302 On the Practkahility 



tude of abont 18" or 19° north, and the parallel of the VVesteni 

 Islands ; and from about the longitude of 29^ to 43° west; within 

 which limits the gulf weed is found floating on the surface, where 

 I suppose it originates, lives its a])pointed time, and decays like 

 any other vegetable production j and I believe it is rarely or never 

 met with beyond these liniits. 



Though I have admitted the hare possililily that sotne of the 

 gulf stream may enter the strait of Gibraltar, I cannot agree with 

 the writer of the article in the Quarterly Review, when he says 

 (speaking of the gulf stream) " that it is of sufficient force and 

 quantity to make its influence be felt in the distant strait of Gi- 

 braltar." Thus implying (if I understand him right) that this 

 " force and quantity," of the gulf stream, are the primary causes 

 of the constant current into the strait. On the contrary, think- 

 ing as I do that the causes of this constant flow of water into the 

 Mediterranean, are of a purely local nature, coiinected exclu- 

 sively with that sea ; I therefore think it most probable, that 

 if the great equinoctial current flowed (as I presume it would, 

 were there a sufficient passage,) through the continent of Ame- 

 rica into the Pacific, and consequently annihilated the present 

 gulf stream, there would be the very same constant flow of water 

 into the Mediterranean that there is now, as long as the sun's 

 power continued, and the localities exclusively belonging to that 

 sea remained the same. In short, I am of opinion that the 

 waters of the Atlantic (approximate to the strait of Gibraltar), 

 feel the influence of purely Mediterranean causes ; and that 

 neither the '-'force" nor "quantity" of the gulf stream has 

 any effect whatever in causing the current that runs into the 

 Mediterranean. It is well known by experience, that this cur- 

 rent is strongest with easterly gales in the hottest weather, with 

 wind at the same time, and is diminished during the prevalence 

 of the westerly winds ; and is weaker in winter generally than in 

 summer. But to return. — The winds, and surface currents in the 

 PacificOcean, are influenced generally in a similar way by the sun's 

 power as those between Africa and America, makirig however 

 due allowance for the difference of the formation and positions 

 of intervening lands, for these obstruct the uniform general ten- 

 dency of the winds and currents from east to west : therefore, 

 from the east coast of New Holland, to the east coast of Africa, 

 and within the limits of the sun's declination, the winds and cur- 

 rents become periodical and changeable, according to his place. 

 But it would be leading us too far out of the way, to attempt to 

 trace the currents iq the Indian seas, influenced as they are so 

 variously and oppositely, in their direction and velocity, at dif- 

 ferent season?, by the monsoons, and the bodies of land withia 



their 



