176 Baron N. Schilling on the Constant Currents 



ward bend, but may be assisted in some degree by the tendency 

 of the particles to move towards the equator, produced by the 

 rotation of the earth. Only a small portion of the east-directed 

 current passes Cape Einisterre unhindered, and continues its 

 course in the natural direction along the north coast of Spain 

 till the coast of France compels it to curve sharply to the north- 

 west and follow exactly the course of the shore of the Bay of 

 Biscay, under the name of the Rennell current, to be lost at the 

 English coast in the general north-east current of the Atlantic. 

 The Rennell current shows distinctly how much power the 

 direction of coasts has to determine that of currents, even to 

 reverse their direction. 



A portion of the South-Atlantic equatorial current turns to 

 the south-west from Cape St. Roque, along the coast of South 

 America. The impelling force of this Brazilian current is the 

 same as that of the Gulf-stream — partly the pressure of the 

 equatorial, partly the high temperature of the water heated in 

 the Atlantic Ocean and collected at the coast by the equatorial 

 current, and partly the attraction of the eastward-directed ebb- 

 current functioning in the middle latitudes, into which the 

 greater portion of the Brazilian current passes to form the South- 

 Atlantic rotation-current. This latter, after crossing the ocean 

 from west to east, and having curved a little to the north, strikes 

 upon the African coast, and (for the same reasons as those above 

 discussed for the northern hemisphere) returns along it again 

 to the equatorial current, forming the South-Atlantic Guinea 

 current. The entire rotation-current, then, is originated by the 

 attraction of the moon and the sun, as this by its direct action 

 carries the water in the equatorial regions from east to west, and 

 in the middle latitudes from west to east, and hence also gene- 

 rates indirectly the currents flowing in the direction of the meri- 

 dian (the Gulf-stream and the North-African current, the Bra- 

 zilian and the South -Guinea currents). 



In the entire southern hemisphere all the cold polar currents 

 are directed north-east, which coincides perfectly with the action 

 of the moon's attraction in higher latitudes. Only in the north- 

 ern hemisphere the directions of the cold polar currents contra- 

 dict the laws of the moon's attraction ; for the Greenland cur- 

 rent and the cold current of the Japanese sea have a south-west 

 direction, and not a south-east one, which they should have ac- 

 cording to our considerations. This, however, may well have 

 its cause in the action of the ebb-current, directed from west to 

 east, which gradually withdraws the warm northward- flowing 

 current from the coast ; and this is replaced partly by the cold 

 water of the bottom, but principally by the less-salt and there- 

 fore lighter water derived from the melting of the ice. A similar 



