The effect was ghastly, unnerving and altogether terrible. Not that Stern feared height. No, it was the unreality of the experience, the inexplicable character of this yawning edge of the world that almost overcame him.
Only by a strong exercise of will-power could he hold the biplane to her course. His every instinct was to veer, to retreat back to solid earth, and land somewhere, and once more, at all hazards, get the contact of reality.
But Stern resisted all these impulses, and now already had driven the Pauillac right to the lip of the vast nothingness.
Now they were over!
“My God!” he cried, stunned by the realization of this thing. “Sheer space! No bottom anywhere!”
For all at once they had shot, as it were, out into a void which seemed to hold no connection at all with the earth they now were quitting.
Stern caught a glimpse of the tall forest growing up to within a hundred yards of the edge, then of smaller trees, dwindling to bushes and grasses, and strange red sand that bordered the gap--sand and rocks, barren as though some up-draft from the void had killed off vegetable growth along the very brink.
Then all slid back and away. The red-ribbed wall of the great chasm, shattered and broken as by some inconceivable disaster, some cosmic cataclysm, fell away and away, downward, dimmer and more dim, until it faded gradually into a blue haze, then vanished utterly.
And there below lay nothingness--and nothingness stretched out in front to where the sight lost itself in pearly vapors that overdimmed the sky.
Beatrice glanced at Stern as the Pauillac sped true as an arrow in its flight, out into this strange and incomprehensible vacuity.
Just a shade paler now he seemed. Despite the keen wind, a glister of sweat-drops studded his forehead. His jaw was set, set hard; she could see the powerful maxillary muscles knotted there where the throat-cords met the angle of the bone. And she understood that, for the first time since their tremendous adventure had begun, the man felt shaken by this latest and greatest of all the mysteries they had been called upon to face.
Already the verge lay far behind; and now the sense of empty space above and on all sides and there below was overpowering.
Stern gasped with a peculiar choking sound. Then all at once, throwing the front steering plane at an angle, he brought the machine about and headed for the distant land.
He spoke no word, nor did she; but they both swept the edge of the chasm with anxious eyes, seeking a place to light.
It was with tremendous relief that they both saw the solid earth once more below them. And when, five minutes later, having chosen a clear and sand-barren on the verge, some two miles southward along the abyss, Stern brought the machine to earth, they felt a gratitude and a relief not to be voiced in words.
“By Jove!” exclaimed the man, lifting Beatrice from the seat, “if that isn't enough to shake a man's nerve and upset all his ideas, geological or otherwise, I'd like to know what is!”
“Going to try to cross it?” she asked anxiously; “that is, if there is any other side? I know, of course, that if there is you'll find out, some way or other!”
“You overestimate me,” he replied. “All I can do, for now, is to camp down here and try to figure the problem out--with your help. Whatever this thing is, it's evident it stands between us and our plan. Either Chicago lies on the other side--(provided, of course, as you say, that there is one)--or else it's been swallowed up, ages ago, by whatever catastrophe produced this yawning gulf.
“In either event we've got to try to discover the truth, and act accordingly. But for now, there's nothing we can do. It's getting late already. We've had enough for one day, little girl. Come on, let's make the machine ready for the night, and camp down here and have a bite to eat. Perhaps by to-morrow we may know just what we're up against!”
The moon had risen, flooding the world with spectral light, before the two adventurers had finished their meal. All during it they had kept an unusual silence. The presence of that terrible gulf, there not two hundred feet away to westward of them, imposed its awe upon their thoughts.
And after the meal was done, by tacit understanding they refrained from trying to approach it or to peer over. Too great the risks by night. They spoke but little, and presently exhausted by the trying events of the day--sought sleep under the vanes of the Pauillac.
But for an hour, tired as he was, the engineer lay thinking of the chasm, trying in vain to solve its problem or to understand how they were to follow any further the search for the ruins of Chicago, where fuel was to be had, or carry on the work of trying to find some living members of the human race.
Morning found them revived and strengthened. Even before they made their fire or prepared their breakfast they were exploring along the edge of the gigantic cleft.
Going first to make sure no rock should crumble under the girl's tread, no danger threaten, Stern tested every foot of the way to the very edge of the sheer chasm.
“Slowly, now!” he cautioned, taking her hand. “We've got to be careful here. My God, what a drop!”
Awed, despite themselves, they stood there on a flat slab of schist that projected boldly over the void. Seen from this point, the immense nothingness opened out below them even more terrible than it had seemed from the biplane.
The fact is common knowledge that a height, viewed from a balloon or aeroplane, is always far less dizzying than from a lofty building or a monument. Giddiness vanishes when no solid support lies under the feet. This fact Stern and the girl appreciated to the full as they peered over the edge. Ten times more ominous and frightful the vast blue mystery beneath them now appeared than it had seemed before.
“Let's look sheer down,” said the girl. “By lying flat and peering over, there can't be any danger.”
“All right, but only on condition that I keep tight hold of you!”
Cautiously they lay down and worked their way to the edge. The engineer circled Beta's supple waist with his arm.
“Steady, now!” he warned. “When you feel giddy, let me know, and we'll go back.”
The effect of the chasm, from the very edge of the rock, was terrifying. It was like nothing ever seen by human eyes. Peering down into the Grand Canon of the Colorado would have been child's play beside it. For this was no question of looking down a half-mile, a mile, or even five, to some solid bottom.
Bottom there was none--nothing save dull purple haze, shifting vapors, and an unearthly dim light which seemed to radiate upward as though the sun's rays, reflected, were striving to beat up again.
“There must be miles and miles of air below us,” said Stern, “to account for this curious light-effect. Air, of course, will eventually cut off the vision. Given a sufficiently thick layer, say a few hundred miles, it couldn't be seen through. So if there
“Yes; but in that case how can we see the sun, or the moon, or stars?”
“Light from above only has to pierce forty or fifty miles of really dense air. Above that height it's excessively rarified. While down below earth-level, of course, it would get more and more dense all the time, till at the bottom of a five-hundred-mile drop the density and pressure would be tremendous.”
Beatrice made no answer. The spectacle she was gazing at filled her with solemn thoughts. Jagged, rent and riven, the rock extended downward. Here vast and broken ledges ran along its flanks--red, yellow, black, all seared and burned and vitrified as by the fire of Hell; there huge masses, up-piled, seemed about to fall into the abyss.
A quarter-mile to southward, a rivulet had found its way over a projecting ledge. Spraying and silvery it fell, till, dissipated by the up-draft from the abyss, it dissolved in mist.
The ledge on which they were lying extended downward perhaps three hundred yards, then sloped backward, leaving sheer empty space beneath them. They seemed to be poised in mid-heaven. It was totally unlike the sensation on a mountain-top, or even floating among the clouds; for a moment it seemed to Stern that he was looking up toward an unfathomable, infinite dome above him.
He shuddered, despite his cool and scientific spirit of observation.
“Some chemical action going on somewhere down there,” said he, half to divert his own attention from his
