Dr Forry on the Climate of the United States. 



97 



winter. Wisdom desires not that " eternal spring," the 

 want of which poets affect to deplore. At the equator there 

 is no difference between tlie mean temperature of summer 

 and winter, but it increases, as a general rule, with the 

 latitude. From Florida to Canada, the contrast in the sea- 

 sons increases in proportion as the mean annual temperature 

 decreases — a general law subject to modification on eveiy 

 parallel, in accordance with the varieties in physical geo- 

 graphy. It has been already seen, that the greatest and 

 the least contrasts of winter and summer are exhibited at 

 Fort Snelling and Key West. Upon this point, Humboldt 

 has, as usual, determined many important laws. 



" The winters of the isothermal curve of C8'," he says, 

 " are not found upon that of 51°, and the winters of bV are 

 not met with on the curve of 42^." In considering sepa- 

 rately what may be regarded as the same systems of climate, 

 for example, the European region, the transatlantic region, 

 or that of eastern Asia, the limits of variation become still 

 more narrow. Wherever in Europe, in 40° of longitude, the 

 mean temperature rises— 



To 59°-00] 

 To 54:°-50 



3r-10 to 37°-40 



To 50°-00 

 To 45"-50 

 To 41°-00 



(44°-60to46°40] 



. , 36°-50to4r-00| 

 . the winters ] , 



are from \ ^SMO to 36°-10 1 

 , 20°-30 to 26°-8o) 



and the 



summers 



from 



73°-00 to 75°00 

 68°-00 to 73°-00 

 62"-60 to 69'-S0 

 57°-20 to 6S°-00 

 55°-40 to 66°-00 



In the United States, if the comparison is confined to the 

 same system of climates, as, for example, the posts on the 

 ocean or lakes, or those remote from the agency of large 

 boflies of water, the limits of variation, as in Europe, are also 

 narrow ; but if the whole extent of our domain is embraced , 

 the results are strikingly diverse. Thus — 



VOL. XXXIX, NO. LXXVII.— JULY 1845. 



