CASTING THE CANNON
"Come on!" yelled Ned. "We'll see how this experiment came out!" and he
started to run from beneath the shelter of the hill.
"Hold on!" shouted Tom, laying a restraining hand on his chum's
shoulder.
"Why, what's the matter?" asked Ned in surprise.
"Some of that powder may not have exploded," went on the young
inventor. "From the sound made I should say the gun burst, and, if it
did, that gelatin is bound to be scattered about. There may be a mass
of it burning loose somewhere, and it may go off. It ought not to, if
my theory about it being harmless in the open is correct, but the
trouble is that it's only a theory. Wait a few seconds."
Anxiously they lingered, the echoes of the blast still in their ears,
and a peculiar smell in their nostrils.
"But there's no smoke," said Mr. Damon. "Bless my spyglass! I always
thought there was smoke at an explosion."
"This is a sort of smokeless powder," explained Tom. "It throws off a
slight vapor when it is ignited, but not much. I guess it's safe to go
out now. Come on!"
He dropped the pushbutton connected with the igniting battery, and,
followed by the others, raced to the scene of the experiment. A curious
sight met their eyes.
A great hole had been torn in the hillside, and another where the
improvised gun had stood. The gun itself seemed to have disappeared.
"Why--why--where is it?" asked Ned.
"Burst to pieces I guess," replied Tom. "I was afraid that charge was a
bit too heavy."
"No, here it is!" shouted Mr. Damon, circling off to one side. "It's
been torn from the carriage, and partly buried in the ground," and he
indicated a third excavation in the earth.
It was as he had said. The terrific blast had sheared the gun from its
temporary carriage, thrown it into the air, and it had come down to
bury itself in the soft ground. The carriage had torn loose from the
concrete base, and was tossed off in another direction.
"Is the gun shattered?" asked Tom, anxious to know how the weapon had
fared. It was, in a sense, a sort of small model of the giant cannon he
intended to have cast.
"The breech is cracked a little," answered Mr. Damon, who was examining
it; "but otherwise it doesn't seem to be much damaged."
"Good," cried Tom. "Another steel jacket will remedy that defect. I
guess I'm on the right road at last. But now to see what became of that
armor plate."
"Dinner plate not here," spoke Koku, who could not understand how there
could be two kind of plates in the world. "Dinner plate gone, but big
hole here, and he indicated one in the side of the hill.
"I expect that is where the armor plate is," said Tom, trying not to
laugh at the mistake of his giant servant. "Take a look in there, Koku,
and, if you can get hold of it, pull it out for us. I'm afraid the
piece of nickel-steel armor proved too much for my projectile. But
we'll have a look."
Koku disappeared into the miniature cave that had been torn in the side
of the bill. It was barely large enough to allow him to go in. But Tom
knew none other of them could hope to loosen the piece of steel,
imbedded as it must be in the solid earth.
Presently they heard Koku grunting and groaning. He seemed to be having
quite a struggle.
"Can you get it, Koku?" asked Tom. "Or shall I send for picks and
shovels."
"Me get, Master," was the muffled answer.
Then came a shout, as though in anger Koku had dared the buried plate
to defy him. There was a shower of earth at the mouth of the cave, and
the giant staggered out with the heavy piece of armor plate. At the
sight of it Tom uttered a cry.
"Look!" he shouted. "My projectile went part way through and then
carried the plate with it into the side of the hill. Talk about a
powerful explosive! I've struck it, all right!"
It was as he had said. The projectile, driven with almost irresistible
force, had bitten its way through the armor plate, but a projection at
the base of the shell had prevented it from completely passing through.
Then, with the energy almost unabated, the projectile had torn the
plate loose and hurled it, together with its own body, into the solid
earth of the hillside. There, as Koku held them up, they could all see
the shell imbedded in the plate, the point sticking out on the other
side, as a boy might spear an apple with a sharp stick.
"Bless my spectacle case!" cried Mr. Damon. "This is the greatest ever!"
"It sure is," agreed Ned. "Tom, my boy, I guess you can now make the
longest shots on record."
"I can as soon as I get my giant cannon, perhaps," admitted the young
inventor. "I think I have solved the problem of the explosive. Now to
work on the cannon."
An examination of the gauges, which, being attached to the cannon and
plate by electric wires, were not damaged when the blast came, showed
that Tom's wildest hopes had been confirmed. He had the most powerful
explosive ever made--or at least as far as he had any knowledge, and he
had had samples of all the best makes.
Concerning Tom's powder, or explosive, I will only say that he kept the
formula of it secret from all save his father. All that he would admit,
when the government experts asked him about it, later, was that the
base was not nitro-glycerine, but that this entered into it. He agreed,
however, in case his gun was accepted by the government, to disclose
the secret to the ordnance officers.
But Tom's work was only half done. It was one thing to have a powerful
explosive, but there must be some means of utilizing it safely--some
cannon in which it could be fired to send a projectile farther than any
cannon had ever sent one. And to do this much work was necessary.
Tom figured and planned, far into the night, for many weeks after that.
He had to begin all over again, working from the basis of the power of
his new explosive. And he had many new problems to figure out.
But finally he had constructed--on paper--a gun that was to his liking.
The most exhaustive figuring proved that it had a margin of safety that
would obviate all danger of its bursting, even with an accidental
over-charge.
"And the next thing is to get the gun cast," said Tom to Ned one day.
"Are you going to do it in your shops?" his chum asked.
"No; it would be out of the question for me. I haven't the facilities.
I'm going to give the contract to the Universal Steel Company. We'll
pay them a visit in a day or two."
But even the great facilities of the steel corporation proved almost
inadequate for Tom's giant cannon. When he showed the drawings, on
which he had already secured a patent, the manager balked.
"We can't cast that gun here!" he said.
"Oh, yes, you can!" declared Tom, who had inspected the plant. "I'll
show you how."
"Why, we haven't a mould big enough for the central core," was another
objection.
"Then we'll make one," declared Tom "We'll dig a pit in the earth, and
after it is properly lined we can make the cast there."
"I never thought of that!" exclaimed the manager. "Perhaps it can be
done."
"Of course it can!" cried Tom. "Do you think you can shrink on the
jackets, and rifle the central tube?"
"Oh, yes, we can do that. The initial cast was what stumped me. But
we'll go ahead now."
"And you can wind the breech with wire, and braze it on; can't you?"
persisted Tom.
"Yes, I think so. Are you going to have a wire-wound gun?"
"That, in combination with a steel-jacketed one. I'm going to take no
chances with 'Swiftite'!" laughed Tom, for so he had named his new
explosive, in honor of his father, who had helped him with the formula.
"It must be mighty powerful," exclaimed the manager.
"It is," said Tom, simply.
I am not going to tire my readers with the details leading up to the
casting of Tom's big cannon. Sufficient to say that the general plan,
in brief, was this: A hole would be dug in the earth, in the center of
the largest casting shop--a hole as deep as the gun was to be long.
This was about one hundred feet, though the gun, when finished, would
be somewhat shorter than this. An allowance was to be made for cutting.
In the center of this hole would be a small "core" made of asbestos and
concrete mixed. Around this would be poured the molten steel from great
caldrons. It would flow into the hole. The sides of earth--lined with
fire-clay--would hold it in, and the middle core would make a hole
throughout the length of the central part of the gun. Afterward this
hole would be bored and rifled to the proper calibre.
After this central part was done, steel jackets or sleeves would be put
on, red-hot, and allowed to shrink. Then would come a winding of wire,
to further strengthen the tube, and then more sleeves or jackets. In
this way the gun would be made very strong.
As the greatest pressure would come at the breech, or in the powder
chamber there, the gun would be thickest at this point, decreasing in
size to the muzzle.
It took many weary weeks to get ready for the first cast, but finally
Tom received word that it was to be made, and with Ned, and Mr. Damon,
he proceeded to the plant of the steel concern.
There was some delay, but finally the manager gave the word. Tom and
his friends, standing on a high gallery, watched the tapping of the
combined furnaces that were to let the molten steel into the caldrons.
There were several of these, and their melted contents were to be
poured into the mould at the same time.
Out gushed the liquid steel, giving off a myriad of sparks. The
workers, as well as the visitors, had to wear violet-tinted glasses to
protect their eyes from the glare.
"Hoist away!" cried the manager, and the electric cranes started off
with the caldrons of liquid fire, weighing many tons.
"Pour!" came the command, and into the pit in the earth splashed the
melted steel that was to form the big cannon. From each caldron there
issued a stream of liquid metal of intense heat. There were numerous
explosions as the air bubbles burst--explosions almost like a battery
in action.
"So far so good!" exclaimed the manager, with a sigh of relief as the
last of the melted stuff ran into the mould. "Now, when it cools, which
won't be for some days, we'll see what we have."
"I hope it contains no flaws," spoke Tom, "That is the worst of big
guns--you never can tell when a flaw will develop. But I hope--"
Tom was interrupted by the sound of a dispute at one of the outer doors
of the shop.
"But I tell you I must go in--I belong here in!" a voice cried. It had
a German accent, and at the sound of it Tom and Ned looked at each
other.
"Who is there?" asked the manager sharply of the foreman..
"Oh, a crazy German. He belongs in one of the other shops, and I guess
he's mixed up. He thinks he belongs here. I sent him about his
business."
"That is right," remarked the manager. "I gave orders, at your
request," he said to Tom, "that no one but the men in this part of the
plant were to be present at the casting. I can't understand what that
fellow wanted."
"I think I can," murmured Tom, to himself.