48 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



of Antarctic waters (Huraboldt's cuiTent) to the north, along the 

 western shores of South America ; and, according to this principle, 

 there ought to be another sargasso somewhere between New Zealand 

 and the coast of Chili. (See Plate IX.) 



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

 The discoveri- of a Warlcj to ovcrhaul om' sea-joumals for notices of 

 new sargasso. . ^ ]j-gjp ^^^^ ^]j,^£^ matter ou the passage from Australia 

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

 abomiding in small patches, with "many birds about," between the 

 parallels of 40° and 50° south, the m'eridians of 140° and 178° 

 west. This sargasso is directly south of the Georgian Islands, and 

 is, perhaps, less abundantly supplied with drift matter, less distinct 

 in outline, and less permanent m position than any one of the 

 others. 



140. There is no warm cmTcnt, or if one, a very feeble one, 

 One in the South flomug out of the South Atlantic. Most of the diift 

 Atlantic. matter borne upon the ice-bearing cm-rent into that 

 sea finds its way to the equator, and then into the veins which 

 give volume to the Gulf Stream, and supply the sargasso of the 

 North Atlantic with extra quantities of diiit. The sargassos of 

 the South Atlantic are therefore small. The formations and 

 physical relations of sargassos v^ill be again alluded to in Chapter 

 XVIII. 



141. Let us return (§ 129) to this great expanse of warm vrater 

 The large volume of whicli, comiug from the torrid zone on the south- 

 of\™Giif stream!^ westcm sido of the Atlantic, drifts along to the north 

 on the outside of the Gulf Stream. Its velocity is slow, not suffi- 

 cient to give it the name of cm-rent ; it is a drift, or what sailors 

 call a " set." By the time this water reaches a parallel of 35° or 

 40^ it has parted with a good deal of its intertropical heat: con- 

 sequent upon this change in temperatm-e is a change in specific 

 gravity also, and by reason of this change, as well as by the diffi- 

 culties of crossing the Gulf Stream, its progress to the north is 

 arrested. It now turns to the east with the Gulf Stream, and, yield- 

 ing to the force of the westerly winds of this latitude, is (§ 107) 

 by them slowhj drifted along : losing temperature by the way, 

 these waters reach the southwardly flow on the east side with their 

 specific gravity so altered that, disregarding the gentle forces of 

 the ^\ind, they heed the voice of the sea, and proceed to unite with 

 this cool flow, and to set south in obedience to those dynamical laws 

 that derive their force in the sea from difiering specific gravity. 



