CHAPTER XV
Over the Sierras
Presently Uncle Brian rejoined his nephew. The flying-boat was now at an altitude of 4000 metres and following the course of the Rio del Morte.
From the island from which they had made their escape rifle bullets were singing harmlessly, for the searchers, upon hearing the hum of the flying-boat's engines, had jumped to the conclusion—a correct one in this case—that the "English dogs" had scored rather heavily.
"She's well stocked in the food department," reported Uncle Brian, "and there's plenty of fuel in the tanks. With reasonable luck we'll cross the Sierras before sunset."
"And then——?"
"Make for Trinidad or Barbadoes," replied Peter's uncle, as he carefully stowed the haversack containing the secret-rays parts into a locker. "She'll do that easily. But I've a notion that I'd like to stop and have a look at the pipe-line between El Toro and Tajeco. We might be able to cut off the fuel supply to the Rioguayan Air Fleet."
"Right-o," agreed Peter. "And what about Antonio?"
"Who?" asked his uncle.
"Antonio, our mechanic," explained Peter, indicating the closed hatchway, underneath which the Rioguayan engineer was quaking and trembling. "He'll be a bit of a nuisance on board, although he hasn't the pluck of a mouse. Can't we land him somewhere? Between us we can manage quite all right."
There was no difficulty in conversation. With the plate glass window in front of the pilot's seat and the hatch to the motor-room closed, the compartment was practically cut off, both from external and internal noises. Except for the muffled pulsations of the motors and the subdued roar from the propellers, there was little to indicate that the flying-boat was cutting through the air at eighty-five miles an hour.
"It's a jolly lucky thing we didn't carry on in the motor-boat," remarked Peter. "Look down there."
He pointed to the sinuous course of the river. Even at that height it was quite easy to see that the Rio del Morte above the lake was not easily navigable. There were rapids at about every half-mile, the foaming water showing up distinctly in the strong sunlight. It was doubtful whether a small boat, or any boat, could force her way against that furious torrent, rendered even more formidable by the numerous rocks that split the swiftly-running water into dangerous cascades.
"Yes," agreed Uncle Brian gravely, "we did the right thing. But don't forget—more than likely the air station at San Antonio is in touch with us by means of the magnetic detectors. We've got to bear in mind the possibility of being pursued."
"But they won't know what has happened," said Peter. "All they know is that the 'bus is proceeding up-country, following the course of the river. They would naturally conclude that the original crew are in pursuit of our late and unlamented 'egg-box'. Until the air station people get to hear from the fellows we left on the island—by the by, what will happen to them?"
"That's not our affair now," replied Uncle Brian. "In a few days another flying-boat will be dispatched to look for them. They've plenty of water, so they won't be thirsty; and, if they're hungry—well, there's the hound. In a way, he is responsible for their present plight."
"Talking of hunger," observed Peter, "isn't it about time we piped to dinner? I think I heard a suggestion about grub a couple of hours ago."
His uncle agreed, and went aft to the store and provision room. A few minutes later, thanks to the stabilizing device that enabled the flying-boat to hold on her course both as regards altitude and direction, Peter and Uncle Brian were enjoying a plain but satisfying meal of the food originally intended for the ill-fated Rioguayan captain.
Nor was the motor-mechanic neglected, although, when Peter opened the trap-hatch to pass the food down to him, he cowered and trembled in a state of utter funk.
"Now," remarked Uncle Brian, after consulting a map, "we ought to be approaching the scene of preliminary operations. The pipe-line should be about here, running in a north-west to south-east direction. It may be overgrown with tropical growth, but I know for a fact that it was laid on the surface and not buried."
"Bad system, that," observed Peter.
"Yes; but it was for economical reasons," continued his uncle. "Apparently the Rioguayan authorities never contemplated an attempt to cut it. We'll do our utmost to prove the fallacy of their belief in its immunity."
By the aid of binoculars, the track of the huge oil-pipe was located. So far so good; but there still remained the task of finding a suitable landing-ground. The flying-boat, although provided with means for alighting both on the water and on land, could not reasonably be expected to come to rest on tree-tops without the almost certain risk of being completely destroyed.
At two hundred metres the aircraft followed the line—until Peter discovered a possible landing in a clearing about fifty yards from the Englishman's objective. Here, for the first time since leaving the island, they saw signs of human habitation—small adobe huts.
"All right, I suppose?" asked Peter.
"Yes, they're Indians in the pay of the Rioguayan Government," replied Uncle Brian. "They are paid, I understand, not for the work they do, but for the damage they don't do—sort of retaining fee, providing they are good and don't start carving pieces out of the iron pipe."
"I see," remarked Peter. "Then, as far as we are concerned, they need not be taken into account. S'pose they won't carve up our engineer bird when we set him ashore?"
"They will more likely take him down to El Toro and get paid for the job," said Uncle Brian.
His nephew nodded. He was now engaged upon the task of bringing the flying-boat to earth, no easy task in a strange 'bus and on a landing-ground of doubtful quality and very limited extent.
With a succession of slight jolts, the flying-boat was brought to rest with her nose within ten feet of one of the huts. No Indians came out to gaze curiously at the wonderful sight, or to beg tobacco from the crew. They had promptly taken to the bush at the first distant view of the strange, enormous mechanical bird.
Bolting the hatch over the for'ard motor-room and at the same time telling the craven Rioguayan that there was nothing to be afraid of, provided he behaved himself, Peter and Brian Strong removed one of the fifty-pound bombs from the dropping gear and carried it ashore. Then, armed with rifles, they transported their bulky load to the enormous rust-red pipe-line that was raised eight feet above the ground, stretching miles in either direction, upon which depended the main kerosene supply to the Rioguayan arsenals and aerodromes.
It was the work of a few minutes to place the bomb close to the pipe and "tamp" it with earth. In the absence of a time fuse, it was necessary to detonate the explosive by rifle-fire.
At a safe distance, Peter put bullet after bullet at the target. The pipe was holed in several places, the oil gushing forth at high pressure, but it was not until the tenth shot that the desired result was attained.
There was a deafening crash. To quote Brian Strong's words: "It was as if the entire contents of an ironmonger's store had been dropped from the top of a skyscraper". A cloud of dust and smoke rose high in the air, mingled with fragments of jagged iron. Flames fifty feet in height shot up from the pipe, spreading far and wide as the inexhaustible supply of highly inflammable oil poured out in torrents to add to the work of destruction.
"That's kippered the show," remarked Peter gleefully, as the two Englishmen retraced their steps to the flying-boat.
The next business was to "pay off" the Rioguayan engineer. He was given a supply of provisions and a liberal quantity of tobacco and told to clear out and not to hurry back to San Antonio; while, for self-protection, he was provided with a rifle and twenty rounds of ammunition.
"You might have made him start up the motors, Peter," remarked his uncle, as the mechanic disappeared in the undergrowth.
"Thought I'd try my hand at the job," replied his nephew.
The for'ard pair of motors fired without hesitation, but the after ones gave a certain amount of trouble. At length, with the four engines throbbing and out of gear, Peter made his way to the pilot's seat.
At a steep angle, the flying-boat rose skywards. As she did so, a rifle bullet "pinged" harmlessly against the light steel armour plating of the fuselage.
"Ungrateful brute, that mechanic," was Peter's only remark.
Ten minutes later the fiercely burning oil pipe was a mere speck in the distance. The flying-boat, at an altitude of three thousand metres, was heading for the distant Sierras, that rose in a far-flung barrier of irregular projection to a height averaging nine thousand feet above the sea-level.
The aircraft was flying "all out", her speed, on account of the rarefaction of the atmosphere, being a little less than 140 miles an hour.
Peter was in a hurry. It was most desirable that the mountains should be crossed well before dark. Apart from the risk of crashing blindly against one of the many almost vertical peaks, there were the dangerous air-pockets and eddies to be taken into consideration, and with the setting of the sun, and the consequent rapid cooling of the earth's surface, the higher altitudes were certain to be disturbed by raging winds that attain the velocity of a hurricane.
For miles the ground rose steadily. Viewed from a height, the rise appeared to be gradual, since the smaller irregularities were apparently flattened out. It was only by judging by the shadows cast by the sun, which was now well down in the west, that the numerous valleys and ridges could be noticed.
For the first hundred miles, the country was well wooded. Then came a wide belt of grass land, gradually merging into an arid waste absolutely destitute of vegetation. The desert marked the beginning of the Sierras, which were now plainly visible at a distance of thirty or forty miles.
"Think she'll do it before dark?" inquired Uncle Brian, glancing at the sun, now only about thirty degrees above the horizon.
"Rather," replied Peter. "It will be quite light up here after the low-lying ground is in darkness. Once we're above the peaks I don't mind. It will be plain sailing after that."
"If you're sure of it, well and good," rejoined Brian. "If not, we'd better make a landing while it is light." The youthful pilot shook his head.
"Twelve hours saved is twelve hours gained," he said sagely. "I don't want to spend another night in Rioguayan territory if it can be avoided. She'll do it."
Fifteen minutes later, a violent bump announced that the flying-boat had struck an air-pocket, a clear indication of the adverse conditions that awaited her above the snowy peaks of the Sierras. She dropped vertically for nearly a thousand feet in spite of the pilot's efforts to counteract the sudden loss of "lift". Then staggering blindly into the furthermost wall of the invisible air chasm, the flying-boat "stalled" and almost stood on her tail, until she picked up and Peter was able to bring her back to her normal trim.
The next five minutes was a perfect nightmare. Above the snowy crags, now pink in the diffused rays of the setting sun, she sped, side-slipping, banking, and plunging, as if scorning the desperate efforts of the pilot to keep her up.
Once she nose-dived, flattened out, and made straight for a sheer wall of rock that a few seconds previously she ought to have cleared with a thousand feet to spare. Vainly Peter put the vertical rudders hard over. It seemed as if a collision was inevitable and that the shattered debris of the flying-boat would fall headlong into the fathomless chasm, when a side gust of terrific force hurled her, like a leaf, crab-fashion, so that she just scraped clear with a few feet between her port wing-tips and the pitiless face of the peak.
Then, propelled upwards by a freak air-current of irresistible strength, the flying-boat was hurled, like a sheet of paper up a tall chimney, between the perpendicular walls of a deep defile. So near did she scrape the summit of one of the twin peaks, that the rush of air dislodged a mass of snow, sending it thundering into the abyss, with a roar plainly audible within the supposedly sound-proof pilot's cabin.
Suddenly the roseate snow peaks gave place to a void of intense darkness. The crossing of the Sierras was accomplished. Ahead lay miles of country, sloping towards the Caribbean Sea, with nothing higher than three thousand feet to be encountered—at least, so the map read.
"We're over!" exclaimed Peter thankfully, as the flying-boat settled down to her normal even style of flight.
"More by luck than by anything else," thought Uncle Brian, who felt bruised and shaken all over.
"I'll take her down to eight thousand feet," continued Peter briskly. "Then I'll get you to stand by, Uncle. There's nothing to be done except to watch the altimeter and the compass. There's no need to bust along now. We've ten hours of darkness in front of us and we don't want to find ourselves miles out over the Atlantic when day breaks. I'll cut out the after motors."
In spite of the fact that the interior of the fuselage was heated by pipes connected with the exhausts, the air within the cabins was bitterly cold, and the temperature fell yet lower after the rear pair of motors was shut down.
Peter was now feeling very sleepy. Lack of proper rest, the excitement of the last two days, and the effect of the rarefied atmosphere all combined to reduce him to a state of resistless drowsiness.
"You turn in," said his uncle peremptorily. "I'm good for another ten hours, if needs must. If there's anything requiring your attention, I'll wake you."
The elder man "took on". Since the flying-boat was built largely after his designs, he was well acquainted with the technical part of the mechanism and construction, but he was quite a novice in the art of actual flight. As long as things went right, there was little for him to do.
Peter, wrapped in half a dozen blankets in addition to a leather flying-coat, was soon sound asleep in spite of the low temperature.
He had not slept for more than ten minutes when his uncle roused him.
"She's faltering—both engines," announced Uncle Brian laconically.
Peter rose stiffly to his feet. He had not the trained ear for mechanism that his uncle possessed, and as far as he could hear, the motors were still keeping up their rhythmic purr.
"Look at the gauge of the main fuel tank," suggested Uncle Brian.
His nephew picked up an electric torch and made his way to the 'midship compartment. He went sceptically enough, but on consulting the indicator, the state of the gauge fairly startled him. It stood at zero.
That meant that only one of the auxiliary tanks contained any kerosene, and owing to its position was useless unless the flying-boat was diving steeply or in an inverted position while "looping".
The tanks were three-quarters full when the flying-boat had passed out of Rioguayan control; and since only a few hours had elapsed, it was a matter of impossibility for the four motors even running all out to "mop up" anything like the quantity that had gone somewhere.
A hasty examination revealed the cause of the leakage. A drain-cock was half open, allowing a steady stream of kerosene to flow into space. At first thoughts, Peter attributed the leakage to the Rioguayan mechanic, until he remembered that the fellow had been locked up when left alone on board.
But there was little time for speculation.
Hastening back to the control compartment, Peter found that the for'ard motors were now firing spasmodically. In a few moments they would cease functioning for lack of fuel, and then there was nothing to keep the flying-boat from descending with fair rapidity. Her weight and relatively small plane-area were against her for prolonged gliding.
He touched his uncle on the shoulder and motioned him away from the controls.
"Luck's out this time," he said grimly. "It's a thundering big drop in the dark."