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TOM SWIFT AND HIS AERIAL WARSHIP or The Naval Terror of the Seas

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"Certainly--why not?" Tom replied. "In warfare accidents may
happen, and if the Mars can't go on, after a little damage like
this, what is going to happen when she's fired on by a hostile
ship? Of course I'm going on!"

"Bless my necktie!" ejaculated the odd man.

"That's the way to talk!" exclaimed Lieutenant Marbury. "I'm
with you."

There really was very little danger in proceeding. The Mars was
just as buoyant as before, for more gas had been automatically
made, and forced into the uninjured compartments of the bag. At
the same time enough sand ballast had been allowed to run out to
make the weight to be lifted less in proportion to the power

True, the speed would be less, with two propellers instead of
three, and the craft would not steer as well, with the torn ends
of the gas bag floating out behind. But this made a nearer
approach to war conditions, and Tom was always glad to give his
inventions the most severe tests possible.

So, after a little while, during which it was seen that the
Mars was proceeding almost normally, the matter of discharging
the guns was taken up again.

The weapons were all ready to fire, and when Tom had attached
the pressure gauges to note how much energy was expended in the
recoil, he gave the word to fire.

The two big weapons were discharged together, and for a moment
after the report echoed out among the cloud masses every soul on
the ship feared another accident had happened.

For the big craft rolled and twisted, and seemed about to turn
turtle. Her forward progress was halted, momentarily, and a cry
of fear came from several of the members of the crew, who had had
only a little experience in aircraft.

"What's the matter?" cried Ned. "Something go wrong?"

"A little," admitted Tom, with a rueful look on his face.
"Those recoil checks didn't work as well in practice as they did
in theory."

"Are you sure they are strong enough?" asked Lieutenant

"I thought so," spoke Tom. "I'll put more tension on the spring
next time."

"Bless my watch chain!" cried Mr. Damon. "You aren't going to
fire those guns again; are you, Tom?"

"Why not? We can't tell what's the matter, nor get things
right without experimenting. There's no danger."

"No danger! Don't you call nearly upsetting the ship danger?"

"Oh, well, if she turns over she'll right herself again," Tom
said. "The center of gravity is low, you see. She can't float in
any position but right side up, though she may turn over once or

"Excuse me!" said Mr. Damon firmly. "I'd rather go down, if
it's all the same to you. If my wife ever knew I was here I'd
never hear the last of it!"

"We'll go down soon," Tom promised. "But I must fire a couple
of shots more. You wouldn't call the recoil checks a success,
would you?" and the young inventor appealed to the government

"No, I certainly would not," was the prompt answer. "I am
sorry, too, for they seemed to be just what was needed. Of course
I understand this is not an official test, and I am not obliged
to make a report of this trial. But had it been, I should have
had to score against you.

"I realize that, and I'm not asking any favors. but I'll try it
again with the recoil checks tightened up. I think the
hydrostatic valves were open too much, also."

Preparations were now made for firing the four-inch guns once
more. All this while the Mars had been speeding around in space,
being about two miles up in the air. Tom's craft was not designed
to reach as great an elevation as would be possible in an
aeroplane, since to work havoc to an enemy's fortifications by
means of aerial bombs they do not need to be dropped from a great

In fact, experiments in Germany have shown that bombs falling
from a great height are less effective than those falling from an
airship nearer the earth. For a bomb, falling from a height of
two miles, acquires enough momentum to penetrate far into the
earth, so that much of the resultant explosive force is expended
in a downward direction, and little damage is done to the
fortifications. A bomb dropped from a lower altitude, expending
its force on all sides, does much more damage.

On the other hand, in destroying buildings, it has been found
desirable to drop a bomb from a good height so that it may
penetrate even a protected roof, and explode inside.

Once more Tom made ready to fire, this time having given the
recoil checks greater resistance. But though there was less
motion imparted to the airship when the guns were discharged,
there was still too much for comfort, or even safety.

"Well, something's wrong, that's sure," remarked Tom, in rather
disappointed tones as he noted the effect of the second shots.
"If we get as much recoil from the two guns, what would happen if
we fired them all at once?"

"Don't do it! Don't do it, I beg of you!" entreated Mr. Damon.
"Bless my toothbrush--don't do it!"

"I won't--just at present," Tom said, ruefully. "I'm afraid
I'll have to begin all over again, and proceed along new lines."

"Well, perhaps you will," said the lieutenant. "But you may
invent something much better than anything you have now. There is
no great rush. Take your time, and do something good."

"Oh, I'll get busy on it right away," Tom declared. "We'll go
down now, and start right to work. I'm afraid, Ned, that our idea
of a door-spring check isn't going to work."

"I might have known my idea wouldn't amount to anything," said
the young bank clerk.

"Oh, the idea is all right," declared Tom, "but it wants
modifying. There is more power to those recoils than I figured,
though our first experiments seemed to warrant us in believing
that we had solved the problem."

"Are you going to try the bomb-dropping device?" asked the

"Yes, there can't be any recoil from that," Tom said. "I'll
drop a few blank ones, and see how accurate the range finders

While his men were getting ready for this test Tom bent over
the broken propeller, looking from that to the recoil checks,
which had not come up to expectations. Then he shook his head in
a worried and puzzled manner.


Dropping bombs from an aeroplane, or a dirigible balloon, is a
comparatively simple matter. Of course there are complications
that may ensue, from the danger of carrying high explosives in
the limited quarters of an airship, with its inflammable gasoline
fuel, and ever-present electric spark, to the possible premature
explosion of the bomb itself. But they seem to be considered
minor details now.

On the other hand, while it is comparatively easy to drop a
bomb from a moving aeroplane, or dirigible balloon, it is another
matter to make the bomb fall just where it will do the most
damage to the enemy. It is not easy to gauge distances, high up
in the air, and then, too, allowance must be made for the speed
of the aircraft, the ever-increasing velocity of a falling body,
and the deflection caused by air currents.

The law of velocity governing falling bodies is well known. It
varies, of course, according to the height, but in general a body
falling freely toward the earth, as all high-school boys know, is
accelerated at the rate of thirty-two feet per second. This law
has been taken advantage of by the French in the present European
war. The French drop from balloons, or aeroplanes, a steel dart
about the size of a lead pencil, and sharpened in about the same
manner. Dropping from a height of a mile or so, that dart will
acquire enough velocity to penetrate a man from his head all the
way through his body to his feet.

But in dropping bombs from an airship the damage intended does
not so much depend on velocity. It is necessary to know how fast
the bomb falls in order to know when to set the time fuse that
will explode it; though some bombs will explode on concussion.

At aeroplane meets there are often bomb-dropping contests, and
balls filled with a white powder (that will make a dust-cloud on
falling, and so show where they strike) are used to demonstrate
the birdman's accuracy.

"We'll see how our bomb-release works," Tom went on. "But we'll
have to descend a bit in order to watch the effect."

"You're not going to use real bombs, are you, Tom?" asked Ned.

"Indeed not. Just chalk-dust ones for practice. Now here is
where the bombs will be placed," and he pointed to the three
openings in the floor of the amidship cabin. The wire nettings
were taken out and one could look down through the holes to the
earth below, the ground being nearer now, as Tom had let out some
of the lifting gas.

"Here is the range-finder and the speed calculator," the young
inventor went on as he indicated the various instruments. "The
operator sits here, where he can tell when is the most favorable
moment for releasing the bomb."

Tom took his place before a complicated set of instruments, and
began manipulating them. One of his assistants, under the
direction of Lieutenant Marbury, placed in the three openings
bombs, made of light cardboard, just the size of a regular bomb,
but filled with a white powder that would, on breaking, make a
dust-cloud which could be observed from the airship.

"I have first to determine where I want to drop the bomb," Tom
explained, "and then I have to get my distance from it on the
range-finder. Next I have to know how fast I am traveling, and
how far up in the air I am, to tell what the velocity of the
falling bomb will attain at a certain time. This I can do by
means of these instruments. some of which I have adapted from
those used by the government," he said, with a nod to the

"That's right--take all the information you can get," was the
smiling response.

"We will now assume that the bombs are in place in the holes in
the floor of the cabin," Tom went on. "As I sit here I have
before me three buttons. They control the magnets that hold the
bombs in place. If I press one of the buttons it breaks the
electrical current, the magnet no longer has any attraction, and
it releases the explosive. Now look down. I am going to try and
drop a chalk bomb near that stone fence."

The Mars was then flying over a large field and a stone fence
was in plain view.

"Here she goes!" cried Tom, as he made some rapid calculations
from his gauge instruments. There was a little click and the
chalk bomb dropped. There was a plate glass floor in part of the
cabin, and through this the progress of the pasteboard bomb could
be observed.

"She'll never go anywhere near the fence!" declared Ned. "You
let it drop too soon, Tom!"

"Did I? You just watch. I had to allow for the momentum that
would be given the bomb by the forward motion of the balloon."

Hardly had Tom spoken than a puff of white was seen on the very
top of the fence.

"There it goes?" cried the lieutenant. "You did the trick,

"Yes, I thought I would. Well, that shows my gauges are
correct, anyhow. Now we'll try the other two bombs."

In succession they were released from the bottom of the cabin,
at other designated objects. The second one was near a tree. It
struck within five feet, which was considered good.

"And I'll let the last one down near that scarecrow in the
field," said Tom, pointing to a ragged figure in the middle of a
patch of corn.

Down went the cardboard bomb, and so good was the aim of the
young inventor that the white dust arose in a cloud directly back
of the scarecrow.

And then a queer thing happened. For the figure seemed to come
to life, and Ned, who was watching through a telescope, saw a
very much excited farmer looking up with an expression of the
greatest wonder on his face. He saw the balloon over his head,
and shook his fist at it, evidently thinking he had had a narrow
escape. But the pasteboard bomb was so light that, had it hit
him, he would not have been injured, though he might have been
well dusted.

"Why, that was a man! Bless my pocketbook!" cried Mr. Damon.

"I guess it was," agreed Tom. "I took it for a scarecrow.

"Well, it proved the accuracy of your aim, at any rate,"
observed Lieutenant Marbury. "The bomb dropping device of your
aerial warship is perfect--I can testify to that."

"And I'll have the guns fixed soon, so there will be no danger
of a recoil, too," added Tom Swift, with a determined look on his

"What's next?" asked Mr. Damon, looking at his watch. "I really
ought to be home, Tom."

"We're going back now, and down. Are you sure you don't want me
to drop you in your own front yard, or even on your roof? I think
I could manage that."

"Bless my stovepipe, no, Tom! My wife would have hysterics.
Just land me at Shopton and I'll take a car home."

The damaged airship seemed little the worse for the test to
which she had been subjected, and made her way at good speed in
the direction of Tom's home. Several little experiments were
tried on the way back. They all worked well, and the only two
problems Tom had to solve were the taking care of the recoil from
the guns and finding out why the propeller had broken.

A safe landing was made, and the Mars once more put away in her
hangar. Mr. Damon departed for his home, and Lieutenant Marbury
again took up his residence in the Swift household.

"Well, Tom, how did it go?" asked his father.

"Not so very well. Too much recoil from the guns.

"I was afraid so. You had better drop this line of work, and go
at something else."

"No, Dad!" Tom cried. "I'm going to make this work. I never had
anything stump me yet, and I'm not going to begin now!"

"Well, that's a good spirit to show," said the aged inventor,
with a shake of his head, "but I don't believe you'll succeed,

"Yes I will, Dad! You just wait."

Tom decided to begin on the problem of the propeller first, as
that seemed more simple. He knew that the gun question would take

"Just what are you trying to find out, Tom?" asked Ned, a few
nights later, when he found his chum looking at the broken parts
of the propeller.

"Trying to discover what made this blade break up and splinter
that way. It couldn't have been centrifugal force, for it wasn't
strong enough."

Tom was "poking" away amid splinters, and bits of broken wood,
when he suddenly uttered an exclamation, and held up something.
"Look!" he cried. "I believe I've found it."

"What?" asked Ned.

"The thing that weakened the propeller. Look at this, and
smell!" He held out a piece of wood toward Ned. The bank employee
saw where a half-round hole had been bored in what remained of
the blade, and from that hole came a peculiar odor.

"It's some kind of acid," ventured Ned.

"That's it!" cried Tom. "Someone bored a hole in the propeller,
and put in some sort of receptacle, or capsule, containing a
corrosive acid. In due time, which happened to be when we took
our first flight, the acid ate through whatever it was contained
in, and then attacked the wood of the propeller blade. It
weakened the wood so that the force used in whirling it around
broke it."

"Are you sure of that?" asked Ned.

"As sure as I am that I'm here! Now I know what caused the

"But who would play such a trick?" asked Ned. "We might all
have been killed."

"Yes, I know we might," said Tom. "It must be the work of some
of those foreign spies whose first plot we nipped in the bud. I
must tell Marbury of this, but don't mention it to dad."

"I won't," promised Ned.

Lieutenant Marbury agreed with Tom that someone had
surreptitiously bored a small hole in the propeller blade, and
had inserted a corrosive acid that would take many hours to
operate. The hole had been varnished over, probably, so it would
not show.

"And that means I've got to examine the other two blades," Tom
said. "They may be doctored too."

But they did not prove to be. A careful examination showed
nothing wrong. An effort was made to find out who had tried to
destroy the Mars in midair, but it came to nothing. The two men
in custody declared they knew nothing of it, and there was no way
of proving that they did.

Meanwhile, the torn gas bag was repaired, and Tom began working
on the problem of doing away with the gun recoil. He tried
several schemes, and almost was on the point of giving up when
suddenly he received a hint by reading an account of how the
recoil was taken care of on some of the German Zeppelins.

The guns there were made double, with the extra barrel filled
with water or sand, that could be shot out as was the regular
charge. As both barrels were fired at the same time, and in
opposite directions, with the same amount of powder, one
neutralized the other, and the recoil was canceled, the ship
remaining steady after fire.

"By Jove! I believe that will do the trick!" cried Tom. "I'm
going to try it."

"Good luck to you!" cried Ned.

It was no easy matter to change all the guns of the Mars, and
fit them with double barrels. But by working day and night shifts
Tom managed it. Meanwhile, a careful watch was kept over the
shops. Several new men applied for work, and some of them were
suspicious enough in looks, but Tom took on no new hands.

Finally the new guns were made, and tried with the Mars held on
the ground. They behaved perfectly, the shooting of sand or water
from the dummy barrel neutralizing the shot from the service

"And now to see how it works in practice!" cried Tom one day.
"Are you with me for a long flight, Ned?"

"I sure am!"

The next evening the Mars, with a larger crew than before, and
with Tom, Ned, Mr. Damon and Lieutenant Marbury aboard, set

"But why start at night?" asked Ned.

"You'll see in the morning," Tom answered.

The Mars flew slowly all night, life aboard her, at about the
level of the clouds, going on almost as naturally as though the
occupants of the cabins were on the earth. Excellent meals were

"But when are you going to try the guns?" asked Ned, as he got
ready to turn in.

"Tell you in the morning," replied Tom, with a smile.

And, in the morning, when Ned looked down through the plate
glass in the cabin floor, he uttered a cry.

"Why, Tom! We're over the ocean!" he cried.

"I rather thought we'd be," was the calm reply. "I told George
to head straight for the Atlantic. Now we'll have a test with
service charges and projectiles!"


Surprise, for the moment, held Mr. Damon, Ned and Lieutenant
Marbury speechless. They looked from the heaving waters of the
ocean below them to the young pilot of the Mars. He smiled at
their astonishment.

"What--what does it mean, Tom?" asked Ned. "You never said you
were going to take a trip as far as this."

"That's right," chimed in Mr. Damon. "Bless my nightcap! If I
had known I was going to be brought so far away from home I'd
never have come."

"You're not so very far from Water ford," put in Tom. "We
didn't make any kind of speed coming from Shopton, and we could
be back again inside of four hours if we had to."

"Then you didn't travel fast during the night?" asked the
government man.

"No, we just drifted along," Tom answered. "I gave orders to
run the machinery slowly, as I wanted to get it in good shape for
the other tests that will come soon. But I told George, whom I
left in charge when I turned in, to head for New York. I wanted
to get out over the ocean to try the guns with the new recoil

"Well, we're over the ocean all right," spoke Ned, as he looked
down at the heaving waters.

"It isn't the first time," replied Tom cheerfully. "Koku, you
may serve breakfast now," for the giant had been taken along as a
sort of cook and waiter. Koku manifested no surprise or alarm
when he found the airship floating over the sea. Whatever Tom did
was right to him. He had great confidence in his master.

"No, it isn't the first time we've taken a water flight," spoke
Ned. "I was only surprised at the suddenness of it, that's all."

"It's my first experience so far out above the water," observed
Lieutenant Marbury, "though of course I've sailed on many seas.
Why, we're out of sight of land."

"About ten miles out, yes," admitted Tom. "Far enough to make
it safe to test the guns with real projectiles. That is what I
want to do."

"And we've been running all night?" asked Mr. Damon.

"Yes, but at slow speed. The engines are in better shape now
than ever before," Tom said. "Well, if you're ready we'll have

The meal was served by Koku with as much unconcern as though
they were in the Swift homestead back in Shopton, instead of
floating near the clouds. And while it was being eaten in the
main cabin, and while the crew was having breakfast in their
quarters, the aerial warship was moving along over the ocean in
charge of George Watson, one of Tom's engineers, who was
stationed in the forward pilot-house.

"So you're going to give the guns a real test this time, is
that it, Tom?" asked Ned, as he pushed back his plate, a signal
that he had eaten enough.

"That's about it."

"But don't you think it's a bit risky out over the water this
way. Supposing something should--should happen?" Ned hesitated.

"You mean we might fall?" asked Tom, with a smile.

"Yes; or turn upside down."

"Nothing like that could happen. I'm so sure that I have solved
the problem of the recoil of the guns that I'm willing to take
chances. But if any of you want to get off the Mars while the
test is being made, I have a small boat I can lower, and let you
row about in that until--"

"No, thank you!" interrupted Mr. Damon, as he looked below.
There was quite a heavy swell on, and the ocean did not appear
very attractive. They would be much more comfortable in the big

"I think you won't have any trouble," asserted Lieutenant
Marbury. "I believe Tom Swift has the right idea about the guns,
and there will be so small a shock from the recoil that it will
not be noticeable."

"We'll soon know," spoke Tom. "I'm going to get ready for the
test now.

They were now well out from shore, over the Atlantic, but to
make certain no ships would be endangered by the projectiles, Tom
and the others searched the waters to the horizon with powerful
glasses. Nothing was seen and the work of loading the guns was
begun. The bomb tubes, in the main cabin, were also to be given a

As service charges were to be used, and as the projectiles were
filled with explosives, great care was needed in handling them.

"We'll try dropping bombs first," Tom suggested. "We know they
will work, and that will be so much out of the way.

To make the test a severe one, small floating targets were
first dropped overboard from the Mars. Then the aerial warship,
circling about, came on toward them. Tom, seated at the range-
finders, pressed the button that released the shells containing
the explosives. One after another they dropped into the sea,
exploding as they fell, and sending up a great column of salt

"Every one a hit!" reported Lieutenant Marbury, who was keeping

"That's good," responded Tom. "But the others won't be so easy.
We have nothing to shoot at."

They had to fire the other guns without targets at which to
aim. But, after all, it was the absence of recoil they wanted to
establish, and this could be done without shooting at any
particular object.

One after another the guns were loaded. As has been explained,
they were now made double, one barrel carrying the projectile,
and the other a charge of water.

"Are you ready?" asked Tom, when it was time to fire.
Lieutenant Marbury, Ned and Mr. Damon were helping, by being
stationed at the pressure gauges to note the results.

"All ready," answered Ned.

"Do you think we'd better put on life preservers, Tom?" asked
Mr. Damon.

"Nonsense! What for?"

"In case--in case anything happens."

"Nothing will happen. Look out now, I'm going to fire."

The guns were to be fired simultaneously by means of an
electric current, when Tom pressed a button.

"Here they go!" exclaimed the young inventor.

There was a moment of waiting, and then came a thundering roar.
The Mars trembled, but she did not shift to either side from an
even keel. From one barrel of the guns shot out the explosive
projectiles, and from the other spurted a jet of water, sent out
by a charge of powder, equal in weight to that which forced out
the shot.

As the projectile was fired in one direction, and the water in
one directly opposite, the two discharges neutralized one

Out flew the pointed steel shells, to fall harmlessly into the
sea, where they exploded, sending up columns of water.

"Well!" cried Tom as the echoes died away. "How was it?"

"Couldn't have been better," declared Lieutenant Marbury.
"There wasn't the least shock of recoil. Tom Swift, you have
solved the problem, I do believe! Your aerial warship is a

"I'm glad to hear you say so. There are one or two little
things that need changing, but I really think I have about what
the United States Government wants."

"I am, also, of that belief, Tom. If only--" The officer
stopped suddenly.

"Well?" asked Tom suggestively.

"I was going to say if only those foreign spies don't make

"I think we've seen the last of them," Tom declared. "Now we'll
go on with the tests."

More guns were fired, singly and in batteries, and in each case
the Mars stood the test perfectly. The double barrel had solved
the recoil problem.

For some little time longer they remained out over the sea,
going through some evolutions to test the rudder control, and
then as their present object had been accomplished Tom gave
orders to head back to Shopton, which place was reached in due

"Well, Tom, how was it?" asked Mr. Swift, for though his son
had said nothing to his friends about the prospective test, the
aged inventor knew about it.

"Successful, Dad, in every particular."

"That's good. I didn't think you could do it. But you did. I
tell you it isn't much that can get the best of a Swift!"
exclaimed the aged man proudly. "Oh, by the way, Tom, here's a
telegram that came while you were gone," and he handed his son
the yellow envelope.

Tom ripped it open with a single gesture, and in a flash his
eyes took in the words. He read:

"Look out for spies during trial flights."

The message was signed with a name Tom did not recognize.

"Any bad news?" asked Mr. Swift.

"No--oh, no," replied Tom, as he crumpled up the paper and
thrust it into his pocket. "No bad news, Dad."

"Well, I'm glad to hear that," went on Mr. Swift. "I don't like

When Tom showed the message to Lieutenant Marbury, that
official, after one glance at the signature, said:

"Pierson, eh? Well, when he sends out a warning it generally
means something."

"Who's Pierson?" asked Tom.

"Head of the Secret Service department that has charge of this
airship matter. There must be something in the wind, Tom."

Extra precautions were taken about the shops. Strangers were
not permitted to enter, and all future work on the Mars was kept
secret. Nevertheless, Tom was worried. He did not want his work
to be spoiled just when it was about to be a success. For that it
was a success, Lieutenant Marbury assured him. The government man
said he would have no hesitation in recommending the purchase of
Tom's aerial warship.

"There's just one other test I want to see made," he said.

"What is that?" Tom inquired.

"In a storm. You know we can't always count on haying good
weather, and I'd like to see how she behaves in a gale."

"You shall!" declared the young inventor.

For the next week, during which finishing touches were put on
the big craft, Tom anxiously waited for signs of a storm. At last
they came. Danger signals were put up all along the coast, and
warnings were sent out broadcast by the Weather Bureau at

One dull gray morning Tom roused his friends early and
announced that the Mars was going up.

"A big storm is headed this way," Tom said, "and we'll have a
chance to see how she behaves in it."

And even as the flight began, the forerunning wind and rain
came in a gust of fury. Into the midst of it shot the big aerial
warship, with her powerful propellers beating the moisture-laden


"Say, Tom, are you sure you're all right?"

"Of course I am! What do you mean?"

It was Ned Newton who asked the question, and Tom Swift who
answered it. The chums were in the pilot-house of the dipping,
swaying Mars, which was nosing her way into the storm, fighting
on an upward slant, trying, if possible, to get above the area of
atmospheric disturbance.

"Well, I mean are you sure your craft will stand all this
straining, pulling and hauling?" went on Ned, as he clung to a
brass hand rail, built in the side of the pilot-house wall for
the very purpose to which it was now being put.

"If she doesn't stand it she's no good!" cried Tom, as he clung
to the steering wheel, which was nearly torn from his hands by
the deflections of the rudders.

"Well, it's taking a big chance, it seems to me," went on Ned,
as he peered through the rain-spotted bull's-eyes of the pilot-

"There's no danger," declared Tom. "I wanted to give the ship
the hardest test possible before I formally offered her to the
government. If she can't stand a blow like this she isn't what I
thought her, and I'll have to build another. But I'm sure she
will stand the racket, Ned. She's built strongly, and even if
part of the gas bag is carried away, as it was when our propeller
shattered, we can still sail. If you think this is anything, wait
until we turn about and begin to fight our way against the wind."

"Are you going to do that, Tom?"

"I certainly am. We're going with the gale now, to see what is
the highest rate of speed we can attain. Pretty soon I'm going to
turn her around, and see if she can make any headway in the other
direction. Of course I know she won't make much, if any speed,
against the gale; but I must give her that test."

"Well, Tom, you know best, of course," admitted Ned. "But to me
it seems like taking a big risk."

And indeed it did seem, not only to Ned, but to some of the
experienced men of Tom's crew, that the young inventor was taking
more chances than ever before, and Tom, as my old readers well
know, had, in his career, taken some big ones.

The storm grew worse as the day progressed, until it was a
veritable hurricane of wind and rain. The warnings of the Weather
Bureau had not been exaggerated. But through the fierce blow the
Mars fought her way. As Tom had said, she was going with the
wind. This was comparatively easy. But what would happen when she
headed into the storm?

Mr. Damon, in the main cabin, sat and looked at Lieutenant
Marbury, the eccentric man now and then blessing something as he
happened to think of it.

"Do you--do you think we are in any danger?" he finally asked.

"Not at present," replied the government expert.

"You mean we will be--later?"

"It's hard to say. I guess Tom Swift knows his business,

"Bless my accident insurance policy!" murmured Mr. Damon. "I
wish I had stayed home. If my wife ever hears of this--" He did
not seem able to finish the sentence.

In the engine-room the crew were busy over the various
machines. Some of the apparatus was being strained to keep the
ship on her course in the powerful wind, and would be under a
worse stress when Tom turned his craft about. But, so far,
nothing had given way, and everything was working smoothly.

As hour succeeded hour and nothing happened, the timid ones
aboard began to take more courage. Tom never for a moment lost
heart. He knew what his craft could do, and he had taken her up
in a terrific storm with a definite purpose in view. He was the
calmest person aboard, with the exception, perhaps, of Koku. The
giant did not seem to know what fear was. He depended entirely on
Tom, and as long as his young master had charge of matters the
giant was content to obey orders.

There was to be no test of the guns this time. They had worked
sufficiently well, and, if need be, could have been fired in the
gale. But Tom did not want his men to take unnecessary risks, nor
was he foolhardy himself.

"We'll have our hands full when we turn around and head into
the wind," he said to his chum. "That will be enough."

"Then you're really going to give the Mars that test?"

"I surely am. I don't want any comebacks from Uncle Sam after
he accepts my aerial warship. I've guaranteed that she'll stand
up and make headway against a gale, and I'm going to prove it"

Lieutenant Marbury was told of the coming trial, and he
prepared to take official note of it. While matters were being
gotten in readiness Tom turned the wheel over to his assistant
pilot and went to the engine-room to see that everything was in
good shape to cope with any emergency. The rudders had been
carefully examined before the flight was made, to make sure they
would not fail, for on them depended the progress of the ship
against the powerful wind.

"I rather guess those foreign spies have given up trying to do
Tom an injury," remarked Ned to the lieutenant as they sat in the
main cabin, listening to the howl of the wind, and the dash of
the rain.

"Well, I certainly hope so," was the answer. "But I wouldn't be
too sure. The folks in Washington evidently think something is
likely to happen, or they wouldn't have sent that warning

"But we haven't seen anything of the spies," Ned remarked.

"No, but that isn't any sign they are not getting ready to make
trouble. This may be the calm before the storm. Tom must still be
on the lookout. It isn't as though his inventions alone were in
danger, for they would not hesitate to inflict serious personal
injury if their plans were thwarted."

"They must be desperate."

"They are. But here comes Tom now. He looks as though something
new was about to happen."

"Take care of yourselves now," advised the young aero-inventor,
as he entered the cabin, finding it hard work to close the door
against the terrific wind pressure.

"Why?" asked Ned.

"Because we are going to turn around and fight our way back
against the gale. We may be turned topsy-turvy for a second or

"Bless my shoe-horn!" cried Mr. Damon. "Do you mean upside
down, Tom?"

"No, not that exactly. But watch out!"

Tom went forward to the pilot-house, followed by Ned and the
lieutenant. The latter wanted to take official note of what
happened. Tom relieved the man at the wheel, and gradually began
to alter the direction of the craft.

At first no change was noticeable. So strong was the force of
the wind that it seemed as though the Mars was going in the same
direction. But Ned, noticing a direction compass on the wall, saw
that the needle was gradually shifting.

"Hold fast!" cried Tom suddenly. Then with a quick shift of the
rudder something happened. It seemed as though the Mars was
trying to turn over, and slide along on her side, or as if she
wanted to turn about and scud before the gale, instead of facing
it. But Tom held her to the reverse course.

"Can you get her around?" cried the lieutenant above the roar
of the gale.

"I--I'm going to!" muttered Tom through his set teeth.

Inch by inch he fought the big craft through the storm. Inch by
inch the indicator showed the turning, until at last the grip of
the gale was overcome.

"Now she's headed right into it!" cried Tom in exultation.
"She's nosing right into it!"

And the Mars was. There was no doubt of it. She had succeeded,
under Tom's direction, in changing squarely about, and was now
going against the wind, instead of with it.

"But we can't expect to make much speed," Tom said, as he
signaled for more power, for he had lowered it somewhat in making
the turn.

But Tom himself scarcely had reckoned on the force of his
craft, for as the propellers whirled more rapidly the aerial
warship did begin to make headway, and that in the teeth of a
terrific wind.

"She's doing it, Tom! She's doing it!" cried Ned exultingly.

"I believe she is," agreed the lieutenant.

"Well, so much the better," Tom said, trying to be calm. "If
she can keep this up a little while I'll give her a rest and
we'll go up above the storm area, and beat back home."

The Mars, so far, had met every test. Tom had decided on ten
minutes more of gale-fighting, when from the tube that
communicated with the engine-room came a shrill whistle.

"See what that is, Ned," Tom directed.

"Yes," called Ned into the mouthpiece. "What's the matter?"

"Short circuit in the big motor," was the reply. "We've got to
run on storage battery. Send Tom back here! Something queer has


Ned repeated the message breathlessly.

"Short circuit!" gasped Tom. "Run on storage battery! I'll have
to see to that. Take the wheel somebody!"

"Wouldn't it be better to turn about, and run before the wind,
so as not to put too great a strain on the machinery?" asked
Lieutenant Marbury.

"Perhaps," agreed Tom. "Hold her this way, though, until I see
what's wrong!"

Ned and the government man took the wheel, while Tom hurried
along the runway leading from the pilot-house to the machinery
cabin. The gale was still blowing fiercely.

The young inventor cast a hasty look about the interior of the
place as he entered. He sniffed the air suspiciously, and was
aware of the odor of burning insulation.

"What happened?" he asked, noting that already the principal
motive power was coming from the big storage battery. The shift
had been made automatically, when the main motor gave out.

"It's hard to say," was the answer of the chief engineer. "We
were running along all right, and we got your word to switch on
more power, after the turn. We did that all right, and she was
running as smooth as a sewing-machine, when, all of a sudden, she
short-circuited, and the storage battery cut in automatically."

"Think you put too heavy a load on the motor?" Tom asked.

"Couldn't have been that. The shunt box would have taken that
up, and the circuit-breaker would have worked, saving us a burn-
out, and that's what happened-a burn-out. The motor will have to
be rewound."

"Well, no use trying to fight this gale with the storage
battery," Tom said, after a moment's thought. "We'll run before
it. That's the easiest way. Then we'll try to rise above the

He sent the necessary message to the pilot-house. A moment
later the shift was made, and once more the Mars was scudding
before the storm. Then Tom gave his serious attention to what had
happened in the engine room.

As he bent over the burned-out motor, looking at the big shiny
connections, he saw something that startled him. With a quick
motion Tom Swift picked up a bar of copper. It was hot to the
touch--so hot that he dropped it with a cry of pain, though he
had let go so quickly that the burn was only momentary.

"What's the matter?" asked Jerry Mound, Tom's engineer.

"Matter!" cried Tom. "A whole lot is the matter! That copper
bar is what made the short circuit. It's hot yet from the
electric current. How did it fall on the motor connections?"

The engine room force gathered about the young inventor. No one
could explain how the copper bar came to be where it was.
Certainly no one of Tom's employees had put it there, and it
could not have fallen by accident, for the motor connections were
protected by a mesh of wire, and a hand would have to be thrust
under them to put the bar in place. Tom gave a quick look at his
men. He knew he could trust them--every one. But this was a queer

For a moment Tom did not know what to think, and then, as the
memory of that warning telegram came to him, he had an idea.

"Were any strangers in this cabin before the start was made?"
he asked Mr. Mound.

"Not that I know of," was the answer.

"Well, there may be some here now," Tom said grimly. "Look

But a careful search revealed no one. Yet the young inventor
was sure the bar of copper, which had done the mischief of
short-circuiting the motor, had been put in place deliberately.

In reality there was no danger to the craft, since there was
power enough in the storage battery to run it for several hours.
But the happening showed Tom he had still to reckon with his

He looked at the height gauge on the wall of the motor-room,
and noted that the Mars was going up. In accordance with Tom's
instructions they were sending her above the storm area. Once
there, with no gale to fight, they could easily beat their way
back to a point above Shopton, and make the best descent

And that was done while, under Tom's direction, his men took
the damaged motor apart, with a view to repairing it.

"What was it, Tom?" asked Ned, coming back to join his chum,
after George Ventor, the assistant pilot, had taken charge of the

"I don't exactly know, Ned," was the answer. "But I feel
certain that some of my enemies came aboard here and worked this

"Your enemies came aboard?"

"Yes, and they must be here now. The placing of that copper bar
proves it."

"Then let's make a search and find them, Tom. It must be some
of those foreign spies."

"Just what I think."

But a more careful search of the craft than the one Tom had
casually made revealed the presence of no one. All the crew and
helpers were accounted for, and, as they had been in Tom's
service for some time, they were beyond suspicion. Yet the fact
remained that a seemingly human agency had acted to put the main
motor out of commission. Tom could not understand it.

"Well, it sure is queer," observed Ned, as the search came to

"It's worse than queer," declared Tom, "it's alarming! I don't
know when I'll be safe if we have ghosts aboard."

"Ghosts?" repeated Ned.

"Well, when we can't find out who put that bar in place I might
as well admit it was a ghost," spoke Tom. "Certainly, if it was
done by a man, he didn't jump overboard after doing it, and he
isn't here now. It sure is queer!"

Ned agreed with the last statement, at any rate.

In due time the Mars, having fought her way above the storm,
came over Shopton, and then, the wind having somewhat died out,
she fought her way down, and, after no little trouble, was housed
in the hangar.

Tom cautioned his friends and workmen to say nothing to his
father about the mysterious happening on board.

"I'll just tell him we had a slight accident, and let it go at
that," Tom decided. "No use in causing him worry."

"But what are you going to do about it?" asked Ned.

"I'm going to keep careful watch over the aerial warship, at
any rate," declared Tom. "If there's a hidden enemy aboard, I'll
starve him out."

Accordingly, a guard, under the direction of Koku, was posted
about the big shed, but nothing came of it. No stranger was
observed to sneak out of the ship, after it had been deserted by
the crew. The mystery seemed deeper than ever.

It took nearly a week to repair the big motor, and, during this
time, Tom put some improvements on the airship, and added the
finishing touches.

He was getting it ready for the final government test, for the
authorities in Washington had sent word that they would have
Captain Warner, in addition to Lieutenant Marbury, make the final
inspection and write a report.

Meanwhile several little things occurred to annoy Tom. He was
besieged with applications from new men who wanted to work, and
many of these men seemed to be foreigners. Tom was sure they were
either spies of some European nations, or the agents of spies,
and they got no further than the outer gate.

But some strangers did manage to sneak into the works, though
they were quickly detected and sent about their business. Also,
once or twice, small fires were discovered in outbuildings, but
they were soon extinguished with little damage. Extra vigilance
was the watchword.

"And yet, with all my precautions, they may get me, or damage
something," declared Tom. "It is very annoying!"

"It is," agreed Ned, "and we must be doubly on the lookout."

So impressed was Ned with the necessity for caution that he
arranged to take his vacation at this time, so as to be on hand
to help his chum, if necessary.

The Mars was nearing completion. The repaired motor was better
than ever, and everything was in shape for the final test. Mr.
Damon was persuaded to go along, and Koku was to be taken, as
well as the two government officials.

The night before the trip the guards about the airship shed
were doubled, and Tom made two visits to the place before
midnight. But there was no alarm.

Consequently, when the Mars started off on her final test, it
was thought that all danger from the spies was over.

"She certainly is a beauty," said Captain Warner, as the big
craft shot upward. "I shall be interested in seeing how she
stands gun fire, though."

"Oh, she'll stand it," declared Lieutenant Marbury. The trip
was to consume several days of continuous flying, to test the
engines. A large supply of food and ammunition was aboard.

It was after supper of the first day out, and our friends were
seated in the main cabin laying out a program for the next day,
when sudden yells came from a part of the motor cabin devoted to
storage. Koku, who had been sent to get out a barrel of oil, was
heard to shout.

"What's up?" asked Tom, starting to his feet. He was answered
almost at once by more yells.

"Oh, Master! Come quickly!" cried the giant. "There are many
men here. There are stowaways aboard!"


For a moment, after hearing Koku's reply. neither Tom nor his
friends spoke. Then Ned, in a dazed sort of way, repeated:


"Bless my--" began Mr. Damon, but that was as far as he got.

From the engine compartment, back of the amidship cabin, came a
sound of cries and heavy blows. The yells of Koku could be heard
above those of the others.

Then the door of the cabin where Tom Swift and his friends were
was suddenly burst open, and seven or eight men threw themselves
within. They were led by a man with a small, dark mustache and a
little tuft of whiskers on his chin--an imperial. He looked the
typical Frenchman, and his words, snapped out, bore out that

What he said was in French, as Tom understood, though he knew
little of that language. Also, what the Frenchman said produced an
immediate result, for the men following him sprang at our
friends with overwhelming fierceness.

Before Tom, Ned, Captain Warner, Mr. Damon or Lieutenant
Marbury could grasp any weapon with which to defend themselves,
had their intentions been to do so, they were seized.

Against such odds little could be done, though our friends did
not give up without a struggle.

"What does this mean?" angrily demanded Tom Swift. "Who are
you? What are you doing aboard my craft? Who are--"

His words were lost in smothered tones, for one of his
assailants put a heavy cloth over his mouth, and tied it there,
gagging him. Another man, with a quick motion, whipped a rope
about Tom's hands and feet, and he was soon securely bound.

In like manner the others were treated, and, despite the
struggles of Mr. Damon, the two government men and Ned, they were
soon put in a position where they could do nothing--helplessly
bound, and laid on a bench in the main cabin, staring blankly up
at the ceiling. Each one was gagged so effectively that he could
not utter more than a faint moan.

Of the riot of thoughts that ran through the heads of each one,
I leave you to imagine.

What did it all mean? Where had the strange men come from? What
did they mean by thus assaulting Tom and his companions? And what
had happened to the others of the crew--Koku, Jerry Mound, the
engineer, and George Ventor, the assistant pilot?

These were only a few of the questions Tom asked himself, as he
lay there, bound and helpless. Doubtless Mr. Damon and the others
were asking themselves similar questions.

One thing was certain--whatever the stowaways, as Koku had
called them, had done, they had not neglected the Mars, for she
was running along at about the same speed, though in what
direction Tom could not tell. He strained to get a view of the
compass on the forward wall of the cabin, but he could not see

It had been a rough-and-tumble fight, by which our friends were
made prisoners, but no one seemed to have been seriously, or even
slightly, hurt. The invaders, under the leadership of the
Frenchman, were rather ruffled, but that was all.

Pantingly they stood in line, surveying their captives, while
the man with the mustache and imperial smiled in a rather
superior fashion at the row of bound ones. He spoke in his own
tongue to the men, who, with the exception of one, filed out,
going, as Tom and the others could note, to the engine-room in
the rear.

"I hope I have not had to hurt any of you," the Frenchman
observed, with sarcastic politeness. "I regret the necessity that
caused me to do this, but, believe me, it was unavoidable."

He spoke with some accent, and Tom at once decided this was the
same man who had once approached Eradicate. He also recognized
him as the man he had seen in the woods the day of the outing.

"He's one of the foreign spies," thought Tom "and he's got us
and the ship, too. They were too many for us!"

Tom's anxiety to speak, to hold some converse with the captor,
was so obvious that the Frenchman said:

"I am going to treat you as well as I can under the
circumstances. You and your other friends, who are also made
prisoners, will be allowed to be together, and then you can talk
to your hearts' content."

The other man, who had remained with the evident ringleader of
the stowaways, asked a question, in French, and he used the name
La Foy.

"Ah!" thought Tom. "This is the leader of the gang that
attacked Koku in the shop that night. They have been waiting
their chance, and now they have made good. But where did they
come from? Could they have boarded us from some other airship?"

Yet, as Tom asked himself that question, he knew it could
hardly have been possible. The men must have been in hiding on
his own craft, they must have been, as Koku had cried out--
stowaways--and have come out at a preconcerted signal to
overpower the aviators.

"If you will but have patience a little longer," went on La
Foy, for that was evidently the name of the leader, "you will all
be together. We are just considering where best to put you so
that you will not suffer too much. It is quite a problem to deal
with so many prisoners, but we have no choice."

The two Frenchmen conversed rapidly in their own language for a
few minutes, and then there came into the cabin another of the
men who had helped overpower Tom and his friends. What he told La
Foy seemed to give that individual satisfaction, for he smiled.

"We are going to put you all together in the largest storeroom,
which is partly empty," La Foy said. "There you will be given
food and drink, and treated as well as possible under the
circumstances. You will also be unbound, and may converse among
yourselves. I need hardly point out," he went on, "that calling
for help will be useless. We are a mile or so in the air, and
have no intention of descending," and he smiled mockingly.

"They must know how to navigate my aerial warship," thought
Tom. "I wonder what their game is, anyhow?"

Night had fallen, but the cabin was aglow with electric lights.
The foreigners in charge of the Mars seemed to know their way
about perfectly, and how to manage the big craft. By the
vibration Tom could tell that the motor was running evenly and

"But what happened to the others--to Mound, Ventor and Koku?"
wondered Tom.

A moment later several of the foreigners entered. Some of them
did not look at all like Frenchmen, and Tom was sure one was a
German and another a Russian.

"This will be your prison--for a while," said La Foy
significantly, and Tom wondered how long this would be the case.
A sharp thought came to him--how long would they be prisoners?
Did not some other, and more terrible, fate await them?

As La Foy spoke, he opened a storeroom door that led off from
the main, or amidship, cabin. This room was intended to contain
the supplies and stores that would be taken on a long voyage. It
was one of two, being the larger, and now contained only a few
odds and ends of little importance. It made a strong prison, as
Tom well knew, having planned it.

One by one, beginning with Tom, the prisoners were taken up and
placed in a recumbent position on the floor of the storeroom.
Then were brought in the engineer and assistant pilot, as well as
Koku and a machinist whom Tom had brought along to help him. Now
the young inventor and all his friends were together. It took
four men to carry Koku in, the giant being covered with a network
of ropes.

"On second thought," said La Foy, as he saw Koku being placed
with his friends, "I think we will keep the big man with us. We
had trouble enough to subdue him. Carry him back to the engine-

So Koku, trussed up like some roped steer, was taken out again.

"Now then," said La Foy to his prisoners, as he stood in the
door of the room, "I will unbind one of you, and he may loose the
bonds of the others."

As he spoke, he took the rope from Tom's hands, and then,
quickly slipping out, locked and barred the door.


For a moment or two, after the ropes binding his hands were
loosed, Tom Swift did nothing. He was not only stunned mentally,
but the bonds had been pulled so tightly about his wrists that
the circulation was impeded, and his cramped muscles required a
little time in which to respond.

But presently he felt the tingle of the coursing blood, and he
found he could move his arms. He raised them to his head, and
then his first care was to remove the pad of cloth that formed a
gag over his mouth. Now he could talk.

"I--I'll loosen you all in lust a second," he said, as he bent
over to pick at the knot of the rope around his legs. His own
voice sounded strange to him.

"I don't know what it's all about, any more than you do," he
went on, speaking to the others. "It's a fierce game we're up
against, and we've got to make the best of it. As soon as we can
move, and talk, we'll decide what's best to do. Whoever these
fellows are, and I believe they are the foreign spies I've been
warned about, they are in complete possession of the airship."

Tom found it no easy matter to loosen the bonds on his feet.
The ropes were well tied, and Tom's fingers were stiff from the
lack of circulation of blood. But finally he managed to free
himself. When he stood up in the dim storeroom, that was now a
prison for all save Koku, he found that he could not walk. He
almost toppled over, so weak were his legs from the tightness of
the ropes. He sat down and worked his muscles until they felt
normal again.

A few minutes later, weak and rather tottery, he managed to
reach Mr. Damon, whom he first unbound. He realized that Mr.
Damon was the oldest of his friends, and, consequently, would
suffer most. And it was characteristic of the eccentric gentleman
that, as soon as his gag was removed he burst out with:

"Bless my wristlets, Tom! What does it all mean?"

"That's more than I can say, Mr. Damon," replied Tom, with a
mournful shake of his head. "I'm very sorry it happened, for it
looks as though I hadn't taken proper care. The idea of those men
stowing themselves away on board here, and me not knowing it; and
then coming out unexpectedly and getting possession of the craft!
It doesn't speak very well for my smartness."

"Oh, well, Tom, anyone might have been fooled by those plotting
foreigners," said Mr. Damon. "Now, we'll try to turn matters
about and get the best of them. Oh, but it feels good to be free
once more!"

He stretched his benumbed and stiffened limbs and then helped
Tom free the others. They stood up, looking at each other in
their dimly lighted prison.

"Well, if this isn't the limit I don't know what is!" cried Ned

"They got the best of you, Tom," spoke Lieutenant Marbury.

"Are they really foreign spies?" asked Captain Warner.

"Yes," replied his assistant. "They managed to carry out the
plot we tried to frustrate. It was a good trick, too, hiding on
board, and coming out with a rush."

"Is that what they did?" asked Mr. Damon.

"It looks so," observed Tom. "The attack must have started in
the engine-room," he went on, with a look at Mound and Ventor.
"What happened there?" he asked.

"Well, that's about the way it was," answered the engineer. "We
were working away, making some adjustments, oiling the parts and
seeing that everything was running smoothly, when, all at once, I
heard Koku yell. He had gone in the oil room. At first I thought
something had gone wrong with the ship, but, when I looked at the
giant, I saw he was being attacked by four strange men. And,
before I, or any of the other men, could do anything, they all
swarmed down on us.

"There must have been a dozen of them, and they simply
overwhelmed us. One of them hit Koku on the head with an iron
bar, and that took all the fight out of the giant, or the story
might have been a different one. As it was, we were overpowered,
and that's all I know until we were carried in here, and saw you
folks all tied up as we were."

"They burst in on us in the same way," Tom explained. "But
where did they come from? Where were they hiding?"

"In the oil and gasoline storeroom that opens out of the motor
compartment," answered Mound, the engineer. "It isn't half full,
you know, and there's room for more than a dozen men in it. They
must have gone in some time last night, when the airship was in
the hangar, and remained hidden among the boxes and barrels until
they got ready to come out and overpower us."

"That's it," decided Tom. "But I don't understand how they got
in. The hangar was well guarded all night."

"Some of your men might have been bribed,"
suggested Ned.

"Yes, that is so," admitted Tom, and, later, he learned that
such had been the case. The foreign spies, for such they were,
had managed to corrupt one of Tom's trusted employees, who had
looked the other way when La Foy and his fellow-conspirators
sneaked into the airship shed and secreted themselves.

"Well, discussing how they got on board isn't going to do us
any good now," Tom remarked ruefully. "The question is--what are
we going to do?"

"Bless my fountain pen!" cried Mr. Damon. "There's only one
thing to do!"

"What is that?" asked Ned.

"Why, get out of here, call a policeman, and have these
scoundrels arrested. I'll prosecute them! I'll have my lawyer on
hand to see that they get the longest terms the statutes call
for! Bless my pocketbook, but I will!" and Mr. Damon waxed quite

"That's easier said than done," observed Torn Swift, quietly.
"In the first place, it isn't going to be an easy matter to get
out of here."

He looked around the storeroom, which was then their prison. It
was illuminated by a single electric light, which showed some
boxes and barrels piled in the rear.

"Nothing in them to help us get out," Tom went on, for he knew
what the contents were.

"Oh, we'll get out," declared Ned confidently, "but I don't
believe we'll find a policeman ready to take our complaint. The
upper air isn't very well patrolled as yet."

"That's so," agreed Mr. Damon. "I forgot that we were in an
airship. But what is to he done, Tom? We really are captives
aboard our own craft."

"Yes, worse luck," returned the young inventor. "I feel foolish
when I think how we let them take us prisoners."

"We couldn't help it," Ned commented. "They came on us too
suddenly. We didn't have a chance. And they outnumbered us two to
one. If they could take care of big Koku, what chance did we

"Very little," said Engineer Mound. "They were desperate
fellows. They know something about aircraft, too. For, as soon as
Koku, Ventor and I were disposed of, some of them went at the
machinery as if they had been used to running it all their

"Oh, the foreigners are experts when it comes to craft of the
air," said Captain Warner.

"Well, they seem to be running her, all right," admitted the
young inventor, "and at good speed, too. They have increased our
running rate, if I am any judge."

"By several miles an hour," confirmed the assistant pilot.
"Though in which direction they are heading, and what they are
going to do with us is more than I can guess."

"That's so!" agreed Mr. Damon. "What is to become of us? They
may heave us overboard into the ocean!"

"Into the ocean!" cried Ned apprehensively. "Are we near the

"We must be, by this time," spoke Tom. "We were headed in that
direction, and we have come almost far enough to put us somewhere
over the Atlantic, off the Jersey coast."

A look of apprehension was on the faces of all. But Tom's face
did not remain clouded long.

"We won't try to swim until we have to," he said. "Now, let's
take an account of stock, and see if we have any means of getting
out of this prison.


With one accord the hands of the captives sought their pockets.
Probably the first thought of each one was a knife--a pocket
knife. But blank looks succeeded their first hopeful ones, for
the hands came out empty.

"Not a thing!" exclaimed Mr. Damon. "Not a blessed thing! They
have even taken my keys and--my fountain pen!"

"I guess they searched us all while they were struggling with
us, tying us up," suggested Ned. "I had a knife with a big,
strong blade, but it's gone.

"So is mine," echoed Tom.

"And I haven't even a screwdriver, or a pocket-wrench,"
declared the engineer, "though I had both."

"They evidently knew what they were doing," said Lieutenant
Marbury. "I don't usually carry a revolver, but of late I have
had a small automatic in my pocket. That's gone, too."

"And so are all my things," went on his naval friend. "That
Frenchman, La Foy, was taking no chances."

"Well," if we haven't any weapons, or means of getting out of
here, we must make them," said Tom, as hopefully as he could
under the circumstances. "I don't know all the things that were
put in this storeroom, and perhaps there may be something we can

"Shall we make the try now?" asked Ned. "I'm getting thirsty,
at least. Lucky we had supper before they came out at us."

"Well, there isn't any water in here, or anything to eat, of so
much I am sure," went on Tom "So we will have to depend on our
captors for that."

"At least we can shout and ask for water," said Lieutenant
Marbury. "They have no excuse for being needlessly cruel."

They all agreed that this might not be a bad plan, and were
preparing to raise a united shout, when there came a knock on the
door of their prison.

"Are you willing to listen to reason?" asked a voice they
recognized as that of La Foy.

"What do you mean by reason?" asked Tom bitterly. "You have no
right to impose any conditions on us."

"I have the right of might, and I intend exercising it," was
the sharp rejoinder. "If you will listen to reason--"

"Which kind--yours or ours?" asked Tom pointedly.

"Mine, in this case," snapped back the Frenchman. "What I was
going to say was that I do not intend to starve you, or cause you
discomfort by thirst. I am going to open the door and put in food
and water. But I warn you that any attempt to escape will be met
with severe measures.

"We are in sufficient force to cope with you. I think you have
seen that." He spoke calmly and in perfect English, though with a
marked accent. "My men are armed, and will stand here ready to
meet violence with violence," he went on. "Is that understood?"

For a moment none of the captives replied.

"I think it will be better to give in to him at least for a
while," said Captain Warner in a low voice to Tom. "We need
water, and will soon need food. We can think and plan better if
we are well nourished."

"Then you think I should promise not to raise a row?"

"For the time being--yes."

"Well, I am waiting!" came in sharp tones from the other side
of the portal.

"Our answer is--yes," spoke Tom. "We will not try to get out--
just yet," he added significantly.

A key was heard grating in the lock, and, a moment later, the
door slid back. Through the opening could be seen La Foy and some
of his men standing armed. Others had packages of food and jugs
of water. A plentiful supply of the latter was carried aboard the

"Keep back from the door!" was the stern command of La Foy.
"The food and drink will be passed in only if you keep away from
the entrance. Remember my men are armed!"

The warning was hardly needed, for the weapons could plainly be
seen. Tom had half a notion that perhaps a concerted rush would
carry the day for him and his friends, but he was forced to
abandon that idea.

While the guards looked on, others of the "pirate crew," as Ned
dubbed them, passed in food and water. Then the door was locked

They all felt better after drinking the water, which was made
cool by evaporation, for the airship was quite high above the
earth when Tom's enemies captured it, and the young inventor felt
sure it had not descended any.

No one felt much like eating, however, so the food was put away
for a time. And then, somewhat refreshed, they began looking
about for some means of getting out of their prison.

"Of course we might batter down the door, in time, by using
some of these boxes as rams," said Tom. "But the trouble is, that
would make a noise, and they could stand outside and drive us
back with guns and pistols, of which they seem to have plenty."

"Yes, and they could turn some of your own quick-firers on us,"
added Captain Warner. "No, we must work quietly, I think, and
take them unawares, as they took us. That is our only plan."

"We will be better able to see what we have here by daylight,"
Tom said. "Suppose we wait until morning?"

That plan was deemed best, and preparations made for spending
the night in their prison.

It was a most uncomfortable night for all of them. The floor
was their only bed, and their only covering some empty bags that
had contained supplies. But even under these circumstances they
managed to doze off fitfully.

Once they were all awakened by a violent plunging of the
airship. The craft seemed to be trying to stand on her head, and
then she rocked violently from side to side, nearly turning
turtle. "What is it?" gasped Ned, who was lying next to Tom.

"They must be trying some violent stunts," replied the young
inventor, "or else we have run into a storm."

"I think the latter is the case," observed Lieutenant Marbury.

And, as the motion of the craft kept up, though less violently,
this was accepted as the explanation. Through the night the Mars
flew, but whither the captives knew not.

The first gray streaks of dawn finally shone through the only
window of their prison. Sore, lame and stiff, wearied in body and
disturbed in mind, the captives awoke. Tom's first move was
toward the window. It was high up, but, by standing on a box, he
could look through it. He uttered an exclamation.

"What is it?" asked Ned, swaying to and fro from the violent
motion ef the aerial warship.

"We are away out over the sea," spoke Tom, "and in the midst of
a bad storm."


Tom turned away from the window, to find his companions
regarding him anxiously.

"A storm," repeated Ned. "What sort?"

"It might turn into any sort," replied Tom. "All I can see now
is a lot of black clouds, and the wind must be blowing pretty
hard, for there's quite a sea on."

"Bless my galvanometer!" cried Mr. Damon. "Then we are out over
the ocean again, Tom?"

"Yes, there's no doubt of it."

"What part?" asked the assistant pilot.

"That's more than I can tell," Tom answered.

"Suppose I take a look?" suggested Captain Warner. "I've done
quite a bit of sailing in my time."

But, when he had taken a look through the window at which Tom
had been standing, the naval officer descended, shaking his head.

"There isn't a landmark in sight," he announced. "We might be
over the middle of the Atlantic, for all I could tell."

"Hardly as far as that," spoke Tom. "They haven't been pushing
the Mars at that speed. But we may be across to the other side
before we realize it."

"How's that?" asked Ned.

"Well, the ship is in the possession of these foreign spies,"
went on Tom. "All their interests are in Europe, though it would
be hard to say what nationality is in command here. I think there
are even some Englishmen among those who attacked us, as well as
French, Germans, Italians and Russians."

"Yes, it seems to be a combination of European nations against
us," admitted Captain Warner. "Probably, after they have made
good their seizure of Tom's aerial warship, they will portion her
out among themselves, or use her as a model from which to make

"Do you think that is their object?" asked Mr. Damon.

"Undoubtedly," was the captain's answer. "It has been the
object of these foreign spies, all along, not only to prevent the
United States from enjoying the benefits of these progressive
inventions, but to use them for themselves. They would stop at
nothing to gain their ends. It seems we did not sufficiently
appreciate their power and daring."

"Well, they've got us, at any rate," observed Tom, "and they
may take us and the ship to some far-off foreign country."

"If they don't heave us overboard half-way there," commented
Ned, in rather gloomy tones

"Well, of course, there's that possibility," admitted Tom.
"They are desperate characters."

"Well, we must do something," declared Lieutenant Marbury.
"Come, it's daylight now, and we can see to work better. Let's
see if we can't find a way to get out of this prison. Say, but
this sure is a storm!" he cried, as the airship rolled and
pitched violently.

"They are handling her well, though," observed Tom, as the
craft came quickly to an even keel. "Either they have a number of
expert birdmen on board, or they can easily adapt themselves to a
new aircraft. She is sailing splendidly."

"Well, let's eat something, and set to work," proposed Ned.

They brought out the food which had been given to them the
night before, but before they could eat this, there came a knock
on the door, and more food and fresh water was handed in, under
the same precautions as before.

Tom and his companions indignantly demanded to be released, but
their protests were only laughed at, and while the guards stood
with ready weapons the door was again shut and locked.

But the prisoners were not the kind to sit idly down in the
face of this. Under Tom's direction they set about looking
through their place of captivity for something by which they
could release themselves. At first they found nothing, and Ned
even suggested trying to cut a way through the wooden walls with
a fingernail file, which he found in one of his pockets, when
Tom, who had gone to the far end of the storeroom, uttered a cry.

"What is it--a way out?" asked Lieutenant Marbury anxiously.

"No, but means to that end," Tom replied. "Look, a file and a
saw, left here by some of my workmen, perhaps," and he brought
out the tools. He had found them behind a barrel in the far end
of the compartment.

"Hurray!" cried Ned. "That's the ticket! Now we'll soon show
these fellows what's what!"

"Go easy!" cautioned Tom. "We must work carefully. It won't do
to slam around and try to break down the door with these. I think
we had better select a place on the side wall, break through
that, and make an opening where we can come out unnoticed. Then,
when we are ready, we can take them by surprise. We'll have to do
something like that, for they outnumber us, you know."

"That is so," agreed Captain Warner. "We must use strategy."

"Well, where would be a good place to begin to burrow out?"
asked Ned.

"Here," said Tom, indicating a place far back in the room. "We
can work there in turns, sawing a hole through the wall. It will
bring us out in the passage between the aft and amidship cabins,
and we can go either way."

"Then let's begin!" cried Ned enthusiastically, and they set to

While the aerial warship pitched and tossed in the storm, over
some part of the Atlantic, Tom and his friends took turns in
working their way to freedom. With the sharp end of the file a
small hole was made, the work being done as slowly as a rat
gnaws, so as to make no noise that would be heard by their
captors. In time the hole was large enough to admit the end of
the saw.

But this took many hours, and it was not until the second day
of their captivity that they had the hole nearly large enough for
the passage of one person at a time. They had not been
discovered, they thought.

Meanwhile they had been given food and water at intervals, but
to all demands that they be released, or at least told why they
were held prisoners, a deaf ear was turned.

They could only guess at the fate of Koku. Probably the giant
was kept bound, for once he got the chance to use his enormous
strength it might go hard with the foreigners.

The Mars continued to fly through the air. Sometimes, as Tom
and his friends could tell by the motion, she was almost
stationary in the upper regions, and again she seemed to be
flying at top speed. Occasionally there came the sound of firing.

"They're trying my guns," observed Tom grimly.

"Do you suppose they are being attacked?" asked Ned, hopefully.

"Hardly," replied Captain Warner. "The United States possesses
no craft able to cope with this one in aerial warfare, and they
are hardly engaging in part of the European war yet. I think they
are just trying Tom's new guns."

Later our friends learned that such was the case.

The storm had either passed, or the Mars had run out of the
path of it, for, after the first few hours of pitching and
tossing, the atmosphere seemed reduced to a state of calm.

All the while they were secretly working to gain their freedom
so they might attack and overpower their enemies, they took
occasional observations from the small window. But they could
learn nothing of their whereabouts. They could only view the
heaving ocean, far below them, or see a mass of cloud-mist, which
hid the earth, if so be that the Mars was sailing over land.

"But how much longer can they keep it up?" asked Ned.

"Well, we have fuel and supplies aboard for nearly two weeks,"
Tom answered.

"And by the end of that time we may all be dead," spoke the
young bank clerk despondently.

"No, we'll be out of here before then!" declared Lieutenant

Indeed the hole was now almost large enough to enable them to
crawl out one at a time. They could not, of course, see how it
looked from the outside, but Tom had selected a place for its
cutting so that the sawdust and the mark of the panel that was
being removed, would not ordinarily be noticeable.

Their set night as the time for making the attempt--late at
night, when it was hoped that most of their captors would be

Finally the last cut was made, and a piece of wood hung over
the opening only by a shred, all ready to knock out.

"We'll do it at midnight," announced Tom.

Anxious, indeed, were those last hours of waiting. The time had
almost arrived for the attempt, when Tom, who had been nervously
pacing to and fro, remarked:

"We must be running into another storm. Feel how she heaves and

Indeed the Mars was most unsteady.

"It sure is a storm!" cried Ned, "and a heavy one, too," for
there came a burst of thunder, that seemed like a report of Tom's
giant cannon.

In another instant they were in the midst of a violent
thunderstorm, the airship pitching and tossing in a manner to
almost throw them from their feet.

As Tom reached up to switch on the electric light again, there
came a flash of lightning that well nigh blinded them. And so
close after it as to seem simultaneous, there came such a crash
of thunder as to stun them all. There was a tingling, as of a
thousand pins and needles in the body of each of the captives,
and a strong smell of sulphur. Then, as the echoes of the clap
died away, Tom yelled:

"She's been struck! The airship has been struck!"


For a moment there was silence, following Tom's wild cry and
the noise of the thunderclap. Then, as other, though less loud
reverberations of the storm continued to sound, the captives
awoke to a realization of what had happened. They had been
partially stunned, and were almost as in a dream.

"Are--are we all right?" stammered Ned.

"Bless my soul! What has happened?" cried Mr. Damon.

"We've been struck by lightning!" Tom repeated. "I don't know
whether we're all right or not."

"We seem to be falling!" exclaimed Lieutenant Marbury.

"If the whole gas bag isn't ripped to pieces we're lucky,"
commented Jerry Mound.

Indeed, it was evident that the Mars was sinking rapidly. To
all there came the sensation of riding in an elevator in a
skyscraper and being dropped a score of stories.

Then, as they stood there in the darkness, illuminated only by
flashes from the lightning outside the window, waiting for an
unknown fate, Tom Swift uttered a cry of delight.

"We've stopped falling!" he cried. "The automatic gas machine
is pumping. Part of the gas bag was punctured, but the unbroken
compartments hold!"

"If part of the gas leaked out I don't see why it wasn't all
set on fire and exploded," observed Captain Warner.

"It's a non-burnable gas," Tom quickly explained. "But come on.
This may be our very chance. There seems to be something going on
that may be in our favor."

Indeed the captives could hear confused cries and the running
to and fro of many feet.

He made for the sawed panel, and, in another instant, had burst
out and was through it, out into the passageway between the after
and amidship cabins. His companions followed him.

They looked into the rear cabin, or motor compartment, and a
scene of confusion met their gaze. Two of the foreign men who had
seized the ship lay stretched out on the floor near the humming
machinery, which had been left to run itself. A look in the other
direction, toward the main cabin, showed a group of the foreign
spies bending over the inert body of La Foy, the Frenchman,
stretched out on a couch.

"What has happened?" cried Ned. "What does it all mean?,'

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