Dr. Forry on the Climate of the United States, fyc. 39 



paper on Isothermal Lines and the Distribution of Heat over the 

 Globe / but these various relations, owing of course to the pau- 

 city of his data, are not characterized by much precision. 



The isothermal line of 41°, which, according to this philoso- 

 pher, passes through the Bay of St. George, in Newfoundland, 

 in the latitude 48°, if correctly ascertained, sinks as it penetrates 

 towards the interior of the continent ; for at Hancock Barracks, 

 Maine, in latitude 46° 10', at a distance of one hundred and fifty 

 miles from the Atlantic, the mean annual temperature is 4P-21, 

 and at Fort Brady, at the outlet of Lake Superior, in latitude 46° 

 39', it is 41°-39 ; and proceeding to the western coast of Amer- 

 ica, we find that at Fort Vancouver, Oregon Territory, in latitude 

 4o° 37', the mean temperature, like similar parallels in western 

 Europe, is as high as 51° 75. 



As the region of the United States, however, exhibits very di- 

 verse systems of climate even on the same parallels, such com- 

 parative tables, as for instance the difference of the seasons from 

 jhe equator to the polar circle, can present only the most general 

 •aws. For example, it shows that on the isothermal line of 41°, 



fi-o 9 1Gan tem P erature of wi »ter is 14°, and that of summer 



■J) a result obtained from observations made in lat. 48°, on 



the Bay of St. George, Newfoundland. Now, according to the 



Army Meteorological Register," this isothermal line is again 



found in the comparatively equalized climate of Fort Brady, at 



the outlet of Lake Superior, in lat. 46° 39', where the mean 



temperature of winter is as high as21°07, while that of summer 



jsonly 63°-l8. Again, the table shows that on the isothermal 



■ne of 50°, the mean temperature of winter is 3CP-20, and that 



°j summer 7P-50; but this too gives only a partial view, as at 



fiqT Wolcott ' Rhode Is,aild > the former is 32°o 1 and the latter 



b9 °*06, and at Council Bluffs, near the junction of the Platte 



and Missouri, 24°-47 and 75° -82; thus showing that the disparity 



the mean temperature of winter and summer, on the same 



same 



Wolcott being 50°-61, and that of Council Bluffs 51°02,) is 



& 



if 



As those who first observed the climatic difference between 

 Western Europe and eastern North America, were natives of the 

 or *ner, they of course regarded the climate of their own coun- 

 ty as constituting the rule, and that of America as the excep- 



