62 THE WATER 



In the INDIAN OCEAN, or half - ocean as it may 

 be termed, the same general circulation is only clearly 

 marked north of the Equator during the south-west 

 monsoon (May to September). Off the Cape of Good 

 Hope the Mozambique Current, which corresponds to 

 the Brazil Current of the Atlantic, is barred by the 

 Easterly Antarctic Drift to an extent which produces 

 a remarkable recurving of the former from a south- 

 westerly to an easterly direction. To the constant 

 conflict between these hot and cold bodies of water 

 off Cape Agulhas are attributable the well-known 

 fogs of this area. 



Movements of Deeper Water. 



The rain, hail, and snow precipitated in vast quantity 

 on the Antarctic Continent, melting to some extent 

 in the summer, give rise to a water of very low salinity, 

 but also of so low a temperature that it sinks below 

 the warmer Salter water of more northern origin, 

 Chiefly from this source appears to be supplied the very 

 cold bottom water, which lies on the bed of all deep 

 oceans. There is some reason to believe that a lesser 

 quantity is derived from Arctic melting. Conse- 

 quently it is nearly always true that the deeper one 

 goes in the great oceans, the colder is the water. Thus, 

 for example, the mean temperature of all oceans at 

 2,200 fathoms was calculated by Dr. Buchan as 

 35-2° F. (i-6° C). Hence, whenever there is an 

 upwelling of water to the surface, due to water being 

 drawn away from the surface by the pull of winds — 

 a phenomena which is particularly observable on the 

 west coasts of all continents— the water thus up- 

 welling is comparatively cold for its latitude, and of 

 low salinity (compare the isohalines on the west of 



