Proximate Causes of certain Winds and Storms. 285 



But that the great efficient causes of these peculiarities, are to be 

 found neither in its forests, lakes* mountains, nor polar seas, is 

 proved by the fact, that they are almost as strongly marked in 

 the territory of Arkansaw, as about Hudson's Bay, though the cold 

 winds which sweep over the former country, and determine its cli- 

 mate, come from the bare and arid plains that are spread out for 

 hundreds of miles at the base of the Rocky Mountains* That these 

 causes are not confined to the eastern part of this continent, is ren- 

 dered certain by the circumstance, that a climate, having the same 

 characteristics with our own, prevails in the northern part of China, 

 and apparently throughout the whole of the eastern part of Asia, ly- 

 ing beyond the limit of the trade winds. 



11 The extremes of heat and cold are much greater at Pekin than 

 at Madrid, though the latitude is much the same ; it freezes daily in 

 December, January and February, and very often in March and 

 November. The cold is often followed by excessive heat — the me- 

 dium heat of the year is 55°." " It is said that Corea, though in 

 the latitude of Italy, has a very cold climate, from the mountains 

 which it contains." " Tussilagos, and the Kamstchatkan lily, thrive 

 in it, (Jesso, lat. 43°) shewing that the climate is moist and cold." 

 " The intelligence of these poor islanders (Leghalien, lat. 50°) strug- 

 gles against a severe climate."* 



With the same latitude on the continent of Europe, instead of 55°, 

 Pekin would have a mean temperature of 62° T. If therefore we 

 would assign the true cause of the peculiarities of the climate of our 

 own country, we must discover one which is common to the eastern 

 part of both continents. Daniell seems at first sight to have ful- 

 filled this condition in the happiest manner. 



" It is explained by the heat evolved in the condensation of va- 

 por, swept from the surface of the ocean by the western winds. 

 This general current, in its passage over the land, deposits more and 

 more of its aqueous particles, and by the time that it arrives upon 

 eastern coasts is extremely dry : as it moves forward, it bears before 

 it the humid atmosphere of the intermediate seas, and arrives upon 

 the opposite shores in a state of saturation. Great part of the vapor 

 is there at once precipitated, and the temperature ot the climate rais- 

 ed by the evolution of its latent heat."f 



• Malta Brim's Geography, in various places. \ Meteorological Essays, p. 105. 



Vol. XIX.— No- 2. 3? 



