CHAPTER V
TOM'S PROJECT
Curious was the sight that met the gaze of Tom Swift and Mr. WakefieldDamon as they rounded the corner of the house and looked into the newlyspaded 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 wasprevented 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'lltell 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 heheld the colored man nearly nine feet from the ground, and a fall fromthat distance would seriously jar Eradicate, if it did nothing else.The colored man's eyes opened wide as he heard what Koku said, and thenhe 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'sidea 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 thegiant 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 tospade 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. "WhenI git so old dat I cain't spade a garden, den me an' Boomerang, we-allgwine to die, dat's all I got to say. I was a-spadin' my part ob degarden, Massa Tom, same laik Mr. Damon done tole me to, an' dish yeahbig mess ob bones steps on my side ob de middle an--"
"Him too slow. Koku scatter dirt twice times so fast!" declared thegiant, whose English was not much better than Eradicate's.
"Yes, I see," said Tom. "You are so strong, Koku, that you finishedyour part before Eradicate did. Well, it was good of you to want tohelp 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 havingdone it so many years."
"Ha! Whut I tell yo', Giant!" boasted the colored man. It was his turnto smile.
"And so," went on Tom, judicially, "I guess I'll let Rad finish spadingthe garden, and you, Koku, can come and help me lift some heavy engineparts. 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 pickedup his dropped spade. And then, with a smile of satisfaction, he fellto work in the mellow soil while Tom led Koku to one of the shops wherehe set him to lifting heavy motor parts about in order to get at acertain 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 inairships?"
"I really think so, Tom. My Whizzer is bound to revolutionize travel inthe air. Let me tell you what I mean. Now cast your mind back. How manyways are now used to propel an airship or a dirigible balloon throughthe air? How many ways?"
"Two, as far as I know," said Tom. "At least there are only two thathave proved to be practical."
"Exactly," said Mr. Damon. "One with the propeller, or propellers, infront, and that is the tractor type. The other has the propeller in therear, and that is the pusher type. Both good as far as they go, but Ihave something better."
"What?" asked Tom with a smile.
"It's a Whizzer," said the eccentric man. "Bless my gold tooth! butthat is the best name I can think of for it. And, really, the propellerI'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 willrise from the ground, don't you?"
"Yes, of course. That's the principle on which an aeroplane rises andkeeps aloft, by its speed in the air. As soon as that speed stops itbegins to fall, or volplane, as we call it."
"Exactly. Now, instead of having to depend on the speed of theaeroplane for this, why not depend on the speed of the propeller--inother words, the whizzer?"
"Well, we do," said Tom, a bit puzzled as to what his friend was tryingto get at. "If the propeller didn't move the airship wouldn'trise--that is, unless it's of the balloon type."
"What I mean," said Mr. Damon, "is to have an aeroplane that will movein the air the same as a boat moves in the water. You don't have to getthe propeller of a boat racing around at the rate of a millionrevolutions a minute, more or less, before your boat will travel, doyou? If the engine turns the screw, or propeller, just over say fiftytimes 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 anairship propeller that sends the craft along, isn't it?"
"Yes. And because of the difference in density between air and water itbecomes necessary to revolve an aeroplane propeller many times fasterthan a boat propeller. It's the density that makes the difference, Mr.Damon. If air were as dense as water we could have comparativelyslow-moving motors and propellers and--"
"Ha! There you have it, Tom! And there is where my Whizzer--WakefieldDamon's Whizzer--is going to revolutionize air travel!" cried theeccentric man. "The difference in density! If air were as dense aswater the problem would be solved. And I have solved it! I'm going toturn the trick, Tom! One more question. How can air be made as dense aswater, Tom Swift?"
"Why, by condensation or compression, I suppose," was the rather slowanswer. "You know they have condensed, or compressed, air until it isliquid. I've done it myself, as an experiment."
"That's it, Tom! That's it!" cried Mr. Damon in delight. "Compressedair will do the trick! Not compressed to a liquid, exactly, but almostso. I'm going to revolve the propellers of my new airship in compressedair, so dense that they will not have to have a speed of more thanseven hundred revolutions a minute. What's that compared to the threeto ten thousand revolutions of the propellers now used? The propellersof Damon's Whizzer will be of the pusher type, and will revolve indense, compressed air, almost like water, and that will do away withhigh speed motors, with all their complications, and make traveling inthe 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 younginventor gazed at his eccentric friend, and then said slowly:
"Well, that's all right in theory, but how is it going to work out inpractice?"
"That's what I came to see you about, Tom," was the reply. "Bless mytall hat! but that's just why I hurried over here. I wanted to tell youwhen I saw you going off on a trip with Miss Nestor. That's my bigidea--Damon's Whizzer--propellers revolving in compressed air likewater. Isn't that great?"
"I'm sorry to shatter your air castle," said Tom; "but for the life ofme I can't see how it will work. Of course, in theory, if you couldrevolve a big-bladed propeller in very dense, or in liquid, air, therewould be more resistance than in the rarefied atmosphere of the upperregions. And, if this could be done, I grant you that you could useslower motors and smaller propeller blades--more like those of a motorboat. But how are you going to get the condensed air?"
"Make it!" said Mr
. Damon promptly. "Air pumps are cheap. Just carryone or two on board the aeroplane, and condense the air as you goalong. That's a small detail that can easily be worked out. I leavethat to you."
"I'd rather you wouldn't," said Tom. "That's the wholedifficulty--compressing your air. Wait! I'll explain it to you."
Then the young inventor went into details. He told of the ponderousmachinery needed to condense air to a form approximating water, andspoke of the terrible pressure exerted by the liquid atmosphere.
"Anything that you would gain by having a slow-speed motor and smallerpropeller blades, would be lost by the ponderous air-condensingmachinery you would need," Tom told Mr. Damon. "Besides, if you couldsurround your propellers with a strata of condensed air, it wouldcreate such terrible cold as to freeze the propeller blades and makethem 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 ofice. The cold of liquid air is beyond belief.
"Attempts have been made to make motors run with liquid air, but theyhave not succeeded. To condense air and to carry it about so thatpropellers 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 anew idea. Well, you ought to know. So Damon's Whizzer goes on the scrapheap before ever it's built. Well, we'll say no more about it. Youought to know best, Tom. I wasn't thinking of it so much for myself asfor 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 onthe eccentric man, as much delighted over Tom's new plan as he had beenover his own Whizzer, doomed to failure so soon.
"It isn't a secret from you," said Tom. "I got the idea while I wasriding with Mary. I wanted to talk to her--to tell her not to jump outwhen we had a little accident--but I had trouble making myselfunderstood because of the noise of the motor."
"They do make a great racket," conceded Mr. Damon. "But I don't supposeanything can be done about it."
"I don't see why there can't!" exclaimed Tom. "And that's my newidea--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'mgoing to do--invent a silent aeroplane. Not because I want so much totalk when I take passengers up in the air, but I believe such a motorwould be valuable, especially for scouting planes in war work. To goover 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, theyoung inventor beheld the form of Mr. Peton Gale, president of theUniversal Flying Machine Company.