CLIMATE. 



153 



lure of Paris for a series of 16 years was only 4. We can thus 

 by a series of well directed observations, determine the general 

 climatic relations of various continents, and the result of such ob- 

 servations are in some instances very different from what would 

 be inferred from mere theoretical considerations. It is found that 

 the decrease of heat as we recede from the equator, follows dif- 

 ferent laws in the two hemispheres. The subjoined table shows 

 the mean annual temperatures of Western Europe and North 

 America, continued from the equator. 



From this table it appears that the decrease of temperature, or 

 increase of cold is much more rapid in America than in Europe, 

 Baron Humbolt, who has added more to our knowledge of the 

 distribution of temperature over the globe, than any other who 

 has labored in the same boundless field, has proposed a system of 

 isothermal lines connecting different places having the same mean 

 annual heat. The differences between the mean annual temper- 

 ature of places upon the same parallels of latitude are thus pre- 

 sented to the eye in a very striking manner. On the next page 

 will be found a little chart of isothermal lines for every 5 in 

 Mercator's proportions. It will be seen that the mean annual 

 heat of Eastern Asia and Eastern America, are much nearer than 

 of Eastern America and Western Europe. A simple inspection 

 of this map will give a clearer idea of the variation of isother- 

 mal lines from the parallels of latitude. Thus, for instance, the 

 mean annual heat at the North Cape, is 32 ; whilst Nain on the 

 coast of Labrador, 14 south of the North Cape, has a mean an- 

 nual heat of 25. The table which we give contains a general 

 summary of Baron Humbolt's observations deduced from a very 

 great number of observations, Tho locality of a place very 



