ABOUT THE 20tH OF DECEMBER, 1836. 153 



mean of all these directions is about N. 74° W. On the southern border, also, 

 the prevalent direction is north-west, although at two stations it is represented 

 as inclining to the east. On the east side of the line of barometric minimum, 

 the prevalent direction is from the south-east. As the observations were not 

 all made at the same hour, thej are not strictly comparable; and it seems ne- 

 cessary to leave out of the account those which were made near the line of 

 minimum, because we cannot know, except conjecturally, whether they were 

 made before or after this line had passed. We thus obtain for the mean direc- 

 tion at the remaining stations about S. 5° E. At a certain distance, however, 

 from the line of minimum the courses are very uniformly south-east. As this 

 line approached, the wind veers to the south, south-west, west, and north-west. 

 In the afternoon of the 21st, the line of barometric minimum had nearly 

 reached Boston, and the north-west wind had become the prevalent one 

 throughout almost the entire United States. In the extreme west the wind 

 had begun to moderate its violence, and at Fort Jesup it blew from the north- 

 east; at Fort Gibson from the east; and at Jefferson Barracks from the south- 

 east. These are the only easterly winds recorded any where upon the west of 

 the line of barometric minimum. The only south winds were at Pomfret and 

 Granville, in New York. All the other winds, eighty-one in number, were 

 from some point between the north and south-west; and their mean direction 

 about N. 70° W. 



On the 22d the north-west wind was almost every where the prevalent one, 

 particularly in the eastern section of the United States, where it blew inva- 

 riably from some point between the north and south-west. On the southern 

 border it blew very uniformly from the north ; and in the western states the 

 winds were becoming more light and irregular, veering round to the south and 

 south-east, as they had done three days previous. 



From the preceding review it will be seen that, in the midst of much irregu- 

 larity, there was a considerable degree of uniformity in the course of the winds 

 throughout the entire period under examination. It blows, at first, fresh from 

 the north-west ; this wind moderates and veers to the southward ; it changes 

 by nearly a calm to some eastern quarter; blows fresh from the south-east, in 

 some places a gale; veers rapidly to the south, south-west, west, and north- 

 west, blowing all the time with great violence. After about a day, the north- 

 west wind moderates into a calm, and is succeeded by a southerly wind. In 



YH — 2 



