THE DUST-EATING MULE
The long, dark corridors of the vast automobile and airplane factory were
silent. The same old ponderous machines loomed here and there, while
smaller ones stood sentry everywhere. At the end of one long alleyway a
small light gleamed. Flickering first to the right, then to the left, it
cast gigantic shadows against the walls.
Two boys were working over a “mule.” A mule in a factory, as you will
remember, is one of those hard-working, snub-nosed little motors that
drag trucks about from department to department. The boys were working
over the motor of this mule. There came now and then the metallic clink
of a wrench, or the tap tap of a hammer, followed by a grunt of
satisfaction or disgust.
“There!” Johnny Thompson straightened up and stretched his cramped
muscles. “I guess she’s about ready to move.”
The trip across-continent and the return had been accomplished. Aside
from the stirring adventure on the desert, they had met with no unusual
experiences. The connecting-rods, struck from the steel of mysterious
composition, had performed wonderfully well. When measured by instruments
that were exact to the ten-thousandth part of an inch, it had been found
that they had worn down only thirty-four ten thousandths of an inch,
while connecting-rods of the best known commercial steel would have worn
one hundred and forty-two ten thousandths of an inch in making the same
mileage. Small figures, but in the history of steel they promised to mark
an epoch.
The inventor’s mind was improving but he had not as yet succeeded in
recalling the formula. While hoping for his recovery, the boys were
preparing to make a more rigorous test of this new steel. The company
were manufacturing a new type of seaplane. Every afternoon the two boys,
togged out in aviator’s garb, were learning to fly this new plane. It was
planned that, when the boys found themselves to be perfect masters of
this new vehicle of the air, the six connecting-rods should be placed in
the motor of the seaplane, and that it be shipped to the Pacific coast.
There, under ideal conditions, they were to test out, not only the
connecting-rods, but the seaplane, flying, as a last trial, a thousand
miles or more.
The pay Johnny had received for the cross-continent trip had enabled him
to make a large payment on his debt of honor. As for Pant, he, for the
first time in his life, had a savings account.
During their forenoons they were busy in the factory. At times Johnny
thought of the vial of dark liquid that reposed on the shelf in the
laboratory, the one he had placed there the night he made the analysis of
the mysterious steel. At one time while in the laboratory he had glanced
up to make sure it was there. It was still in its place. He had been
tempted to tell the chemist about it but was afraid of being laughed at.
“Never mind,” he told himself, “in time I will learn to make a chemical
analysis myself. Then I’ll see what’s what.”
The question of the strange white fire puzzled him at times. He wondered,
too, how the automobile of the contortionist had happened to catch fire
in the desert. But these were mere vague wonderings which had no answer.
Though they were well occupied during the day, the boys found time at
night for working upon a new, strange problem of which as yet, their
friend, Mr. McFarland, the president and manager, knew nothing. It was
this problem that occupied their minds at the present moment. It was a
stirring moment. Many nights they had spent working over a new type of
engine, one that had never been set in a motor vehicle before. Now it was
ready for the try-out.
“Track clear?” breathed Johnny.
“All clear,” Pant whispered back.
“All right; here goes!”
There followed a series of sudden sharp explosions. These increased
rapidly until they became a loud and insistent purr. Then, with the force
and speed of a frightened pig, the little motor car shot forward.
The movement was too sudden for the boys. Johnny was thrown backward upon
the floor. Pant, thrown in a wild whirl to the right, saw the motor, a
black streak, shoot down the dark alley-way.
“She’s got speed,” he muttered.
The wild snorting of the motor awakened echoes in every corner of the
factory. This was followed almost immediately by a deafening crash.
Pant started quickly forward, then paused. Johnny was now on his feet.
“Did she explode or hit the wall?” Pant asked.
“Hit the wall.”
Johnny rubbed his bruised head ruefully.
“Wouldn’t believe she could make such time.”
“That was a powerful engine.”
The two boys were now on the run. They arrived at the scene of the
disaster just ahead of a tall man carrying a flashlight and a bunch of
keys.
This man—the watchman—flashed his light upon the bent and twisted metal
that lay against the wall, then demanded sternly:
“What’s that?”
“That,” said Johnny with a wry smile, “is a pile of scrap.”
“Don’t get fresh,” the watchman warned. “What is it?”
“It’s what I said it is,” said Johnny seriously. “If you want to know
what it was, I’ll tell you; it was a dust-eating mule.”
The watchman’s mouth flew open. “A—A,” he sputtered incredulously. “I
told you before, young fellow, don’t get fresh.” He moved a hand toward
Johnny menacingly.
“I have told you the truth,” said Johnny stoutly. “Perhaps I should have
said a dust-burning mule. That’s what she was. It wouldn’t be a bit of
good to explain to you; you wouldn’t understand, and besides, I don’t
want to. That’s our secret. We have permission from Mr. McFarland to
conduct experiments here nights.”
“But you have no permission to endanger men’s lives.”
“That’s right,” Johnny admitted; “we were a bit careless.”
“I’ll just turn the facts in to the boss and you can fight it out with
him,” said the watchman sourly as he turned away.
“Well, that’s that,” said Johnny sorrowfully. “It’s a complete loss.
We’ll have to begin all over again. But from that little test I am
convinced that the engine has a wonderful future.”
“This particular one had a brief but eventful past, I’d say,” grinned
Pant.
After one more look at the wreck, they turned and went their way.
That night before he fell asleep Johnny reviewed in his mind the events
that led up to the happenings of that evening.
He, Johnny, had been standing on the steps of the official entrance to
the plant one afternoon, when Mr. McFarland had said to him: “Johnny,
please go down to the north gate and request that old man to go away. He
is stopping the workers as they pass and trying to engage them in
conversation. He looks like he is a propagandist for some radical
organization trying to make the men discontented. Get rid of him if you
can.”
The man had turned out to be not a radical at all, but a friendly and
harmless old man who was seeking some one who could be interested in a
new type of engine which he had invented. Such a fine spoken and polished
old gentleman had he proved to be that Johnny had been prevailed upon to
accompany him to his home to see the engine.
He had found the home of the aged inventor to be a fourth-floor back
flat, being merely two dark rooms upon an alley. Here, with his wife, a
pleasant-faced old lady, he lived and labored.
“You see,” he had said, as he uncovered the engine with the dramatic
movement of one who unveils a great work of art, “this engine of mine is
different from all other internal-combustion engines. It doesn’t burn
gasoline; it burns dust.”
“Dust!” Johnny had exclaimed.
“Dust!” the old man had smiled. “Watch it!”
He touched a lever. There followed a succession of rapid and sharp
explosions. These increased in number per second until they became a
prolonged purr, as the one in the “mule” had done. The engine was now
revolving at full speed.
“You see?” the old man had smiled. “She runs—on dust!”
“On dust,” Johnny had repeated in a daze.
The old man had touched the lever and the engine had stopped.
“You think it strange,” the old man had smiled, motioning Johnny to a
chair and taking one himself; “but, after all, is it so strange? The
first internal-combustion engine, we have it on good authority, did not
burn gasoline but a composition of gun powder and other substances. The
greatest grain elevator in the world was destroyed by a dust explosion.
Billions of fine particles of carbon dust gathered in the air space above
the wheat. A spark touched it off. A tremendous explosion followed. There
is unlimited power there. Why not harness it?
“You are looking,” he pointed at the engine, “upon the motor power of the
future. It ran, as you saw a moment ago, on coal dust, a very finely
powdered coal dust. A little is let in at a time. A slight ash is formed.
This drops out at the top of the cylinder, as you will see the engine
runs inverted. It was burning coal dust, but any carbon dust will do.
Wood ground fine, wheat dust, peat dust, any carbon dust will drive it.
Think what that means to the world-traveler of the future! No more
disgusting waiting for gasoline; no more weary miles on foot. You land in
the heart of Africa, India, Siberia. You have with you a small grinder
like a wheat mill. It is run by batteries. You are out of fuel. You
merely grind up a dry tree-trunk, a sack of wheat or a few pounds of
coal, and you are away again.”
“Sounds like a dream,” Johnny had sighed.
“It is a dream—a dream that has come true,” the old man had fairly
shouted. “All that is needed is capital to perfect larger motors, to put
them upon the market. If only your president can be made to see it, as
you and I see it—”
“I’ll try,” Johnny had gripped the old inventor’s hand. “I’ll see what I
can do.”
The next night Pant had accompanied Johnny to the aged inventor’s room,
and there over some wonderful coffee and doughnuts prepared by the
inventor’s wife, they talked over the future of the strange dust-burning
engine.
It was decided that, since the engine had never been tried out in any
vehicle, Johnny and Pant should obtain permission to experiment with it
in the factory after hours to perfect it further before it was presented
to the busy president.
Three weeks of spare time experimenting had resulted in the complete
wreck of the engine, smashed against a brick wall.
“Now we’ll have to begin all over again, and because that watchman turns
us in we’ll have to show our plans to the president,” said Johnny.
The revealing of their plans was not the misfortune they thought it, for
Mr. McFarland at once became keenly interested in the enterprise. He took
them off their regular work and set them doing full time in experimenting
with this new engine.
In two weeks they had a new mule doing double-quick time all over the
shop. Another two weeks saw them riding about the streets of the city in
a car driven by a dust-burning motor.
Their happiness knew no bounds. Boundless, too, were their ambitions.
This should be the airplane engine of the future. Two twelve-cylinder
motors were manufactured for the seaplane they were to drive and the
plane and motors were shipped to the Pacific coast where, over the placid
waters of a bay, they might experiment with little danger of disaster.
They had been on the Pacific coast, driving the plane equipped with the
two dust-burning motors and with one of the motors using the six
connecting-rods of mysterious steel, for a week when one day Johnny
decided to make a short drive over the country alone. Not suspecting that
anyone could, this time, be on their trail, he told Pant of his intention
while in the lobby of their hotel while a number of persons were present.
He made a successful trip of some two hundred miles. A fog had blown up
from the sea but he knew the location of a beautiful mountain lake which
he had often longed to visit. On an island in this lake, he had been
told, were to be found traces of the wonderful fossilized forests for
which the West is famous.
By circling low he succeeded in locating the placid surface of the lake
and in making a creditable landing. Unbuckling his harness he rose
stiffly, stretched his cramped limbs, then, turning hastily, unlashed a
small skiff from the back of the fuselage and, having tossed it lightly
into the water, seized the paddle, leaped into the skiff and paddled
rapidly toward the shore.
He had been gone for perhaps five minutes when, without warning, from out
of the white fog there appeared the prow of a small motorboat. The engine
was not going. The two occupants of the boat were rowing, each with one
oar. Their destination, beyond doubt, was the seaplane.
Not a word was spoken until the taller of the two men, a
strange-appearing fellow with unusually long fingers, put out a hand and,
steadying himself for a moment, leaped from the boat to the lower wing of
the plane.
“Work fast,” the shorter man cautioned in a whisper. “He may be back any
moment.”
“Count on me. Don’t want any mix-up. Nasty business,” whispered the
other, then with a spring he was away down the length of the plane. The
next minute he had climbed to a narrow platform parallel with the
powerful motors which hung suspended halfway between the upper and lower
planes.
Drawing a wrench and a pair of pliers from his pocket, he worked over the
engine to the right for some eight or ten minutes. When he had finished,
he mumbled something that sounded like:
“Guess that’ll slow him up,” then thrusting his tools, together with some
other small objects, into his pocket, he leaped back to the plane, and,
racing down its length, sprang into the motorboat.
“Thought you had decided to stay,” grumbled the waiting man.
“Time enough,” the other drawled. Seizing his oar, he pushed the boat
away from the plane.
The next moment they disappeared silently into the fog. They had been
gone but an incredibly short time when Johnny reappeared in his shallow
skiff.
“Well, she’s still here,” he breathed with a sigh of satisfaction. “Guess
I ought not to take such chances, but who’d be out here that knows our
secret?”
He climbed happily back to his seat in the plane, buckled on his harness,
then touched his lever.
But what was this? The engine gave a few sput-sputs, then stopped dead.
“What?”
He could not believe his senses. He tried it again. No better results.
Snatching off his harness, he leaped to the platform beside the motor.
For a moment his eyes and his fingers played over the line of spark plugs
of the twelve-cylinder motor, as a skilled musician plays over the keys
of an organ.
Then his face went blank.
“Changed!” he muttered. “Somebody’s been here. That spark plug there;
never had one like that. And that one; I cracked the enamel when I put
one in there. It’s gone. Perfectly good-looking one there now. Somebody’s
tampered—”
He drew from his pocket a wrench. Quickly unscrewing the spark plug, he
placed it on top of the cylinder, then gave the propeller a whirl.
“No spark,” he mumbled. “Dead! Dead as a last year’s ragweed!”
Again he paused in thought.
The next moment he was all action. Dropping to the fuselage, he dragged
from within the space back of the seat numerous odds and ends of wooden
rods, coils of wire, clamps, bolts and glass insulators. These he pieced
together with incredible speed. At length a wire-strung pole was thrust
high in air. Wires were attached at the bottom, a receiver thrust over
his head, and then, seated in his place before the wheel, he was allowing
his fingers to play upon the key of a wireless.
“Sput—sput—sput!” The snap of the electric current sounded above him. He
was sending out an S. O. S. addressed to Pant at the home station.
“Sput-sput-sput,” the instrument sounded again and again. Each time he
waited for an answer. At last, to his great joy, it came. The buzzing in
his receiver resolved itself into the dots and dashes of the Morse code:
“Shoot, Pant.”
“Thank God!” Johnny exclaimed.
The purpose of the intruders was plain enough. They had hoped to drive
Johnny to desert his plane in this lonely spot, then they would return
and strip it of its priceless steel at their leisure.
“I’ll show them!” he hissed.
Again his fingers played on the key. He instructed Pant to bring twelve
spark plugs to the island on Lake Poncetrane. He was to make a landing
there, if possible, then to bring the spark plugs to the northeast corner
of the island where he, Johnny, would be waiting for him.
He listened until the other boy’s O. K. rang in his ears then, removing
the receiver from his head, he settled back in his seat. It would be two
hours before Pant arrived. Everything would be all right if—suddenly he
sat up straight, his brow wrinkled—“if he can land on the island!” he
exclaimed; “and I doubt if he can. There’s a small bare space in the very
center, and that is covered with rocks; the rest is timbered. If he can’t
land, we lose!”
At last he rose and, having drawn himself up beside the motor, busied
himself with the task of removing the faulty spark plugs.
“The villains!” he muttered. “It’s a dirty trick!”
He had just completed his task of removing the spark plugs, when there
came to his waiting ear the drum of a powerful motor.
“Pant,” he murmured, “good old Pant. He’s made it in record time. Now if
only—”
He did not finish. He dared not hope that it could be done.
The thunder of the motor grew louder. The fog had cleared now, and he
could see the plane, an airplane Pant had borrowed, like some gigantic
dragon fly, drifting down upon him.
Before it reached the spot in the sky above him, it swerved to the right
and went skimming low over the tree-tops of the island.
Johnny made no move to go ashore; there would be time enough for that
after Pant had effected a landing—if he did.
For a second or two the drum of the motor ceased, and Johnny’s heart
stopped beating with it. Could Pant make it?
But again came the thunder of the motor. Again the plane appeared above
the trees. He had not found a safe landing place.
Once more the plane circled over the island, then dipped out of sight.
Again the motor stopped. This time Johnny was sure Pant had been
successful, but again his hopes fell, for the plane rose to circle once
more.
Four times he attempted it; four times failed.
“Can’t do it. It’s no use!” Johnny sank limply down into his seat.
But Pant was swinging around. He was preparing to pass low over the
seaplane. What could he want?
As he came scudding along with engine shut off, Johnny heard him shout:
“Watch this!”
The next moment he saw his hand shoot out. Something dropped from that
hand. Straight down it dropped for a hundred feet, then something
resembling a parachute filled with air appeared, and checked its fall.
Quickly Johnny leaped into his skiff and was away to the spot where this
miniature parachute would fall. The thing was heavy. Could he reach it
before it dragged the parachute to the bottom of the lake? Straining
every muscle, he sent the skiff flying over the surface of the water.
The parachute had fallen into the lake. Now he was a hundred feet from
it, now fifty, now twenty-five, and now—now, his hand shot out and seized
it just as, water-logged, it was beginning to sink.
As he dragged the cloth affair from the water, from his lips there
escaped a glad shout. Attached to the parachute’s cord were three spark
plugs.
Hardly had he made this discovery than there came again the shout:
“Watch this!”
He did watch, and did do his best, but in spite of his efforts the second
parachute sank before he reached it.
But there were others. Twice more he succeeded and three times failed.
But he now had nine new spark plugs. Surely there were enough.
Paddling hastily to the plane, he made the changes, dropped into his
seat, and again touched his lever. This time there came a welcome burst
of thunder and he was away.
He gazed for a second behind him to see Pant, his purpose fulfilled,
speeding away toward home.
“That,” smiled Johnny, “was a clever trick. I’d never have thought of it.
But trust good old Pant for that. Who’d have thought, though,” his brow
wrinkled, “that old Slim Jim, the contortionist, was still on our trail?”
Strangely enough, during the days that followed the contortionist put in
no second appearance.
Three weeks of testing proved to them that their engines were a complete
success. Then began what proved to be their great adventure.
There came to them a short, bald-headed man of middle age, with a letter
from Mr. McFarland, their employer.
The letter read: “This gentleman, Professor Paul Lasky, is a very close
friend of mine. He may ask you to do something difficult and dangerous.
Do it if you can, for his cause is worthy and his need imperative.”
The stranger was not slow in laying his needs before them. A tramp
steamer had gone on the shoals of a coral island some two thousand miles
from the Pacific coast of America. Some passengers and members of the
crew had been drowned. The others had been rescued. The wreck was driven
high on the sand in a sheltered bay, so she would not break up at once.
Some hardy adventurers, claiming to have owned the steamer, had put off
in another steamer four days previous with the purpose of salvaging her
cargo. It was imperative that he, the professor, should reach the wreck
before them. A seaplane was the only craft that could bring him to the
island in time, and of all the air-craft then on the coast, none had the
possibilities of such protracted flight save their own. He wished them to
take him there. The reward would be ample and, should his mission be
successfully accomplished, they would be real benefactors of mankind,
since some tens of thousands of children would be benefited.
Johnny and Pant held a long consultation. The undertaking was a serious
one. Could it be that the stranger knew the type of engine their plane
carried? His mission must indeed be an important one if a mere landsman,
accustomed to neither the sea nor the air, would attempt such a perilous
flight to accomplish it.
“What can it be?” Johnny demanded of Pant.
“Can’t tell. Some treasure on the ship, perhaps.”
“But the ship and the cargo belong to the men who have gone to strip the
wreck, don’t they?”
“Perhaps. Then again, perhaps not. Perhaps, at least, not all.”
“Well, if you are ready to undertake it, I am.”
“You’re on!” exclaimed Pant, gripping Johnny’s hand. “It will be a
wonderful test for our motors.”
“And I don’t think our contortionist friend can follow us,” smiled
Johnny.
Twenty hours later, after having covered fifteen hundred miles in steady
flight, they realized that it was indeed to be a wonderful test for their
motors, and to them as well; a test out of which they might never emerge.
They were sailing high over a boundless expanse of water, when Johnny
suggested that they drop to the level of the sea and rest their motors
for an hour as they drifted, sea-gull-like, on the surface of the gently
heaving ocean.
“Perfectly calm down there,” he called through his speaking-tube.
“Guess so.” Pant, who was acting as pilot, set her nose downward and
slowed his engine for volplaning.
As they neared the surface of the water, an exclamation of surprise
escaped Pant’s lips.
“Why, she’s rolling in great billows. Not a breath of air, either!”
“It’s stifling,” grumbled Johnny.
Pant gave one look at the barometer. Instantly his face clouded.
“Didn’t know the glass could drop so low,” he mumbled. “Nasty weather
coming. Can’t float on that water. Better climb back up.”
Slowly the plane climbed skyward again. When she had reached a high
altitude, with the suddenness of thought she ceased to climb.
It was as if she had run, head on, into an immense filmy veil of silk
that hung from the high heavens, its fringe touching the sea. The veil
was dark, the darkness of midnight blue. It seized the plane and set it
twirling, whirling, pitching, plunging. It was as if a giant hand had
seized the veil from above and twisted it, as one twists a damp towel to
wring it.
It was then that Pant at the wheel lost all control. Johnny, in the
cabin, became an over-large punching-bag. Harnessed to his seat from
every side, he swung now into space, and now jammed hard into place, to
feel himself banged against the side of the narrow cabin. With head sunk
limply forward, with his whole body relaxed, he waited dumbly for the
end. What that end might be, he could not even guess. They were caught in
a typhoon, hundreds of miles from land, somewhere in mid-Pacific.