300 On Ihc Practtculilili/ 



face all rouii;! tlie globe, witliiti tl/e limits of t];e sun's uecUim- 

 tioii. If this general effect be adniilted, then, cii tlie ground it 

 rests, we may presume that, if there was a passage through the 

 isthmus of Darien for the immense bodv of water which coii- 

 tiniiailv flows from east to west, into the Caribbean sea and gulf 

 of Mexico, what is called the gulf-stream would no longer esisti 

 And as it seems probable, that the surface of the water must be 

 -vomewhat higher on the eastern side of America, thtrealvvlSy 

 than on the other, owing to the land's obstruction to the natural 

 course of the great equinoctial current, and the necessity imposed 

 on it, to find vent through the gulf of Florida into the Atlantic, 

 it is not unreasonable to conclude, that, if this accumulation of 

 water was at lil)ertv to flow through the continent of America 

 into the Pacific Ocean, the surface of the sea on this side would 

 be lower than it now is ; and parts of land, now under water, 

 would be exposed to view. This effect wouhi however be in- 

 jurious to commerce with the West Indies, for it would lender 

 the homeward-bound passage more difficult. Instead of a con- 

 stant weather current to assist ships, it is pretty certain there 

 would be a lee one from the N.E. along the east coast of Florida, 

 and its influence would most proljablv be felt far up to the N.E. 

 from whence the current of colder water would flow nearer l!ie 

 feurface than it now can, covered superficially as it may be suj>- 

 posed to be by the warmer gulf-stream. The lugh degree of 

 temperature which this great body of water acquires by the sun's 

 constant action uj)on it, being slowly reduced during its pru- 

 peiled progress to the N.E., it is pro!)ai)]o that ii: may advance 

 even bevond the Banks of Newfoundland before it is reduced to 

 the colder temperature of the fluid below it, wliich must be flou'- 

 ing from the northern regions of condensation towards the points 

 of greatest rarefaction and evaporation between the tropics, to 

 supply the place of that which the heat is, as constantly, rarefying 

 and evaporating ; and so sending back in the upper strata of tlie 

 atmosphere to the colder rcgiotis. The gulf-stream thus pro- 

 ))clled by lateral pressure up towards the Banks of Neufound- 

 land, is seldom found to affect a ship beyond those banks; at 

 the same time, it is possible, that some of it may advance further 

 to the northward, before that reduction is effected in its tempe- 

 rature which gives it a tendency to the southward ; for many 

 articles, the produce of tropical ciinies, and some known to have 

 been from the West Indies, have been cast ashore on the coi.st 

 of Europe. Some of these places being to the N.E. of New« 

 foundland, it is difficult to believe these articles could have been 

 driven thither by the winds and the swell of the sea only. For, 

 these prevailing as much from N.W. as IS.W. would give them 

 about aa east direction 3 and if ihey were immersed sufficiently 

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