The dusky brightness that falls from the stars, of which Corneille speaks, would have been sufficient without the gleams from the aurora borealis to enable them to distinguish the whole of the aerial skiff. The car was hung to the net which enveloped the silken vessel by strong ropes tied to the basket-work and interlaced under the feet of the aeronauts. The silence was impressively solemn; the beating of their hearts could have been heard. They were sailing at a height of five thousand metres, with an unaccustomed gravity; the upper wind was carrying them along without the faintest breath being felt in the car, for the balloon floated in the moving air like a simple bubble,--motionless, except as the current carried it along. Our travellers--sole inhabitants of these lofty regions, in full enjoyment of the exquisite elation which aeronauts know when once they have breathed that rare and sublimated atmosphere--looked down upon the realms below, forgetful of all earthly cares and associations, in the silence of their vast isolation. But they appreciated and enjoyed their unique situation more than any of those who had preceded them, for they added to the pleasures of an aerial voyage the rapture of their own happiness. They spoke in low tones, as if afraid of being overheard by the angels, and of seeing the magic charm dissolved which held them so near to heaven.... Sometimes sudden flashes came to them,--gleams from the aurora borealis; then darkness, deeper and more unfathomable than before, reigned again. They were floating thus in their starry dream when a quick, shrill noise, like that of a new whistle, sounded in their ears. They listened, leaned far out over the car, and listened again. The noise did not come from the earth. Was it an electrical blast from the aurora borealis? Was it the hiss of some magnetic storm in the upper air? Lightning coming from the depths of space flashed about them and disappeared. They listened breathlessly again. The sound was quite close to them.... It was the gas escaping from the balloon! Either the valve had partly opened of itself, or they had pressed upon the connecting rope while incautiously moving about in the car; at all events, the gas was escaping.