Away and away behind them slid the lip of this gigantic gash across the world; and now already with the swift rush of the plane the solid earth had begun to fade and to grow dim.
Stern only cast a glance at the sun and at his compass, hung there in gimbals before him, and with firm hand steadied the machine for the long problematical flight to westward. Behind them the sun kept even with their swift pace; and very far below and ahead, at times they thought to see the fleeing shadow of the biplane cast now and then on masses of formless vapor that rose from the unsounded deeps.
Definitely committed now to this tremendous venture, both Stern and the girl settled themselves more firmly in their seats. No time to feel alarm, no time for introspection, or for thoughts of what might lie below, what fate theirs must be if the old Pauillac failed them now!
No time save for confidence in the stout mechanism and in the skill of hand and brain that was driving the great planes, with a roaring rush like a gigantic gull, a swooping rise and fall in long arcs over the hills of air, across the vast enigma of that space!
Stern's whole attention was fixed on driving, just on the manipulation of the swift machine. Exhaust and interplay, the rhythm of each whirling cam and shaft, the chatter of the cylinders, the droning diapason of the blades, all blent into one intricate yet perfect harmony of mechanism; and as a leader knows each instrument in the great orchestra and follows each, even as his eye reads the score, so Stern's keen ear analyzed each sound and action and reaction and knew all were in perfect tune and resonance.
The machine--no early and experimental model, such as were used in the first days of flying, from 1900 to 1915, but one of the perfected and self-balancing types developed about 1920, the year when the Great Death had struck the world--responded nobly to his skill and care. From her landing-skids to the farthest tip of her ailerons she seemed alive, instinct with conscious and eager intelligence.
Stern blessed her mentally with special pride and confidence in her mercury equalizing balances. Proud of his machine and of his skill, superb like Phaeton whirling the sun-chariot across the heavens, he gave her more and still more speed.
Below nothing, nothing save vapors, with here and there an open space where showed the strange dull purple of the abyss. Above, to right, to left, nothing--absolute vacant space.
Gone now was all sight of the land that they had left. Unlike balloonists who always see dense clouds or else the earth, they now saw nothing. All alone with the sun that rushed behind them in their skimming flight, they fled like wraiths across the emptiness of the great void.
Stern glanced at the barometer, and grunted with surprise.
“H'm! Twelve thousand four hundred and fifty feet--and I've been jockeying to come down at least five hundred feet already!” thought he. “How the devil can that be?”
The explanation came to him. But it surprised him almost as much as the noted fact.
“Must be one devil of a wind blowing up out of that place,” he pondered, “to carry us up nearly four thousand feet, when I've been trying to descend. Well, it's all right, anyhow--it all helps.”
He looked at the spinning anemometer. It registered a speed of ninety-seven miles an hour. Yet now that they were out of sight of any land, only the rush of the wind and the enormous vibration of the plane conveyed an idea of motion. They might as well have been hung in mid-space, like Mohammed's tomb, as have been rushing forward; there was no visible means of judging what their motion really might be.
“Unique experience in the history of mankind!” shouted Stern to the girl. “The world's invisible to us.”
She nodded and smiled back at him, her white teeth gleaming in the strange, bluish light that now enveloped them.
Stern, keenly attentive to the engine, advanced the spark another notch, and now the needle crept to 102 1/2.
“We'll be across before we know it,” thought he. “At this rate, I shouldn't be surprised to sight land any minute now.”
A quarter-hour more the Pauillac swooped along, cradling in her swift flight to westward.
But all at once the man started violently. Forward he bent, staring with widened eyes at the tube of the fuel-gage.
He blinked, as though to convince himself he had not seen aright, then stared again; and as he looked a sudden grayness overspread his face.
“What?” he exclaimed, then raised his head and for a moment sniffed, as though to catch some odor, elusive yet ominous, which he had for some time half sensed yet paid no heed to.
Then suddenly he knew the truth; and with a cry of fear bent, peering at the fuel-tank.
There, quivering suspended from the metal edge of the aluminum tank, hung a single clear white drop--alcohol!
Even as Stern looked it fell, and at once another took its place, and was shaken off only to be succeeded by a third, a fourth, a fifth!
The man understood. The ancient metal, corroded almost through from the inside, had been eaten away. That very morning a hole had formed in the tank. And now a leak--existing since what moment he could not tell--was draining the very life-blood of the machine.
“The alcohol!” cried Stern in a hoarse, terrible voice, his wide eyes denoting his agitation. With a quivering hand he pointed.
“My God! It's all leaked out--there's not a quart left in the tank! We're lost--lost in the bottomless abyss!”
CHAPTER XXII. LIGHTS!
At realization of the ghastly situation that confronted them, Stern's heart stopped beating for a moment. Despite his courage, a sick terror gripped his soul; he felt a sudden weakness, and in his ears the rushing wind seemed shouting mockeries of death.
As in a dream he felt the girl's hand close in fear upon his arm, he heard her crying something--but what, he knew not.
Then all at once he fought off the deadly horror. He realized that now, if ever, he needed all his strength, resource, intelligence. And, with a violent effort, he flung off his weakness. Again he gripped the wheel. Thought returned. Though the end might be at hand, thank God for even a minute's respite!
Again he looked at the indicator.
Yes, only too truly it showed the terrible fact! No hallucination, this. Not much more than a pint of the precious fluid now lay in the fuel tank. And though the engine still roared, he knew that in a minute or two it must slacken, stop and die.
What then?
Even as the question flashed to him, the engine barked its protest. It skipped, coughed, stuttered. Too well he knew the symptoms, the imperative cry: “More fuel!”
But he had none to give. In vain for him to open wide the supply valve. Vain to adjust the carburetor. Even as he made a despairing, instinctive motion to perform these useless acts--while Beatrice, deathly pale and shaking with terror, clutched at him--the engine spat forth a last, convulsive bark, and grew silent.
The whirling screws hummed a lower note, then ceased their song and came to rest.
The machine lurched forward, swooped, spiraled, and with a sickening rush, a flailing tumult of the stays and planes, plunged into nothingness!
Had Stern and the girl not been securely strapped to their seats, they must have been precipitated into space by the violent, erratic dashes, drops, swerves and rushes of the uncontrolled Pauillac.
For a moment or two, instinctively despite the knowledge that it could do no good, Stern wrenched at the levers. A thousand confused, wild, terrible impressions surged upon his consciousness.
Swifter, swifter dropped the plane; and now the wind that seemed to rise had grown to be a hurricane! Its roaring in their ears was deafening. They had to fight even for breath itself.