AERONAUTIC VOYAGES. 345 



from — 10°.5 to — 9°.8; tlie height we have reached varies from 6,330 to 6,902 

 meters. 



" The fog, much less dense, permits our seeing a white and feehlc image of 

 the sun. 



"A renewed discharge of ballast occasions a new ascension of the balloon, 

 which attains a new stationary position, indicated by renewed oscillations of the 

 barometer. We are covered with small particles of ice, in the shape of ex- 

 tremely fine needles, whioh accumulate in the folds of our clothing. AVlrile the 

 barometric oscillation is descending, and the movement of the balloon is conse- 

 quently ascensional, these particles fall upon our open, note-book in such quan- 

 tity as to produce a sort of crepitation. Nothing similar is observed while the 

 barometer is rising and the balloon, of course, descending. 



"The horizontal glass thermometer indicates —4°.69; the silver-plated ther- 

 mometer — 8 ".95. 



"We distinctly see the disc of the sun through the frozen mist; but at the 

 same time, in the same vertical plane, we perceive a second image of the sun, 

 almost as intense as the former. The two images appear symmetrically dis- 

 posed above and below the horizontal plane of the car, each 'making with this 

 plane an angle of about thirty degrees. This phenomenon is apparent for more 

 than ten minutes. 



" The temperature lowers rapidly. We prepare to make a complete series 

 of observations on the thermometers of radiation and those of the psychrometer, 

 but the mercurial columns are liidden by the stoppers, inasmuch as no such 

 rapid fall in the temperature had been anticipated. The thermometer with con- 

 centric envelopes of tin gives — 23^.79. 



" We open a cage iu which two pigeons are confined, but they refuse to 

 ©scape. We cast them off" into space, when, spreading their wings and wheel- 

 ing in large circles, they sink downwards and are soon lost to sight in the mist 

 wdiich surrounds us. We cannot perceive the anchor which is suspended below, 

 at the end of a cord 50 meters long. 



" 4^' 32™. — We discharge ballast and rise still higher. The clouds separate 

 above, and we see in- the sky a space of bright azure blue, similar to that seen 

 on earth in clear weather. The polariscope indicates no polarization, in any 

 direction, on the clouds immediately around or remote from us. The blue of 

 the sky, on the contrary, is strongly polarized. 



" The oscillations of the barometer indicating that we have ceased to ascend, 

 we throw out ballast, and obtain a new ascensional movement. 



" Our fingers are stiffened with cold, but we experience no pain in the ears. 



nor is respiration at all embarrassed. The sky is covered anew with clouds, 

 but the sun, though veiled, is still seen, as well as its image. We think it would 

 be interesting to find if the cold Avill still increase on ascending yet higher. We 

 throw out ballast, which determines a further ascension. 



" 4^' 50'". — The barometer marks 315.02 millimeters. The extremity of the 

 column of the thermometer of the barometer is lower by about two degrees than 

 the last division marked on the instrument. This division is —.37^ ; the tem- 

 perature, therefore, Avas about— 39°; the height, consequently, which we had 

 attained is 7,039 meters. 



"The barometer oscillates from 315.02 millimeters to 326.20; hence the bal- 

 loon oscillates from 7,039 to 6,798 meters. There are only four kilograms of 



