21 



It may be proper to observe, that neither extreme 

 elevations nor extreme depressions occur suddenly, the 

 mercury being usually for some few days preceding 

 them in a gradually rising or falling state. 



The horizontal pressure of the most violent gusts was 

 20 and 25 Ibs. on the square foot, the wind having a 

 velocity of 60 and 80 miles an hour. 



A Table showing the age, declination, and position of the 

 Moon in her orbit, in some of the most remarkable ele- 

 vations of the Barometer. 



