CUEKEXTS or THE SOUTH ATLANTIC. 79 



its course to the north-east towards St. Helena, where it joins the 

 great equatorial river. The whole circuit is accomplished in a period 

 which may be estimated at about two or three years.* 



Dissimilar, and often contradictory, observations recorded by various 

 navigators who have studied the phenomena of the waters in the Soutli 

 Atlantic, seem to put it beyond doubt that the currents of this basin 

 have not the same regularity of course as those of the Northern Atlantic. 

 It frequently happens that the water does not flow in the direction 

 indicated on maps, or even tends in an opposite direction to the 

 normal movement. The reason of this difierence between the two 

 basins is quite natural. While the North Atlantic is a very regular 

 sea in its general form, bounded on each side by almost parallel 

 shores, the marine area lying between Africa and South America 

 expands very widely from the coast of the southern polar land. 

 It may be considered simply as a gulf of the great ocean, which 

 extends around the globe to the south of the extremities of the 

 three southern continents. As a consequence of this irregular dis- 

 position of the coasts, the variations from the normal circumstances 

 of the waters cannot fail to be very great. The cold waters from 

 the Antarctic Pole, charged with fragments of ice-fields and ice- 

 bergs, flow it is true Avith a continuous motion to replace the vapours 

 which rise incessantly from the equatorial Atlantic. But the regular 

 play of the currents is modified now at one point now at another, ac- 

 cording to the greater or less activity of evaporation in those parts 

 of the sea. Besides, the changing coast- winds which blow alter- 

 nately from the ocean to the land and from the land to the ocean, 

 impress their varying movements on its surface. 



The Indian Ocean has likewise its great circuit of water. There 

 too the mass of fluid, chilled by its sojourn in the icy zone, is incess- 

 antly flowing towards the equator, in order to fill up the vacancy 

 produced by the annual evaporation of 13 to 16 feet. It flows 

 along the western coast of Australia, and afterwards unites with 

 the waters that come from the Pacific Ocean, through Torres 

 Straits and the East Indian archipelago. But there the regular 

 current seems to lose itself; and we onlv see in the Gulfs of Beno-al 

 and Oman, marine rivers changing their course with the mon- 

 soons. Nevertheless it must really be that the general movement 

 of the waters is continued from the east to the west around the vast 

 basin, for on the eastern coast of Africa a current of warm water, 

 incessantly supplied by the seas w^hich bathe Hindostan and Arabia, 



* Mittheilungen von retermann, t. x. 1866. 



