344 Limits of perpetual Snow in the North. [May, 



of latitude, published in the Memoirs of the Swedish Academy for 

 178^', page 121, after the reductions and alterations to be after- 

 wards stated, which 1 consider myself as warmnted to make, give 

 US the following mean temperature of the months in that place. ' 



January 7-630° Fahr. 



February 14-308 



iVlarch 14-203 



April 26-145 



May 40-8^9 



June 55-184 



July 61-560 



August 56-673 



September 4G-490 



October 38-732 



November 22*651 



December , 1 3-595 



Mean for the year S3" 172 



If we compare these numbers with the preceding table, we shall 

 find th it there is very little difference between the mean annual 

 temptratiire at I'leoborg and at the North Cane Yet the mean 

 heat of the months above the freezing point at Uleoborg amounts 

 to 4'.) 92h°, while at Mageroe it is not higher than 39.312°. By 

 this difflrtnce is 'he height of the snow line regulated; and not- 

 withstanding the severity of the winter, it rises at Uleoborg to a 

 considerable height. 



These cirtu instances render the snow line of still greater im- 

 portance to us. As it depends entirely upon the heat of the snow 

 melting months its height becomes a measure of the quantity of 

 living beings in the places where we survey it; for the number of 

 living beings is determined by the height of the thermometer 

 above the freezing point. Below that point vegetables will not 

 grow, and animals support themselves with difficulty. The ther- 

 mometer in Siberia may show a degree of cold and a winter tem- 

 perature lower than is known in any other part of the Continent: 

 the P'ediuin temperature of Jakuisk may be 6*75° below the 

 freezing joint; and yet the trees in the country show that the snow 

 line there is higher than at Alien , and probably even higher than 

 at 'ioriieo. And wc may assure ourselves that in such summers 

 both the vegetables and animals of Torvco will thrive. But what 

 shall we say of Icdaiid, where the inhabitants spend their winter 

 ill their houses without fire, and yet in the 65th degree of latitude 

 the height of the snow line is only 3086 feet above the level of the 

 eea.* 



Swedish Lapland to the south of Alten, and especially the 



■» At O.lerjockul, according to the nbservatioDii of Lientenauti Olafsen and 

 Wetlefien, coinmunicated to me by Mr. J. R. Biigge. 



