CHAPTER V

TOM'S PROJECT

Curious was the sight that met the gaze of Tom Swift and Mr. Wakefield

Damon as they rounded the corner of the house and looked into the newly

spaded garden. There stood the giant, Koku, holding aloft in the air,

by one hand, the form of the struggling colored man, Eradicate Sampson.

And Eradicate was vainly trying to get at his enemy and rival, but was

prevented by the long-distance hold the giant had on him.

"Yo' let me go, now! Yo' let me go, big man," cried Eradicate. "Ef yo'

don't I'll bust yo' wide open, dat's whut I'll do! An' 'sides, I'll

tell Massa Tom on yo', dat's whut I'll do!"

"Ho! You tell--I let you fall!" threatened Koku.

His threat was dire enough, for such was his size and strength that he

held the colored man nearly nine feet from the ground, and a fall from

that distance would seriously jar Eradicate, if it did nothing else.

The colored man's eyes opened wide as he heard what Koku said, and then

he cried:

"Let me down! Let me down, an' I won't say nuffin!"

"An' you let me scatter dirt?" asked Koku, for such was the giant's

idea of working in the garden.

"Yes, yo' kin scatter de dirt seben ways from Sunday fo' all I keers!"

conceded Eradicate. Then, as he was lowered to the ground, he and the

giant turned and saw Mr. Damon and Tom approaching.

"What's wrong?" asked the young inventor.

"'Scuse me, Massa Tom," began Eradicate, "but didn't yo' tell me to

spade de garden?"

"I guess I did," admitted Tom Swift.

"An' you tell me help--yes?" questioned Koku.

"Well, I thought it would be a little too much for you, Rad," said Tom,

gently. "I thought perhaps you'd like help."

"Hu! Not him, anyhow!" declared the colored man in great disgust. "When

I git so old dat I cain't spade a garden, den me an' Boomerang, we-all

gwine to die, dat's all I got to say. I was a-spadin' my part ob de

garden, Massa Tom, same laik Mr. Damon done tole me to, an' dish yeah

big mess ob bones steps on my side ob de middle an--"

"Him too slow. Koku scatter dirt twice times so fast!" declared the

giant, whose English was not much better than Eradicate's.

"Yes, I see," said Tom. "You are so strong, Koku, that you finished

your part before Eradicate did. Well, it was good of you to want to

help him."

At this the giant grinned at his rival.

"At the same time," went on Tom, winking an eye at Mr. Damon,

"Eradicate knows a little more about garden work, on account of having

done it so many years."

"Ha! Whut I tell yo', Giant!" boasted the colored man. It was his turn

to smile.

"And so," went on Tom, judicially, "I guess I'll let Rad finish spading

the garden, and you, Koku, can come and help me lift some heavy engine

parts. Mr. Damon wants to explain something to me."

"Ha! Nothing what so heavy Koku not lift!" boasted the giant.

"Go on! Lift yo'se'f 'way from heah!" muttered Eradicate as he picked

up his dropped spade. And then, with a smile of satisfaction, he fell

to work in the mellow soil while Tom led Koku to one of the shops where

he set him to lifting heavy motor parts about in order to get at a

certain machine that was stored away in the back of one of the rooms.

"That will keep him busy," said the young inventor. "And now, Mr.

Damon, I can listen to you. Do you really think you have a new idea in

airships?"

"I really think so, Tom. My Whizzer is bound to revolutionize travel in

the air. Let me tell you what I mean. Now cast your mind back. How many

ways are now used to propel an airship or a dirigible balloon through

the air? How many ways?"

"Two, as far as I know," said Tom. "At least there are only two that

have proved to be practical."

"Exactly," said Mr. Damon. "One with the propeller, or propellers, in

front, and that is the tractor type. The other has the propeller in the

rear, and that is the pusher type. Both good as far as they go, but I

have something better."

"What?" asked Tom with a smile.

"It's a Whizzer," said the eccentric man. "Bless my gold tooth! but

that is the best name I can think of for it. And, really, the propeller

I'm thinking of inventing does whiz around."

"But are you going to use a tractor or pusher type?" Tom wanted to know.

"It's a combination of both," answered Mr. Damon. "As it is now, Tom,

you have to get an aeroplane in pretty speedy motion before it will

rise from the ground, don't you?"

"Yes, of course. That's the principle on which an aeroplane rises and

keeps aloft, by its speed in the air. As soon as that speed stops it

begins to fall, or volplane, as we call it."

"Exactly. Now, instead of having to depend on the speed of the

aeroplane for this, why not depend on the speed of the propeller--in

other words, the whizzer?"

"Well, we do," said Tom, a bit puzzled as to what his friend was trying

to get at. "If the propeller didn't move the airship wouldn't

rise--that is, unless it's of the balloon type."

"What I mean," said Mr. Damon, "is to have an aeroplane that will move

in the air the same as a boat moves in the water. You don't have to get

the propeller of a boat racing around at the rate of a million

revolutions a minute, more or less, before your boat will travel, do

you? If the engine turns the screw, or propeller, just over say fifty

times a minute you would get some motion of the boat, wouldn't you?"

"Why, yes, some," admitted Tom.

"And what causes it?" asked Mr. Damon, anticipating a triumph.

"The resistance of the water to the blades of the screw, or propeller,"

answered Tom.

"Exactly! And it's the resistance of the air to the blades of an

airship propeller that sends the craft along, isn't it?"

"Yes. And because of the difference in density between air and water it

becomes necessary to revolve an aeroplane propeller many times faster

than a boat propeller. It's the density that makes the difference, Mr.

Damon. If air were as dense as water we could have comparatively

slow-moving motors and propellers and--"

"Ha! There you have it, Tom! And there is where my Whizzer--Wakefield

Damon's Whizzer--is going to revolutionize air travel!" cried the

eccentric man. "The difference in density! If air were as dense as

water the problem would be solved. And I have solved it! I'm going to

turn the trick, Tom! One more question. How can air be made as dense as

water, Tom Swift?"

"Why, by condensation or compression, I suppose," was the rather slow

answer. "You know they have condensed, or compressed, air until it is

liquid. I've done it myself, as an experiment."

"That's it, Tom! That's it!" cried Mr. Damon in delight. "Compressed

air will do the trick! Not compressed to a liquid, exactly, but almost

so. I'm going to revolve the propellers of my new airship in compressed

air, so dense that they will not have to have a speed of more than

seven hundred revolutions a minute. What's that compared to the three

to ten thousand revolutions of the propellers now used? The propellers

of Damon's Whizzer will be of the pusher type, and will revolve in

dense, compressed air, almost like water, and that will do away with

high speed motors, with all their complications, and make traveling in

the clouds as simple as taking out a little one-cylinder motor boat.

How's that, Tom Swift? How's that for an idea?"

To Mr. Damon's disappointment, Tom was not enthusiastic. The young

inventor gazed at his eccentric friend, and then said slowly:

"Well, that's all right in theory, but how is it going to work out in

practice?"

"That's what I came to see you about, Tom," was the reply. "Bless my

tall hat! but that's just why I hurried over here. I wanted to tell you

when I saw you going off on a trip with Miss Nestor. That's my big

idea--Damon's Whizzer--propellers revolving in compressed air like

water. Isn't that great?"

"I'm sorry to shatter your air castle," said Tom; "but for the life of

me I can't see how it will work. Of course, in theory, if you could

revolve a big-bladed propeller in very dense, or in liquid, air, there

would be more resistance than in the rarefied atmosphere of the upper

regions. And, if this could be done, I grant you that you could use

slower motors and smaller propeller blades--more like those of a motor

boat. But how are you going to get the condensed air?"

"Make it!" said Mr. Damon promptly. "Air pumps are cheap. Just carry

one or two on board the aeroplane, and condense the air as you go

along. That's a small detail that can easily be worked out. I leave

that to you."

"I'd rather you wouldn't," said Tom. "That's the whole

difficulty--compressing your air. Wait! I'll explain it to you."

Then the young inventor went into details. He told of the ponderous

machinery needed to condense air to a form approximating water, and

spoke of the terrible pressure exerted by the liquid atmosphere.

"Anything that you would gain by having a slow-speed motor and smaller

propeller blades, would be lost by the ponderous air-condensing

machinery you would need," Tom told Mr. Damon. "Besides, if you could

surround your propellers with a strata of condensed air, it would

create such terrible cold as to freeze the propeller blades and make

them as brittle as glass.

"Why, I have taken a heavy piece of metal, dipped it into liquid air,

and I could shatter the steel with a hammer as easily as a sheet of

ice. The cold of liquid air is beyond belief.

"Attempts have been made to make motors run with liquid air, but they

have not succeeded. To condense air and to carry it about so that

propellers might revolve in it, would be out of the question."

"You think so, Tom?" asked Mr. Damon.

"I'm sure of it!"

"Oh, dear! That's too bad. Bless my overshoes, but I thought I had a

new idea. Well, you ought to know. So Damon's Whizzer goes on the scrap

heap before ever it's built. Well, we'll say no more about it. You

ought to know best, Tom. I wasn't thinking of it so much for myself as

for you. I thought you'd like some new idea to work on."

"Much obliged, Mr. Damon, but I have a new idea," said Tom.

"You have? What is it? Tell me--that is, if it isn't a secret," went on

the eccentric man, as much delighted over Tom's new plan as he had been

over his own Whizzer, doomed to failure so soon.

"It isn't a secret from you," said Tom. "I got the idea while I was

riding with Mary. I wanted to talk to her--to tell her not to jump out

when we had a little accident--but I had trouble making myself

understood because of the noise of the motor."

"They do make a great racket," conceded Mr. Damon. "But I don't suppose

anything can be done about it."

"I don't see why there can't!" exclaimed Tom. "And that's my new

idea--to make a silent aircraft motor--perhaps silent propeller blades,

though it's the motor that makes the most noise. And that's what I'm

going to do--invent a silent aeroplane. Not because I want so much to

talk when I take passengers up in the air, but I believe such a motor

would be valuable, especially for scouting planes in war work. To go

over the enemy's lines and not be heard would be valuable many times.

"And that's what I'm going to do--work on a silent motor for Uncle Sam.

I've got the germ of an idea and now--"

"Excuse me," said a voice behind Mr. Damon and Tom, and, turning, the

young inventor beheld the form of Mr. Peton Gale, president of the

Universal Flying Machine Company.

Tom Swift and His Air Scout; Or, Uncle Sam's Mastery of the Sky · 第 5 / 25 章