ON THE UOTATION OF ASCENDING BODIES. 243 



We are now prepared to understand why the barometer sinks in the 

 -centre of a storm, notwithstduding the air blows in from all directions 

 towards that point. The expansion and ascension of the air within the 

 column, and its emission above, will rapidly carry off the inward cur- 

 rent below; and, so long as the causes, which diminish the specific 

 gravity of the air within the storm, continue to operate, so long the bar- 

 ometer will continue below the mean. 



Thus far, I have confined my observations to the phenomena that 

 occur, during the action of a storm, to the atmosphere, without regard- 

 ing the vapors which it contains. But as this has an essential connex- 

 ion with these several conditions of the air, and with the formation of 

 clouds, and as its consideration would make this communication too 

 lengthy, I will reserve this interesting part of the subject for my next 

 number. 



ON THE ROTATION OF ASCENDING BODIES. 



On Saturday, September 10th, 1842, Mr. J Wise of Lancaster, Pa. 

 made a balloon ascension from Gettysburg. During tiie early part of 

 the day, it was cloudy, causing considerable apprehensions of unfavor- 

 able weather for the ascension on the part of the aeronaut and his nu- 

 merous spectators. But, at 1 o'clock, P. M. the clouds broke away, and 

 the wind, which was very gentle and had until that hour been from the 

 N. N. E., gradually veered round to the N. W. 



Upon looking at the first pilot ialloon, which Mr. Wise sent up at 

 noon, I observed it, as it moved off towards the south, to be revolving 

 on its axis from right to left in front, or in a direction contrary to the 

 motion of the hands of a watcii lying with its face upwards. My curi- 

 osity was excited by it, and believing that, if its rotation was in obedi- 

 ence to a great physical law, it would, if at starting it were made to re- 

 volve in a contrary direction, viz: from left to right, gradually lose the 

 communicated rotation and acquire that which it was observed to have. 

 Accordingly I requested Mr. Wise to give his pilot balloon a rapid rev- 

 olution from left to right, before he permitted them to escape from his 

 hands. This he kindly permitted me to do, giving me their entire con- 

 trol. I noticed that, in every instance after they had ascended to the 

 height of about one hundred yards, the communicated rotation was lost 

 and gradually one, in the direction in which the first was observed to 

 rotate, was acquired, with which it moved off at a height above the 

 earth of about three hundred yards. The large balloon, moreover, 

 wilh which he made his^ ascent, altfo bepau to icvolve in a similar man- 



