46 THE PHYSICAL GEOGRAPHY OF THE SEA. 



The drift matter con- reacli the high latitudcs (§ 80), for it can not cross 

 currents. the Gulf Stream. Two streams of water can not 



cross each other, unless one dip down and underrun the other; 

 and if this drift water do dip down, as it may, it can not carry 

 with it its floating matter, which, like its weeds, is too light to 

 sink. They, therefore, are cut off from a passage into higher 

 latitudes. 



136. According to this view, there ought to be a sargasso sea 

 Theory as to the for- somcwhcre iu thc sort of middle ground between 

 mation of sargassos. ^^iQ grand cquatorial flow and reflow which is per- 

 formed by the waters of all the great oceans. The place whete 

 the drift matter of each sea would naturally collect would be in 

 this sort of pool, into which every current, as it goes from the 

 equator, and again as it returns, would slough off its drift matter. 

 The forces of diurnal rotation would require this collection of 

 drift to be, in the northern hemisphere, on the right-hand side of 

 the current, and, in the southern, to be on the left. (See Chap. 

 XYIII. and Plate IX.) 



137. Thus, with the Gulf Stref^m of the Atlantic, and the "Black 

 Sargassos of south- Stream" of the Paciiic, their sargassos are on the 

 o™thrsoithera/tJ right, as they are also on the right of the returning 

 poL"S.d'equlforili ^^d cooler currents on the eastern side of each one 

 flow and reflow. ^^ ^}^QgQ northcm occaus. So, also, with the Mo- 

 zambique current, which runs south along the east coast of Africa 

 from the Indian Ocean, and with the cooler current setting to the 

 north on the Australian side of the same sea. Between these 

 there is a sargasso on the left. 



138. Again, there is in the South Pacific a flow of equatorial 

 Their position con- watcrs to the Autarctic on the east of Australia, 

 forms to the theory. ^^^ ^^ Autarctic watcrs (Humboldt's current) to the 

 north, along the western shores of South America ; and, according 

 to this principle, there ought to be another sargasso somewhere 

 between l^ew Zealand and the coast of Chili. (See Plate IX.) 



139. To test the correctness of this view, I requested Lieut. 

 The discovery of a Warlcy to ovcrhaul our sea-journals for notices of 

 new sargasso. j^^jp ^^-^^ ^^[^^ matter ou the passage from Australia 



to Cape Horn and the Chincha Islands. He did so, and found it 

 abounding in small patches, with " many birds about," between 

 the parallels of 40^ and 50° south, the meridians of 140° and 178° 



