344 M. Humboldt 07i the Difference of the 



Jias been recently confirmed by careful inquiries. The in- 

 jurious influence which small isolated masses of ice, driven 

 sometimes by currents into the neighbourhood of the Azores, 

 exercise, as it is said, upon the continent of Europe, is one of 

 those tales, first derived from philosophers, and received by the 

 vulgar, after the former have long ceased to believe in them. 



In the same latitudes, where, in the north of Europe, agri- 

 culture and gardening are carried on, we find in North 

 America and North Asia only marshes and tracts of land co- 

 vered with mosses : in the interior of Asia, on the other hand, 

 the powerful radiation of heat, between the almost parallel 

 chains of the Himalaya, the Zungling' and the Himmelsgehirge^ 

 (a country on which Klaproth's geographical researches have 

 thrown great light), exercises the most beneficial influence on 

 the Asiatic population. The line of permanent snow, on the 

 northern declivity of the Himalaya, lies 4000 feet higher than 

 on the southern ; and the physical explanation which I have 

 given of this singular phenomenon *, has, according to a report 

 of Mr Colebrooke, been confirmed by recent measurements and 

 observations in the East Indies. Millions of men of Thibetian 

 origin, of a gloomy religious cast of mind, occupy populous 

 towns, in a country where fields and towns would, during the 

 whole year, be buried in deep snow, if this high table-land was 

 less extensive and less continuous. 



As the currents of the atmosphere are modified in many dif- 

 ferent manners, by changes in the declination of the sun, and 

 by the direction of the chains of mountains on the declivities of 

 which they descend, the currents, also, of the Hquid ocean 

 carry the warmer waters of the lower degrees of latitude into 

 the temperate zone. I need not here mention how the waters 

 of the Atlantic, always moved in the same direction by the 

 trade-winds, are carried against the dike formed by the isthmus 

 of Nicaragua, then turn to the north, make the round of the 

 Gulf of Mexico, flow out through the Channel of the Bahamas, 

 proceed as a current of warm water to the north-east towards 

 the banks of Newfoundland, then to the south-east, towards the 

 'group of the Azores ; and, when favoured by the north-west 



• Annales de Chimie et de Physique, torn. iii. p. 297 > torn. ix. p. 310 ; torn, 

 xiv. p. 5. 



