Di* Forry on the Climate of the United States. 89 



the formei' is 64°-76, and the latter 81°-25, and at Key West 

 70°-05 and 81"-39. Thus, though the winter at Fort Snel- 

 ling is 54:°'10 colder than at Key West, yet the mean tem- 

 perature of summer at the latter is only 8''-64 higher. In 

 like manner, although the mean annual temperature of Petite 

 Coquille, Louisiana, is 2° lower — that of Augusta Arsenal, 

 Georgia, nearly 8^ — and that of Fort Gibson, Arkansas, up- 

 ward of 10'' lower — than that of Fort Brooke ; yet at all, the 

 mean summer temperature is higher. Between Fort Snel- 

 ling, on the one hand, and Fort Brooke and Key AVest on 

 the other, the relative distribution of temperature stands 

 thus : difference between the mean tempei'ature of summer 

 and winter at the former 56°-60, and at the two latter 16°'49 

 and 11°"34 ; difference between the mean temperature of the 

 warmest and coldest month, 61''"86, compared with 18°-66 and 

 14°-66 ; difference between the mean temperature of winter 

 and spring, 30°-83 to 8°-35 and 5'-99 ; and the mean differ- 

 ence of successive months, 10''-29 to 3^-09 and 2°-44. 



The diverse climatic peculiarities of Fort Snelling and 

 Key West are delineated in the accompanying engraving, 

 Plate II. The contrast in the course of the mean annual 

 temperature of these two posts, as traced through each 

 month, is indeed striking, while the variation of temperature 

 on each of these monthly lines is still more marked. Al- 

 though the average minimum temperatui'e of Fort Snelling 

 in January is as low as 22° below zero, while that of Key 

 West is 57° above ; yet, strange to say, we find the mean 

 maximum temperature of July at the former 5° higher than at 

 the latter. The course of the seasons are equally marked in 

 their conti'asts ; for, while the curves of Key West are confined 

 within a few degrees, those of Fort Snelling are so oppo- 

 site that the lines of spring and autumn traverse each other at 

 right angles, and those of summer and winter are so remote 

 that the one is truly hyperborean, and the other tropical. 



This remarkable equality in the distribution of tempera- 

 ture among the seasons in Florida, compared with the other 

 regions of the United States, constitutes its chief climatic 

 peculiarity ; and the comparison, if extended to the most fa- 

 voured situations on the continent of Europe, and the va- 



