ILLUSTRATIONS (18). CLIMATE OF AMERICA. 101 



In the preceding table the number placed before the frac- 

 tion represents the mean annual temperature, the numerator 

 of the fraction, the mean winter temperature, and the deno- 

 minator the mean summer temperature. Besides the more 

 marked difference between the mean annual temperatures, 

 there is also a very striking contrast between the opposite 

 coasts in respect to the distribution of heat over the different 

 seasons of the year ; and it is indeed this distribution which 

 exerts the greatest influence on our bodily feelings and on the 

 process of vegetation. Dove* makes the general remark, that 



* Temperatur-tafeln nebst Bemerkungen iiber die Verbreitung der 

 Warme aufder Oberftache der Erde, 1848, s. 95. 



