Dr Forry on the Climate of the United States. 101 



difference between the mean temperature of winter and 

 summer, varying from 38'' to 54°. Tiiis does not, however, 

 in the least affect the law of the climatic analogy of the 

 eastern and western continental coasts. 



But this law, that the same causes which increase the 

 mean annual temperature also equalize the seasons, does 

 not hold good in the United States, in receding from the 

 Atlantic ; for, on comparing the climate of the coast of New 

 England with the still more excessive climate of the interior, 

 it is found that the moan annual temperature of the latter is 

 higher. That the climate should become more austere, the 

 seasons being less equalized, is in accordance with the laws 

 established by Humboldt ; but that the isothermal line, at 

 the same time, should become more convex, is in diametrical 

 opposition. 



Forts Sullivan, Snelling, and Howard, for example, have 

 very nearly the same latitude ; the first, on the ocean, has a 

 mean annual temperature of 42''-95, while the last two, in 

 the opposite system of climate, have a mean respectively of 

 45°-83 and 44°-92 — a result the more unexpected, at first 

 sight, as the latter are in a region elevated six hundred to 

 eight hundred feet above the level of the sea. Comparing 

 Fort Wolcott, on the ocean, with Fort Armstrong, West 

 Point, and Council Bluffs, in the interior, the same relation 

 is found. Foi't Trumbull, it is true, offers an exception ; but 

 it is necessary to bear in mind that the results of this post 

 are based on two years' observation only, while those of 

 Fort Wolcott are calculated from ten ; and in further evi- 

 dence of its probable erroneousness, it may be mentioned 

 that the mean annual temperature at Fort Columbus, which 

 is (f 40' farther south than Fort Trumbull, based on nine 

 years' observation, is 2° less. Again, we find that while at 

 Salem, near the Atlantic, in lat. 42° 34', the mean annual 

 temperature, based on thirty-tlu-ee years' observations, is 

 4o"-Gl, it is, on the oilier hand, at Fort Armstrong, lat. 

 41° 28', Council Bluffs, lat. 41° 45', and at West Point, lat. 

 41° 22', respectively .'51°-G3, 50°-50, and 52°-47. Here, then, 

 i.s actually an increase of from two to four degrees in the 

 annual temperature, while the interior posts are only about 



