United States Weather Maps and other sources. 3 



the wind. A northerly direction occurs 10 times ; southerly, 

 6 times ; easterly 7 times ; and westerly, 5 times. In every 

 instance (except one) these winds were faint, and generally 

 very faint. In two-thirds of the cases the sky was entirely 

 clear, and in only two cases was the sky entirely overcast. In 

 three-fourths of the cases the barometer stood above its mean 

 height. 



Lowest temperature for each month at JaMtsk, Siberia, f 



or the 





years 18U, 5 and Q. 





























in.n4u°m. | 



temp-r 



direction. 



force. 



Face of sky. 



bar.'^m'nbar 



Inches. 



1844, Sept. 30 



-3°1 



~N~W~~ 



very faint 



overcast. 



i^'i^ 



+ 019 



Oct. 31 





Calm. 





clear. 





+ 0-29 



Nov. 29 





N.N.W 



very faint 







+ 0-25 



Dec. 18 





Calm. 





partly clear. 











S. S. W. 



. 







-0-06 



''^'' ^.^^l 



I40-; 



Calm. 





clear. 

















601-21 594-9 +0-31 



April 5 



-20-£ 





very faint 





601-9 592-4 +0-48 





- 7-8! W. 



strong. 







JUM 9 



- 1-3! E. 







584-4 587-3 -0-14 



July 30 





N.E. 



very faint 



clear 











very faint 





589-6 588-7 1 0-05 



Sept 26 





Calm. 





partly clear. 



596-2 594-2+0-10 



Oct. 31 







faint. 



pa«;.*„. 





Nov. 23 



-39-8 



V' 







Dec. 25 





N.E. 



very faint. 



clear. 



604-6 601-2' +0-17 



1846, Jan. 10 



141-9 



N. N. E. 



faint. 



partly clear. 



595-9 597-9| -0-10 



Feb. 2 



-43-6 N. N. E. 



faint. 



partly clear. 





Mar. 14 









599-5 594-9: +0-23 



April 10 





veryflint 



clear! 





May 3 



-17-41 N. 









June 9 



+ 2-4iW.S.W. 



faint 



mostly overcast. 



582-4 587-31 -0-24 



In all these particulars, except the direction of the wind, the 

 phenomena at Jakutsk are quite similar to those observed at 

 New Haven. So far as I have yet learned it is true universally 

 that periods of unusual cold are generally accompanied by a 

 barometer above the mean. Now it has been shown (this Jour., 

 vol. ix,p. 2) that within areas of high barometer the motion of 

 the air is outward from the center of this area, and therefore 

 there must be a downward motion to supply the air flowing 

 outward. In other words, it must be regarded as an observed 

 fact that periods of unusual cold are generally accompanied by 

 a descent of air from the upper regions of the atmosphere. 



Influence of Winds on the temperature, moisture and 2yresmre of 

 the atmosphere. 

 In order to determine the influence of winds upon the tem- 

 perature, etc., of the atmosphere, I selected the Meteorological 

 observations made at Girard College, Philadelphia, from 1840 



