THE OCEAN FEEDING-GROUNDS 85 



great North Equatorial current, while the eastern branch 

 follows the west coast of Africa as far as the Gulf of 

 Guinea, where it encounters the contrary Guinea current 

 coming from the west and the south-western African 

 current, or the Benguela current, coming from the south, 

 to form the south equatorial current." 



Now let us go into details for a moment. At the level 

 of Cape Blanco the north-to-south current breaks up, 

 as will be remembered, into three currents which are 

 differentiated by their temperature a cold current wash- 

 ing the coast, a warm current far out at sea, and a tepid 

 current between the two. The first gathers its waters 

 from the North Atlantic, by way of the Gulf Stream, and 

 from the Mediterranean ; the second and third draw 

 their waters more especially from the tropical Atlantic. 

 The cold belt and the tepid belt have an average speed 

 of one knot per hour ; the speed of the warm current 

 varies from ten to twelve knots in the twenty-four hours. 

 When the winds blow from the west they force the cold 

 and even the tepid current upon the coast ; they then 

 form a back-current (the counter-current of Arguin, vide 

 Gruvel), which runs up towards the Greyhound Bay and 

 flows round the Arguin bank. As for the tidal wave, 

 it progresses from south to north, enters Greyhound Bay 

 between Cape Blanco and the western slope of the 

 Arguin bank, strikes against the eastern shore of the 

 bay, runs along that shore, and overflows to a slight 

 extent by the shallow channel which lies between the 

 eastern slopes of the bank and the shoals of the African 

 coast. From this results a number of eddies, turning 

 towards the south of the bank. At the moment of ebb- 

 tide the water runs out of Greyhound Bay at two and a 

 half knots per hour, winding round the western slopes 

 of the bank. 



