less distance 



