76 Dr Forry on the Climate of the United States. 



distant only one hundred and fifty miles from the sea-coast, 

 exhibits a disparity of 46°-19 ; and comparing the warmest 

 and coldest month, the difference of the former is 47°'22, and 

 that of the latter 54°-70. Again, Forts Sullivan and Snelling, 

 in opposite systems of climate, are very nearly in the same 

 latitude, the former at Eastport, on the coast of Maine, and 

 the latter at the junction of the St Peter's and Mississippi, 

 Iowa. At Fort Sullivan, the difference of winter and sum- 

 mer is 39°-15, and that of the warmest and coldest month, 

 43°-87 ; while at Fort Snelling, these ratios are respectively 

 b&'-QQ and 61°-86. Fort Howai-d is also in the same latitude, 

 but as it is situated at the extreme point of one of the smaller 

 lakes (Green Bay, Wiskonsan), the temperature is partially 

 modified, these averages being 50°-05 and 54°-ll. Next 

 come four posts, all of which are nearly on the same parallel, 

 three being of the class of uniform climates, and one of that 

 of excessive. Of the former, two. Forts Preble and Constitu- 

 tion, are on the ocean, and the other. Fort Niagara, is on 

 Lake Ontario. At these posts, in the order just named, the 

 difference between the mean temperature of winter and 

 summer is respectively 41°-03, 36°- 33, and 41°-73 ; while, on 

 the other hand, at the excessive post, Fort Crawford, Wis- 

 konsan — a point a few minutes farther south than the three 

 former — the difference is SO^-SQ. The results at Salem, Massa- 

 chusetts, based on thirty three years' observation by Dr 

 Holyoke, though not dii'ectly under the influence of the ocean, 

 confirms the same law, the differences between the mean 

 temperature of winter snd summer being only 41°-66. At 

 all these points, the contrast in the difference of the mean 

 temperature of the warmest and the coldest month, is equally 

 striking. The next points of comparison, as lying on the 

 same parallel, are Forts Wolcott and Trumbull on the At- 

 lantic, and Council Bluffs, Fort Armstrong, and West Point, 

 in the opposite localities. The difference between the mean 

 temperature of summer and winter at Fort Wolcott, New- 

 port, Rhode Island, is 36'''55, and at Fort Trumbull, New 

 London, Connecticut, it is 32°-56 ; while at Council Bluffs, 

 near the junction of the Platte and Missouri, it is 51°-35 — at 

 Fort Armstrong, Illinois, 49°05 — and at West Point, N. Y., 



