756 WINDS OFTHE GLOBE. 



PLATE 2 6. 



Deflecting Forces. 



The " S-shaped" curves ■ y — ^ are divided into twelve parts to denote the path traversed by a 



particle of air, in each of the months of the year, when subjected to the winds that are found at 

 Amherst, Massachusetts, Easton, Pennsylvania, New York City, Paris and Pekin, which are taken 

 as representative places. In each case is seen the "parallelogram of forces," of which the diagonal 

 represents the monthly resultant, one side one-twelfth of the yearly resultant, and another side the 

 monsoon influence. Near each is gathered a parallel series of arrows to show the position of these 

 monsoon influences relative to each other. 



The law of the Monsoon Influences is seen in two facts: 1st. All these places, except Paris, are 

 situated on the western shore of the adjacent oceans, and their monsoon influences are from the south- 

 southeast in summer, and from the north-northwest in winter; but at Paris, not thus situated, their 

 direction is reversed. And 2d. The monsoon influences at Pekin, which is emphatically in the 

 monsoon region, and at New York, which is near the ocean, are greater than those at the other 

 places which are not thus situated. 



In the diagram at the right, in this Plate, representing an aggregate period of 5G0 years of obser- 

 vation, taken at more than CO places in the State of New York, the approximate parallelism and 

 equality of the arrows show the permanent character of the winds, and their divergence or insquality 

 their annual mutations ; yet the latter are rather apparent than real, since they are due chiefly to 

 the introduction of new stations or discontinuance of old stations, so producing a slight modification 

 of the result, and not indicating any really marked differences in the annual resultants. Two striking 

 instances of diurnal variation in the direction of the wind are given on the lower part of the Plate 

 for Hudson, Ohio, and St. Petersburg, which are easily explained by the proximity of each of these 

 places to a considerable body of water situated north and northwest of them. 



