344 



AERONAUTIC VOYAGES. 



"Above us there extends an uniuterrupted bed of elouds ; below we perceive 

 here and there detached clouds which appear to float over Paris. The wind is 



frc-^li. 



" The cloud which we enter presents the appearance of an ordinary dense 

 fogr. The earth is no longer discernible. 



"A few solar rays become perceptible through the clouds. 



"The barometer oscillates from 366.99 millimeters to 386.42 millimeters ; the 

 thermometer marks — 9°.0; calculation gives from 5,911 to 5,492 as the height 

 reached at this point of time. 



" The balloon is entirely inflated. The appendage, compressed till now by 

 the external atmosphere, is at present distended, and the gas escapes by its 

 lower orifice under the form of a whitish trail ; we perceive its odor very dis- 

 tinctly. We discover in the balloon, at the distance of about 1.5 millimeter from 

 the insertion of the appendage, a rent, which afibrds issue to a greater amount of 

 gas, without diminishing, howevei-, in any important degree, the ascensional 

 force of the aerostat. 



"An opening in the cloud enables tis vaguely to perceive the position of the 

 Bun, 



" The balloon resumes its ascendant movement after a new discharge of 

 ballast. 



" 4'^ 25^. — Oscillations of the barometer between 347.75 millimeters and 

 367.04 millimeters indicate a new station of the balloon ; the thermometer varies 



* All (he barometric heif^hts taken have been reduced to the temperature of 0° by calcula- 

 tion. By means of the barometric and thermometric observations, made at the observatory 

 and in the car, the heicfhts of nineteen stations above the observatory and above the sea ^vere 

 calculated, increasing them by 65 meters. But the three heights, 6,512, 7,049, and 6,765 

 meters, where the temperature had sunk to — 35°, — 36'^, and — 39'^, were obtained by cal- 

 culating, not from the observatory, but from the intermediate station of 5,902 meters, where 

 the temperature was — 9'^.8, and the pressure 367.04 millimeters. There results 7,004 for the 

 highest station. But it is still necessary to add a correction of 12 meters, due to the height (5,902 

 meters) of the inferior station of comparison, and 33 meters on account of the influence of the 

 hour of .the day, as was justly remarked by M. Bravais, which makes in all 7,049 meters. 



