From Station 253 to Station 288. 119 



paratively narrow channel between the latter cape and Cape 

 Palmas in Africa, and partly to the fact that the northern limit of 

 the south-east trades is placed for the greater part of the year 

 north of the equator, a considerable portion of the South Atlantic 

 Equatorial Current is diverted along the north-east coast of South 

 America into the Northern Atlantic. On the other hand, nearly 

 the whole of the South Pacific Equatorial Current remains on its 

 own side of the equator, hence the western half of the South 

 Pacific is much warmer than the western half of the South 

 Atlantic. Although the North Atlantic receives such an impor- 

 tant contribution from the South Atlantic, the accumulation of 

 warm water in its western half is much inferior to that in the 

 western half of the North Pacific ; yet, on account of the restricted 

 area of the Atlantic, its eastern half, both north and south of the 

 equator, receives a greater quantity of warm water in the shape 

 of equatorial return-currents than the eastern half of the Pacific, 

 and the eastern half of the former is therefore much warmer than 

 that of the latter. 



Another remarkable phenomenon in the circulation of the 

 oceanic waters, and one the explanation of which has exercised 

 many minds, is to be found in the equatorial counter-currents 

 of the Atlantic, Indian, and Pacific Oceans. In all the three 

 oceanic basins this current is identified with the equatorial belt 

 of calms, and is known to flow from west to east, while the 

 equatorial currents on both sides of it flow from east to west. 

 Its presence in the belt of calms, to which it is exclusively 

 confined, is no doubt not accidental, and leads to the conclusion 

 that the absence of all permanent atmospheric currents must 

 be a circumstance favourable to the formation of a current with 

 a tendency, as in the present case, to flow in an easterly direc- 

 tion. At the same time, we are led to examine whether there is 

 anything in the temperature-conditions of this belt and of the 

 zones immediately adjoining which may cause the formation of a 



