742 



The heights of the barometer are in hun- 

 dredths of millimeter. We shall choose two 

 months only on the whole year, of which we 

 are in possession. M. Boussingault justly ob- 

 serves, that " the mean monthly heights are 

 greatest in June and July; and the least in 

 December and January, when the earth is 

 nearest the sun. M The following are the mean 

 heights reduced, as in the table of the month of 

 August and December, to the temperature of 

 zero. I have placed by the barometric mean, 

 the mean extent of the diurnal oscillations from 

 9 h till 4 h , and the mean of the temperature cor- 

 responding to those epochas of the morning and 

 afternoon. M. Ramond, from the year 1814, 

 has thrown great light on the curious phenome- 

 non of the monthly oscillations of the barome* 

 ter, 



