DISCUSSION AND ANALYSIS OP WINDS. 697 



flows towards the southern parts of the Mexican and Caribbean Seas, where the 

 rainy season is at its height in October. (See also Plates 8 and 14.) 



The British Provinces north of the United States have mostly the same system 

 of winds as the latter country. This is especially the case in New Brunswick, 

 Nova Scotia, and Newfoundland. Here we find the same conditions as in New 

 England, that is, prevailing N. W. in winter, spring, and autumn, and S. W. in 

 summer. 



In Lower Canada the winds are influenced by the direction of the valley of the 

 St. Lawrence, and therefore the S. W. are more frequent than they would be 

 otherwise. The same is the case in N. E. New York, where most stations along 

 the St. Lawrence show also prevailing S. W. winds. Labrador has N. W. 

 winds, but the mean direction is more northerly in winter than in other parts 

 of the Atlantic coast, and the ratio of resultant is extremely great. In fact, the 

 N. W. wind in Labrador is so constant as to remind us of the Avinter monsoon of 

 the eastern coast of Asia. As is the case there, this wind is caused by the great 

 difi'erence of pressure between the land to the W. and the ocean to the E., and, 

 as this difi'erence continues nearly all winter in the same direction, the wind is 

 very constant from the N. W. 



In summer the winds are from the N. and N. E. in Labrador, coming from the 

 ice-laden seas in this direction. The frequency of N. W. winds, even in summer, 

 seems to indicate that pressure is high in the interior of the continent also at that 

 season. The great number of lakes and morasses, which are full of ice till the 

 middle or end of summer, as also the long continuance of snow in the woods of 

 Labrador, may be the cause of this relatively high pressure. (See Plates 8 

 and 14.) 



A very instructive table, compiled by Prof. Coffin from observations at forty dif- 

 ferent places in Delaware, Southeastern Pennsylvania, and Southern New Jersey, 

 shows the mean number of days of each month on which every wind blew. (See 

 Table, Zone 11, p. 432.) The mean direction and ratio of resultant for this im- 

 portant region of the Middle States is given below. 



January N. 81° W. .28 July S. 83° W. .41 



February N. 78 W. .38 August S. 64 W. .26 



March N. 83 W. .30 September N. 89 W. .31 



April S. 89 W. .20 October N. 88 W. .37 



May S 89 W. .33 November N. 79 W. .39 



June S. 84 W. .33 December N. 79 W. .44 



Here, as generally on the Middle Atlantic coast, the change in the mean direc- 

 tion is slight, the wind being westerly in all months, and the difference but 38° 

 between February, when the winds incline most to tlie north, and August, Avhen 

 the most southerly direction is reached. 



A similar calculation of Prof Coffin for forty-nine stations in New England, 

 south of 45° L. N., shows the following. (See p. 360.) 



