For a long time they sat in the deepening gloom, their rifles close at hand, saying little, but thinking much. The coming of night had sobered them to a sense of what now inevitably lay ahead. The solemn purple pall that adumbrated the world and the huge nothingness before them, so silent, so immutable and pregnant with terrible mysteries, brought them close together. The vague, untrodden forest behind them, where the night-sounds of the wild dimly reechoed now and then, filled them with indefinable emotions. And that night sleep was slow in coming. Each realized that, despite all calculations and all skill, the morrow might be their last day of life. But the morning light, golden and clear above the eastern sky-line of tall conifers, dispelled all brooding fears. They were both up early and astir, in preparation for the crucial flight. Stern went over the edge of the chasm, while Beatrice prepared breakfast, and made some final observations of wind, air currents and atmosphere density. An eagle which he saw soaring over the abyss, more than half a mile from its edge, convinced him a strong upward current existed to-day, as on the day when they had made their short flight over the void. The bird soared and circled and finally shot away to northward, without a wing-flap, almost in the manner of a vulture. Stern knew an eagle could not imitate the feat without some aid in the way of an up-draft. "And if that draft is steady and constant all the way across," thought he, "it will result in a big saving of fuel. Given a sufficient rising current, we could volplane all the way across with a very slight expenditure of alcohol. It looks now as though everything were coming on first-rate. Couldn't be better. And what a day for an excursion!" By nine o'clock all was ready. Along the land a mild south wind was blowing. Though the day was probably the 5th of October or thereabout, no signs of autumn yet were blazoned in the forest. The morning was perfect, and the travelers' spirits rose in unison with the abounding beauty of the day. Stern had given the Pauillac another final going over, tightening the stays and laterals, screwing up here a loosened nut, there a bolt, making certain all was in perfect order. At nine-fifteen, after he had had a comforting pipe, they made a clean getaway, rising along the edge of the chasm, then soaring in huge spirals. "I want all the altitude I can get," Stern shouted at the girl as they climbed steadily higher. "We may need it to coast on. And from a mile or two up maybe we can get a glimpse of the other side." But though they ascended till the aneroid showed eight thousand five hundred feet, nothing met their gaze but the same pearly blue vapor which veiled the mystery before them. And Stern, satisfied now that nothing could be gained by any further ascent, turned the machine due west, and sent her skimming like a swallow out over the tremendous nothingness below.