( 335 ) 



4.— THE SARGASSO SEA. 



(288.) The central portion of the North Atlantic Ocean, which is com- 

 prised between the Trade Wind and Anti-Trade Wind systems (42), page 

 124, also bounded on the South by the Westerly Drifts of the Trade 

 Winds, and to the North by the Easterly Current, presently described, 

 appears to be in a different physical condition to the other portions of the 

 Atlantic Ocean, and indeed from any other portion of the globe. 



Its apparently chief characteristic is well expressed by the name bow 

 usually applied to it — the Sargasso, or Weedy Sea. The well-known gulf- 

 toeed, which is found more or less over its whole area, seems to be quite 

 peculiar to it. There may be a somewhat analogous physical condition in 

 the North Pacific Ocean, but this is not so easily defined. This gulf-weed 

 is constantly found, in greater or less quantity, scattered over its whole 

 area, and when it is found in places not its usual habitat, it may be safely 

 inferred that it has drifted out of this extensive area by the action of the 

 Current. 



(289.) It is very difficult to define the limits within which this gulf- weed 

 is found. The fluctuations of the seasons greatly affect them, as they do 

 the limits of the Trade Winds and intervening Calms, the more particularly 

 as it is to the varying Currents caused by these winds that the weed is 

 retained in its locality. Consequently, we may look for its North and 

 South boundaries more to the Southward during the Northern winter 

 months, and the reverse during the summer. The Tropic, or about the 

 parallel of 23° N., may be its Southern edge in the longitude of the Azores, 

 from whence this limit extends to the Virgin Islands and the Bahamas. 

 Its Northern edge runs from the Azores to the outer edge of the Gulf 

 Stream oS Cape Hatteras. This will give a breadth of 1,000 miles in its 

 Eastern part, and a length of 3,000 miles from East to West. As before 

 stated, its limits may change greatly at different times, but it may always 

 be looked for within this area, that is between the Southern edge of the 

 Gulf Stream and the Northern limit of the Equatorial Current. 



According to the investigations of Dr. O. Kriimmel,* the area of maximum 

 weediness (where the weed covers from 10 to 25 per cent, of the surface) 

 forms an ellipse between lat. 25° and 35° N., and long. 40° to 73° W. 

 The weed has been found as far North as lat. 52°, in long. 45° W., and as 

 far South as 15° N., but it is only found Northward of lat, 45° N. in late 

 summer and autumn. 



(290.) There has been much speculation as to the causes and conditions 

 which have made and retained this peculiar area in its integrity. 



* A good account of this weedy sea, which is called by the French " Mer de Varec'h," 

 by Captain Leps, of the French Navy, is given in the " Annales Hydrographiques,' 

 1857, page 565, &c. ; another more recent account, illustrated by a map, is given by 

 Dr. 0. Kriimmel, in Petermann's " Mitteiluugen," 1891, pp. 129—141. As the con- 

 clusions there arrived at entirely accord with the particulars given in this volume, it haa 

 not been thought necessary to quote from thorn to any large extent. 



