performed ly Messrs. Guy-Lussac and Blot. 377 



horizontal position • which would not have hccn the case 

 had the force which tends to incline them experienced any 

 sensible change. 



The declination also was an object of our researches ; but 

 the weather and the disposition of o.ur apparatus did not 

 permit us to determine it exactly. It is, however, equally 

 probable, that it does not vary in a sensible manner; but 

 he this as it may, we have now the means of measuring it 

 exactly during another voyage ; we can also ascertain cor- 

 rectly the inclination. That we might not interrupt this 

 narrative, we passed over in silence some other experiments 

 .of less importance, to which it is necessary now to recur. 



We observed our animals at various heights, but they 

 did not seem to be in the least incommoded. In regard to 

 ourselves, we experienced no other effect than an accelera- 

 tion of our pulse, which I have already mentioned. At the 

 height or 3400 metres we set at liberty a small bird called 

 a greenfinch: it immediately Hew away, but in an instant 

 returned, and perched on the cordage of the balloon ; it 

 then took a new flight, darting towards the earth, and de- 

 scribing a serpentine line very little different from the ver- 

 tical. We followed it with our eyes to the clouds, where we 

 lost sight of it ; but a pigeon which we let go in the same 

 manner, and at the same height, exhibited a spectacle. much 

 more curious. When set at liberty on the edge of the car, 

 jt remained there a few moments, as if to measure the ex- 

 tent it had to traverse ; it then darted off, hovering about in 

 an irregular manner, as if it were trying its wings ; but after 

 a few strokes it confined itself to extenoino; them, and, aban- 

 doning itself to them entirely, began to descend towards the 

 clouds, describing large circles like the birds of prey. Its 

 descent was rapid, but regular ; it soon entered the clouds, 

 and we could still see it below them. 



W r e had not yet tried the electricity of the air, because 

 our attention had been engrossed almost entirely by observ- 

 ing the compass, which was the most important object, and 

 which made it necessary for us to embrace the moments 

 favourable for that purpose. Besides, we had always had 

 clouds below us, and it is well known that the clouds are 

 ciiiierently charged with electricity ; we had not then the 

 means necessary for calculating their distance, according to 

 the height of the barometer, and we did not know what in- 

 fluence they might have upon us. Howeyer, to try our ap- 

 paratus, we extended a wire of 240 feet in length; and hav- 

 ing insulated it from us, as already said, we extracted elec- 

 tricity from its upper extremity, and applied it to the elec- 



C c 3 trometer ; 



