346 



AERONAUTIC VOYAGES. 



ballast remaining, whicli we judge it prudent to keep for the descent. Besides, 

 it is useless to try to mount higher Avith instruments \A'hich have become mute; the 

 mercury is congealed. We could, at most, only strive to maintain ourselves for 

 gome time at the same height, but, although the appendage is raised to prevent 

 the escape of gas by its orilicc, the balloon begins to descend. We proceed to 

 secure portions of the air, and, though the tube of one of the receptacles is 

 broken in attempting to turn the stop-cock, the other is filled without accident. 

 But the cold paralyzes all our efforts; observations Jiave become impossible; 

 our fingers are disqualified for every operation. We resign ourselves to a 

 descent. 



** We still encounter the little needles of ice 



Hours. 



5h 7m 

 5 10 

 5 12 

 5 14 



Barometer. Temperature. 



Millimeters. 

 483.16 

 540. 39 

 559. 70 



582. 90 



Height. 



Meters. 

 3, 688 

 2, 796 

 2, 452 

 2, 185 



" The thermometer with a glass surface marks +2°. 50 ; that with a silvered 

 surface +1°.91. 



a Qh iQm — rpj^g barometer oscillates from 598. 5 millimeters to 618.0 millime- 

 ters, because we throw over our ballast, and this arrests our descent ; the tem- 

 perature is l'-\8; the height varies from 1,973 to 1,707 meters. 



" The oscillations are prolonged by the discharge of the last portions of our 

 ballast. We are now only occupied with moderating the descent by sacrificing 

 all that we have at our disposal, except the instruments, and we place the 

 thermometers in their cases. 



" 5^ 30™. — We touch the earth at the hamlet of Peux, a commune of Saint 

 Denis les llebris, arrondissement of Coulommiers, (Seine et Marne,) at some 

 paces from the residence of M. Brulfert, mayor of the commune, 70 kilometers 

 distant from Paris. 



" We had the good fortune to break no instrument in our descent. The 

 village afforded but a single vehicle to carry us to the Strasbourg railroad, 18 

 kilouicters distant, and the transfer was rendered troublesome by a violent storm 

 of wind and rain ; the horse fell, breaking two of the instruments, which we 

 greatly desired to carry safe to Paris, namely, the balloon for air, and the instru- 

 ment indicating the minimum of barometric pressure. Fortunately the minimum 

 thermometer of M. Walferdin, with his seal, was conyeyed intact to the College 

 of France. Here the seal was removed by MM. Hegnault and Walferdin, and 

 the minimum of temperature determined, by direct experiment, was found to be 

 — 39^.G7, consequently very little difierent from the lowest temperature observed 

 by ourselves on the thermometer of the barometer." 



In rendering my report to the Academy of Sciences, I remarked that the fact 

 of the presence of a cloud composed of small particles of ice having a temper- 

 ature of about —40° in mid-summer, at a height of from 6,000 to 7,000 meters 

 above the surface of Europe, is the gi'catest discovery which meteorology has 



