22 REPORT OF THE SECRETARY. 



In winter it is northwest by north; in summer north ^ths of a point 

 west; for the whole year, N.NW|W. The corresponding directions 

 for Baffin's bay are nearly the same, and the final resultant direction 

 for the year at the two localities are practically identical. 



In the first year, while in Baffin's bay, the velocity of the wind 

 was greatest in February and March, and least in June and July. 

 In the second year, at Port Kennedy, it was greatest in October and 

 November, and least in March and April. 



The greatest amount of wind, both at Port Kennedy and Baffin's 

 bay, was from the northwest, in accordance with the theory of the de- 

 scent or sinking down of the heavier air in the colder regions, and its 

 flowing thence to warmer portions of the earth. For the purpose of 

 ascertaining the law of the rotation of the winds, the records were 

 examined in reference to the number of times the vane arrived at 

 each of the eight principal points, and also in reference to the sum 

 total of angular movement in a direct and retrograde direction. 



From this investigation it appears that the direction of the shift- 

 ing of the wind in spring was direct; at other seasons retrogade, and 

 that the toti^^ amount of angular motion in the course of a year was 

 very nearly balanced. 



At Rensselaer harbor the resultant rotation of the wind was found 

 to be direct, and this was also the case in Baffin's bay, although it 

 would appear from these discussions, that the law of the rotation of 

 the wind which has been found to prevail in lower latitudes, does not 

 hold with the same constancy in the arctic regions. 



In the year 1857-58, in Baffin's bay, there were 26 storms of an 

 average duration of 19 hours; in these storms the prevailing winds 

 w^ere, almost to the exclusion of all others, from the northwest and 

 soutlieast. At Rensselaer harbor, according to Kane, the winds 

 during the prevailing storms were from the same points of the hori- 

 zon. At Port Kennedy during the year 1858-'59 there were 22 

 storms recorded, in which the wind was from the northwest; in a 

 few cases it was from the northeast; but in not one from the north- 

 west or southeast. 



The third part of the McClintock observations relate to the pres- 

 sure of the atmosphere. These observations were recorded at equal 

 intervals of two hours at one period, and of four hours at others. 

 They were made with a mercurial barometer, and also with an 

 aneroid. 



The records of the readings of the two instruments were compared. 



