190 Europe :—a popular Physical Sketch. 



The difference in the summer temperature between Pa- 

 lermo and Vienna thus amounts to only 6°; in the winter 

 temperature to 20.2°. The summer in Stockholm is only 13.5°, 

 while the winter is 27.2° below the winter temperature in 

 Palermo. 



That this applies still more to the highest degrees of heat 

 and cold,* will be seen in the table : — 



Highest. Lowest. 



Stockholm, 68 years, 95'° 26*5° below zero. 



Copenhagen, 52 years, 93*85° 13'° ditto ditto. 



Rome, 40 years, 100*62° 21.88° above zero. 



Palermo, .... 34 years, 106*2° 32.° ditto ditto. 



This difference between the seasons and the proportion- 

 ally great summer heat in the north, exerts a very salutary 

 influence over the vegetation ; the severe winter cold indeed 

 checks the vital activity, but does not destroy it ; whereas 

 the high summer temperature of the long summer days, 

 promotes the growth of the plants, tjie ripeness of the fruits 

 and seeds. If there were no difference in the seasons, or in 

 other words, had the north of Europe perpetual spring, we 

 should in Copenhagen, for instance, never see snow or ice to 

 be sure, but we should also never see corn or fruit ripen, 

 nay, we should see no trees at all. In the high land of 

 South America, under the line, where there is no great 

 difference between the heat of the seasons, grain cultivation 

 ceases already at 25° above the freezing point, (the mean 

 temperature of Milan,) and the tree vegetation at 18°, (the 

 mean temperature of Carlsruhe) ; if such was the case in 

 Europe, there would exist no grain cultivation north of 



* Every comparison of observations of the highest and lowest temperature is 

 rendered somewhat uncertain, from the circumstance, that the spot where the 

 thermometer is placed, by name the elevation over the ground, exerts a much 

 greater influence over the highest and lowest temperature, than it does over the 

 moan temperature. Supposing even the data in the Table be incorrect, say one or 

 two degrees, the correctness of the statement will be apparent nevertheless. 



