Dr. Forry on the Climate of the United States, S)''c. 47 



It may be well to add, that with the exception of the last, the 

 writer is not aware of the local position of these points of com- 

 parison, — a consideration which may be supposed to be of some 

 importance, inasmuch as the northern division of the United 

 States presents, on the same isothermal line, a difference between 

 the mean temperature of winter and summer, varying from 38° 

 to 54°, This 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 

 mean annual temperature of the latter is higher. That the cli- 

 mate should become more austere, the seasons being less equal- 

 ized, 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 an- 

 nual temperature of 42°-95, while the last two, in the opposite 

 system of climate, have a mean respectively of 45°-83 and 

 A4P-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 in- 

 terior, the same relation is found. Fort 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 evidence of its probable erroneousness, it may be men- 

 tioned that the mean annual temperature at Fort Columbus, 

 which is 0° 40' farther south than Fort Trumbull, based on nine 

 years' observations, is 2° less. Again, we find that while at Sa- 

 lem, near the Atlantic, in lat. 42° 34', the mean annual tempera- 

 ture, based on thirty three years' observations, is 48°'61, it is, on 

 the other hand, at Fort Armstrong, lat. 41° 28', Council Bluffs, 

 lat. 41° 45', and at West Point, lat. 41° 22', respectively 51°-63, 

 50° -50, and 52°-47. Here then is actually an increase of from 



