22 Questions Jbr Solutio7i relating to Meteorology, 



It will be seen, from the inspection of this table, that the di- 

 rection of the wind occasions a variation in the state of the ba- 

 rometer at Paris of S"'"', 1 above the mean, and of 2""*", 6 below 

 it, forming a total variation of 5""% 7 ; and that the opposite 

 winds, combined two by two, give a mean height which, in ex- 

 treme cases, scarcely differs by half a millimetre from the mean 

 of all the observations. 



M. Bouvard has presented to the academy the results of an 

 investigation analogous to that of Burckhardt ; it is founded on 

 the observations of the barometer made at the observatory of 

 Paris from 1816 to 1831, and leads in general to the same con- 

 sequences. By assigning to the letter H. the signification which 

 we gave it in the preceding table, we shall have the following 

 barometrical heights, corresponding to the different directions 

 of the winds : — 



South wind, 



South-west, 



West, 



North-west, 



North, 



North-east, 



East, . 



South-east, 



The daily observations at nine o'clock in the morning, at 

 mid-day, and at three in the afternoon, have all concurred in 

 the formation of these numbers. Very nearly the same results 

 will be obtained by employing only the maxima heights of nine 

 o'clock, and the minima heights of three o'clock. 



In this instance, as well as in the table of Burckhardt, half 

 the suras of the heights corresponding to the opposite winds, are 

 nearly equal to H, that is to say to the total mean. The high- 

 est mean effect of the wind is 6™™, 9, which surpasses the result 

 afforded by the observations of Messier by l'""", 2. 



