52 THE PHYSICAL GEOGRAPHY OF THE SEA. 



Everj west wind that blows crosses the stream on its way to 

 Europe, and carries with it a portion of this heat to temper there 

 the northern winds of winter. It is the influence of this stream 

 upon climate that makes Erin the "Emerald Isle of the Sea," and 

 that clothes the shores of Albion in evergi-een robes ; while in the 

 same latitude, on this side, the coasts of Labrador are fast bound 

 in fetters of ice. In a valuable paper on currents,* Mr. Hedfield 

 states, that in 1831 the harbor of St. John's, Newfoundland, was 

 closed with ice as late as the month of June ; yet who ever heard 

 of the port of Liverpool, on the other side, though 2° farther north, 

 being closed with ice, even in the dead of winter ? 



65. The Thermal Chart (Plate IV.) shows this. The isother- 

 mal lines of 60°, 50°, &c., starting oflf from the parallel of 40° 

 near the coasts of the United States, run off in a northeastwardly 

 direction, showing the same oceanic temperature on the European 

 side of the Atlantic in latitude 55° or 60°, that we have on the 

 western side in latitude 40°. Scott, in one of his beautiful novels, 

 tells us that the ponds in the Orkneys (latitude near 60°) are not 

 frozen in winter. The people there owe their soft climate to this 

 grand heating apparatus, for drift-wood from the West Indies is 

 occasionally cast ashore there by the Gulf Stream. 



66. Nor do the beneiic-ial influences of this stream upon climate 

 end here. The West Indian Archipelago is encompassed on one 

 side by its chain of islands, and on the other by the Cordilleras 

 of the Andes, contracting with the Isthmus of Darien, and stretch- 

 ing themselves out over the plains of Central America and Mexi- 

 co. Beginning on the summit of this range, we leave the regions 

 of perpetual snow, and descend first into the tierra tdmjjlada, and 

 then into the tierra caliente, or burning land. Descending still 

 lower, we reach both the level and the surface of tlie Mexican seas, 

 where, were it not for this beautiful and benign system of aqueous 

 circulation, the peculiar features of the surrounding country assure 

 us we should have the hottest, if not the most pestilential climate 

 in the world. As the waters in these two caldrons become heat- 

 ed, they are borne off by the Gulf Stream, and are replaced by 

 cooler currents tlirough the Caribbean Sea ; the surface water, as 



* American Journal of Science, vol. xiv., p. 293. 



