On the Physical Geography of Norway. 301 



exposed to the sea, and less than one degree of latitude far- 

 ther north, nature seems almost torpid, the fogs are conti- 

 nual, the birch-trees are mere bushes at the level of the sea, 

 and scarcely anything can be reared in the gardens. In 

 short, we have the climate of Iceland, neither excessive heat 

 nor cold, but a benumbing mediocrity of temperature and 

 a perpetual cloud. 



§ 3. On the Position of the Snow Line in Norway. — The 

 occurrence of perpetual snow at a certain height above the 

 sea in even the warmest regions in the globe, has in all ages 

 excited the curiosity of geographers and naturalists. — Re- 

 garded at first as a very simple indication of the depression of 

 temperature as we ascend in the atmosphere, it has been care- 

 fully studied and applied (often erroneously) to the determina- 

 tion of climate. Closer examination has shewn that the pre- 

 sence of perennial snow, — in other words, a predominance of all 

 the causes tending to its accumulation over those which tend to 

 its waste of fusion — is, indeed, a very complicated fact, and 

 cannot be taken as the simple expression of any one of the ele- 

 ments of climate. The snow line is far from having invariably a 

 mean temperature of 32°, as was at one time supposed. Under 

 the equator it is about 35°; in the Alps and Pyrenees about 25° ; 

 and in latitude 68° in Norway it is (according to Von Buch) 

 only 21°; yet, though there are regions both in the extremity 

 of Siberia and in arctic America, of which the mean tempera- 

 ture is below zero of Fahrenheit (as, for example, Melville 

 Island), it is quite established, on the concurrent authority of 

 those best aquainted with these regions, that nowhere in the 

 Northern Hemisphere does the snow line attain the level of 

 the sea. The explanation is to be sought principally in the 

 intensity of the summer heat during the period of perpetual 

 day, which effectually thaws the soil, though only to a trifling 

 depth, and raises upon its surface a certain amount of brief 

 vegetation suitable for the support of arctic animals. 



Another cause affecting exceedingly the level of the snow 

 line is the amount of snow which falls. The interior of con- 

 tinents being far drier than the coasts, the snow to be melted 

 is a comparatively slight covering. The snow line on the north 

 side of the Himalaya is at least 3000 feet higher than towards 



VOL. LVI. NO. CXII. — APRIL 1854. X 



