284* AEROSTATIC VOYAGE. 



cifely in oppofilion lo, and in the fame proportion as the co- 

 line of its inclination, which is by no means probable. In 

 iupport of our conclusion we have, befides, the experiment 

 on the inclination made at the height of 3S63- metres 

 (12651.325 ket), which proves that, at that elevation, the 

 variation did not vary in a fenftbie manner. 



When at the height of 451 1 metres, I prefcnted to a fmall 

 touched needle, and in the direction of the magnetic power, 

 the lower extremity of a key ; the needle was attracted, and 

 afterwards repelled by the other extremity of the key, which 

 I brought down parallel to itfelf. The fame experiment, 

 repeated at 6107 metres, had the fame ilTiie : another very 

 evident proof of the a&ion of terreftrial magnetifm. 



At the height of 6561 metres (21487.275 feet), I opened 

 one of my two balloons of glafs; and at 6636 metres 

 (21733.9 feet), I opened the Second : the air entered both 

 with a hilling noife. Finally, at 3 h 11', the aeroftat being 

 perfectly full, and having only 15 kilogrammes of ballaft, I 

 determined to defcend. The thermometer was then at 9.5 U 

 below the temperature of melting ice, and the barometer at 

 32.88 centimetres ; which gives for my greateft elevation 

 above Paris, 6977.37 metres (22S50.S87 feet), or 7016 

 metres (22977.4 feel) above the level of the fea. 



Although well clothed I began to feel the cold, particularly 

 in my hands, which I was obliged to keep expofed to the air. 

 My refpiration was fenfibly obftrucied ; but I was far from 

 Seeling any inconvenience Sufficient to induce me to defcend. 

 My pulfe and my refpiration were greatly accelerated ; hence 

 from refpiring very frequently in a very dry air, I could not 

 be Surprifed at my throat being fo dry, that it was with diffi* 

 cuHy I fwallowed bread. Before felting out I had a flight 

 head-ach, arifing from the fatigues of the preceding day and 

 the want of reft in the night, and I retained it all the day, 

 without perceiving that it was increafed. Thefe are all the 

 inconveniences I experienced. 

 Clouds at a very A phenomenon which Struck me at this great height, was 

 - ght the feeing clouds above me, and at a diftance which appeared 

 lo me to be very considerable. During our firft afcent the 

 clouds did not rife above 1169 metres (3828.475 feet), and 

 above, the Iky was in its greateft purity. Its colour at the 

 zenith was fo intenfe, that it might be compared with that of 



Prutlian 



Further proofs 

 of the magnet- 

 ifm being the 

 fame as on the 

 earth. 



Heights at 

 which the ?ir 

 was taken for 

 examination. 



Greateft ek\ 

 tion. 



Effects on the 

 animal economy 

 at this height. 



during this 

 afcent. 



Their extreme 

 height in the 

 fprmer one. 



