TOM SWIFT AND HIS AIR SCOUT

OR

Uncle Sam's Mastery of the Sky

 

 

 

 

CONTENTS

CHAPTER

 

I      A SKY RIDE

II     A NEW IDEA

III    THE BIG OFFER

IV     MR. DAMON'S WHIZZER

V      TOM'S PROJECT

VI     MAKING PLANS

VII    A PROBLEM IN SOUND

VIII   THROUGH THE ROOF

IX     AFTER A SPY

X      A BIG SPLASH

XI     A NIGHT TRIP

XII    THE CRY FOR HELP

XIII   SOMETHING QUEER

XIV    THE TELEPHONE CALL

XV     A VAIN SEARCH

XVI    THE LONG NIGHT

XVII   SILENT SAM

XVIII  SUSPICIONS

XIX    ANOTHER FLIGHT

XX     QUEER MARKS

XXI    THE DESERTED CABIN

XXII   CLEWS AT LAST

XXIII  THE GOVERNMENT TEST

XXIV   IN THE MOONLIGHT

XXV    THE GOLD TOOTH

 

 

 

 

TOM SWIFT AND HIS AIR SCOUT

 

 

 

 

CHAPTER I

A SKY RIDE

 

 

"Oh Tom, is it really safe?"

 

A young lady--an exceedingly pretty young lady, she could be

called--stood with one small, gloved hand on the outstretched

wing of an aeroplane, and looked up at a young man, attired in a

leather, fur-lined suit, who sat in the cockpit of the machine

just above her.

 

"Safe, Mary?" repeated the pilot, as he reached in under the

hood of the craft to make sure about one of the controls. "Why,

you ought to know by this time that I wouldn't go up if it wasn't

safe!"

 

"Oh, yes, I know, Tom. It may be all right for you, but I've

never been up in this kind of airship before, and I want to know

if it's safe for me."

 

The young man leaned over the edge of the padded cockpit, and

clasped in his rather grimy hand the neatly gloved one of the

young lady. And though the glove was new, and fitted the hand

perfectly, there was no attempt to withdraw it. Instead, the

young lady seemed to be very glad indeed that her hand was in

such safe keeping.

 

"Mary!" exclaimed the young man, "if it wasn't safe--as safe as

a church--I wouldn't dream of taking you up!" and at the mention

of "church" Mary Nestor blushed just the least bit. Or perhaps it

was that the prospective excitement of the moment caused the

blood to surge into her cheeks. Have it as you will.

 

"Come, Mary! you're not going to back out the last minute, are

you?" asked Tom Swift. "Everything is all right. I've made a

trial flight, and you've seen me come down as safely as a bird.

You promised to go up with me. I won't go very high if you don't

like it, but my experience has been that, once you're off the

ground, it doesn't make any difference how high you go. you'll

find it very fascinating. So skip along to the house, and Mrs.

Baggert will help you get into your togs."

 

"Shall I have to wear all those things--such as you have on?"

asked Mary, blushing again.

 

"Well, you'll be more comfortable in a fur-lined leather suit,"

asserted Tom. "And if it does make you look like an Eskimo, why

I'm sure it will be very becoming. Not that you don't look nice

now," he hastened to assure Miss Nestor, "but an aviation suit

will be very--well, fetching, I should say."

 

"If I could be sure it would 'fetch' me back safe, Tom--"

 

"That'll do! That'll do!" laughed the young aviator. "One joke

like that is enough in a morning. It was pretty good, though. Now

go on in and tog up."

 

"You're sure it's safe, Tom?"

 

"Positive! Trot along now. I want to fix a wire and--"

 

"Oh, is anything broken?" and the girl, who had started away

from the aeroplane, turned back again.

 

"No, not broken. It's only a little auxiliary dingus I put on

to make it easier to read the barograph, but I think I'll go back

to the old system. Nothing to do with flying at all, except to

tell how high up one is."

 

"That's just what I don't care to know, Tom," said Mary Nestor,

with a smile. "If I could imagine I was sailing along only about

ten feet in the air I wouldn't mind so much."

 

"Flying at that height would be the worst sort of danger. You

leave it to me, Mary. I won't take you up above the clouds on

this sky ride; though, later, I'm sure you'll want to try that.

This is only a little flight. You've been promising long enough

to take a trip with me, and now I believe you're trying to back

out."

 

"No, really I'm not, Tom! Only, at the last minute, the machine

looks so small and frail, and the sky is so--big--"

 

She glanced up and seemed to shiver just a trifle.

 

"Don't be thinking of those things, Mary!" laughed Tom Swift.

"Trot along and get ready. The motor never worked better, and we

may break a few speed records this morning. No traffic cops to

stop us, either, as there might be if we were in an auto."

 

"There you go, Mary !" exclaimed Tom, as if struck with a new

thought. "You've ridden in an auto with me many a time, and you

never were a bit afraid, though we were in more danger than we'll

be this morning."

 

"Danger, Tom, in an auto? How?"

 

"Why, danger of a wheel collapsing as we were going full speed;

or the steering knuckle breaking and sending us into a tree;

danger of running into a stone wall or a ditch; danger of some

one running into us, or of us running into some one else. There

isn't one of these dangers on a sky ride."

 

"No," said Mary slowly. "But there's the danger of falling."

 

"One against twenty. That's the safety margin. And, if we do

fall, it will be like landing in a feather bed! There, don't wait

any longer. Go and get ready."

 

Mary sighed, and then, seeming to summon her nerve to her aid,

she smiled brightly, waved her hand to Tom, and hastened toward

his home, where Mrs. Baggert the matronly housekeeper, was

waiting to help the girl attire herself in a flying-suit of

leather.

 

Mary Nestor, who had a very warm place in the heart of Tom

Swift, had, as he stated, some time since promised to take a trip

in the air with the young inventor. But she had kept putting it

off, for one reason or another, until Tom began to despair of

ever getting her to accompany him. To-day, however, when she had

called to inquire about his father, who had been slightly ill,

Tom had, after the social visit, insisted on the promise being

kept.

 

He had his mechanic get out one of the safest, though a speedy,

double machine, and, with Mary to watch, Tom had taken a trial

flight, just to show her how easy it was. It was not the first

time she had seen him take to the air, but now she watched with

different emotions, for she was vitally interested.

 

Tom had sailed down from aloft, making a landing in the

aviation field he had constructed near his home, and then he had

insisted that Mary should keep her promise to take a sky ride

with him.

 

"Don't be too long now!" called Tom to the girl, as she hurried

toward the house. "Never mind about your hair, or whether your

hat's on straight. You're going to wear a cap, anyhow, and tuck

your hair up under that. It's hot down here, but it will be cold

up above; so tell Mrs. Baggert to see that you're warmly

dressed."

 

"All right," and gaily she waved her hand to him. Now that she

had made her decision, and was really going up, she was not half

so frightened as she had been in the contemplation of it.

 

As Tom climbed out of the machine, to give it a careful

inspection, though he was certain there was nothing wrong, an

aged colored man shuffled toward him.

 

"Yo'--yo'll be mighty careful ob Miss Nestor now, won't yo',

Massa Tom?" asked the man.

 

"Of course I will, Eradicate," was the young inventor's answer.

 

"Case we ain't got many laik her no mo', an' dat's de truf,

Massa Tom," went on the old man. "So be mighty careful laik!"

 

"That's what I will, Rad! And, while I'm up in the air, don't

you and Koku have any trouble."

 

"Ho! Trouble wif dat onery no-'count giant! I guess not!" and

the colored man limped off, highly indignant.

 

Satisfied, from an inspection of his machine, that it was as

nearly mechanically perfect as it was possible to be, Tom Swift

finished his trip around it and stood near the big propeller,

waiting for Mary Nestor to reappear. Presently she did so, and

Tom gaily waved his hand to her.

 

"You're a picture!" he cried, as he saw how particularly

"fetching" she looked in the aviator's costume which was like his

own. Because of the danger of entanglement, Miss Nestor had

doffed her skirts, and wore the costume of all aviators--men and

women.

 

"I wish I had my camera!" cried Tom. "You look--stunning!"

 

"I hope that isn't any comment on how I'm going to feel if we

have to make a--forced landing, I believe you call it," she

retorted.

 

"Oh, I'll take care of that!" exclaimed Tom. "Now up you go,

and we'll start," and he helped her to climb into the padded seat

of the cockpit, behind where he was to sit.

 

"Oh, Tom! Don't be in such a hurry !" expostulated Mary. "Let

me get my breath!"

 

"No!" laughed the young inventor. "If I did you might back out.

Get in, fasten the strap around you and sit still. That's all you

have to do. Don't be afraid, I'll be very careful. And don't try

to yell at me to go slower or lower once we're up in the air.

 

"Why not?" Mary wanted to know, as she settled herself in her

seat.

 

"Because I can't very well bear you, or talk to you. The motor

makes so much noise, you know. We can do a little talking through

this speaking tube," and he indicated one, "but it isn't very

satisfactory. So if you have anything to say--"

 

"In the language of the poets," interrupted Mary, "if I have

words to spill, prepare to spill them now. Well, I haven't! Now

I'm here, go ahead! I shall probably be too frightened to talk,

anyhow."

 

"Oh, no you won't--after the first little sensation," Tom

assured her. "You'll be crazy about it.  Come on, Jackson!" he

called to the mechanician. "Start the ball rolling!"

 

Tom was in his place, his goggles and cap well down over his

face, and he was adjusting the switch as the mechanic prepared to

spin the propellers.

 

Suddenly a man came running from the Swift house, waving his

arms not unlike the blades of an aircraft propeller, he also

shouted, but Tom, whose ears were covered with his fur cap, could

not hear. However, Jackson did, and stopped whirling the blades,

turning about to see what was wanted.

 

"Why, it's Mr. Damon!" exclaimed Tom, as he caught sight of the

excited man. "Hello, what's the matter?" the youth asked, pulling

aside one flap of his head-covering so he might hear the answer.

 

"Tom! Wait a minute! Bless my mouse trap!" exclaimed Mr. Damon,

"I want to speak to you!" He was panting from his run across the

field. "I just got to your house--saw your father--he said you

were going up with Miss Nestor, but--bless my dog biscuit--"

 

"Can't stop now, Mr. Damon!" answered Tom, with a laugh. "I

have only just succeeded, by hard work, in getting Mary to a

point where she has consented to take a sky ride. If I stop now

she'll back out and I'll never get her in again. See you when I

come back," and Tom pulled the covering over his ear once more.

 

"But, Tom, bless my shoe laces! This is important!"

 

"So's this!" answered Tom, with a grin. He saw, by the motion

of Mr. Damon's lips, what the latter had said.

 

Around swung the propeller blades. The gasoline vapor in the

cylinders was being compressed.

 

"Contact!" called Tom sharply, as he pressed the switch to give

the igniting spark at the proper moment. The mechanic had stepped

back out of the way, in case there should be a premature starting

of the powerful engine, in which event the blades would have cut

him to pieces.

 

"Wait, Tom! Wait! This is very important! Bless my collar

button, Tom Swift, but this is--"

 

Bang! Bang! Bang!

 

With a series of explosions, like those of a machine gun, the

motor started, and further talk was out of the question. Tom

turned on more gas. The propellers became almost invisible blades

of light and shadow, and the aeroplane began moving over the

grassy field. The mechanic had sprung out of the way, pulling Mr.

Damon with him.

 

"Come back! Come back! Wait a minute, Tom Swift! Bless my pansy

blossoms, I want to tell you something!" cried the little man.

 

But Tom Swift was away and out of hearing. He had started on

his sky ride with Mary Nestor.

 

 

 

CHAPTER II

A NEW IDEA

 

 

Any one who has taken a flight in an aeroplane or gone up in a

balloon, will know exactly how Mary Nestor felt on this, her

first sky ride of any distance. For a moment, as she looked over

the side of the machine, she had a distinct impression, not that

she was going up, but that some one had pulled the earth down

from beneath her and, at the same time, given her a shove off

into space. Such is the first sensation of going aloft. Then the

rush of air all about her, the slightly swaying motion of the

craft, and the vibration caused by the motor took her attention.

But the sensation of the earth dropping away from beneath her

remained with Mary for some time.

 

This sensation is much greater in a balloon than in an

aeroplane, for a balloon, unless there is a strong wind blowing,

goes straight up, while an aeroplane ascends on a long slant, and

always into the teeth of the wind, to take advantage of its

lifting power on the underside of the planes. The reason for this

sensation--that of the earth's dropping down, instead of one's

feeling, what really happens, that one is ascending--is because

there are no objects by which comparison can be made. If one

starts off on the earth's surface at slow, or at great speed, one

passes stationary objects--houses, posts, trees, and the like--

and judges the speed by the rapidity with which these are left

behind.

 

Going up is unlike this. There is nothing to pass. One simply

cleaves the air, and only as it rushes past can one be sure of

movement. And as the air is void of color and form, there is no

sensation of passing anything.

 

So Mary Nestor, as she shot into the air with Tom Swift, had a

sensation as though the earth were dropping from beneath her. For

a moment she felt as though she were in some vast void--floating

in space--and she had a great fear. Then she calmed herself. She

looked at Tom sitting in front of her. Of course, all she could

see was his back, but it looked to be a very sturdy back, indeed,

and he sat there in the aircraft as calmly as though in a chair

on the ground. Then Mary took courage, and ceased to grasp the

sides of the cockpit with a grip that stiffened all her muscles.

She was beginning to "find herself."

 

On and on, and up and up, went Mary and Tom, in this the girl's

first big sky ride. The earth below seemed farther and farther

away. The wide, green fields became little emerald squares, and

the houses like those in a toy Noah's ark.

 

Down below, Mr. Wakefield Damon, who had hurried over from his

home in Waterfield to see Tom Swift, gazed aloft at the fast

disappearing aeroplane and its passengers.

 

"Bless my coal bin!" cried the eccentric man, "but Tom is in a

hurry this morning. Too bad he couldn't have stopped and spoken

to me. It might have been greatly to his advantage. But I suppose

I shall have to wait."

 

"You want to see Master?" asked a voice behind Mr. Damon, and,

turning, he beheld a veritable giant.

 

"Yes, Koku, I did," Mr. Damon answered, and he did not appear

at all surprised at the sight of the towering form beside him. "I

wanted to see Tom most particularly. But I shall have to wait.

I'll go in and talk to Mr. Swift."

 

"Yaas, an' I go talk to Radicate," said the giant. "Him diggin'

up ground where Master told me to make garden. Radicate not

strong enough for dat!"

 

"Huh! there's trouble as soon as those two get to disputing,"

mused Mr. Damon, as he went toward the house.

 

Meanwhile, Mary was beginning to enjoy herself. The sensation

of moving rapidly through the air in a machine as skillfully

guided as was the one piloted by Tom Swift was delightful. Up and

up they went, and then suddenly Mary felt a lurch, and the plane,

which was now about a thousand feet high, seemed to slip to one

side.

 

Mary screamed, and began reaching for the buckle of the safety

belt that fastened her to her seat. She saw that something

unusual had occurred, for Tom was working frantically at the

mechanism in front of him.

 

But, in spite of this, he seemed aware that Mary was in danger,

not so much, perhaps, from what might happen to the machine, as

what she might do in her terror.

 

"Oh! Oh!" cried the girl, and Tom heard her above the terrific

noise of the motor, for she was speaking with her lips close to

the tube that served as a sort of inter-communicating telephone

for the craft. "Oh, we are falling! I'm going to jump!"

 

"Sit still! Sit still for your life!" cried Tom Swift. "I'll

save you all right! Only sit still! Don't jump!"

 

Mary, her red cheeks white, sank back, and the young inventor

redoubled his efforts at the controls and other mechanisms.

 

And that Tom was perfectly qualified to make a safe landing,

even with engine trouble, Mary Nestor well knew. Those of you who

have read the previous books of this series know it also, but,

for the benefit of my new readers, I shall state that this was by

no means Tom's first ride in an aeroplane.

 

He had operated and built gasoline engines ever since he was

about sixteen years old. As related in the initial volume of this

series, entitled, "Tom Swift and His Motorcycle," he became

possessed of this machine after it had started to climb a tree

with Mr. Damon on board. After that experience the eccentric man

--blessing everything he could think of--had no liking for the

speedy motorcycle and sold it to Tom at a low price.

 

That was the beginning of a friendship between the two, and

also started Tom on his career as an inventor and a possessor of

many gasoline craft. For he was not content with merely riding

the repaired motorcycle. He made improvements on it.

 

Tom lived with his father in the town of Shopton, their home

being looked after, since the death of Mrs. Swift, by Mrs.

Baggert. Mr. Wakefield Damon lived in the neighboring town of

Waterfield, and spent much time at Tom's home, often going on

trips with him in various vehicles of the land, sea or air.

 

As related in the various volumes of this series, Tom was not

content to remain on earth. He built a speedy motor boat, and

then secured an airship, following that with a submarine. He also

made an electric runabout that was the speediest car on the road.

Sending wireless messages, having thrilling experiences among the

diamond makers, journeying to the caves of ice, and making

perilous trips in his sky racer took up part of the young

inventor's time.

 

With his electric rifle he did some wonderful shooting, and in

the "City of Gold" made some strange discoveries, part of the

fortune he secured enabling him to build his sky racer. It was in

a land of giants that Tom was made captive, but he succeeded in

escaping, and brought two giants, of whom Koku was one, away

with him.

 

Following this achievement Tom invented a wizard camera and a

great searchlight, which, with his giant cannon, was purchased by

the United States Government. Work on his photo-telephone and his

aerial warship, the problem of digging a big tunnel, and then

traveling to the land of wonders, kept Tom Swift very busy, and

he had just completed a wonderful piece of work when the present

story opens.

 

This last achievement was the perfecting of a machine to aid in

the great World War and you will find the details set down in the

volume which immediately precedes this. "Tom Swift and His War

Tank," it is called, and in that is related how he not only

invented a marvelous machine, but succeeded in keeping its secret

from the plotters who tried to take it from him. In this Tom was

helped by the inspiration of Mary Nestor, whom he hoped some day

to marry, and by Ned Newton, a chum, who, though no inventor

himself, could admire one.

 

Ned and Tom had been chums a long while, but Ned inclined more

to financial and office matters than to machinery. At times he

had managed affairs for Tom, and helped him finance projects. Ned

was now an important bank official, and since the United States

had entered the war had had charge of some Red Cross work, as

well as Liberty Bond campaigns.

 

Somehow, as she sat there in the craft which seemed disabled,

Mary Nestor could not help thinking of Tom's many activities, in

some of which she had shared.

 

"Oh, if he falls now, and is killed!" she thought. "Oh, what

will happen to us?"

 

"It's all right, Mary! Don't worry! It's all right!" cried Tom,

through the speaking tube.

 

"What's that? I can't hear you very well !" she called back.

 

"No wonder, with the racket this motor is making," he answered.

"Why can't something be done so you can talk in an aeroplane as

well as in a balloon? That's an idea! If I could tell you what

was the matter now you wouldn't be a bit frightened, for it isn't

anything. But, as it is--"

 

"What are you saying, Tom? I can't hear you!" cried Mary, still

much frightened.

 

"I say it's all right--don't get scared. And don't jump!" Tom

shouted until his ears buzzed. "It's all nonsense--having a motor

making so much noise one can't talk!" he went on, irritatedly.

 

A strange idea had come to the young inventor, but there was no

time to think of it now. Mentally he registered a vow to take up

this idea and work on it as soon as possible. But, just now, the

aeroplane needed all his attention.

 

As he had told Mary, there was really nothing approaching any

great danger. But it was rather an anxious moment. If Tom had

been alone he would have thought little of it, but with Mary

along he felt a double responsibility.

 

What had happened was that the craft had suddenly gone into an

"air pocket" or partial vacuum, and there had been a sudden fall

and a slide slip. In trying to stop this too quickly Tom had

broken one of his controls, and he was busily engaged in putting

an auxiliary one in place and trying to reassure Mary at the same

time.

 

"But it's mighty hard trying to do that through a speaking tube

with a motor making a noise like a boiler factory," mused the

young inventor. Tom worked quickly and to good purpose. In a few

moments, though to Mary they seemed like hours, the machine was

again gliding along on a level keel, and Tom breathed more

easily.

 

"And now for my great idea!" he told himself.

 

But it was some time before he could give his attention to

that.

 

 

 

CHAPTER III

THE BIG OFFER

 

 

Working with all the skill he possessed, Tom had got the

aeroplane in proper working order again. As has been said, the

accident was a trivial one, and had he been alone, or with an

experienced aviator, he would have thought little of it. Then,

very likely, he would have volplaned to earth and made the

repairs there. But he did not want to frighten Mary Nestor, so he

fixed the control while gliding along, and made light of it. Thus

his passenger was reassured.

 

"Are we all right?" asked Mary through the tube, as they sailed

along.

 

"Right as a fiddle," answered Tom, shouting through the same

means of communication.

 

"What's that about a riddle?" asked Mary, in surprise at his

seeming flippancy at such a time.

 

"I didn't say anything about a riddle--I said we are as fit as

a fiddle!" cried Tom. "Never mind. No use trying to talk with the

racket this motor makes, and it isn't the noisiest of its kind,

either. I'll tell you when we get down. Do you like it?"

 

"Yes, I like it better than I did at first," answered Mary, for

she had managed to understand the last of Tom's questions. Then

he sailed a little higher, circled about, and, a little later,

not to get Mary too tired and anxious, he headed for his landing

field.

 

"I'll take you home in the auto," he cried to his passenger.

"We could go up to your house this way--in style--if there was a

field near by large enough to land in. But there isn't. So it

will have to be a plain, every-day auto."

 

"That's good enough for me," said Mary. "Though this trip is

wonderful--glorious! I'll go again any time you ask me."

 

"Well, I'll ask you," said Tom. "And when I do maybe it won't

be so hard to hold a conversation. It will be more like this,"

and he shut off the motor and began to glide gently down. The

quiet succeeding the terrific noise of the motor exhaust was

almost startling, and Tom and Mary could converse easily without

using the tube.

 

Then followed the landing on the soft, springy turf, a little

glide over the ground, and the machine came to a halt, while

mechanics ran out of the hangar to take charge of it.

 

"I'll just go in and change these togs," said Mary, as she

alighted and looked at her leather costume.

 

"No, don't," advised Tom. "You look swell in em. Keep 'em on.

They're yours, and you'll need 'em when we go up again. Here

comes the auto. I'll take you right home in it. Keep the aviation

suit on.

 

"I wonder what Mr. Damon could have wanted," remarked Tom, as

he drove Mary along the country road.

 

"He seemed very much excited," she replied.

 

"Oh, he almost always is that way--blessing everything he can

think of. You know that. But this time it was different, I'll

admit. I hope nothing is the matter. I might have stopped and

spoken to him, but I was afraid if I did you'd back out and

wouldn't come for a sky ride."

 

"Well, I might have. But now that I've had one, even with an

accident thrown in, I'll go any time you ask me, Tom," and Mary

smiled at the young inventor.

 

"Shucks, that wasn't a real accident!" he laughed. "But I do

wonder what Mr. Damon wanted."

 

"Better go back and find out, Tom," advised Mary, as they

stopped in front of her house.

 

"Oh, I want to come in and talk to you. Haven't had a chance

for a good talk today, that motor made such a racket"

 

"No, go along now, but come back and see me this afternoon if

you like."

 

"I do like, all right! And I suppose Mr. Damon will be fussing

until he sees me. Well, glad you liked your first ride in the

air, Mary--that is, the first one of any account," for Mary had

been in an aeroplane before, though only up a little way--a sort

of "grass-cutting stunt," Tom called it.

 

Waving farewell to the pretty girl, the young aviator turned

the auto about and speeded for his home and the shops adjoining

it. His father had not been well, of late, and Tom was a bit

anxious about him.

 

"Mr. Damon may bother him, though he wouldn't mean to," thought

Tom. "He seemed to have his mind filled with some new idea. I

wonder if it is anything like mine? No, it couldn't be. Well,

I'll soon find out," and, putting his foot on the accelerator,

Tom sent the machine along at a pace that soon brought him within

sight of his home.

 

"Is father all right?" he asked Mrs. Baggert, who was out on

the front porch, as though waiting for him.

 

"Oh, yes, Tom, he's all right," the housekeeper answered.

 

"Is Mr. Damon with him ?"

 

"No."

 

"He hasn't gone home, has he?"

 

"No, he's around somewhere. But some one else is with your

father. Some visitors."

 

"Any relations?"

 

"No; strangers. They came to see you, and they're rather

impatient. I came out to see if you were in sight. Your father

sent me."

 

"Are they bothering him--talking business that I ought to

attend to when he's ill? That mustn't be."

 

"Well, I suppose it is business that the strangers are talking

over with your father, Tom," said Mrs. Baggert, "for I heard sums

of money spoken of. But your father seems to be all right, only

a trifle anxious that you should come."

 

"Well, I'm here now and I'll attend to things. Where are the

strangers, and who are they?"

 

"I don't know," answered the housekeeper. "I never saw them

before, but they're in the library with your father. Do you think

they'll stay to dinner? If you do, I'll have Eradicate or Koku

catch and kill a chicken."

 

"If you let one do it don't tell the other about it," said Tom

with a laugh, "or you'll have a chicken race around the yard that

will make the visitors sit up and take notice."

 

There was great rivalry between Eradicate Sampson, the aged

colored man, and Koku, the giant, and they were continually

disputing. Each one loved and served Tom in his own way, and

there was jealousy between them. Koku, the giant Tom had brought

with him from the land where the young inventor had been made

captive, was a big, powerful man, and could do things the aged

colored servant could not attempt. But "Rad," as he was often

called, and his mule "Boomerang" had long been fixtures on the

Swift homestead. But old age crept on apace with Eradicate,

though he hated to admit it, and Koku did many things the colored

man had formerly attended to, and Rad was always on the lookout

not to be supplanted. Hence Tom's warning to Mrs. Baggert about

letting the two be entrusted with the same mission of catching a

chicken for the pot.

 

"Better get the fowl yourself and say nothing to either of them

about it," Tom advised the housekeeper. "Mr. Damon will stay to

dinner, as he always does when he comes, and as it's near twelve

now, and as I may be delayed talking business to these strangers,

you'd better get up a bigger meal than usual."

 

"I will, Tom," promised Mrs. Baggert. And then the young

inventor, having seen that one of the men took the automobile to

the garage, went into the house.

 

"Oh, here you are!" was his father's greeting, as he came out

into the hall from the library. "I've been waiting anxiously for

you, my boy. I couldn't think what was keeping you."

 

"Oh, I had a little trouble with the air machine--nothing

serious."

 

A moment later Tom was standing before two well-dressed,

prosperous-looking business men, who smiled pleasantly at him.

 

"Mr. Thomas Swift?" interrogated one, the elder, as he held out

his hand.

 

"That's my name," answered Tom, pleasantly.

 

"I'm Peton Gale, and this gentleman is Boland Ware," went on

the man who had taken Tom's hand. "I'm president and he's

treasurer of the Universal Flying Machine Company, of New York."

 

"Oh, yes," said Tom, as he shook hands with Mr. Ware. "I have

heard of your concern. You are doing a lot of government work,

are you not?"

 

"Yes; war orders. And we're up to our neck in them. This war is

going to be almost as much fought in the air as on the ground,

Mr. Swift."

 

"I can well believe that," agreed Tom. "Won't you have a

chair?"

 

"Well, we didn't come to stay long," said Mr. Gale with a

laugh, which, somehow or other, grated on Tom and seemed to him

insincere. "Our business is such a rushing one that we don't

spend much time anywhere. To get down to brass tacks, we have

come to see you to put a certain proposition before you, Mr.

Swift. You are open to a business proposition, aren't you?"

 

"Oh, yes," answered Tom. "That's what I'm here for."

 

"I thought so. Well, now I'll tell you, in brief, what we want,

and then Mr. Ware, our treasurer, can elaborate on it, and give

you facts and figures about which I never bother myself. I attend

to the executive end and leave the details to others," and again

came that laugh which Tom did not like.

 

"You came here to make me an offer?" asked the young inventor,

wondering to which of his many machines the visitors had

reference.

 

"Yes," went on Mr. Gale, "we came here to make you a big offer.

In short, Mr. Swift, we want you to work for our company, and we

are willing to pay you ten thousand dollars a year for the

benefit of your advice and your inventive abilities. Ten thousand

dollars a year! Do you accept?"

 

 

 

CHAPTER IV

MR. DAMON'S WHIZZER

 

 

Characteristic it was of Tom Swift that he did not seem at all

surprised at what most young men would call a liberal offer.

Certainly not many youths of Tom's age would be sought out by a

big manufacturing concern, and offered ten thousand dollars a

year "right off the reel," as Ned Newton expressed it later. But

Tom only smiled and shook his head in negation.

 

"What!" cried Mr. Gale, "you mean you won't accept our offer?"

 

"I can't," answered Tom.

 

"You can't!" exclaimed the treasurer, Mr. Ware. "Oh, I see. Mr.

Gale, a word with you. Excuse us a moment," he added to Tom and

his father.

 

The two men consulted in a corner of the library for a moment,

and then, with smiles on their faces, once more turned toward the

young inventor.

 

"Well, perhaps you are right, Tom Swift," said Mr. Gale. "Of

course, we recognize your talents and ability, but you cannot

blame us for trying to get talent, as well as material for our

airships, in the cheapest market. But we are not hide-bound, nor

sticklers for any set sum. We'll make that offer fifteen thousand

dollars a year, if you will sign a five-year contract and agree

that we shall have first claim on anything and everything you may

patent or invent in that time. Now, how does that strike you?

Fifteen thousand dollars a year--paid weekly if you wish, and our

Mr. Ware, here, has a form of contract which can be fixed up and

signed within ten minutes, if you agree."

 

"Well, I don't like to be disagreeable," said Tom with a smile;

"but, really, as I said before, I can't accept your very kind

offer. I may say liberal offer. I appreciate that."

 

"You can't accept!" cried Mr. Gale.

 

"Are you sure you don't mean 'won't'?" asked Mr. Ware, in a

half growl.

 

"You may call it that if you like," replied Tom, a bit coolly,

for he did not like the other's tone, "Only, as I say, I cannot

accept. I have other plans."

 

"Oh, you--" began the brusk treasurer, but Mr. Gale, the

president of the Universal Flying Machine Company, stopped his

associate with a warning look.

 

"Just a moment, Mr. Swift," begged the president. "Don't be

hasty. We are prepared to make you a last and final offer, and I

do not believe you can refuse it."

 

"Well, I certainly will not refuse it without hearing it," said

Tom, with a smile he meant to make good-natured. Yet, truth to

tell, he did not at all like the two visitors. There was

something about them that aroused his antagonism, and he said

later that even if they had offered him a sum which he felt he

ought not, in justice to himself and his father, refuse, he would

have felt a distaste in working for a company represented by the

twain.

 

"This is our offer," said Mr. Gale, and he spoke in a pompous

manner which seemed to say: "If you don't take it, why, it will

be the worse for you." He looked at his treasurer for a

confirmatory nod and, receiving it, went on. "We are prepared to

offer and pay you, and will enter into such a contract, with the

stipulation about the inventions that I mentioned before--we are

prepared to pay you--twenty thousand dollars a year! Now what do

you say to that, Tom Swift?

 

"Twenty-thousand-dollars-a-year!" repeated Mr. Gale unctuously,

rolling the words off his tongue. "Twen-ty-thou-sand-dol-lars-a-

year! Think of it!"

 

"I am thinking of it," said Tom Swift gently, "and I thank you

for your offer. It is, indeed, very generous. But I must give you

the same answer. I cannot accept."

 

"Tom!" exclaimed his aged father.

 

"Mr. Swift!" exclaimed the two visitors.

 

Tom smiled and shook his head.

 

"Oh, I know very well what I am saying, and what I am turning

down," he said. "But I simply cannot accept. I have other plans.

I am sorry you have had your trip for nothing," he added to the

visitors, "but, really, I must refuse."

 

"Is that your final answer?" asked Mr. Gale.

 

"Yes."

 

"Don't you want to take a day or two to think it over?" asked

the treasurer. "Don't be hasty. Remember that very few young men

can command that salary, and I may say you will find us liberal

in other ways. You would have some time to yourself."

 

"That is what I most need," returned Tom. "Time to myself. No,

thank you, gentlemen, I cannot accept."

 

"Be careful!" warned Mr. Gale, and it sounded as though there

might be a threat in his voice. "This is our last offer, and your

last chance. We will not renew this. If you do not accept our

twenty thousand dollars now, you will never get it again."

 

"I realize that," said Tom, "and I am prepared to take the

consequences.

 

"Very well, then," said Mr. Gale. "There seems nothing for us

to do, Mr. Ware, but to go back to New York. I bid you good-day,"

and he bowed stiffly to Tom. "I hope you will not regret your

refusal of our offer."

 

"I hope so myself," said Tom, lightly.

 

When the visitors had gone Mr. Swift turned toward his son,

and, shaking his head, remarked:

 

"Of course, you know your own business best, Tom. Yet I cannot

but feel you have made a mistake."

 

"How?" asked Tom. "By not taking that money? I can easily make

that in a year, with an idea I have in mind for an improvement on

an airship. And your new electric motor will soon be ready for

the market. Besides, we don't really need the money."

 

"No, not now, Tom, but there is no telling when we may," said

Mr. Swift, slowly. "This big war has made many changes, and

things that brought us in a good income before, hardly sell at

all, now."

 

"Oh, don't worry, Dad! We still have a few shots left in the

locker--in other words, the bank. I'm expecting Ned Newton over

any moment now, to give us the annual statement of our account,

and then we'll know where we stand. I'm not afraid from the money

end. Our business has done well, and it is going to do better. I

have a new idea."

 

"That's all very well, Tom," said Mr. Swift, who seemed

oppressed by something. "As you say, money isn't everything, and

I know we shall always have enough to live on. But there is

something about those two men I do not like. They were very angry

at your refusal of their offer. I could see that. Tom, I don't

want to be a croaker, but I think you'll have to watch out for

those men. They're going to be your enemies--your rivals in the

airship field," and Mr. Swift shook his head dolefully.

 

"Well, rivalry, when it's clean and above board, is the spice

of trade and invention," returned ~Tom, lightly. "I'm not afraid

of that."

 

"No, but it may be unfair and underhand," said Mr. Swift. "I

think it would have been better, Tom, to have accepted their

offer. Twenty thousand a year, clear money, is a good sum."

 

"Yes, but I may make twice that with something that occurred to

me only a little while ago. Forget about those men, Dad, and I'll

tell you my new idea. But wait, I want Mr. Damon to hear it, too.

Where is he?"

 

"He was here a little while ago. He went out when those two men

came and--"

 

At that moment, from the garden at the side of the library, the

sound of voices in dispute could be heard.

 

"Now yo' all g'wan 'way from yeah!" exclaimed some one who

could be none other than Eradicate Sampson. "Whut fo' yo' all

want to clutter up dish yeah place fo'? Massa Tom said I was to

do de garden wuk, an' I'se gwine to do it! G'wan 'way, Giant!"

 

"Ho! You want me to get out, s'pose you put me, black face!"

cried a big voice, that of Koku, the giant.

 

"There they go! At it again!" cried Tom with a smile. "Might

have known if I told Rad to do anything that Koku would be

jealous. Well, I'll have to go out now and give that giant

something to do that will tax his strength."

 

But as Tom was about to leave the room another voice was heard

in the garden.

 

"Now, boys, be nice," said some one soothingly. "The garden is

large enough for you both to work in. Rad, you begin at the lower

end and spade toward the middle. Koku, you begin at the upper end

and work down. Whoever gets to the middle first will win."

 

"Ha! Den I'll show dat giant some spade wuk as is spade wuk!"

cried the colored man. "Garden wuk is mah middle name."

 

"Be careful, Rad!" laughed Mr. Damon, for he it was who was

trying to act as peacemaker. "Remember that Koku is very strong."

 

"Yas, sah! He may be strong, but he's clumsy!" chuckled

Eradicate. "You watch me beat him!"

 

"Ho! Black man get stuck in mud!" challenged Koku. "I show

him!"

 

Then there was silence, and Tom and his father, looking out,

saw the two disputants beginning to spade the soil while Mr.

Damon, satisfied that he had, for the time being, stopped a

quarrel, turned toward the house.

 

"I was just coming to look for you," said Tom. "Sorry I had to

go off in such a hurry and leave you, but I had promised to take

Mary for a ride, and as it was her first one, for a distance, I

didn't want her to back out."

 

"That's all right, Tom, that's all right!" said Mr. Damon

genially. "Ladies first every time. But I do want to see you, and

it's about something important."

 

"No trouble, I hope?" queried Tom, for the manner of the

eccentric man was rather grave.

 

"Trouble? Oh, no! Bless my frying pan, no trouble, Tom! In

fact, it may be the other way about. Tom, I have an idea, and

there may be millions in it! That's it--millions!"

 

"Good!" cried the young inventor. "Might as well bite off a big

lump while you're at it. So you have a new idea! Well, I have

myself, but I'll listen to yours first. What is it, Mr. Damon?"

 

"It's a new kind of airship, Tom. I haven't got it all worked

out yet, but I can give you a rough outline. On my way over I got

to thinking about balloons, aeroplanes and the like, and it

occurred to me that the present principles are all wrong."

 

"So I evolved a new type of machine. I'm going to call it the

Damon Whizzer. Maybe Demon Whizzer would be more appropriate, but

we won't decide on that now. Anyhow, it's going to be a whizzer,

and I want to talk to you about it. There is an entirely new

principle of elevation and propulsion involved in my Whizzer, and

I--"

 

At that moment there came a crash and clatter of steel and wood

from the garden, out of sight of which Tom and Mr. Damon had

walked while talking. Then followed a jangle of words.

 

"They're at it again!" cried Tom, as he ran toward the side of

the house. "I guess it's a fight this time!"

 

 

 

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.

 

 

 

CHAPTER VI

MAKING PLANS

 

 

Tom Swift had drawn pencil and paper from his pocket, and, as

he and Mr. Damon were sitting on the steps of one of the shops,

the young inventor was about to demonstrate by a drawing part of

his new project, when the interruption came in the shape of one

of the men who had, an hour before, made a business offer to Tom.

 

"Excuse me," went on Mr. Peton Gale, "but Mr. Ware and I got to

talking it over on our way to the station--the matter of having

you in our company, Mr. Swift--and we concluded that it was worth

twenty-five thousand dollars a year for us to have you. So I came

back--"

 

"It isn't of the slightest use, Mr. Gale, I assure you," said

Tom, a bit heatedly, for he did not like the persistency of this

man, nor did he like his coming on the factory grounds

unannounced and in this secret manner. "I told you I could not

accept your offer. It is not altogether a matter of money. My

word was final."

 

"Oh very well, if you put it that way," said Mr. Gale stiffly,

"of course there is nothing more to say. But I thought perhaps

you did not consider we had offered you enough and--"

 

"Your offer is fair enough from a financial standpoint," said

Tom; "but I simply cannot accept it. I have other plans.

Jackson!" he called to one of his mechanics who was passing,

"kindly see Mr. Gale to the gate, and then let me know how it was

any one came in here without a permit."

 

"Yes, sir," said the mechanic, as he stood significantly

waiting.

 

"There was no one at the gate when I came in," said Mr. Gale,

and his manner was antagonizing. "I wanted to speak to you--to

ask you to reconsider your offer--so I came back."

 

"It is against the rules to admit strangers to the shop

grounds," said Tom. "Good-day!"

 

The president of the Universal Flying Machine Company did not

respond, but there was a look on his face as he turned away that,

had Tom seen it, might have caused him some uneasiness. But he

did not see. Instead, he resumed his talk with Mr. Damon.

 

"Tom, your idea is most interesting," declared the eccentric

man. "I hope you will be able to work it out!"

 

"I'm going to try," said the young inventor. "I hope that man--

Mr. Gale--didn't hear anything of what I was saying. He sneaked

up on us before I was aware any one was near but ourselves."

 

"I don't imagine he heard very much, Tom," said Mr. Damon. "He

may have heard you mention a silent motor--"

 

"That's just what I wish he hadn't heard," broke in Tom.

"That's the germ of the idea, and once it becomes known that I am

working on that-- Well, there's no use crying over spilled milk,"

and he smiled at the homely proverb. "I'll have to work in

secret, once I've started."

 

"Do you think the government would use it, Tom?" asked his

friend.

 

"I should think it would be glad to. Consider what a wonderful

part airships are playing in the present war. It really is a

struggle to see which will be the master of the sky--the Allies

or the Germans--and, up to recently, the Huns had the advantage.

Then the Allies, recognizing how vital it was, began to forge

ahead, and now Uncle Sam with his troops under General Pershing

is leading everything, or will lead shortly. We have been a bit

slow with our aircraft production, but now we are booming along.

Uncle Sam will soon have the mastery of the sky."

 

"I hope so," sighed Mr. Damon. "We must beat the Germans!"

 

Briefly, Tom spoke of what Pershing's men were doing with their

aeroplanes in France, and mention was made of what the French and

British had done prior to the entrance of the United States into

the World War.

 

"While we were yet neutral, Americans had made gallant names

for themselves flying for France, and with my silent motor they

ought to do better," declared Tom.

 

"Is silence its chief recommendation?" asked Mr. Damon.

 

"Yes," replied Tom. "Or rather, it will be when I have it

perfected. Aeroplane motors now are about as compact and speedy

as they can be made. It is only the terrific noise that is a

handicap. It is a handicap to the pilots and observers in the

craft, as they cannot communicate except through a special

speaking tube, and this is not always satisfactory or sure. Then,

too, the noise of an airship proclaims its approach to the enemy,

sometimes long before it can be seen.

 

"With a silent motor all this would be done away with. With my

new craft, in case I can perfect it, the enemy's lines can be

approached as silently as the Indians used to approach the log

cabins of the white settlers. That will be its great advantage--

not that conversation can be more easily carried on, for that is,

after all, an unimportant detail. But to approach the enemy's

lines in the silence of the night would be a distinct gain."

 

"I believe it would, Tom!" exclaimed Mr. Damon. "And I should

think, too, that Uncle Sam would be glad to get such a motor," he

added.

 

"Well, he'll have one to take if he wants it, if I can make my

plans a success," declared Tom. "That is, unless those other

fellows get ahead of me."

 

"What other fellows?" asked Mr. Damon.

 

"Gale, Ware and their crowd," was the answer. "I fancy they are

provoked because I wouldn't agree to work for them, and now, that

Gale overheard--as he must have--what I propose working on, they

may try that game themselves."

 

"You mean try to turn out a silent motor?"

 

"Yes. It would be a big feather in their cap for their company,

so far, hasn't been very successful on government orders. That's

why they came to me, I guess."

 

"I shouldn't be surprised, Tom," conceded Mr. Damon. "Since the

government accepted your giant cannon and your great searchlight,

you have come into greater prominence than ever before. And those

two things are a wonderful success."

 

"Yes," admitted Tom, modestly enough, "the big electric light

seems to have been of some benefit on the European battle front,

and though they haven't been able to make and transport as many

of my giant cannons as I'd like to see over there, it is

progressing, I understand."

 

And this is true. For the details of these two inventions of

Tom Swift's I refer my readers to the books bearing those titles.

Sufficient to state here that the government was using these two

inventions, and there had been no necessity for commandeering

them either, since Tom had freely offered them at the declaration

of war with Germany.

 

"Well, since I can't help you with my 'Whizzer,'" said Mr.

Damon, with a smile, "let me do what I can toward your silent

motor, Tom. What are you going to call it?"

 

"Oh, I don't know--hadn't thought of a name. I guess 'Air

Scout' would be as good as any. That's what it will be--a machine

for silently scouting in the air. And now to get down to brass

tacks, as the poet says, I believe I will--"

 

"Gentleman to see you, Mr. Swift," interrupted Jackson.

 

"Bless my penwiper!" cried Mr. Damon. "More visitors! I hope it

isn't Gale or Ware come back to see what they can spy on!"

 

 

 

CHAPTER VII

A PROBLEM IN SOUND

 

 

Tom Swift looked up with a distinct appearance of being annoyed

that was unusual with him, for he was, nearly always,

good-natured. But the frown that had replaced the pleasant look

on his face while he was talking to Mr. Damon about the projected

new air scout was at once wiped away as he looked at the card

Jackson held out to him.

 

"Bring him in right away!" he ordered. "He needn't have stood

on that ceremony."

 

"Well, he said it was a business call," returned the

mechanician with a cheerful grin, and he said he wanted it done

according to form. So he gave me his card to bring you."

 

"Who is it?" asked Mr. Damon, with the privilege of an old

friend.

 

"It's Ned Newton," Tom answered; "though why he's putting on

all this formality I can't fathom."

 

Jackson went back to the main gate and told the man on guard

there to admit Ned, who had so formally sent in his card.

 

"Ah, Mr. Swift, I believe?" began the bank employee with that

suave, formal air which usually precedes a business meeting.

 

"That is my name," said Tom, with a suppressed grin, and he

spoke as stiffly as though to a perfect stranger.

 

"Mr. Tom Swift, the great inventor?" went on Ned.

 

"Yes."

 

"Ah, then I am at the right place. Just sign here, please, on

the dotted line," and be held out a blank form, and a fountain

pen to Tom, who took them half mechanically.

 

"Huh? What's the big idea, Ned?" asked the young inventor,

unable longer to carry on the joke. "Is this a warrant for my

arrest, or merely a testimonial to you. If it's the latter, and

concerns your nerve, I'll gladly sign it."

 

"Well, it's something like that!" laughed Ned. "That's your

application for another block of Liberty Bonds, Tom, and I want

you, as a personal favor to me, as a business favor to the bank,

and as your plain duty to Uncle Sam, to double your last

subscription."

 

Tom looked at the sum Ned had filled in on the blank form, and

uttered a slight whistle of surprise.

 

"That's all right now," said Ned, with the air of a

professional salesman. "You can stand that and more, too. I'm

letting you off easy. Why, I got Mary's father--Mr. Nestor--for

twice what he took last time, and Mary herself--hard as she's

working for the Red Cross--gave me a nice application. So it's up

to you to--"

 

"Nuff said!" exclaimed Tom, sententiously, as he signed his

name. "I may have to reconsider my recent refusal of the offer of

the Universal Flying Machine Company, though, if I haven't money

enough to meet this subscription, Ned."

 

"Oh, you'll meet it all right! Much obliged," and Ned folded

the Liberty Bond subscription paper and put it in his pocket.

"But did you turn down the offer from those people?"

 

"I did," answered Tom. "But how did you know about it, Ned?"

 

"First let me say that I'm glad you decided to have nothing to

do with them. They're a rich firm, and have lots of money, but I

wouldn't trust 'em, even if they have some government contracts.

The way I happened to know they were likely to make you an offer

is this," continued Ned Newton.

 

"They do business with one of the New York banks with which my

bank--notice the accent on the my, Tom--is connected. The other

day I happened to see some correspondence about you. These flying

machine people asked our bank to find out certain things about

you, and, as a matter of business, we had to give the

information. Sort of a commercial agency report, you know,

nothing unusual, and it isn't the first time it's been done since

your business got so large. But that's how I happened to know

these fellows contemplated dickering with you."

 

"Do you know Gale or Ware?" Tom asked.

 

"Not personally. But in a business way, Tom, I'd warn you to

look out for them, as they're sharp dealers. They put one over on

the government all right, and there may be some unpleasant

publicity to it later. But they're putting up a big bluff, and

pretending they can turn out a lot of flying machines for use in

Europe. Why don't you get busy on that end of the game, Tom?"

 

"I know you've more than done your bit, with Liberty Bonds,

subscriptions to the Y. M. C. A. and other war work, besides your

war tank and other inventions. But you're such a shark on flying

machines I should think you'd offer your factory to the

government for the production of aeroplanes."

 

"I would in a minute, Ned, and you know it; but the fact of the

matter is my shops aren't equipped for the production of anything

in large numbers. We do mostly an experimenting business here,

making only one or two of a certain machine. I have told the

government officials they can have anything I've got, and you

know they wouldn't let me enlist when I was working on the war

tank."

 

"Yes, I remember that," said Ned. "You're no slacker! I wanted

to shoulder a rifle, too, but they keep me at this Liberty Loan

work. Well, Uncle Sam ought to know."

 

"That's what I say," agreed Tom, "and that's why I haven't gone

to the front myself. And now, as it happens, I've got something

else in mind that may help Uncle Sam."

 

"What is it?"

 

"A silent flying machine for scout work on the battle front,"

Tom told his friend, and then he gave a few details, such as

those he had been telling Mr. Damon.

 

"Then I don't wonder you turned down the offer of the Universal

people," remarked Ned, at the conclusion of the recital. "This

will be a heap more help to the government, Tom, than working for

those people, even at twenty-five thousand dollars a year. And if

you get short, and can't meet your newest Liberty Bond payments,

why, I guess the bank will stretch your credit a little."

 

"Thanks!" laughed Tom, "but I'll try not to ask them."

 

The friends talked together a little longer, and then Ned had

to take his departure to solicit more subscriptions, while Mr.

Damon went with him, the eccentric man saying he would go home to

Waterfield.

 

"But, bless my overshoes, Tom!" he exclaimed, as he departed,

"don't forget to let me know when you have your silent motor

working. I want to see it."

 

"I'll let you know," was the promise given by the young

inventor.

 

"And watch out for those Universal people," warned Ned. "I'm

not telling you this as a bank official, for I'm not supposed to,

but it's personal."

 

"I'll be on the watch," said Tom. And, as he went into his

private workshop, he wondered why it was his father and Ned had

both warned him not to trust Gale and Ware.

 

The next few days were busy ones for Tom Swift. Once he had

made up his mind to go to work seriously on a silent motor, all

else was put aside. He sent a note to Mary Nestor, telling her

what he was going to do, and, asking her to say nothing about it,

which, of course, Mary agreed to.

 

"Come and see me when you can," she sent back word, "but I know

you won't have much chance when you're experimenting with your

invention. And I shall be working so hard for the Red Cross that

I sha'n't get much chance to entertain you. But the war can't

last forever."

 

"No," agreed Tom with a sigh, as he put away her letter, "and

thank goodness that it can't!"

 

The young inventor threw himself into the perplexing work of

inventing a silent motor with all the fervor he had given to the

production of his war tank, his giant cannon, his wonderful

searchlight and other machines.

 

"And," mused Tom, as he sat at his work table with pencil and

paper before him, "since this is a problem in acoustics, I had

best begin. I suppose by going back to first principles, and

after determining what makes an aeroplane engine noisy, try to

figure out how to make it quiet. Now as to the first, the

principle causes of noise are--"

 

And at that instant there broke on Tom's ears a succession of

discordant sounds which seemed to be a combination of an Indian's

war whoop and a college student's yells at a football game.

 

"Now I wonder what that is!" mused the young inventor as he

hastily arose. "Better solve that problem before I tackle the

aeroplane motor."

 

 

 

CHAPTER VIII

THROUGH THE ROOF

 

 

 

Tom rushed from his private office, and when he reached the

outer door he heard with more distinctness the sounds that had

alarmed him. They seemed to come from a small building given over

to electrical apparatus, and which, at the time, was not supposed

to be in use. It had been Tom's workroom, so to speak, when he

was developing his electric runabout and rifle, but of late he

had not spent much time in it.

 

"Somebody's in there !" reflected the young inventor, as he

heard yells coming from the open door of the place. "And if it

isn't Koku and Eradicate I miss my guess! Wonder what they can be

doing there."

 

He crossed the yard between his private office and the

electrical shop in a few rapid strides, and, as he entered the

latter place, he was greeted with a series of wild yells.

 

"Good volume of sound here, at all events," mused Tom. "Almost

as much as my motor made when I was trying to talk to Mary. Hello

there! What's going on? Is any one hurt? What's the matter?" he

cried, for, at first, he could see no one in the dim light of the

place. The interior was a maze of electrical apparatus.

 

"Who's here?" demanded Tom, as he advanced.

 

"Oh, Master! Come quick! Koku 'most dead an' no can let go!"

was the cry.

 

"Yo' jest bet yo' cain't let go!" chimed in the voice of

Eradicate. "I done knowed yo would git into trouble ef yo' come

heah, an' I'se glad ob it! So I is!"

 

"What is it, Rad? What has happened to Koku?" cried Tom,

running forward, for though no very powerful current could be

turned on in the electrical shop at this period of unuse, there

was enough to be very painful. "What is it, Rad?"

 

"Oh, dat big foolish giant, Koku, done got his se'f into

trouble!" chuckled the colored man. "He done got holt ob one ob

dem air contraptions, Massa Tom, an' he cain't let go! Ha! Ha!

Golly! Look at him squirm!" and Rad laughed shrilly, which

accounted for some of the sounds Tom had heard.

 

Then came yells of rage and pain from the giant, and they were

so loud and vigorous, mingling with Eradicate's as they did, that

it was no wonder Tom was startled. The sounds were heard in the

other shops, and men came running out. But before then Tom had

put an end to the trouble.

 

One look showed him what had happened. Just how or why Koku and

Eradicate had entered the electrical shop Tom did not then stop

to inquire. But he saw that the giant had grasped the handles of

one of the electric machines, designed for charging Leyden jars

used in Tom's experiments, and the powerful, though not

dangerous, current had so paralyzed, temporarily, the muscles of

the giant's hands and arms that he could not let go, and there he

was, squirming, and not knowing how to turn off the current, and

unable to ease himself, while Eradicate stood and laughed at him,

fairly howling with delight.

 

"Ha! Guess yo' won't do no mo' spadin' in' Massa Tom's garden

right away, big man!" taunted Eradicate.

 

"Be quiet, Rad!" ordered Tom, as he reached up and pulled out

the switch, thus shutting off the current. "This isn't anything

to laugh at."

 

"But he done look so funny, Massa Tom!" pleaded the colored

man. "He done squirm laik--"

 

But Eradicate did not finish what he intended to say. Once free

from the powerful current, the giant looked at his numb hands,

and then, seeming to think that Eradicate was the cause of it

all, he sprang at the colored man with a yell. But Eradicate did

not stay to see what would happen. With a howl of terror, he

raced out of the door, and, old and rheumatic as he was, he

managed to gain the stable of his mule, Boomerang, over which he

had his humble but comfortable quarters.

 

"Well, I guess he's safe for a while!" laughed Tom, as he saw

the giant turn away, shaking his fist at the closed door, for

Koku, big as he was, stood in mortal terror of the mule's heels.

 

Tom locked the door of the electrical shop and Went back to his

interrupted problem. From Jackson he learned that Koku and

Eradicate had merely happened to stroll into the forbidden place,

which had been left open by accident. There, it appeared, Koku

had handled some of the machinery, ending by switching on the

current of the machine the handles of which he later

unsuspectingly picked up. Then he received a shock he long

remembered, and for many days he believed Eradicate had been

responsible for it, and there was more than the usual hostile

feeling between the two. But Eradicate was innocent of that

trick, at all events.

 

"Though," said Tom, telling his father about it later, "Rad

would have turned on the current if he had known he could make

trouble for Koku by it. I never saw their like for having

disagreements!"

 

"Yes, but they are both devoted to you, Tom," said the aged

inventor. "But what is this you hinted at--a silent motor you

called it, I believe? Are you really serious in trying to invent

one?"

 

"Yes, Dad, I am. I think there's a big field for an aeroplane

that could travel along over the enemy's lines--particularly at

night--and not be heard from below. Think of the scout work that

could be done.

 

"Well, yes, it could be done if you could get a silent motor,

or propellers that made no noise, Tom. But I don't believe it can

be done."

 

"Well, maybe not, Dad. But I'm going to try!" and Tom, after a

further talk with his father, began work in earnest on the big

problem. That it was a big one Tom was not disposed to deny, and

that it would be a valuable invention even his somewhat skeptical

father admitted.

 

"How are you going to start, Tom?" asked Mr. Swift, several

days after the big idea had come to the young man.

 

"I'm going to experiment a bit, at first. I've got a lot of old

motors, that weren't speedy enough for any of my flying machines,

and I'm going to make them over. If I spoil them the loss won't

amount to anything, and if I succeed --well, maybe I can help out

Uncle Sam a bit more."

 

As Tom had said he would do, he began at the very foundation,

and studied the fundamental principles of sound.

 

"Sound," the young inventor told Ned Newton, in speaking about

the problem, "is a sensation which is peculiar to the ear, though

the vibrations caused by sound waves may be felt in many parts of

the body. But the ear is the great receiver of sound."

 

"You aren't going to invent a sort of muffler for the ears, are

you, Tom?" asked Ned. "That would be an easy way of solving the

problem, but I doubt if you could get the Germans to wear your

ear-tabs so they wouldn't hear the sound of the Allied

aeroplanes."

 

"No, I'm not figuring on doing the trick that way," said Tom

with a laugh. "I've really got to cut down the sound of the motor

and the propeller blades, so a person, listening with all his

ears, won't hear any noise, unless he's within a few feet of the

plane."

 

"Well, I can tell you, right off the reel, how to do it," said

the bank employee.

 

"How?" asked Tom eagerly.

 

"Run your engine and propellers in a vacuum," was the prompt

reply.

 

"Hum!" said Tom, musingly. "Yes, that would be a simple way

out, and I'll do it, if you'll tell me how to breathe in a

vacuum."

 

"Oh, I didn't agree to do that," laughed Ned.

 

But he had spoken the truth, as those who have studied physics

well know. There must be an atmosphere for the transmission of

sound, which is the reason all is cold and silent and still at

the moon. There is no atmosphere there. Sound implies vibration.

Something, such as liquid, gas, or solid, must be set in motion

to produce sound, and for the purpose of science the air we

breathe may be considered a gas, being composed of two.

 

Not only must the object, either solid, liquid, or gaseous, be

in motion to produce sound, but the air surrounding the vibrating

body must also be moving in unison with it. And lastly there must

be some medium of receiving the sound waves--the ear or some part

of the body. Totally deaf persons may be made aware of sound

through the vibrations received through their hands or feet. They

receive, of course, only the more intense, or largest, sound

waves, and can not hear notes of music nor spoken words, though

they may feel the vibration when a piano is played. And, as Ned

has said, no sound is produced in a vacuum.

 

"But," said Tom, "since I can't run my aeroplane in a vacume,

or even have the propellers revolve in one, it's up to me to

solve the problem some other way. The propellers don't really

make noise enough to worry about when they're high in the air.

It's the exhaust from the motor, and to get rid of that will be

my first attempt."

 

"Can it be done?" asked Ned.

 

"I don't know," was Tom's frank answer.

 

"They do it on an automobile to a great extent," went on Ned.

"Some of 'em you cant hardly hear."

 

"Yes, but an aeroplane engine runs many, many times faster than

the motor of an auto," said Tom, "and there are more explosions

to muffle. I doubt if the muffler of an auto would cut down the

sound of an aero engine to any appreciable extent. But, of

course, I'll try along those lines."

 

"They have mufflers or silencers for guns and rifles," went on

Ned. "Couldn't you make a big one of those contraptions and put

it on an aeroplane?"

 

"I doubt it," said Tom, shaking his head. "Of course it's the

same principle as that in an auto muffler, or on a motor boat--a

series of baffle plates arranged within a hollow cylinder. But

all such devices cut down power, and I don't want to do that.

However, I'm going to solve the problem or--bust!"

 

And Tom came near "busting," Ned remarked later, when he and

his friend talked over the progress of the invention.

 

Two weeks had passed since the start of his evolution of his

new idea, and following the visiting of the representatives of

the Universal Flying Machine Company. Since then neither Gale nor

Ware had communicated with Tom.

 

"But I must be on the watch against them," thought the young

inventor. "I'm pretty sure Gale heard me mention what I was going

to try to invent, and he may get ahead of me, and put a silent

motor on the market first. Not that I'm afraid of being done out

of any profits, but I simply don't want to be beaten."

 

The details of Tom's invention cannot be gone into, but,

roughly, it was based on the principle of not only a muffler but

also of producing less noise when the charges of gasoline

exploded in the cylinders. It is, of course, the explosion of

gasoline mixed with air that causes an internal combustion engine

to operate. And it is the expulsion of the burned gases that

causes the exhaust and makes the noise that is heard.

 

Tom was working along the well-known line of the rate of travel

of sound, which progresses at the rate of about 1090 feet a

second when air is at the freezing point. And, roughly, with

every degree increase in the atmosphere's temperature the

velocity of sound increases by one foot. Thus at a temperature of

100 degrees Fahrenheit, or 68 degrees above freezing, there would

be added to the 1090 feet the 68 feet, making sound travel at 100

degrees Fahrenheit about 1158 feet a second.

 

Tom had set up in his shop a powerful, but not very speedy, old

aeroplane engine, and had attached to it the device he hoped

would help him toward solving his problem of cutting down the

noise. He had had some success with it, and, after days and

nights of labor, he invited his father and Ned, as well as Mr.

Damon, over to see what he hoped would be a final experiment.

 

His visitors had assembled in the shop, and Eradicate was

setting out some refreshments which Tom had provided, the colored

man being in his element now.

 

"What's all this figuring, Tom ?" asked Mr. Damon, as he saw a

series of calculations on some sheets of paper lying on Tom's

desk.

 

"That's where I worked out how much faster sound traveled in

hydrogen gas than in the ordinary atmosphere," was the answer.

"It goes about four times as fast, or nearly four thousand two

hundred feet a second. You remember the rule, I suppose. 'The

speed of sonorous vibrations through gases varies inversely as

the squares of the weights of equal volumes of the gases,' or, in

other words--"

 

"Give it to us chiefly in 'other words,' if you please, Tom!"

pleaded Ned, with a laugh. "Let that go and do some tricks. Start

the engine and let's see if we can hear it."

 

"Oh, you can hear it all right," said Tom, as he approached the

motor, which was mounted on a testing block. "The thing isn't

perfected yet, but I hope to have it soon. Rad! Where is that

black rascal? Oh, there you are! Come here, Rad!"

 

"Yaas sah, Massa Tom! Is I gwine to help yo' all in dish yeah

job?"

 

"Yes. Just take hold of this lever, and when I say so pull it

as hard as you can."

 

"Dat's whut I will, Massa Tom. Golly! ef dat no 'count giant

was heah now he'd see he ain't de only one whut's got muscle.

I'll pull good an' hard, Massa Tom."

 

"Yes, that's what I want you to. Now I guess we're all ready.

Can you see, Dad--and Ned and Mr. Damon?"

 

"Yes," they answered. They stood near the side wall of the

shop, while Tom and Eradicate were at the testing block, on which

the motor, with the noise-eliminating devices attached, had been

temporarily mounted.

 

"All ready," called the young inventor, as he turned on the gas

and threw over the electrical switch. "All ready! Pull the

starting lever, Rad. and when it's been running a little I'll

throw on the silencer and you can see the difference."

 

The motor began to hum, and there was a deafening roar, just as

there always is when the engine of an aeroplane starts. It was as

though half a dozen automobile engines were being run with the

mufflers cut out.

 

"Now I'll show you the difference!" yelled Tom, though such was

the noise that not a word could be heard. "This shows you what my

silencer will do."

 

Tom pulled another lever. There was at once a cessation of the

deafening racket, though it was not altogether ended. Then, after

a moment or two, there suddenly came a roar as though a blast had

been let off in the shop.

 

Tom and Eradicate were tossed backward, head over heels, as

though by the giant hands of Koku himself, and Mr. Damon, Ned,

and Tom's father saw the motor fly from the testing block and

shoot through the roof of the building with a rending, crashing,

and splintering sound that could be heard for a mile.

 

 

 

CHAPTER IX

AFTER A SPY

 

 

Curious as it may seem, Eradicate, the oldest and certainly not

the most energetic of the party assembled in the experiment room,

was the first to recover himself and arise. Tottering to his feet

he gave one look at the testing block, whence the motor had torn

itself. Then he looked at the prostrate figures around him, none

of them hurt, but all stunned and very much startled. Then the

gaze of Eradicate traveled to the hole in the roof. It was a

gaping, ragged hole, for the motor was heavy and the roof of

flimsy material. And then the colored man exclaimed:

 

"Good land ob massy! Did I do dat?"

 

His tone was one of such startled contrition, and so tragic,

that Tom Swift, rueful as he felt over the failure of his

experiment and the danger they had all been in, could not help

laughing.

 

"I take it, hearing that from you, Tom, that we're all right,"

said Ned Newton, as he recovered himself and brushed some dirt

off his coat. Ned was a natty dresser.

 

"Yes, we seem to be all right," replied Tom slowly. "I can't

say what damage the flying motor has done outside, but--"

 

"Bless my insurance policy! but what happened?" asked Mr.

Damon. "I saw Eradicate pull on that lever as you told him to,

Tom, and then things all went topsy-turvy! Did he pull the wrong

handle?"

 

"No, it wasn't Rad's fault at all," said Tom. "The trouble was,

as I guess I'll find when I investigate, that I put too much

power into the motor, and the muffler didn't give any chance for

the accumulated exhaust gases to expand and escape. I didn't

allow for that, and they simply backed up, compressed and

exploded. I guess that's the whole explanation."

 

"I'm inclined to agree with you, Son," said Mr. Swift dryly.

"Don't try to get rid of all the noise at once. Eliminate it by

degrees and it will be safer."

 

"I guess so," agreed Tom.

 

By this time a score of workmen from the other shops had

congregated around the one though the roof of which the motor had

been blown. Tom opened the door to assure Jackson and the others

that no one was hurt, and then the young inventor saw the

exploded motor had buried in the dirt a short distance away from

the experiment building.

 

"Lucky none of us were standing over it when it went up," said

Tom, as he made an inspection of the broken machine. "We'd have

gone through the roof with it."

 

"She certainly went sailing!" commented Ned. "Must have been a

lot of power there, Tom."

 

And this was evidenced by the bent and twisted rods that had

held the motor to the testing block, and by the cylinders, some

of which were torn apart as though made of paper instead of heavy

steel. But for the fact that all the force of the explosion was

directly upward, instead of at the sides, none might have been

left alive in the shop. All had escaped most fortunately, and

they realized this.

 

"Well," queried Ned, as Tom gave orders to have the damaged

machine removed and the roof repaired, "does this end the

wonderful silent motor, Tom?"

 

"End it! What do you mean--"

 

"I mean are you going to experiment any further?"

 

"Why, of course! Just because I've had one failure doesn't mean

that I'm going to give up. Especially when I know what the matter

was--not leaving any vent for the escaping gases. Why this isn't

anything. When I was perfecting my giant cannon I was nearly

blown up more than once, and you remember how we got stuck in the

submarine."

 

"I should say I did!" exclaimed Ned with a shudder. "I don't

want any more of that. But as between being blown through a roof

and held at the bottom of the sea, I don't know that there's much

choice."

 

"Well, perhaps not," agreed Tom. "But as for ending my

experiments, I wouldn't dream of such a thing! Why, I've only

just begun! I'll have a silent motor yet!"

 

"And a non-explosive one, I hope," added Mr. Damon dryly.

"Bless my shoe buttons, Tom, but if my wife knew what danger I'd

been in she'd never let me come over to see you any more."

 

"Well, the next time I invite you to a test I'll be more

careful," promised the young inventor.

 

"There isn't going to be any next time as far as I'm

concerned!" laughed Ned. "I think it's safer to sell Liberty

Bonds."

 

And, though they joked about it, they all realized the narrow

escape they had had. As for Eradicate, once he knew he had not

been the one who caused the damage, he felt rather proud of the

part he had taken in the mishap, and for many days he boasted

about it to Koku.

 

True to his determination, Tom Swift did not give up his

experimental work on the silent motor. The machine that had been

blown through the roof was useless now, and it was sent to the

scrap heap, after as much of it as possible had been salvaged.

Then Tom got another piece of apparatus out of his store room and

began all over again.

 

He worked along the same lines as at first--providing a chamber

for the escaping gases of the exhaust to expend their noise and

energy in, at the same time laboring to cut down the concussion

of the explosions in the cylinder without reducing their force

any. And that it was no easy problem to do either of these, Tom

had to admit as he progressed. All previous types of mufflers or

silencers had to be discarded and a new one evolved.

 

"Jackson, I need some one to help me," said Tom to his chief

mechanician one day. "Haven't you a good man who is used to

experimental work that you can let me take from the works?"

 

"Why, yes," was the answer. "Let me see. Roberts is busy on the

new bomb you got up, but I could take him off that--"

 

"No, don't!" interposed Tom. "I want that work to go on. Isn't

there some one else you can let me have?"

 

"Well, there's a new man who came to me well recommended. I

took him on last week, and he's a wonderful mechanic. Knows a lot

about gas engines. I could let you have him--Bower his name is.

The only thing about it, though, is that I don't like to give you

a man of whom I am not dead certain, when you're working on a new

device."

 

"Oh, that will be all right," said Tom. "There won't be any

secrets he can get, if you mean you think he might be up to spy

work."

 

"That's what I did mean, Tom. You never can tell, you know, and

you have some bitter enemies."

 

"Yes, but I'll take care this man doesn't see the plans, or any

of my drawings. I only want some one to do the heavy assembling

work on the experimental muffler I'm getting up. We can let him

think it's for a new kind of automobile."

 

"Oh, then I guess it will be all right. I'll send Bower to

you."

 

Tom rather liked the new workman, who seemed quiet and

efficient. He did not ask questions, either, about the machine on

which he was engaged, but did as he was told. As Tom had said, he

kept his plans and drawing under lock and key--in a safe to be

exact--and he did not think they were in any danger from his new

helper.

 

But Tom Swift held into altogether too slight regard the powers

of those who were opposed to him. He did not appreciate the

depths to which they would stoop to gain their ends.

 

He had been working hard on his new device, and had reached a

point further along than when the other motor had exploded. He

began to see success ahead of him, and he was jubilant. Whether

this made him careless does not matter, but the fact was that he

left Bower more to himself, and alone in the experimental shop

several times.

 

And it was on one of these occasions, when Tom had been for

some time in one of the other shops, where he and Jackson were in

consultation over a new machine, that as he came back to the test

room unexpectedly, he saw Bower move hastily away from in front

of the safe. Moreover, Tom was almost certain he had heard the

steel door clang shut as he approached the building.

 

And then, before he could ask his helper a question, Tom looked

from a window and saw a stranger running hastily along the side

of the building where his trial motor was being set up.

 

"Who's that? Who is that man? Did he come in here? Was he

tampering with my safe?" cried Tom. He saw Bower hesitate and

change color, and Tom knew it was time to act.

 

The window was open, and with one bound the young inventor was

out and running after the stranger he had seen departing in such

a hurry. The man was but a short distance ahead of him, and Tom

saw he was stuffing some papers into his pocket.

 

"Here! Come back! Stop!" ordered Tom, but the man ran on the

faster.

 

"That's a spy as sure as guns!" reflected Tom Swift. "And Bower

is in with him!" he added. "I've got to catch that fellow!" and

he speeded his pace as he ran after the fellow.

 

 

 

CHAPTER X

A BIG SPLASH

 

 

There was no question in the mind of Tom Swift but that the man

he was running after was guilty of some wrong-doing. In the first

place he was a stranger, and had no right inside the big fence

that surrounded the Swift machine plant. Then, too, the very fact

that he ran away was suspicious.

 

And this, coupled with the confusion on the part of Bower, and

his proximity to the safe, made Tom fear that some of his plans

had been stolen. These he was very anxious to recover if this

strange man had them, and so he raced after him with all speed.

 

"Stop! Stop!" called Tom, but the on-racing stranger did not

heed.

 

The cries of the young inventor soon attracted the attention of

his men, and Jackson and some of the others came running from

their various shops to give whatever aid was needed. But they

were all too far away to give effective chase.

 

"Bower might have come with me if he had wanted to help,"

thought Tom. But a backward glance over his shoulder did not show

that the new helper was engaging in the pursuit, and he could

have started almost on the same terms as Tom himself.

 

The runaway, looking back to see how near the young inventor

was to him, suddenly changed his course, and, noting this, Tom

Swift thought:

 

"I've got him now! He'll be bogged if he runs that way," for

the way led to a piece of swampy land that, after the recent

rains, was a veritable bog which was dangerous for cattle at

least; and more than one man had been caught there.

 

"He can't run across the swamp, that's sure," reflected Tom

with some satisfaction. "I'll get him all right!"

 

But he wanted to capture the man, if possible, before he

reached the bog, and, to this end, Tom increased his speed to

such good end that presently, on the firm ground that bordered

the swamp, Tom was almost within reaching distance of the

stranger.

 

But the latter kept up running, and dodged and turned so that

Tom could not lay hands on him. Suddenly, turning around a clump

of trees the fleeing man headed straight for a veritable mud hole

that lay directly in his path. It was part of the swamp--the most

liquid part of the bog and a home of frogs and lizards.

 

Too late, the man, who was evidently unaware of the proximity

of the swamp, saw his danger. His further flight was cut off by

the mud hole, but it was too late to turn back. Tom Swift was at

his heels now, and seeing that it was impossible to grab the man,

Tom did the next best thing. He stuck out his foot and tripped

him, and tripped him right on the edge of the mud hole, so that

the man fell in with a big splash, the muddy water flying all

around, some even over the young inventor.

 

For a moment the man disappeared completely beneath the

surface, for the mud hole was rather deep just where Tom had

thrown him. Then there was another violent agitation of the

surface, and a very woebegone and muddy face was raised from the

slough, followed by the rest of the figure of the man. Slowly he

got to his feet, mud and water dripping from him. He cleared his

face by rubbing his hands over it, not that it made his

countenance clean, but it removed masses of mud from his eyes,

nose, and mouth, so that he could see and speak, though his first

operation was to gasp for breath.

 

"What--what are you doin'?" he demanded of Tom, and as the man

opened his mouth to speak Tom was aware of a glitter, which

disclosed the 'fact that the man had a large front tooth of gold.

 

"What am I doing?" repeated Tom. "I think it's up to you to

answer that question, not me. What are you doing?"

 

"You--you tripped me into this mud hole!" declared the man.

 

"I did, yes; because you were trespassing on my property, and

ran away instead of stopping when I told you to," went on Tom.

"Who are you and what are you doing? What were you doing with

Bower at my shop?"

 

"Nothin'! I wasn't doin' nothin'!"

 

"Well, we'll inquire into that. I want to see what you have in

your pockets before I believe you. Come on out!"

 

"You haven't any right to go through my pockets!" blustered the

stranger.

 

"Oh, haven't I? Well, I'm going to take the right. Jackson--

Koku--just see that he doesn't get away. We'll take him back and

search him," and Tom motioned to his chief machinist and the

giant, who had reached the scene, to take charge of the man. But

Koku was sufficient for this purpose, and the mud-bespattered

stranger seemed to shrink as he saw the big creature approach

him. There was no question of running away after that.

 

"Bring him along," ordered Tom, and Koku, taking a tight grip

on the man by the slack of his garments behind, walked him along

toward the office, the mud and water splashing and oozing from

his shoes at every step.

 

"Now you look here!" the gold-toothed man cried, as he was

forced along, "you ain't got any right to detain me. I ain't done

nothin'!" And each time he spoke the bright tooth in his mouth

glittered in the sun.

 

"I don't know whether you've done anything or not," said Tom.

"I'm going to take you back and see what you and Bower have to

say. He may know something about this."

 

"If he does I don't believe he'll tell," said Jackson.

 

"Why not?" asked Tom, quickly.

 

"Because he's gone."

 

"Gone! Bower gone?"

 

"Yes," answered Jackson. "I saw him running out of the

experiment shop as we raced along to help you. I didn't think, at

the time, that he was doing more than go for aid, perhaps. But I

see the game now."

 

"Oh, you mean--him?" and Tom pointed to the dripping figure.

 

"Yes," said Jackson in a low voice, as Koku went on ahead with

his prisoner. "If, as you say, this man was in league with Bower,

the latter has smelled a rat and skipped. He has run away, and I

only hope he hasn't done any damage or got hold of any of your

plans."

 

"We'll soon know about that," said Tom. "I wonder who is at the

bottom of this?"

 

"Maybe those men you wouldn't work for," suggested the

machinist.

 

"You mean Gale and Ware of the Universal Flying Machine

Company?"

 

"Yes."

 

"Oh, I don't believe they'd stoop to any such measures as this-

-sending spies around," replied Tom. "But I can't be too careful.

We'll investigate."

 

The first result of the investigation was to disclose the fact

that Bower was gone. He had taken his few possessions and left

the Swift plant while Tom was racing after the stranger. A hasty

examination of the safe did not reveal anything missing, as Tom's

plans and papers were intact. But they showed evidences of having

been looked over, for they were out of the regular order in which

the young inventor kept them.

 

"I begin to see it," said Tom, musingly. "Bower must have

managed to open the safe while I was gone, and he must have made

a hasty copy of some of the drawings of the silent motor, and

passed them out of the window to this gold-tooth man, who tried

to make off with them. Did you find anything on him?" he asked,

as one of the men who had been instructed to search the stranger

came into the office just then.

 

"Not a thing, Mr. Swift! Not a thing!" was the answer. "We took

off every bit of his clothes and wrapped him in a blanket. He's

in the engine room getting dry now. But there isn't a thing in

any of his pockets."

 

"But I saw him stuffing some papers in as he ran away from me,"

said Tom. "We must be sure about this. And don't let the fellow

get away until I question him."

 

"Oh, he's safe enough," answered the man. "Koku is guarding

him. He won't get away."

 

"Then I'll have a look at his clothes," decided Tom. "He may

have a secret pocket."

 

But nothing like this was disclosed, and the most careful

search did not reveal anything incriminating in the man's

garments.

 

"He might have thrown away any papers Bower gave him," said

Tom. "Maybe they're at the bottom of the mud hole! If they're

there they're safe enough. But have a search made of the ground

where this man ran."

 

This was done, but without result. Some of the workmen even

dragged the mud hole without finding anything. Then Tom and his

father had a talk with the stranger, who refused to give his

name. The man was sullen and angry. He talked loudly about his

innocence and of "having the law on" Tom for having tripped him

into the mud.

 

"All right, if you want to make a complaint, go ahead," said

the young inventor. "I'll make one against you for trespass. Why

did you come on my grounds?"

 

"I was going to ask for work. I'm a. good machinist and I

wanted a job."

 

"How did you get in? Who admitted you at the gate?"

 

"I--I jest walked in," said the man, but Tom knew this could

not be true, as no strangers were admitted without a permit and

none had been issued. The man denied knowing anything about

Bower, but the latter's flight was evidence enough that something

was wrong.

 

Not wishing to go to the trouble of having the man arrested

merely as a trespasser, Tom let him go after his clothes had been

dried on a boiler in one of the shops.

 

"Take him to the gate, and tell him if he comes back he'll get

another dose of the same kind of medicine," ordered Tom to one of

the guards at the plant, and when the latter had reported that

this had been done, he added in an earnest tone:

 

"He went off talking to himself and saying he'd get even with

you, Mr. Swift."

 

"All right," said Tom easily. "I'll be on the watch."

 

The young inventor made a thorough examination of his

experiment shop and the test motor. No damage seemed to have been

done, and Tom began to think he had been too quick for the

conspirators, if such they were. His plans and drawings were

intact, and though Bower might have given a copy to the stranger

with the gold tooth, the latter did not take any away with him.

That he had some papers he wished to conceal and escape with,

seemed certain, but the splash into the mud hole had ended this.

 

No trace was found of Bower, and an effort Tom made to

ascertain if the man was a spy in the employ of Gale and Ware

came to naught. The machinist had come well recommended, and the

firm where he was last employed had nothing but good to say of

him.

 

"Well, it's a mystery," decided Tom. "However, I got out of it

pretty well. Only if that gold-tooth individual shows up again he

won't get off so easily.

 

 

 

CHAPTER XI

A NIGHT TRIP

 

 

Taking a lesson from what had happened, Tom was very much more

careful in the following experiments on his new, silent motor. He

made some changes in his shop, and took Jackson in to help on the

new machine, thus insuring perfect secrecy as the apparatus

developed.

 

Tom also changed the safe in which he kept his plans, for the

one he had used previous to the episode in which Bower and the

stranger who took the mud bath figured, was one the combination

of which could easily be ascertained by an expert. The new safe

was more complicated, and Tom felt that his plans,

specifications, and formulae which he had worked out were in less

danger.

 

"I can just about figure out what happened," said Ned Newton to

Tom, when told of the circumstances. "These Universal people were

provoked because you wouldn't give them the benefit of your

experience on their flying machines, and so they sent a spy to

get work with you. They, perhaps, hoped to secure some of your

ideas for their own, or they may have had a deeper motive."

 

"What deeper motive could they have, Ned?" "They might have

hoped to disable you, or some of your machines, so that you

couldn't compete with them. They're unscrupulous, I hear, and

will do anything to succeed and make money. So be on your guard

against them."

 

"I will," Tom promised. "But I don't believe there's any more

danger now. Anyhow, I have to take some chances."

 

"Yes, but be as careful as you can. How is the silent motor

coming on?"

 

"Pretty good. I've had a lot of failures, and the thing isn't

so easy as I at first imagined it would be. Noise is a funny

thing, and I'm just beginning to understand some of the laws of

acoustics we learned at high school. But I think I'm on the right

track with the muffler and the cutting down of the noise of the

explosions in the cylinders. I'm working both ends, you see--

making a motor that doesn't cause as much racket as those now in

use, and also providing means to take care of the noise that is

made. It isn't possible to make a completely silent motor of an

explosive gas type. The only thing that can be done is to kill

the noise after it is made."

 

"What about the propeller blades?"

 

"Oh, they aren't giving me any trouble. The noise they make

can't be heard a hundred feet in the air, but I am also working

on improvements to the blades. Take it altogether, I'll have an

almost silent aeroplane if my plans come out all right."

 

"Have you said anything to the government yet?"

 

"No; I want to have it pretty well perfected before I do.

Besides, I don't want any publicity about it until I'm ready. If

these Universal people are after me I'll fool 'em."

 

"That's right, Tom! Well, I must go. Another week of this

Liberty Bond campaign!"

 

"I suppose you'll be glad when it's over."

 

"Well, I don't know," said Ned slowly. "It's part of my small

contribution to Uncle Sam. I'm not like you--I can't invent

things."

 

"But you have an awful smooth line of talk, Ned!" laughed his

chum. "I believe you could sell chloride of sodium to some of the

fishes in the Great Salt Lake--that is if it has fishes."

 

"I don't know that it has, Tom. And, anyhow, I'm not posing as

a salt salesman," and Ned grinned. "But I must really go. Our

bank hasn't reached its quota in the sale of Liberty Bonds yet,

and it's up to me to see that it doesn't fall down."

 

"Go to it, Ned! And I'll get busy on my silent motor."

 

"Getting busy" was Tom Swift's favorite occupation, and when he

was working on a new idea, as was the case now, he was seldom

idle, night or day.

 

"I have hardly seen you for two weeks," Mary Nestor wrote him

one day. "Aren't you ever coming to see me any more, or take me

for a ride?"

 

"Yes," Tom wrote back. "I'll be over soon. And perhaps on the

next ride we take I won't have to shout at you through a speaking

tube because the motor makes so much noise."

 

From this it may be gathered that Tom was on the verge of

success. While not altogether satisfied with his progress, the

young inventor felt that he was on the right track. There were

certain changes that needed to be made in the apparatus he was

building--certain refinements that must be added, and when this

should be done Tom was pretty certain that he would have what

would prove to be a very quiet aeroplane, if not an absolutely

silent one.

 

The young inventor was engaged one day with some of the last

details of the experiment. The new motor, with the silencer and

the changed cylinders, had been attached to one of Tom's speedy

aeroplanes, and he was making some intricate calculations in

relation to a new cylinder block, to be used when he started to

make a completely new machine of the improved type.

 

Tom had set down on paper some computations regarding the

cross-section of one of the cylinders, and was working out the

amount of stress to which he could subject a shoulder strut, when

a shadow was cast across the drawing board he had propped up in

his lap.

 

In an instant Tom pulled a blank sheet over his mass of figures

and looked up, a sudden fear coming over him that another spy was

at hand. But a hearty voice reassured him.

 

"Bless my rice pudding!" cried Mr. Damon, "you shut yourself up

here, Tom, like a hermit in the mountains. Why don't you come out

and enjoy life?"

 

"Hello! Glad to see you!" cried Tom, joyfully. "You're just in

time!"

 

"Time for what--dinner?" asked the eccentric man, with a

chuckle. "If so, my reference to rice pudding was very proper."

 

"Why, yes, I imagine there must be a dinner in prospect

somewhere, Mr. Damon," said Tom with a smile. "We'll have to see

Mrs. Baggert about that. But what I meant was that you're just in

time to have a ride with me, if you want to go."

 

"Go where?"

 

"Oh, up in cloudland. I have just finished my first sample of a

silent motor, and I'm going to try it this evening. Would you

like to come along?"

 

"I would!" exclaimed Mr. Damon. "Bless my onion soup, Tom, but

I would! But why fly at night? Isn't it safer by daylight?"

 

"Oh, that doesn't make much difference. It's safe enough at any

time. The reason I'm going to make my first flight after dark is

that I don't want any spies about."

 

"Oh, I see! Are they camping on your trail?"

 

"Not exactly. But I can't tell where they may be. If I should

start out in daylight and be forced to make a landing-- Well, you

know what a crowd always collects to see a stranded airship."

 

"That's right, Tom."

 

"That decided me to start off after dark. Then if we have to

come down because of some sort of engine trouble or because my

new attachment doesn't work right, we sha'n't have any prying

eyes."

 

"I see! Well, Tom, I'll go with you. Fortunately I didn't tell

my wife where I was going when I started out this afternoon, so

she won't worry until after it's over, and then it won't hurt

her. I'm ready any time you are."

 

"Good! Stay to dinner and I'll show you what I've made. Then

we'll take a flight after dark."

 

This suited the eccentric man, and a little later, after he had

eaten one of Mrs. Baggert's best meals, including rice pudding,

of which he was very fond, Mr. Damon accompanied Tom to one of

the big hangars where the new aeroplane had been set up.

 

"So that's the Air Scout, is it, Tom?" asked Mr. Damon, as he

viewed the machine.

 

"Yes, that's the girl. 'Air Scout' is as good a name as any,

until I see what she'll do."

 

"It doesn't look different from one of your regular craft of

the skies, Tom."

 

"No, she isn't. The main difference is here," and Tom showed

his friend where a peculiar apparatus had been attached to the

motor. This was the silencer--the whole secret of the invention,

so to speak.

 

To Mr. Damon it seemed to consist of an amazing collection of

pipes, valves, baffle-plates, chambers, cylinders and reducers,

which took the hot exhaust gases as they came from the motor and

"ate them up," as he expressed it.

 

"The cylinders, too, and the spark plugs are differently

arranged in the motor itself, if you could see them," said Tom to

his friend. "But the main work of cutting down the noise is done

right here," and he put his hand on the steel case attached to

the motor, the case containing the apparatus already briefly

described.

 

"Well, I'm ready when you are, Tom," said Mr. Damon.

 

"We'll go as soon as it's dark," was the reply. "But first I'll

give you a demonstration. Start the motor, Jackson!" Tom called

to his chief helper.

 

Mr. Damon had ridden in aeroplanes before, and had stood near

when Tom started them; so he was prepared for a great rush of air

as the propellers whirled about, and for deafening explosions

from the engine.

 

The big blades, of new construction, were turned until the gas

in the cylinders was sufficiently compressed. Then Jackson

stepped back out of danger while Tom threw over the switch.

 

"Contact!" cried the young inventor.

 

Jackson gave the blades a quarter pull, and, a moment later, as

he leaped back out of the way, they began to revolve with the

swiftness of light. There was the familiar rush of air as the

wooden wings cut through the atmosphere, but there was scarcely

any noise. Mr. Damon could hardly believe his ears.

 

"I'm not running her at full speed," said Tom. "If I did she'd

tear loose from the holding blocks. But you can see what little

racket she makes."

 

"Bless my fountain pen!" cried Mr. Damon. "You are right, Tom

Swift! Why, I can hear you talk almost as easily as if no engine

were going. And I don't have to shout my head off, either."

 

This was perfectly true. Tom could converse with Mr. Damon in

almost ordinary tones. The exhaust from the motor was nearly

completely muffled.

 

"Out in the air it will seem even more quiet," said Tom. "I'll

soon give you a chance to verify that statement."

 

He ran the engine a little longer, the aeroplane quivering with

the vibrations, but remaining almost silent.

 

"I'm anxious to see what she'll do when in motion," said Tom,

as he shut off the gas and spark.

 

Soon after supper, when the shades of evening were falling, he

and Mr. Damon took their places in the first of the Air Scouts,

to give it the preliminary test in actual flying.

 

Would Tom's hopes be justified or would he be disappointed?

 

 

 

CHAPTER XII

THE CRY FOR HELP

 

 

"All ready, Mr. Damon?" asked Tom, as he looked to see that all

the levers, wheels, valves, and other controls were in working

order on his Air Scout.

 

"As ready as I ever shall be, Tom," was the answer. "I don't

know why it is, but somehow I feel that something is going to

happen on this trip."

 

"Nonsense!" laughed Tom. "You're nervous; that's all."

 

"I suppose so. Don't think I'm going to back out, or anything

like that, but I wish it were successfully over with, Tom Swift,

I most certainly do."

 

"It will be in a little while," returned Tom, as he settled

himself comfortably in his seat and pulled the safety strap

tight. "You've gone up in this same plane before, when it didn't

have the silent motor aboard."

 

"Yes, I know I have. Oh, I dare say it will be all right, Tom.

And yet, somehow, I can't help feeling--"

 

But Tom Swift felt that the best way to set Mr. Damon's

premonitions to rest was to start the motor, and this he gave

orders to have done, Jackson and some others of the men from the

shops congregating about the craft to see the beginning of the

night flight. Mr. Swift was there also, and Eradicate. Mary

Nestor had been invited, but her Red Cross work engaged her that

evening, she said. Ned Newton was away from town on Liberty Bond

business, and he could not be present at the test.

 

However, as Tom expected to have other trials when his motor

was in even better shape, he was not exactly sorry for the

absence of his friends.

 

"Contact!" called the young inventor, when Jackson had stepped

back, indicating it was time to throw over the switch.

 

"Let her go!" cried Tom, and the next moment the motor was in

operation, but so silently that his voice and that of Mr. Damon's

could easily be heard above the machinery.

 

"Good, Tom! That's good!" cried Mr. Swift, and Tom easily heard

his father's voice, though under other, and ordinary,

circumstances this would have been impossible.

 

True, the hearing of Tom and Mr. Damon was muffled to a certain

extent by the heavy leather and fur-lined caps they wore. But Tom

had several small eyelet holes set into the flaps just over the

opening of the ears, and these holes were sufficient to admit

sounds, while keeping out most of the cold that obtains in the

upper regions.

 

The aeroplane moved swiftly along the level starting ground,

and away from the lighted hangars. Faster and faster it swung

along as Tom headed it into the wind, and then, as the speed of

the motor increased, the Air Scout suddenly left the earth and

went soaring aloft as she had done before.

 

But there was this difference. She moved almost as silently as

a great owl which swoops down out of the darkness--a bit of the

velvety blackness itself. Up and up, and onward and onward, went

the Air Scout. Tom Swift's improved, silent motor urged it

onward, and as the young inventor listened to catch the noise of

the machinery, his heart gave a bound of hope. For he could

detect only very slight sounds.

 

"She's a success!" exulted Tom to himself. "She's a success,

but she isn't perfect yet," he added. "I've got to make the

muffler bigger and put in more baffle-plates. Then I think I can

turn the trick."

 

He swung the machine out over the open country, and then, when

they were up at a height and sailing along easily, he called back

to Mr. Damon in the seat behind him:

 

"How do you like it?"

 

"Great!" exclaimed the eccentric man. "Bless my postage stamp,

but it's great! Why, there's hardly a sound, Tom, and I can hear

you quite easily."

 

"And I can hear you," added Tom. "I don't believe, down below

there," and he nodded toward the earth, though Mr. Damon could

not see this, as the airship, save for a tiny light over the

instrument board, was in darkness, "they know that we're flying

over their heads."

 

"I agree with you," was the answer. "Tom, my boy, I believe

you've solved the trick! You have produced a silent aeroplane,

and now it's up to the government to make use of it."

 

"I'm not quite ready for that yet," replied the young inventor.

"I have several improvements to make. But, when they are

finished, I'll let Uncle Sam know what I have. Then it's up to

him."

 

"And you must be careful, Tom, that some of your rivals don't

hear of your success and get it away from you," warned Mr. Damon,

as Tom guided the Air Scout along the aerial way--an unlighted

and limitless path in the silent darkness.

 

"Oh, they'll have to get up pretty early in the morning to do

that!" boasted Tom, and afterward he was to recall those words

with a bit of chagrin.

 

On and on they sailed, and as Tom increased the speed of the

motor, and noted how silently it ran, he began to have high hopes

that he had builded better than he knew. For even with the motor

running at almost full speed there was not noise enough to hinder

talk between himself and Mr. Damon.

 

Of course there was some little sound. Even the most perfect

electric motor has a sort of hum which can be detected when one

is close to it. But at a little distance a great dynamo in

operation appears to be silence itself.

 

"I can go this one better, though," said Tom as he sailed along

in the night. "I see where I've made a few mistakes in the baffle

plate of the silencer. I'll correct that and--"

 

As he spoke the machine gave a lurch, and the motor, instead of

remaining silent, began to cough and splutter as in the former

days.

 

"Bless my rubber boots, Tom! what's the matter?" cried Mr.

Damon.

 

"Something's gone wrong," Tom answered, barely able to hear and

make himself heard above the sudden noise. "I'll have to shut off

the power and glide down. We can make a landing in this big

field," for just then the moon came out from behind a cloud, and

Tom saw, below them, a great meadow, not far from the home of

Mary Nestor. He had often landed in this same place.

 

"Something has broken in the muffler, I think, letting out some

of the exhaust," he said to Mr. Damon, for, now that the motor

was shut off, Tom could speak in his ordinary tones. "I'll soon

have it fixed, or, if I can't, we can go back in the old style--

with the machine making as much racket as it pleases."

 

So Tom guided the machine down. It went silently now, of

course, making, with the motor shut off, no more sound than a

falling leaf. Down to the soft, springy turf in the green meadow

Tom guided the machine. As it came to a stop, and he and Mr.

Damon got out, there was borne to their ears a wild cry:

 

"Help! Help!"

 

 

 

CHAPTER XIII

SOMETHING QUEER

 

 

"DiD you hear that?" asked Tom Swift of his companion.

 

"Hear it? Bless my ear drums, I should say I did hear it! Some

one is in trouble, Tom. Caught in a bog, most likely, the same as

that spy chap who was at your place. That's it--caught in a bog!"

 

"There isn't any bog or swamp around here, Mr. Damon. If there

was I shouldn't have tried a landing. No, it's something else

besides that. Hark!"

 

Again the cry sounded, seeming to come from a point behind the

landing place of the silent airship. It was clear and distinct:

 

"Help! Help! They are--"

 

The voice seemed to die away in a gurgle, as though the

person's mouth had been covered quickly.

 

"He's sinking, Tom! He's sinking!" cried Mr. Damon. "I once

heard a man who almost drowned cry out, and it sounded exactly

like that!"

 

"But there isn't any water around here for any one to drown

in," declared Tom. "It's a big, dry meadow. I know where we are."

 

"Then what is it?"

 

"I don't know, but we're going to find out. Some one attacked

by some one else--or something, I should say," ventured the young

inventor.

 

"Something! do you mean a wild beast, Tom?"

 

"No, for there aren't any of those here any more than there is

water. Though it may be that some farmer's bull or a savage dog

has got loose and has attacked some traveler. But, in that case I

think we would hear bellows or barks, and all I heard was a cry

for help."

 

"The same with me, Tom. Let's investigate;"

 

"That's what I intend doing. Come on. The airship will be all

right until we come back."

 

"Better take a light--hadn't you? It's dark, even if the moon

does show now and then," suggested Mr. Damon.

 

"Guess you are right," agreed Tom. Aboard his airship there

were several small but powerful portable electric lights, and

after securing one of these Tom and Mr. Damon started for the

spot whence the call for help had come. As they walked along,

their feet making no noise on the soft turf, they listened

intently for a repetition of the call for aid.

 

"I don't hear anything," said Tom, after a bit.

 

"Nor I," added Mr. Damon. "We don't know exactly which way to

go, Tom."

 

"That's right. Guess we'd better give him a hail; whoever it

is."

 

Tom came to a halt, and raising his voice to a shout called:

 

"Hello there! What's the matter? We'll help you if you can tell

us which way to come!"

 

They both listened intently, but no voice answered them. At the

same time, however, they were aware of a sound as of hurrying

feet, and there seemed to be muttered imprecations not far away.

Tom and Mr. Damon looked in the direction of the sound, and the

young inventor flashed his light. But there was a clump of bushes

and trees at that point and the electrical rays did not penetrate

very far.

 

"Some one's over there!" exclaimed Tom in a whisper. "We'd

better go and see what it is."

 

"All right," agreed Mr. Damon, and he, too, spoke in a low

voice.

 

Why they did this when their previous talk had been in ordinary

tones, and when Tom had shouted so loudly, they did not stop to

reason about or explain just then. But later they both admitted

that they whispered because they thought there was something

wrong on foot--because they feared a crime was being committed

and they wanted to surprise the perpetrators if they could.

 

And it was this fact of their whispering that enabled the two

to hear something that, otherwise, they might not have heard. And

this was the sound of some vehicle hurrying away--an automobile,

if Tom was any judge. The cries for help had been succeeded by

stifled vocal sounds, and these, in turn, by the noise of wheels

on the ground.

 

"What does it all mean?" asked Mr. Damon in a whisper.

 

"I don't know," answered Tom, resolutely, "but we've got to

find out. Come on

 

They advanced toward the dark clump of trees and low bushes.

There was no need to be especially cautious in regard to being

silent, as their feet made little, if any, sound on the deep

grass. And, as Tom walked in advance, now and then flashing his

light, Mr. Damon suddenly caught him by the coat.

 

"What is it?" asked the young inventor.

 

"Look! Just over the top of that hill, where the moon shines.

Don't you see an automobile outlined?"

 

Tom looked quickly.

 

"I do," he answered. "There's a road from here, just the other

side of those trees, to that hill. The auto must have gone that

way. Well, there's no use in trying to follow it now. Whoever it

was has gotten away."

 

"But they may have left some one behind, Tom. We'd better look

in and around those trees."

 

"I suppose we had, but I don't believe we'll find anything. I

can pretty nearly guess, now, what it was."

 

"What?" asked Mr. Damon.

 

"Well, some chauffeur was out for a ride in his employer's car

without permission. He got here, had an accident--maybe some

friends he took for a ride were hurt and they called for help.

The chauffeur knew if there was any publicity he'd be blamed, and

so he got away as quickly as he could. Guess the accident--if

that's what it was--didn't amount to much, or they couldn't have

run the car off. We've had our trouble for our pains."

 

"Well, maybe you're right, Tom Swift, butt all the same, I'd

like to have a look among those trees," said Mr. Damon.

 

"Oh. we'll look, all right," assented Tom, "but I doubt if we

find anything."

 

And he was right. They walked in and about the little grove,

flashing the light at intervals, but beyond marks of auto wheels

in the dust of the road, which was near the clump of maples,

there was nothing to indicate what had happened.

 

"Though there was some sort of fracas," declared Tom. "Look

where the dust is trampled down. There were several men here,

perhaps skylarking, or perhaps it was a fight."

 

"Some one must have been hurt, or they wouldn't have cried for

help," said Mr. Damon.

 

"Well, that's so. But perhaps it was some one not used to

riding in autos, and he may have imagined the accident was worse

than it was, and called for help involuntarily. There is no

evidence of any serious accident having happened--no spots of

blood, at any rate," and Tom laughed at his own grimness. "It was

a new car, too, or at least one with new tires on."

 

"How do you know?" asked Mr. Damon.

 

"Tell by the plain marks of the rubber tread in the dust," was

the answer. "Look," and Tom pointed to the wheel marks in the

focus of his electric lamp. "It's a new tire, too, with square

protuberances on the tread instead of the usual diamond or round

ones. A new kind of tire, all right."

 

He and Mr. Damon remained for a few minutes looking about the

place whence had come the calls for help, and then the eccentric

man remarked:

 

"Well, as long as we can't do anything here, Tom, we might as

well travel on; what do you say?"

 

"I agree with you. There isn't any use in staying. We'll get

the Air Scout fixed up and travel back home. But this was

something queer," mused Tom. "I hope it doesn't turn out later

that a crime has been committed, and we didn't show enough

gumption to prevent it."

 

"We couldn't prevent it. We heard the cries as soon as we

landed."

 

"Yes, but if we had rushed over at once we might have caught

the fellows. But I guess it was only a slight accident, and some

one was more frightened than hurt. We'll have to let it go at

that."

 

But the more he thought about it the more Tom Swift thought

there was something queer in that weird cry for help on the

lonely meadow in the darkness of the night.

 

 

 

CHAPTER XIV

THE TELEPHONE CALL

 

 

The defect in the motor which had caused Tom Swift to shut off

the power and drift down to earth was soon remedied, once the

young inventor began an examination of the craft. One of the oil

feeds had become choked and this automatically cut down the

gasoline supply, causing one or more cylinders to miss. It was a

safety device Tom had installed to prevent the motor running dry,

and so being damaged.

 

Once the clogged oil feed was cleared the motor ran as before,

and just as silently, though, as Tom had said, he was not

entirely satisfied with the quietness, but intended to do further

work toward perfecting it.

 

"I'll start the propellers now, Mr. Damon," said Tom, when the

trouble had been remedied. "You know how to throw the switch,

don't you?"

 

"I guess so," was the answer. Mr. Damon and Tom had traveled so

often together in gasoline craft that the young inventor had

taught his friend certain fundamentals about them, and in an

emergency the eccentric man could help start an aeroplane. This

he now did, taking charge of the controls which could be operated

from his seat as well as from Tom's. Tom whirled the propellers,

and soon the motor was in motion.

 

Mr. Damon, once the big wooden blades were revolving, slowed

down the apparatus until Tom could jump aboard, after which the

latter took charge and soon speeded up the machine, sending it

aloft.

 

As the green meadow, dimly seen in the light of the moon,

seemed to drop away below them, and the clump of trees vanished

from sight, both Tom and Mr. Damon wondered who it was that had

called for help, and if the matter were at all serious. They were

inclined to think it was not, but Tom could not rid himself of a

faint suspicion that there might have been trouble.

 

However, thoughts of his new silent Air Scout soon drove

everything else from his mind, and as he guided the comparatively

silent machine on its quiet way toward his own home he was

thinking how he could best improve the muffler.

 

"Well, here we are again, safe and sound," remarked Tom, as he

brought the craft to a stop in front of the hangar, and Jackson

and his helpers, who were awaiting the return, hurried out to

take charge.

 

"Yes, everything seems to point to success, Tom," agreed Mr.

Damon. "That is, unless the slight accident we had means

trouble."

 

"Oh, no, that had nothing to do with the operation of the

silencer. But I'm going to do better yet. Some day I'll take you

for a ride in a silent machine which will make so little noise

that you can hear a pin drop."

 

"Well," remarked Mr. Damon' with a laugh, "I don't know that

listening to falling pins will give me any great amount of

pleasure, Tom, but I appreciate your meaning."

 

"Everything all right?" asked Mr. Swift, as he came out to hear

the details from his son. "Do you think you have solved the

problem?"

 

"Not completely, but I'll soon be able to write Q. E. D. after

it. Some refinements are all that are needed, Dad."

 

"Glad to hear it. I was a bit anxious."

 

Mr. Swift questioned his son about the technical details of the

trip, asking how the motor had acted under the pressure caused by

so completely muffling the exhaust, and for some minutes the two

inventors, young and old, indulged in talk which was not at all

interesting to Mr. Damon. They went into the house, and Tom asked

to have a little lunch, which Mrs. Baggert set out for him.

 

"It's rather late to eat," said the young inventor, "but I

always feel hungry after I test a new machine and find that it

works pretty well. Will you join me in a sandwich or two, Mr.

Damon?"

 

"Why, bless my ketchup bottle, I believe I will."

 

And so they ate and talked. Tom was on the point of telling his

father something of the queer cry for help they had heard on the

lonely meadow when Mrs. Baggert produced a letter which she said

had come for Tom that afternoon, but had been mislaid by a new

maid who had been engaged to help with the housework.

 

"She took it to the shop after you had left, and only now told

me about it," explained Mrs. Baggert. "So I sent Eradicate for

it."

 

"How long ago was that?" asked Tom, as he took the missive.

 

"Oh, an hour ago," answered Mrs. Baggert, with a smile. "But

don't blame poor Rad for that. He wanted to deliver the letter to

you personally, and so did Koku. The result was your giant kept

after Rad, trying to get the letter from him, and Rad kept

hiding and slinking about for a chance to see you himself until I

saw what was going on, a little while ago, and took the letter

myself. Else you might never have gotten it, so jealous are those

two," and Mrs. Baggert laughed.

 

"Guess it isn't of much importance," Tom said, as he tore open

the envelope. "It's from the Universal Flying Machine Company, of

New York, and I imagine they're trying to get me to reconsider my

refusal to link up with them."

 

"Yes," he went on, as he read the missive, "that's it. They've

raised the amount to thirty thousand a year now, Dad, and they

say they feel sure I shall regret it if I do not accept.

 

"This is a bit queer, though," went on the young inventor.

"This letter was written three days ago, but it reached Shopton

only to-day. And it says that unless they hear from me at once

they will have to take steps that will cause me great

inconvenience. They have nerve, at any rate, and impudence, too!

I won't even bother to answer. But I wonder what they mean, and

why this letter was delayed?"

 

"The mails are all late on account of the transportation

congestion caused by moving troops to the camps," said Mr. Damon.

"Some of my letters are delayed a week. But, as you say, Tom,

these fellows are very impudent to threaten that way."

 

"It's all bluff," declared Tom. "I'm not worrying. And now,

Dad, since I've almost reached the top of the hill with my Air

Scout, I may be able to help you on that new electric motor

you're puzzling over."

 

"I wish you would, Tom. I am trying to invent a new system of

interchangeable brush contacts, but so far I've been unable to

make them work. However, there is no great hurry about that. If

you are going to offer your silent machine to the government

finish that first. We need all the aircraft we can get. The

battles on the other side seem to be all in favor of the Germans,

so far."

 

"We haven't got into our stride yet," declared Mr. Damon. "Once

Uncle Sam gets the boys over there in force, there'll be a

different story to tell. I only wish--"

 

At that moment the telephone set up an insistent ringing,

breaking in on Mr. Damon's remarks.

 

"I'll answer," said Tom, as Mrs. Baggert moved toward the

instrument, which was an extension from the main one.

 

"Hello!" called the young inventor into the transmitter, and as

he received an answer a look of pleasure came over his face.

 

"Yes, Mary, this is Tom," he said. He remained silent a moment,

while it was evident he was listening to the voice at the other

end of the wire. Then he suddenly exclaimed:

 

"What's that? Tell him to come home? Why, he isn't here. I just

came in and--what--wait a minute!"

 

With a rather strange look on his face Tom covered the mouth-

piece of the instrument with his hand, and, turning to his

father, asked:

 

"Is Mr. Nestor here?"

 

"No," replied Mr. Swift slowly, "He was here, though. He came a

little while after you and Mr. Damon started off in the Air

Scout. But he didn't stay. Said he wanted to see you about

something and would call again."

 

"Oh," remarked the young man. "I didn't know he had been

there."

 

"I meant to tell you," said Mrs. Baggert; "but getting the

lunch made me forget it, I guess."

 

Tom uncovered the transmitter of the telephone again, and spoke

to Mary Nestor.

 

"Hello," he said. "I was wrong, Mary. Your father was here, but

he left when he found I wasn't at home. How long ago? Wait a

minute and I'll inquire.

 

"How long ago did Mr. Nestor leave?" asked the young inventor

of the housekeeper. "Nearly an hour," he said into the

instrument, after he had received the answer. Then, after

listening a moment, he added: "Yes, I guess he'll be home soon

now. Probably stopped down town to see some of his friends. Yes,

Mr. Damon and I tried out the Air Scout. Yes, she worked pretty

well, for a starter, but there is something yet to be done. Oh,

yes, now I'll have time to come over to see you, and take you for

a ride too. We won't have to talk through a speaking tube,

either. Tell your father I am sorry I was out when he called.

I'll come to see him to-morrow, if he wants me to. Yes--yes. I

guess so!" and Tom laughed, it being evident that his remarks at

the end of the conversation had to do with personal matters.

 

"A telegram has come for Mr. Nestor and they were anxious that

he should get it," Tom explained to his little audience as he

hung up the receiver and put aside the telephone. "I wonder what

he wanted to see me about?"

 

"He didn't say," replied Mrs. Baggert.

 

Mr. Damon, Tom, and his father remained in conversation a

little while longer, and the eccentric man was thinking that it

was about time for him to return home, when the telephone rang

again.

 

"Hello," answered Tom, as he was nearest the instrument. "Oh,

yes, Mary, this is he. What's that? Your father hasn't reached

home yet? And your mother is worried? Oh tell her there is no

cause for alarm. As I said, he probably stopped on his way to see

some friends."

 

Tom listened for perhaps half a minute to a talk that was

inaudible to the others in the room, and they noticed a grave

look come over his face. Then he said:

 

"I'll be right over, Mary. Yes, I'll come at once. And tell

your mother not to worry. I'm sure nothing could have happened.

I'll be with you in a jiffy!"

 

As Tom Swift hung up the receiver he said:

 

"Mr. Nestor hasn't reached home yet, and as he promised to

return at once in case he didn't find me, his wife is much

worried. I'll go over and see what I can do."

 

"I'll come along!" volunteered Mr. Damon. "It isn't late yet."

 

"Yes, do come," urged Tom. "But I suppose when we get there

we'll find our friend has arrived safely. We'll go over in the

electric runabout."

 

 

 

CHAPTER XV

A VAIN SEARCH

 

 

Tom Ssift's speedy little electric car was soon at the door in

readiness to take him and Mr. Damon to the Nestor home. The

electric runabout was a machine Tom had evolved in his early

inventive days, and though he had other automobiles, none was

quite so fast or so simple to run as this, which well merited the

name of the most rapid machine on the road. In it Tom had once

won a great race, as has been related in the book bearing the

title, "Tom Swift and His Electric Runabout."

 

"Mary didn't telephone again, did she?" Tom asked his father,

as he stopped at the house to get Mr. Damon, having gone out to

see about getting the electric runabout in readiness.

 

"No," was the answer. "The telephone hasn't rung since."

 

"Then, I guess, Mr. Nestor can't have arrived home," said Tom.

"It's a bit queer, his delay, but I'm sure it will be explained

naturally. Only Mary and her mother are alone and, very likely,

they're nervous. I'll telephone to let you know everything is all

right as soon as I get there," Tom promised his father and Mrs.

Baggert as he drove off down the road, partly illuminated by the

new moon.

 

Rapidly and almost as silently as his Air Scout Tom Swift drove

the speedy car down the highway. It was about three miles from

his home to that of Mary Nestor, and though the distance was

quickly covered, to Tom, at least, the space seemed interminable.

But at length he drove up to the door. There were lights in most

of the rooms, which was unusual at this time of night.

 

The sound of the wheels had not ceased echoing on the gravel of

the drive before Mary was out on the porch, which she illuminated

by an overhead light.

 

"Oh, Tom," she cried, "he hasn't come yet, and we are so

worried! Did you see anything of father as you came along?"

 

"No," was Tom's answer. "But we didn't look for him along the

road, as we came by the turnpike, and he wouldn't travel that

way. But he will be along at any moment now. You must remember

it's quite a walk from my house, and--"

 

"But he was on his bicycle," said Mary. "We wanted him to go in

the auto, but he said he wanted some exercise after supper, and

he went over on his wheel. He said he'd be right back, but he

hasn't come yet."

 

"Oh, he will!" said Tom reassuringly. "He may have had a

puncture, or something like that. Bicyclists are just as liable

to them as autoists," he added with a laugh.

 

"Well, I'm sure I hope it will be all right," sighed Mary. "I

wish you could convince mother to that effect. She's as nervous

as a cat. Come in and tell us what to do."

 

"Oh, he'll be all right," declared Mr. Damon, adding his

assurances to Tom's.

 

They found Mrs. Nestor verging on an attack of hysteria. Though

Mr. Nestor often went out during the evening, he seldom stayed

late.

 

"And he said he'd be right back if he found you weren't at

home, Tom," said Mrs. Nestor. "I'm sure I don't know what can be

keeping him!"

 

"It's too soon to get worried yet," replied the young inventor

cheerfully. "I'll wait a little while, and then, if he doesn't

come, Mr. Damon and I will go back over the road and look

carefully. He may have had a slight fall--sprained his ankle or

something like that--and not be able to ride. We came by the

turnpike, a road he probably wouldn't take on his wheel. He's all

right, you may be sure of that."

 

Tom tried to speak reassuringly, but somehow, he did not

believe himself. He was beginning to think more and more how

strange it was that Mr. Nestor did not return home.

 

"We'll wait just a bit longer before setting out on a search,"

he told Mary and her mother. "But I'm sure he will be along any

minute now."

 

They went into the library, Mary and her mother, Tom and Mr.

Damon. And there they sat waiting. Tom tried to entertain Mary

and Mrs. Nestor with an account of his trial trip in the Air

Scout, but the two women scarcely heard what he said.

 

All sat watching the clock, and looking from that to the

telephone, which they tried to hope would ring momentarily and

transmit to them good news. Then they would listen for the sound

of footsteps or bicycle wheels on the gravel walk. But they heard

nothing, and as the seconds were ticked off on the clock the

nervousness of Mrs. Nestor increased, until she exclaimed:

 

"I can stand it no longer! We must notify the police--or do

something!"

 

"I wouldn't notify the police just yet," counseled Tom. "Mr.

Damon and I will start out and look along the road. If it should

happen, as will probably turn out to be the case, that Mr. Nestor

has met with only a simple accident, he would not like the

notoriety, or publicity, of having the police notified."

 

"No, I am sure he would not," agreed Mary. "Tom's way is best,

Mother."

 

"All right, just as you say, only find my husband," and Mrs.

Nestor sighed, and turned her head away.

 

"Even if Mr. Nestor had had a fall," reasoned Tom, "he could

call for help, and get some one to telephone, unless--"

 

And as he reasoned thus Tom Swift gave a mental start at his

own use of the word "help."

 

That weird cry on the lonely meadow came back to him with

startling distinctness.

 

"Come on, Mr. Damon!" cried Tom, in a voice he tried to make

cheerful. "We'll find that Mr. Nestor is probably walking along,

carrying his disabled bicycle instead of having it carry him.

We'll soon have him safe back to you," he called to the two

women.

 

"I wish I could go with you, and help search," observed Mary.

 

"Oh, I couldn't bear to be left alone!" exclaimed her mother.

 

"We'll telephone as soon as we find him," called Tom to Mrs.

Nestor, as he and Mr. Damon again got into the runabout and

started away from the place.

 

"What do you think of it, Tom?" asked the eccentric man, when

they were once more on the road.

 

"Why, nothing much--as yet," Tom said. "That is, I think

nothing more than a simple accident has happened, if, indeed, it

is anything more than that he has delayed to talk to some

friends."

 

"Would he delay this long?"

 

"I don't know."

 

"And then, Tom--bless my spectacles! what of that cry we heard?

Could that have been Mr. Nestor?"

 

There! It was out! The suspicion that Tom had been trying to

keep his mind away from came to the fore. Well, he might as well

race the issue now as later.

 

"I've been thinking of that," he told Mr. Damon. "It might have

been Mary's father calling for help."

 

"But we looked, Tom, near the trees, and couldn't discover

anything. If he had been calling for help--"

 

Mr. Damon did not finish.

 

"He may have fallen from his wheel and been hurt," said Tom, as

he turned the electric runabout into the highway that Mr. Nestor

would, most likely, have taken on his way from Shopton. "Then be

may have called for help, and some autoists, passing, may have

heard and taken him away."

 

"Yes, but where, Tom? Whoever called for help was taken away,

that's sure. But where?"

 

"To some hospital, I suppose."

 

"Then hadn't we better inquire there? There are only two

hospitals of any account around here. The one in Shopton and the

one in Waterfield. My wife is on the board of Lady Managers

there. We could call that hospital up and--"

 

"We'll look along the road first," said Tom. "If we begin to

make inquiries at the hospitals there will be a lot of questions

asked, and a general alarm may be sent out. Mr. Nestor wouldn't

like that, if he isn't in any danger. And it may turn out that he

has met an old friend, and has been talking with him all this

while, forgetting all about the passage of time."

 

They were now driving along the highway that led from the

little suburb where Mr. Nestor lived, to the main part of

Shopton, just beyond which was Tom's home. This section was

country-like, with very few houses and those placed at rather

infrequent intervals. The road was a good one, though not the

main-traveled one, and Mr. Nestor, as was known, frequently used

it when he rode his bicycle, an exercise of which he was very

fond.

 

As Tom and Mr. Damon drove along, they scanned, as best they

could in the light from the young moon and the powerful lamps on

the runabout, every part of the highway. They were looking for

some dark blot which might indicate where a man had fallen from

his wheel and was lying in some huddled heap on the road. But

they saw nothing like this, much to their relief.

 

"Do you know, Tom," said Mr. Damon, when they were nearing the

town, and their search, thus far, had been in vain, "I think

we're going at this the wrong way."

 

"Why, so?"

 

"Because Mr. Nestor may have fallen, and been hurt, and have

been carried into any one of a dozen houses along the road. In

that case we wouldn't see him. We've passed over the most lonely

part of the journey and haven't seen him. If the accident

occurred near the houses his cries would have brought some one

out to help him. He is well known around here, and, even if he

were unconscious and couldn't tell who he was, he could be

identified by papers in his pockets. Then his family would be

notified by telephone."

 

"Perhaps you are right, Mr. Damon. We may be wasting time this

way. What do you suggest?" asked Tom.

 

"That we don't delay any longer, but call up the hospitals at

once. If he isn't in either of those he must be in some house,

and in such condition that his identity cannot be established. In

that event it is a case for the police. We haven't found him, and

I think we had better give the alarm."

 

Tom Swift thought it over for a moment. Then he came to a

sudden decision.

 

"You're right!" he told Mr. Damon. "We mustn't waste any more

time. He isn't along the road he ought to have traveled in coming

from my house to his home--that's sure. But before I call up the

hospitals I want to try out one more idea."

 

"What's that, Tom?"

 

"I want to go to the place where we heard that cry for help."

 

"Do you think that could have been Mr.

Nestor?"

 

"It may have been. We'll go and take another look around there.

Some man was evidently hurt there, and was taken away. We may get

a clew. The lights on the runabout will give us a better chance

to look around than we had by the little pocket lamp. We'll try

there, and, if we don't find anything, then I'll call up the

hospitals."

 

 

 

CHAPTER XVI

THE LONG NIGHT

 

 

With the speedy runabout it did not take Tom Swift and Mr.

Damon long to reach the place where the Air Scout had been

grounded a few hours before, and where they had heard the cry for

help. All was as dark and as silent as when they had been there

before.

 

But, as Tom had said, the lights from his electric runabout

would give a brilliant illumination, and these he now directed

toward the clump of trees whence the cry for help had seemed to

come.

 

"Doesn't appear to have been visited by any one since we were

here," remarked Torn, as he observed the marks of the new

automobile tire in the dust. "Now we'll look about more

carefully."

 

This they did, but they were about to give up in despair and

start for the nearest telephone to call up the hospitals, when

Mr. Damon gave an exclamation.

 

"What is it?" asked Tom.

 

"Something bright and shining!" said his companion. "I saw it

gleam in the light of the lamps. You nearly put your foot on it,

Tom. Just step back a moment."

 

Tom did so, and the eccentric man, with another exclamation,

this time of satisfaction, reached down and picked something up

from the dusty road.

 

"It's a watch!" he exclaimed. "A gold watch! And it's been

stepped on, evidently, or run over by an auto. Not much damaged,

but the case is a bit bent and scratched. It's stopped, too!" he

added as he held it to his ear.

 

"What time does it show?" asked Tom.

 

"Eight forty-seven," answered Mr. Damon, as he consulted the

dial. "Why, Tom, that was just about when we heard the cries for

help!"

 

"Yes, it must have been. Let me see that watch."

 

No sooner had the young inventor taken the timepiece into his

hands than he, too, uttered a cry of amazement.

 

"Do you recognize it?" asked Mr. Damon, in great excitement.

 

"It's Mr. Nestor's watch!" cried Tom. "He must have fallen

here, and been hurt. It was Mr. Nestor who cried for help, and

who was taken away by the autoists. They've probably taken him to

some hospital. There's been an accident all right."

 

Tom and Mr. Damon were of one mind now in thinking that Mr.

Nestor had met with some mishap on the road--an automobile

accident most likely--and that he was the person who had called

for help.

 

"If they had only answered when we hallooed at them," said Tom,

"we wouldn't be in all this stew now. We could have told the

strangers who came to his aid who he was, and we might even have

taken him to the hospital in the airship."

 

"Well, it's too late to think of that now," returned Mr. Damon.

"We had better get into communication with him as soon as we can,

and then send word to his wife and daughter. I hope he isn't

badly hurt."

 

Tom hoped so, too, with all his heart.

 

There was nothing to do but to get back in the runabout and

make all speed for the nearest telephone, and Tom Swift lost

little time in doing this. They found a drug store which was open

a little later than usual, and at once Tom went into the booth

and called up the Shopton hospital. He was well known there, as

he and his father were liberal supporters of the institution,

which was a private affair. Many of Tom's men were treated at the

dispensary, and, as accidents were of more or less frequent

occurrence at the works, the young inventor had frequent

occasions to call up the place.

 

"Mr. Nestor would ask to be taken there, as it's nearest his

home--that is, if he was able to speak," Tom said to Mr. Damon,

who agreed with him. There was a little delay in getting the

hospital on the wire, but when Tom had it, and was talking to the

superintendent, he was rather surprised, to tell the truth, to be

told that Mr. Nestor had not been brought in.

 

"We haven't had any accident cases all day, nor to-night, Mr.

Swift," the superintendent reported. "Was this some one special

you were inquiring about?"

 

For Tom, determining not to give Mr. Nestor's name, except as a

last resort, had merely inquired whether any recent accident

cases had been brought in.

 

"I'll let you know later, Mr. Millard," he told the

superintendent, not exactly answering the question. He hung up

the receiver, and, opening the door of the booth, said to Mr.

Damon: "He isn't there."

 

"Then try Waterfield," was the suggestion; and Tom did so,

though he could not imagine why an injured man, such as Mr.

Nestor might prove to be, should be taken as far as Waterfield,

when the hospital at Shopton was nearer.

 

"Unless," he told Mr. Damon, "the people which ran down Mary's

father didn't know about our hospital."

 

The reply from the institution in Mr. Damon's home town was

just as discouraging as had been the answer from Shopton. At

first, when Tom inquired, the head nurse had said there was an

accident case at that moment being brought in. Tom was all

excitement until she went to inquire the name and circumstances,

and then he learned that it was the case of a little boy who had

fallen downstairs at his home and broken a leg. There was no

record of any one answering the description of Mr. Nestor having

been brought in that evening.

 

"Hum! This is getting to be mysterious," mused Tom, as he came

out of the booth. "What shall we do--go back and tell Mrs. Nestor

and Mary, or communicate with the police?"

 

"Why not try the Alexian Hospital?" asked Mr. Damon. "That's

away over in Center-fiord, to be sure, but it's more likely to be

known to passing tourists than either of our institutions around

here, especially if the autoists were strangers."

 

"That's so," agreed Tom. The Alexian Hospital was operated

under the direction of the Brothers of that faith, and was well

known in that part of the state. Often cases of persons who had

been injured by passing automobiles had been taken there for

treatment, for, as Mr. Damon had said, it was well known, and

Centerford was the nearest large city.

 

"I can just about see how it happened," said Tom. "They ran Mr.

Nestor down, and stopped to pick him up after they heard his

cries for help. And the Alexian Hospital was the first one they

thought of. We should have called that up first."

 

But once more disappointment awaited the young inventor and his

friend. Word came back over the wire that no accident case, which

bore any resemblance to Mary's father, had been brought in.

 

"Well, I'm stumped!" exclaimed Tom. "What shall we do now, Mr.

Damon?"

 

"Much as I dislike it," said the eccentric man who was too much

worried, now, to do any "blessing," which was his favorite

expression, "I think we ought to communicate with Mrs. Nestor.

She will be very anxious."

 

"I guess we'll have to," said Tom. "But wait! I'll call up my

house first, and see if he has gone back there."

 

But Mr. Nestor had not done this, and Mrs. Baggert, who

answered the telephone, said Mary had been calling frantically

for Tom, as her mother was now on the verge of complete collapse.

 

"No help for it," said Tom, ruefully. "We've got to tell 'em we

have no news, and can't find him."

 

And, hearing this, Mrs. Nestor did collapse, and a doctor was

called in.

 

Thereupon Tom, who with Mr. Damon had gone back to the Nestor

home, took charge of matters, sending for Mrs. Nestor's sister to

come and stay with her and take charge of the house.

 

"You'll need some one to stay with you," he told Mary.

 

"Yes, I shall," she admitted, trying bravely not to give way to

her emotion. "Oh, Tom, I wish you could stay, too. I'm sure

something dreadful must have happened to poor father. Please stay

and help us find him!"

 

"I will," Tom promised. "As soon as your aunt comes I'll take

Mr. Damon home, and then I'll give the rest of my time to you."

 

And this Tom did, sending word home that he would remain at the

Nestor's all night and part of the next day.

 

Tom got but little sleep that night. He communicated with the

police and saw to it that a general alarm was sent out. He called

up all hospitals within a radius of fifty miles, but could get no

trace of any injured man whose description resembled that of Mr.

Nestor.

 

"What can have happened?" asked Mary tearfully.

 

"Well, the way I figure it out is this," said Tom. "Your father

left my house soon after Mr. Damon and I did in the Air Scout.

Mr. Nestor was riding his bicycle, and he must have been run into

by an automobile. That is how his watch was damaged and that was

when Mr. Damon and I heard the cries for help."

 

"Oh, do you think he was badly hurt?" asked Mary.

 

"No, I don't," and Tom answered truthfully. "The voice sounded

as though he was in pain, certainly, but it was strong and

vigorous, and not at all as though he was dangerously hurt."

 

"And what do you think happened to him after he was hurt?"

asked Mary.

 

"The autoists took him away," decided Tom. "In fact, we heard

the machine go, but of course we never connected the call for

help and what followed with your father. The autoists took him

away."

 

"Where?"

 

"I should say to some hospital. Perhaps a private one of which

we know nothing, and which may be near here. I'll get a full list

from the Board of Health to-morrow. Or it may be that the

autoists, seeing the damage they had done, took your father to

the home of one of themselves, and summoned a doctor there."

 

"Why would they do that?"

 

"Well, they may have been so frightened they didn't realize

what they were doing, or they may have thought he would get

better treatment in a private house, if he were not badly

injured, than if he should be taken to a hospital. It may have

been that one of the persons in the auto was a physician, and

wished to try his own skill on the man he had hurt."

 

"You make me feel more comfortable, Tom," said Mary. "But, even

supposing all this, why couldn't they telephone to us that my

father was all right? He always carries an identification card

with him, and if he were unconscious it could be ascertained who

he was."

 

"That's what I can't understand," said Tom frankly. "It puzzles

me. But we'll find him--never fear!"

 

And so he kept on with his telephone inquiries, while a

physician and her sister ministered to Mrs. Nestor. The night was

very, very long, and no good news came in.

 

 

 

CHAPTER XVII

SILENT SAM

 

 

Slowly the dawn broke through the mists of darkness, and made

the earth light. The sun came straggling in through cracks in the

shutters in the home of Mr. Nestor, the gradually increasing

gleam paling the electric lights, in the glare of which Tom

Swift, Mary, and her aunt sat, waiting for some word of the

missing man. But none came.

 

"What shall we do now?" asked Mary, as she looked at Tom.

 

"Oh, there's lots to do," he said, trying to make his voice

sound cheerful. "We'll be busy all day. I sent word to have one

of my touring cars ready to hurry to any part of the country the

moment we should get word from your father."

 

"And do you think we shall get word, Tom?" the girl went on

wistfully.

 

"Of course we shall!" he cried. "Word may come in at any time.

Now get ready, eat a good breakfast, and then you can go with me

as soon as we hear anything definite. Come, we'll have

breakfast!"

 

"I can't eat a thing!" protested Mary.

 

"Oh, yes you can," said her aunt, who was a cheerful sort of

person. "I'll see about getting something for you and Mr. Swift,

and see that your mother is all right."

 

She left the room to give orders to the servant about the meal,

and returned to say that Mrs. Nestor was sleeping quietly. She

had been given a sedative. Mary managed to eat a little, and she

gave Tom the address of several friends who were called up in the

vain hope that, somehow, Mr. Nestor might have gone to see them.

 

"Tom, what do you really think has happened?" asked Mary again,

as they sat facing one another in the library, during a respite

from the telephone.

 

Tom Swift repeated, to the girl his theory of what had happened

with an assumption of confidence he did not altogether feel.

 

His prediction of a speedy end to the suspense did not come

true that day, nor for many days. No news was heard of Mr.

Nestor. After the first day, when there was no information and

when no reports came of any one of his description having been

hurt in an automobile accident or having been taken to any

hospital, the police started an energetic search.

 

The authorities in all near-by cities were notified, and all

thought of keeping from the public what had happened was given

over. Tom's story, of how he and Mr. Damon had heard the cry for

help on the lonely meadow, was printed in the papers, though the

young inventor did not say that he had been out trying his new

aeroplane. That was a detail not needed in the finding of Mr.

Nestor.

 

But Mary's father was not found. The mystery regarding his

disappearance deepened, and there was no trace of him after he

had left Tom's house that eventful evening. Persons living along

the roads he might have taken in riding his bicycle were

questioned, but they had seen nothing of him, nor were they aware

of any accident. Tom's testimony and that of Mr. Damon was all

the clew there was.

 

"I don't believe he's dead!" stoutly declared the young

inventor, when this dire possibility had been hinted at. "I

believe the persons who were responsible for the accident are

afraid to reveal his whereabouts until he recovers from possible

injuries. You'll see! Mr. Nestor will come back safe!"

 

And, somehow, though her mother was skeptical, Mary believed

what Tom said.

 

The search was kept up, but without result, and Tom aided all

he could. But there was not much he could do. The police and

other authorities were at a total loss.

 

In the intervals of visiting Mary and her mother, and doing

what he could for them, Tom worked on his new motor. He knew that

he was on the right track and that all that was needed now was to

make certain refinements and adjustments in the apparatus he had

already constructed, so that it would operate more quietly.

 

"Absorbing the vibrations from the exhaust, caused by the

exploded gases in the cylinders, does the trick," Tom told his

father.

 

"But there is enormous pressure to overcome, Tom. You must be

sure your muffler will stand the strain. Otherwise she is going

to blow out a gasket some day, when you least expect it. Then the

sudden resumption of pressure outside the cylinders is going to

cause a change in the equilibrium, and you may turn turtle in the

air."

 

"I've thought of that," said Tom. "At worst it can't be any

more than looping the loop. But I'll make the muffler doubly

strong."

 

"Better provide an auxiliary chamber to take care of part of

the exhaust in case your main apparatus breaks," advised the

older inventor, and Tom said he would. He did, too, for he valued

his father's expert advice.

 

Meanwhile he was busy fitting one of his latest aeroplanes with

the new motor. The motor he and Mr. Damon had used in their

flight was one patched up from an old one. But now Tom was

working on a complete new one, made after his revised model, and

in which the silencer was an integral part, instead of being

built on.

 

While giving Mary and her mother all the assistance in his

power, Tom still found time to work on his new, pet scheme. He

had matters now where he did not fear any tampering with his

plans, for he had filed away his papers in a safe place, and was

making his new machine from memory.

 

"But if some one got in and had a look at the inside of your

silencer he could see how it is constructed, couldn't he?" asked

Ned Newton.

 

"Yes," assented Tom, "But they're not going to get in very

easily. Koku sleeps in the experiment shop now, and my machine is

there."

 

"Oh, well that explains your confidence. I feel sorry for the

burglar who makes the attempt, once Koku wakes up. Heard anything

more from those Universal people?"

 

"No, not directly. I understand they are working hard on some

new type of plane for army use, but I haven't bothered my head

about them. I'm too much occupied with my own affairs and trying

to help Mary."

 

"Very strange about Mr. Nestor, isn't it?"

 

"Worse than strange," said Tom. "If this keeps on, and he isn't

heard from, it will be tragic pretty soon."

 

"He must be held a prisoner somewhere," declared Ned.

 

"It begins to look that way," assented Tom. "Though who would

have an object in that I can't understand. He had no enemies, as

far as is known, and his business affairs were in excellent

shape. Unless, as I said, the persons who ran him down are,

through fear, keeping him hidden until he recovers, I can't

imagine what has become of him."

 

"Well, it certainly is a puzzle," said Ned. And Tom agreed with

his chum.

 

It was about a week after the disappearance of Mr. Nestor that

Mr. Damon came over to see Tom.

 

"Bless my shoe laces, Tom!" exclaimed the eccentric man, "but

you are as busy as ever." For he found the young inventor in the

experiment shop, surrounded by a mass of papers and all sorts of

mechanical devices.

 

"Yes, I'm working a little," said Tom. "But you are just in

time. Come on out, I want to introduce you to Silent Sam."

 

"'Silent Sam!'" exclaimed Mr. Damon. "Have you been taking a

new trip to the Land of Wonders? Have you brought back some new

kind of servant?"

 

"Not exactly a servant," said Tom with a laugh, "though I hope

Silent Sam will serve me well."

 

"'Silent Sam?' What does it mean? Is that a joke?" asked the

puzzled Mr. Damon.

 

"I hope it doesn't turn out a joke," replied Tom. "But come on,

I'll introduce you to him, Mr. Damon."

 

He led the way to one of the big hangars where his various

machines of the air were housed. On the way Mr. Damon asked about

news of Mr. Nestor, but was told there was none.

 

Tom Swift opened the big, swinging doors and pulled aside an

enveloping canvas curtain. There stood revealed a big aeroplane,

of somewhat new pattern, the wings gleaming like silver from the

varnish that had been applied. In shape it was not unlike the

machines already in use, except that the propellers were of

somewhat different design.

 

The engine was mounted in front, and even with his slight

knowledge of mechanics Mr. Damon could tell that it was

exceedingly powerful. But it was certain devices attached to the

engine that attracted his attention, for they were totally

different from any on any other aeroplane, though they bore some

resemblance to apparatus on the plane in which Tom and the

eccentric man had made the night flight.

 

"Is this your new machine, Tom?" asked Mr. Damon.

 

"Yes."

 

"Well, I don't see anything of that fellow you spoke of--Silent

Sam."

 

"This is Silent Sam," returned Tom, with a laugh. "I've named

my new noiseless aeroplane -Ämy Air Scout--I've named that Silent

Sam. Wait until you hear it, or rather, don't hear it, and I

think you'll agree with me. Silent Sam for Uncle Sam!"

 

"Good!" cried Mr. Damon. "Bless my dictionary, but that's a

good name! Does it sail silently, Tom?"

 

"I'll let you judge presently. Silent Sam is all ready for his

first trial, and I'll be glad to have you with me. Now, I'll

just--"

 

Tom suddenly ceased speaking and held up a hand to enjoin

silence. Then, while Mr. Damon watched, the young inventor began

moving noiselessly toward the rear of the big shed, inside which

was his new machine.

 

 

 

CHAPTER XVIII

SUSPICIONS

 

 

"Who's there?" suddenly called Tom, and in such a sharp voice

that Mr. Damon started, ready as he was for something unusual.

 

There was no answer and Tom suddenly switched on all the lights

in the shed. Up to then there had been only a few glowing--just

enough for him to show the new Air Scout to his friend.

 

"Who's there?" asked Tom again, sharply.

 

"Bless my opera glasses, Tom!" cried Mr. Damon, "but are you

seeing things?"

 

"No; but I'm hearing them," answered Tom with a short laugh.

"Did you think you heard some one moving around near the rudders

of Silent Sam, Mr. Damon?"

 

"No, I can't say that I did. Everything seems to me to be all

right."

 

"Well, it doesn't to me," went on Tom grimly. "I think there

is an intruder in this shed, though how any one could get in when

the doors have been locked all day, is more than I can figure

out. But I'm going to have a look."

 

"I'll help you," offered Mr. Damon, and, in the bright glare

from many electric lights, the two began a search of the big

hangar where the new craft was kept.

 

But though the young inventor and his friend went around to the

rear of the aeroplane, walking in opposite directions, they saw

no one, nor did any one try to escape past them.

 

"And yet I was sure I heard some one in here," declared Tom,

when a search had revealed nothing. "It sounded as if some one

were scuffling softly about in rubber-soled shoes, trying to

hide."

 

"Bless my suspenders!" cried Mr. Damon, "who do you think it

could have been, Tom?"

 

"Who else but some spy trying to get possession of my secrets?"

was the answer. "But I guess I was too quick for them. They

couldn't learn much from looking at the outside of my muffler,

and it hasn't been disturbed, as far as I can see."

 

"Who would want to gain a knowledge of it in that unlawful

way?" asked Mr. Damon.

 

"Perhaps some of the Universal crowd. They may have been

disappointed in perfecting a silent motor themselves, and think

stealing my idea would be the easiest way out of it."

 

"Do they know you are working on such a model as this Silent

Sam of yours, Tom?"

 

"Yes, I imagine they do. One of the firm members, as you

recall, overheard something, I think, that gave them a hint as to

what my plans were, though, thanks to the time I fooled the spy,

they haven't any real data to go by, I believe."

 

"Let us hope not," said Mr. Damon.

 

Tom and he made a thorough search of the big shed, but found no

one, nor was there any trace of an intruder. Tom notified

Jackson, who, in turn, told the guards and watchmen to be on the

lookout for any suspicious strangers, but none was seen in the

vicinity of the Swift works.

 

"Well, everything seems to be all right, so we'll have the

test," remarked Torn, after a further search of the premises.

"Now, Mr. Damon, if all goes as I hope you will see what my new

machine can do. Strain your ears for a sound, and let me know how

much you hear."

 

His men helping him, Tom started the new motor which was tried

for the first time attached to the new craft. No flight was to be

made yet, the motor being tested as though on the block, though,

in reality, the craft was ready for instant flight if need be.

 

Slowly the great propellers began to revolve, and then Tom,

taking his place in the cockpit, turned on more power. The new

craft--Silent Sam--was made fast so it could not progress even

though the propellers revolved at high speed.

 

"I'm not sending her to the limit," said Tom to his friend, as

the young inventor throttled down the motor. "If I did I'd tear

her loose from the holding blocks."

 

"Her!" cried Mr. Damon. "Bless my typewriter, Tom! but I

thought Silent Sam was a gentleman aeroplane.

 

"So he is!" laughed the young man, frankly. "I forgot about

'Silent Sam.' Guess I'll have to say 'him' instead of 'her,'

though the latter sounds more natural. Anyhow what do you think?"

 

"I think it's wonderful!" exclaimed Mr. Damon. "There the motor

is, going at almost full speed, and I can hardly hear a thing.

You can the easier believe that when I say that I can hear you

talk perfectly well. And I guess you hear me, don't you?"

 

"Yes," replied Tom. "And we don't have to shout, either. This

is the best test ever! I think everything is a success."

 

"Are you going to take her aloft, Tom?" the eccentric man went

on.

 

"Yes, now that I'm sure the engine is all right. Will you go

for a flight with me?"

 

"I certainly will! I only wish we could find him, though. I'd

go with a better heart."

 

"Oh! Mr. Nestor?"

 

"Yes, I can't imagine what has become of him. It is almost as

if the earth had opened and swallowed him. His disappearance is a

great mystery."

 

"It surely is," agreed Tom. "Can't seem to get any trace of

him. But if we hear another cry for help, when we have to land,

you can make up your mind I'll investigate more quickly than I

did at first."

 

"I agree with you," said Mr. Damon.

 

It was nearly evening then, and until it was dark enough for

his flight Tom spent the time tuning up the engine and seeing

that all was in readiness for the latest test. He had decided not

to go aloft while it was light enough for curiosity seekers to

note the flight.

 

Tom rather wished Mary Nestor might have a sail with him in his

latest improved silent Air Scout, but the girl was too much

occupied at home and in trying to find some trace of her father.

 

Tom, his father, and Mr. Damon had helped all they could, but

there were no results. A private detective had been engaged, but

he had no more of a clew than the regular police.

 

At last it was dark enough for the flight, and Tom and Mr.

Damon took their places in the machine. Once more the propellers

were turned around, and when the compression had been made, and

the spark switched on, around spun the big wooden blades, and the

great craft moved over the grass.

 

On and on and up and up sailed Tom and Mr. Damon, and as they

left behind them the shops and the Swift homestead, the two

passengers were aware of their almost silent flight. The big

aeroplane, the exhaust of which, ordinarily, would have nearly

deafened them, was now as silent as a bird.

 

"Silent Sam for Uncle Sam!" cried Tom in delight, as he went on

faster. "I'm sure the government ought to be glad to get this

plane for air scout work. It's a success! A great success!"

 

"Yes, so it is!" agreed Mr. Damon. "You do well to speak of it

so, Tom."

 

For, modest as the young inventor was, he felt, in justice to

himself, that he must acknowledge the fact that his craft was a

success. For it rose and sailed almost as silently as a bat, and

a few hundred feet away no one, not seeing it, would have

believed a big aeroplane was in motion.

 

Tom and Mr. Damon flew about twenty miles at a swift pace, and

all the fault Tom had to find was that the machine was not as

steady in flight as she should have been.

 

"But I can remedy that with the use of some of dad's gyroscope

stabilizers," he told Mr. Damon.

 

They returned to the hangar safely, and the first trip of the

new Silent Sam was an assured success.

 

It was the following day, when Tom was busy in the machine shop

installing the gyroscopes spoken of, that Jackson came to tell

him there was a visitor to see him.

 

"Who is it?" asked the young inventor.

 

"Mr. Gale of the Universal Company," was the answer.

 

"I don't want to see him!" declared Tom quickly. "I have

nothing to say to him after his clumsy threats."

 

"He seems very much in earnest," said Jackson. "Better see him,

if only for a minute or so."

 

"All right, I will," assented Tom. "Show him in."

 

Mr. Gale, as blusteringly bluff as ever, entered the shop. Tom

had carefully put away all papers and models, as well as the

finished machines, so he had no fear that his visitor might

discover some secret.

 

"Oh, Mr. Swift!" began the president of the Universal Company,

when he met the young inventor, "I wish to assure you that what

has been done was entirely without our knowledge. And, though

this man may have acted as our agent at one time, we repudiate

any acts of his that might

 

"What are you talking about?" asked Tom in surprise. "Have I

been so impolite as to sleep during part of your talk? I don't

understand what you are driving at."

 

"Oh, I thought you did," said Gale, and he showed surprise. "I

understood that the man who--"

 

"Do you mean there was some one here in the shed last night?"

cried the young inventor suddenly, all his suspicions aroused.

 

"Some one here last night?" repeated Mr. Gale. "No, I don't

refer to last night. But perhaps I am making a mistake.

I--er--I--"

 

"Some one is making a mistake!" said Tom significantly.

 

 

 

CHAPTER XIX

ANOTHER FLIGHT

 

 

For perhaps a quarter of a minute Tom Swift and the president

of the Universal Flying Machine Company of New York sat staring

at one another. Mr. Gale's face wore a puzzled expression, and so

did Tom's. And, after the last remark of the young inventor, the

man who had called to see him said:

 

"Well, perhaps we are talking at cross purposes. I don't blame

you for not feeling very friendly toward us, and if I had had my

way that last correspondence with you would never have left our

office."

 

"It wasn't very business-like," said Tom dryly, referring to

the veiled threats when he had refused to sell his services to

the rival company.

 

"I realize that," said Mr. Gale. "But we have some peculiar men

working for us, and sometimes there is so much to do, so many

possibilities of which to take advantage, that we may get a

little off our balance. But what I called for was not to renew

our offer to you. I understand that is definitely settled."

 

"As far as I am concerned, it is," said Tom, as his caller

seemed to want an answer.

 

"Yes. Well, then, what I called to say was that if you are

thinking of taking any legal action against us because of the

action of that man Lydane, I wish to state that he had absolutely

no authority to--"

 

"Excuse me!" broke in Tom, "but by Lydane do you mean the man

who also posed as Bower, the spy?"

 

"No, I do not. Though I regret to say that Bower once worked

for us. He, too, had no authority to come here and get a

position. He was still in our service when he did that."

 

"So I have suspected," said Tom. "I realize now that he was a

spy, who came here to try to find out for you some of my

secrets."

 

"Not with my permission!" exclaimed Mr. Gale. "I was against

that from the first and I came to tell you so. But Bower really

did you no harm."

 

"No, he didn't get the chance!" chuckled Tom. "Nor did that

other spy--the one with the gold tooth. I wonder how he liked our

mud hole?"

 

"He was Lydane," said Mr. Gale. "It is about him I came."

 

"You might have saved yourself the trouble," returned Tom. "I

don't wish to discuss him."

 

"But I wish to make sure," said Mr. Gale, that what he has done

will not come back on us. We repudiate him entirely. His methods

we can not countenance. He is too daring--"

 

"Oh, don't worry!" interrupted Tom. "He hasn't done anything to

me--he didn't get the chance, as I guess he's told you. You

needn't apologize on his account. He did me no harm, and--"

 

"But I understood from him that--"

 

"Now I don't want to seem impolite!" broke in Tom, "nor do I

want to take pattern after some of your company's acts, if not

your own. But I am very busy. I have an important test to make

for the government, and my time is fully occupied. I am afraid I

shall have to bid you good-morning and--"

 

"But won't you give me a chance to--" began the president.

 

"Now, the less we discuss this matter the better!" interrupted

Tom. "Lydane, as you call the man with the gold tooth didn't

really do anything to me nor any great harm to any of my

possessions, as far as I can learn. His career is a closed book--

a book with muddy covers!" and the young inventor laughed.

 

"Oh, well, if you look at it that way, there is nothing further

for me to say" said Mr. Gale stiffly. "I understood-- But hasn't

my partner, Mr. Ware, seen you?" he asked Tom quickly.

 

"No. And I don't care to see him."

 

"Oh, then that accounts for it," was the quick answer. "Well,

if you regard the matter as closed I suppose we should also. We

are not to blame for what Lydane does when he is no longer in our

employ, and we repudiate anything he may do, or may have done."

 

This struck Tom, afterward, as being rather a queer remark, but

he did not think so at the time.

 

The truth was that the young inventor wished very much to try

out a new device on his noiseless aeroplane and wanted to get rid

of Mr. Gale before doing so. So he did not pay as much attention

to the remarks of the president as, otherwise, he might have

done.

 

It was not until after Mr. Gale had taken his leave and Tom had

finished the particular work on which he was engaged when the

president of the rival company came in, that the young man did

some hard thinking. And this thinking was done after he had

received a telephone call from Mary Nestor, asking, if by any

chance, he had beard anything like a clew as to the whereabouts

of her father.

 

Tom had been obliged to tell her that he had not. Everything

possible was being done to find the missing man but he had

disappeared as completely as though he had ridden on his bicycle

into the crater of some extinct volcano on the meadow, and had

fallen to the bottom.

 

An effort was made to trace him through an automobile

association which had a large membership. That is, the members

were asked to make inquiries to ascertain, if possible, whether

any one had heard of an unreported accident--one in which Mr.

Nestor might have been carried away by persons who accidently ran

him down.

 

But this came to naught, and the police and other authorities

were at a loss how farther to proceed. It was a theory in some

quarters that Mr. Nestor was perfectly safe, but that he was out

of his mind, and was either wandering around, not knowing who he

was, or was, in this condition, detained somewhere, the persons

having him in charge not realizing that he was the missing man so

widely sought.

 

This belief was a relief to Mrs. Nestor and Mary in many ways

for it prevented them from giving way to the fear that Mr. Nestor

was dead. That he was alive was Tom Swift's firm opinion, and he

was doing all he could to prove it.

 

It was not until the day after the visit of Mr. Gale that Tom,

having concluded some intricate calculations about the strength

of cylinder valves, uttered an exclamation.

 

"I wonder if he could have meant that?" cried the young

inventor. "I wonder if he could have meant that? I must find out

at once! Queer I didn't think of that before!"

 

He put in a long distance call to New York, asking to speak to

Mr. Gale. But when, eventually, he was connected with the office

of the Universal Flying Machine Company he was told that Mr. Gale

and Mr. Ware had sailed for France that day, going over as

government representatives to investigate aeroplane motors.

Gale's visit to Tom had been just previous to taking the boat, it

was said.

 

"This is tough luck!" mused Tom, his suspicions doubly aroused

now. "I can't let this rest here! I've got to get after it! As

soon as I make this final test, and invite Uncle Sam's experts

out to see how my noiseless motor works, I'll get after Gale and

Ware if I have to follow them to the battlefields of France! I

wonder if it was that he was hinting at all the while! I begin to

believe it was!"

 

Tom Swift had decided on another flight for his new craft

before he would let the government experts see it.

 

"Silent Sam must do his very best work for Uncle Sam before I

turn him over," said the young inventor.

 

"And after this flight I'll offer the machine to the

government, and then devote all my time to finding Mr. Nestor,"

said Tom. "I'd do it now, but private matters, however deeply

they affect us, must be put aside to help win the war. But this

will end my inventive work until after Mr. Nestor is found--if

he's alive."

 

Preparations for the test flight went on apace, and one

afternoon Tom and Jackson took their places in the big, new

aeroplane. He no longer feared daylight crowds in case of an

accident. They made a good start, and the motor was so quiet that

as Tom passed over his own plant the men working in the yard, who

did not know of the flight, did not look up to see what was going

on. They could not hear the engine.

 

"I think we've got everything just as we want it, Jackson,"

said Tom, much pleased.

 

"I believe you," answered the mechanician. "It couldn't be

better. Now if--"

 

And at that moment there came a loud explosion, and Silent Sam

began drifting rapidly toward the earth, as falls a bird with a

broken wing.

 

 

 

CHAPTER XX

QUEER MARKS

 

 

"What happened?" cried Jackson to Tom, as he leaned forward in

his seat which was in the rear of the young inventor's.

 

"Don't know, exactly," was the answer, as Tom quickly shifted

the rudders to correct the slanting fall of his craft. "Sounded

as though there was a tremendous back-fire, or else the muffler

blew up. The engine is dead."

 

"Can you take her down safely?"

 

"Oh, yes, I guess so. She's a bit out of control, but the

stabilizer will keep her on a level keel. Good thing we installed

it."

 

"You're right!" said Jackson.

 

Now they were falling earthward with great rapidity, but,

thanks to the gyroscope stabilizer, the "side-slipping," than

which there is no motion more dreaded by an aviator, had nearly

ceased. The craft was volplaning down as it ought, and Tom had it

under as perfect control as was possible under the

circumstances.

 

"We'll get down all right if something else doesn't happen," he

said to Jackson, with grim humor.

 

"Well, let's hope that it won't," said the mechanic. "We're a

good distance up yet."

 

They were, as a matter of fact, for the explosion, or whatever

had happened to the craft, had occurred at a height of over two

miles, and they at once began falling. As yet Tom Swift was

unaware of the exact nature of the accident or its cause. All he

knew was that there had been a big noise and that the engine had

stopped working. He could not see the silencer from where he sat,

as it was constructed on the underside of the motor, but he had

an idea that the same sort of mishap had occurred as on the

occasion when the test machine had sailed through the roof of his

workshop.

 

"But, luckily, this wasn't as bad," mused Tom. "Anyhow the

motor is out of business."

 

And this was very evident. The young inventor had tried to

start the apparatus after its stoppage by the explosion, but it

had not responded to his efforts, and then he had desisted,

fearing to cause some further damage, or, perhaps, endanger his

own life and that of Jackson.

 

Down, down swept Silent Sam--doubly silent now, and Tom began

looking about for a good place to make a landing. This was

nothing new for either him or his mechanician, and they accepted

the outcome as a matter of course.

 

"Not a very lively place down there," remarked Jackson, as he

looked over the side of the cockpit.

 

"If we have to depend for help on any one down there, I guess

we'll be a long time waiting," agreed Tom. They were about to

land in a very lonely spot. It was one he had never before

visited, though he knew it could not be much more than twenty

miles from his own home, as they had not flown much farther than

that distance.

 

But, somehow or other, Tom had not visited this particular

section, and knew nothing of it. He saw below him, as Jackson had

seen, a lonely stretch of country--a big field, once a wood-lot,

evidently, as scattered about were some stumps and some second

growth trees. There were also a number of evergreens--Christmas

trees Jackson called them. And this was the only open place for

miles, the surrounding country being a densely wooded one. There

did not appear to be a house or other building in sight where

they might seek help.

 

"But maybe we can make the repairs ourselves and keep on," the

lad thought.

 

With practiced eye he picked out a smooth, grassy, level spot,

in the midst of scattered evergreen trees, and there Tom Swift

skillfully brought his Air Scout to rest. With a gentle thud the

rubber-tired wheels struck the Earth, rolled along a little

distance, and then called to a stop.

 

Hardly had the aeroplane ceased moving when Tom and his

companion jumped out and began eagerly to examine the machinery

to see the extent of damage.

 

"I thought so!" Tom exclaimed. "The silencer cracked under the

strain. Those exhaust gases have more pressure that I believed

possible. I increased the margin of safety on this muffler, too.

But she's cracked, and I can't use the machine until I put on a

new one. Good thing I didn't ask for a government inspection

until after this trial flight."

 

"That's so," agreed Jackson. "But can't you patch it up, or go

on without a muffler, so we can get back home?"

 

"I'm afraid not," Tom answered. "You see I removed all the old

exhaust pipe fittings when I put on my new silencer. Now if I

took off my attachment there wouldn't be anything to carry off

the discharged gases, and they'd form a regular cloud about us.

We couldn't stand it without gas masks, such as they use in the

trenches, and we haven't any of those with us."

 

"That's right," agreed Jackson. "Well, what do you want to do?

Have me stay here and guard the machine while you go for help? Or

shall I go?"

 

"I don't know why we both can't go," said Tom. "There is no use

trying to patch up this machine here. I'll have to send a truck

after it, and dismantle it before I can get it home.

 

"As for either of us staying here on guard, I don't quite see

the need of that. This looks like the jumping-off place to me. I

don't believe there's a native within miles. I didn't see any

houses as we came down, and I think Silent Sam will be perfectly

safe here. No one can run off with him, anyhow. He'd be as hard

to start as an automobile with all four wheels gone. Let's leave

it here and both walk back."

 

"All right," agreed Jackson. "That suits me. Might as well

leave our togs here, too. It will be easier walking without

them," and he began taking off the fur-lined suit, his cap, and

his goggles, such as he and Tom wore against the piercing cold of

the upper regions.

 

"We can stuff them in the cockpit and leave them," went on the

mechanician, as he divested himself of his garments. As he stowed

them away in his seat he gave one more look at the broken

muffler. As Tom Swift said, his new silencer had literally blown

up, a large piece having been torn from the gas chamber.

 

Something that Jackson saw caused him to utter an exclamation

that brought Tom Swift to his side.

 

"What is it?" asked the young inventor.

 

"Look!" was the answer. "See! Just at the edge of that break!

It's been filed to make the metal thinner there than anywhere

else. You didn't do that, did you?"

 

"I should say not!" cried Tom. "Why, to file there would mean

to weaken the whole structure."

 

"And that's exactly what's happened!" declared Jackson, as he

gave another look. "Some one has filed this nearly

throughÄleaving only a thin metal skin, and when the gas pressure

became too much it blew out. That's what happened!"

 

Tom Swift made a quick but thorough examination.

 

"You're right, Jackson!" he exclaimed. "That was filed

deliberately to cause the accident. And it must have been done

lately, for I carefully inspected the silencer when I put it on,

and it was in perfect order. There's been spy work here. Some one

got into the hangar and filed that casing. Then the accumulated

pressure of the gases did the rest."

 

"As sure as you're alive!" agreed Jackson. "Maybe that's what

Gale did when he called."

 

"No," returned Tom, shaking his head, "he didn't get a chance to

do anything like that. I watched him all the while. But perhaps

this is what he referred to when he said he and his company would

repudiate any act of that spy with the gold tooth--Lydane, so

Gale said his name was. Maybe that's what Lydane did."

 

"He was capable of it," agreed the mechanic, "but he couldn't

have done it that time you tripped him into the mud puddle. This

silencer wasn't built then."

 

"No, you're right," assented Tom. "Then he must have been

around since, doing some of his tricky work!"

 

"I don't see how that could have been," said Jackson slowly.

"We've kept a very careful watch, and your shop has been

specially guarded."

 

"I know it has," said Tom. "There couldn't much get past Koku;

but some one seems to have done it, or else how could that filing

have been done?"

 

Jackson shook his head. The problem was too much for him. He

looked carefully at the exploded and broken silencer, and Tom,

too, gave it a critical eye. There was no doubt but that it had

been filed in several places to weaken the structure of the

metal.

 

"When did you last see that it was in perfect condition?" asked

Jackson.

 

Tom named a certain date.

 

"That was just before Gale called," observed the mechanician.

"He might have known of it."

 

"I wish I'd known of it at the time," said Tom savagely. "He

wouldn't have gotten away as easily as he did. Well, there's no

use standing here talking about it. Let's get back to

civilization and we'll send back one of the trucks. Luckily I

have another silencer I can put on for the government test. This

one will never be of any more use, though I may be able to save

some of the valves and baffle plates."

 

Slowly they turned from the disabled aeroplane and started to

look for a path that would lead them out of the lonely place. Tom

as the first to strike what seemed to be a cow path, or perhaps

what had been a road into the wood lot in the early days.

 

As he tramped along it, followed by Jackson, the young inventor

suddenly stopped, as he came to a sandy place, and, stooping

over, looked intently at some queer marks in the soil.

 

"What is it?" asked the mechanician.

 

"Looks like the marks of an automobile," said Tom slowly. "And

I was just trying to remember where I'd seen marks like these

before."

 

 

 

CHAPTER XXI

THE DESERTED CABIN

 

 

For several seconds the young inventor remained bending over

the queer marks in that little sandy path of the lonely field in

the midst of the silent woods. Jackson watched him curiously,

and then Tom straightened up, exclaiming as he did so:

 

"I have it! Now I know where it was! I saw marks like these the

night Mr. Nestor disappeared. Mr. Damon and I noticed the marks

in the dust on the road the time we made the forced landing the

first night we tried out the silent motor. That's it! They are

the same marks! I'm sure of it!"

 

"I wouldn't go so far as to say that," said Jackson slowly. He

was more deliberate than Tom Swift, a fact for which the young

inventor was often glad, as it saved him from impulsive mistakes.

 

"This may not be the same auto," went on the mechanician. "I'll

admit I never saw square tire marks like those before. Most of

the usual ones are circular, diamond-shape or oblong. Some tire

manufacturer must have tried a new stunt. But as for saying these

marks were made by the same machine you saw evidences of the

night Mr. Nestor disappeared, why, that's going a little too far,

Tom."

 

"Yes, I suppose it is," admitted the young inventor. "But it's

a clew worth following. Maybe Mr. Nestor has been brought to some

lonely place like this, and is being held."

 

"Why would any one want to do that?" asked Jackson. "He had no

enemies.

 

"Well, perhaps those who ran him down and injured him are

afraid to let him go for fear he will prosecute them and ask for

heavy damages," suggested Tom. "They may be holding him a captive

until he gets well, and aim on treating him so nicely that he

won't bring suit."

 

"That's a pretty far-fetched theory," said the mechanician as

he carefully looked at the tracks. "But of course it may be true.

Anyhow, these tire marks are rather recent, I should say, and

they are made by a new tire. Do you think we can follow them?"

 

"I'm going to try !" declared Tom. "The only trouble is we

can't tell whether it was going or coming--that is we don't know

which way to go."

 

"That's so," agreed his companion. "And so the only thing to do

is to travel a bit both ways. The path, or road, or whatever you

call it, is plainly enough marked here, though you can't always

pick out the tire marks. They show only on bare ground. The grass

doesn't leave any tracks that we can see, though doubtless they

are there.

 

"But as for thinking this car is the same one the marks of

which you saw on the lonely moor, the night you heard the call

for help--that's going too far, Tom Swift."

 

"Yes, I realize that. Of course there must be more than one car

with tires which have square protuberances. But it's worth taking

a chance on--following this clew."

 

"Oh, sure!" agreed Jackson.

 

"The only question is, then, which way to go," returned Tom.

 

They settled that, arbitrarily enough, by going on in the

direction they had started after leaving the stranded airship.

They followed a half-defined path, and were rewarded by getting

occasional glimpses on bare ground of the odd tire marks.

 

Through a devious winding way, now hidden amid a lane of trees,

and again cutting across an open space, the path led. They saw

the marks often enough to make sure they were on the right trail,

and in one place they saw several different patches of the odd

marks.

 

They went on perhaps half a mile more. when they came to a

lonely road and saw where the car had turned from that into the

wood-lot, as Tom called the place where his craft had settled

down.

 

"Look!" cried the young inventor to Jackson. "They've been here

more than once, and have gone along the road in both directions.

They seem to have used this turning into the lot as a sort of

stopping place."

 

This was plain enough from an examination of the marks in the

sandy soil of the road, which was one not often used. The

automobile with the queer, square marks on the tires had turned

into the lot, coming and going in both directions.

 

"This settles it!" cried Tom, when he finished making an

examination. "There's something farther back in this lot that

we've got to see. This auto has been coming and going, and we

should have followed the tracks the other way from the point

where we first saw them, instead of coming this way."

 

"Except that we've learned the place of departure," suggested

Jackson. "Evidently the wood-lot is a blind alley. The car goes

in, but it can come out only just at this point, or, at least, it

does."

 

"That's right!" agreed Tom. "Now the thing to do is to follow

our track back to where we started. There must be some place

where the car went to--some headquarters, or meeting place with

some one, farther back in the lot. If we can only follow the

trail back as well as we did coming, we may find out something."

 

"Well, let's try, anyhow," suggested Jackson.

 

They had no difficulty in making their way back to the spot

where they had first seen the queer marks. But from then on their

task was not so easy. For sandy or bare patches of earth were not

frequent, and they had to depend on these to give them direction,

for the road was overgrown and not well defined.

 

Often they would search about for some time after leaving one

patch of the marks before they found another that would justify

them in keeping on.

 

"They have headquarters, or a rendezvous, somewhere back in

this lot!" declared Tom, as they hurried on. "I think we're on

the track of a mystery."

 

"Unless it turns out that some farmer has treated himself to an

auto with new tires of square tread, and is hauling wood," said

Jackson. "It may turn out that way."

 

"Yes, it may," agreed Tom. "But, taking everything into

consideration, I think we're on the verge of finding out

something. Even if we do discover that the owner of this auto is

only hauling wood, he may be able to help us to a clew as to the

whereabouts of Mr. Nestor."

 

"How?"

 

"Well, maybe he was in his machine on the moor the night the

call for help came. He may even have aided to carry Mr. Nestor

away. And if he doesn't know a thing about it--which, of course,

is possible--the man who bought these queer tires can tell us who

makes them, or who deals in them, and we can find out what

autoists around here have their cars equipped with this odd

tread."

 

"Yes," agreed Jackson, "that can be done."

 

And so they kept on, scouting here and there to either side of

the half-defined path, until they were far back from the spot

where they had left the Air Scout.

 

"We don't appear to be getting any warmer, as the children

say," remarked Jackson, as he straightened up and looked about,

for his back ached from so much stooping over to look for the odd

marks.

 

"We haven't seen anything yet, I'll admit," said Tom. "But it

won't be dark for another hour or so, and I vote that we keep

on."

 

"Oh, I wasn't thinking of giving up!" exclaimed Jackson. "If

there's anything here--at the end of the route, as you might say

--we'll find it. Only I hope it doesn't turn out to be just a

wood pile, from which some farmer has been hauling logs."

 

"That would be a disappointment," assented Tom.

 

The day was waning, and they realized that they ought not to

spend too much time on what might turn out to be a wild goose

chase. They were in a lonely neighborhood, and while they were

not at all apprehensive of danger, they felt it would be best to

get to shelter before dark.

 

"We'll want to send word to Mr. Swift that we're all right."

 

"Yes," said Tom, "I'd like to get to a place where I can

telephone to him or Mrs. Baggert. Well, if we don't find

something pretty soon we'll have to turn back. I must complete

work on the new motor, for if I'm to offer it to Uncle Sam for

air scout purposes, the sooner I can do so the better. Things are

getting pretty hot over in Europe, and if ever the United States

needed aircraft on the western front they need them now. I want

to help all I can, and I also want to help Mary--you understand--

Miss Nestor."

 

"I understand," said Jackson simply. "I only hope you can help

her. But I'm afraid--this may turn out to be nothing--following

these marks, you know."

 

"And yet," said Tom slowly, "it would be strange if it was only

a coincidence--the two tire marks being the same--the night Mr.

Nestor disappeared and now."

 

And so they kept on, hoping.

 

The half-defined path through the wood-lot led them in a series

of turns and twists, and it extended through a dense patch of

woods, growing thickly, where it was so dark that it seemed as if

night had fallen.

 

"We can't spend much more time here," said Tom. "If we don't

find something in the next half mile we'll go back and take up

the search to-morrow. I'm going to find out what's at the end of

this road--even if it's only a wood pile."

 

For ten minutes more the two went on, making sure, by

occasional glimpses at the marks, that they were on the right

track. Then, suddenly, they saw something which made them feel

sure they had reached their goal.

 

In a clearing among the trees was a little cabin --a shack of

logs--and from the appearance it was deserted. There was not a

sign of life around

 

 

 

CHAPTER XXII

CLEWS AT LAST

 

 

For a moment, at sight of the deserted cabin, staring at Tom

and his friend, as it were, from its hiding place amid the trees,

the young inventor and his companion did not move. They just

stood looking at the place.

 

"Well," said Tom,. at length, "we found it, didn't we

 

"We found something anyhow," agreed Jackson. "Whether it

amounts to anything or not, we've got to see."

 

"Come on!" cried Tom, impulsively. "I'm going to see what's

there."

 

"There doesn't appear to be much of anything," said Jackson, as

he looked toward the lonely cabin with critical eyes. "I should

say that place hadn't been used, even as a chicken coop, in a

long while."

 

"We can soon tell!" exclaimed Tom, striding forward.

 

"Wait just a minute!" cried his companion, catching him by the

coat. "Don't be in such a hurry."

 

"Why not?" asked Tom. "There isn't any danger, is there?"

 

"I don't know about that. There's no telling who may be hidden

in that cabin, in spite of its deserted appearance. And though

there aren't any 'No Trespass' signs up, it may be that we

wouldn't be welcome. If there are some tramps there, which is

possible, they might take a notion to shoot at us first and ask

questions as to our peaceable intentions afterward--when it would

be too late."

 

"Nonsense!" exclaimed Tom. "There aren't any tramps there and,

if there were, they wouldn't dare shoot. I'm going to see what

the mystery is--if there is one."

 

But there was no sign of life, and, taking this as an

indication that their advance would not be disputed, Jackson

followed Tom. The latter advanced until he could take in all the

details of the shack. It was made of logs, and once had been

chinked with mud or clay. Some of this had fallen out, leaving

spaces between the tree trunks.

 

"It wasn't a bad little shack at one time," decided Tom. "Maybe

it was a place where some one camped out during the summer. But

it hasn't been used of late. I never knew there was such a place

around here, and I thought I knew this locality pretty well."

 

"I never heard of it, either," said Jackson. "Let's give a

shout and see if there's any one around. They may be asleep.

Hello, there !" he called in sufficiently vigorous tones to have

awakened an ordinary sleeper.

 

Put there was no answer, and as the shadows of the night began

to fall, the place took on a most lonely aspect.

 

"Let's go up and knock--or go in if the door's open," suggested

Tom. "We can't lose any more time, if we're to get out of here

before night."

 

"Go ahead," said Jackson, and together they went to the cabin

door.

 

"Locked!" exclaimed Tom, as he saw a padlock attached to a

chain. It appeared to be fastened through two staples, driven one

into the door and the other into the jamb, at right angles to one

another and overlapping.

 

"Knock!" suggested Jackson. But when Tom had done so, and there

was no answer, the machinist took hold of the lock. To his own

surprise and that of Tom, one of the staples pulled out and the

door swung open. The place had evidently been forced before, and

the lock had not been opened by a key. The staple had been pulled

out and replaced loosely in the holes.

 

For a moment nothing could be made out in the dark interior of

the shack. But as their eyes became used to the gloom, Tom and

his companion were able to see that the shack consisted of two

rooms.

 

In the first one there was a rusty stove, a table, and some

chairs, and it was evident, from pans and skillets hanging on the

wall, as well as from a small cupboard built on one side, that

this was the kitchen and living room combined.

 

"Anybody here?" cried Tom, as he stepped inside.

 

Only a dull echo answered.

 

The two could now see where a door gave entrance to an inner

room, and this, a quick glance showed, was the sleeping

apartment, two bunks being built on the side walls.

 

"Well, somebody had it pretty comfortable here," decided Tom,

as he looked around. "They've been cooking and sleeping here, and

not so very long ago, either. It wouldn't be such a bad place if

it was cleaned out."

 

"That's right," agreed Jackson. "Wouldn't mind camping here

myself, if there was any fishing near."

 

"The river can't be far away," suggested Tom. "And now let's

see what we can find, and see if we can get a line on who has

been here. But first we'll let in a little light."

 

He opened a window in the sleeping room, and pushed back the

heavy plank shutter that had been closed. When the light entered

it was seen that both bunks bore evidence of having been lately

slept in. The blankets were tossed back, as if the occupants had

risen, and in the outer room, on the stove, were signs that

indicated a meal had been served not many days gone by.

 

"Now," observed Tom musingly, as he wandered about the place,

"if we could only find out who owns this, and who has been here

lately--"

 

Jackson stooped over, and, thrusting aside an end of the

blankets that trailed on the floor from one of the bunks, picked

up something.

 

"What is it?" asked Tom.

 

"Looks like a leather pocketbook," was the answer. "That's what

it is," the mechanic went on, as he held the object to the light.

"It's a wallet."

 

"Let me see it!" exclaimed Tom quickly. He took the wallet from

the hands of Jackson. Then the young inventor uttered a cry. "A

clew at last!" he exclaimed. "A clew at last! Mr. Nestor has been

in this cabin!"

 

"How do you know?" asked Jackson quickly.

 

"This is his wallet," said Tom excitedly. "I've often seen him

have it. In fact he had it with him on Earthquake Island, the

time I sent the wireless message for help. I saw it several times

then. He kept in it what few papers he had saved from the wreck.

And I've seen it often enough since. That's Mr. Nestor's wallet

all right. Besides, if you want any other evidence--look!" He

opened the leather flaps and showed Jackson on one, stamped in

gold letters, the name of Mary's father.

 

"Well, what do you make of it, Tom?" asked the mechanician, as

he finished his examination of the wallet. "What does it mean?

The pocket-book is empty and that--"

 

"Might mean almost anything," completed Tom. "But it's a clew

all right! He's been here, and I'm pretty certain he was brought

here in the auto with the odd tires--the one Mr. Damon and I saw

traces of the night we heard the cries for help."

 

"But that doesn't help us now," said Jackson. "The point is to

find out how lately Mr. Nestor was here, and what has happened to

him since. There isn't anything in the wallet, is there?"

 

"Nothing," answered Tom, making a careful examination so as to

be sure. "It's as empty as a last year's bird nest. He's been

robbed--that's what has happened to Mr. Nestor. He was waylaid

that night, instead of being run down as I thought--waylaid and

robbed and then his body was brought here."

 

"There you go again, Tom! Jumping to conclusions!" said

Jackson, with a friendly smile, and with the familiarity of an

old and valued helper. "Maybe he's in perfectly good health. Just

because you found his empty wallet doesn't argue that your friend

is in serious trouble. He may have dropped this on the road and

some one picked it up. I'll admit they may have taken whatever

was in it, but that doesn't prove anything. The thing for us to

do is to find out who knows about this shack; who owns it, on

whose land it is, and whether any one has been seen here lately."

 

"They've been here lately whether they've been seen or not,"

said Tom positively. "There are the auto tracks. It rained two

days ago, and the tracks were made since. Mr. Nestor must have

been here within two days."

 

"He may or may not," said Jackson. "Say, rather, that some one

was here and left his wallet after him. Now see if we can find

other clews!"

 

They looked about in the fast fading light, but at first could

discover nothing more than evidences that three or four persons

had been living in the shack and at some recent date--probably

within a day or two.

 

They had had their meals there and had slept there. But this

seemed to be all that could be established, other than that Mr.

Nestor's wallet was there, stripped of its contents.

 

Tom was looking through the closet, from which a frightened

chipmunk sprang as he opened the door. There were the remains of

some food, which accounted for the presence of the little striped

animal. And, as Tom poked about, his hand came in contact with

something wrapped in paper on an upper shelf. It was something

that clinked metallicly.

 

"What's that?" asked Jackson. "Knives, or some other weapons?"

 

"Neither," answered Tom. "It's a couple of files, and they've

been used lately. I can see something in the grooves yet and--"

 

Suddenly Tom ceased speaking and drew from his pocket a small

but powerful magnifying glass. Through this he looked at one of

the files, taking it out in front of the shack where the light

was better.

 

"I thought so!" he cried. "Look here, Jackson!"

 

"What is it?"

 

"Another clew!" answered Tom.

 

 

 

CHAPTER XXIII

THE GOVERNMENT TEST

 

 

For a moment Jackson thought Tom had discovered a clew to, or

evidences of, some crime. He had an unpleasant suspicion, for an

instant, that there was blood on the files, and that it might

prove to be the blood of Mr. Nestor.

 

But the satisfaction that showed on Tom's face did not seem to

indicate such dire possibilities as these.

 

"What is it?" asked Jackson, unable to guess at what Tom was

looking through the powerful glass. "What do you see?"

 

"Metal filings on the grooves of these files," said the young

inventor. "And, unless I'm greatly mistaken, the particles of

filings are from the case of my aircraft silencer!"

 

"What!" cried the machinist. "Do you mean those are the files

used in weakening the outer case of your new machine, so that it

burst a little while ago?"

 

"That what I think," answered Tom. "I know it sounds pretty

far-fetched," he went on. "But take a look for yourself. If those

particles on, the files aren't exactly of the same color and

texture as the material of which the silencer case is made, I'll

never build another machine."

 

Jackson peered through the powerful glass moving out a little

farther from the shack, so as to get the best light possible on

the subject of his examination. It was fast getting dark, but

there was enough glow in the western sky for his purpose.

 

"Am I right?" asked Tom.

 

"You're right!" declared his helper. "This is exactly the same

metal as that of which your silencer case is made. It's a

peculiar mixture of aluminum and vanadium steel. I never knew it

used in any shop but yours, and these filings are certainly of

that metal. It would seem, Tom, that these were the files used to

cut a crease in the case of your silencer to weaken it so it

would burst."

 

"My idea exactly!" cried Tom. "The spy, who got into my shop in

some undiscovered manner, did his work and then fled here to

hide. He left his files behind. Mr. Nestor must have been here,

either before or after. No, I'll not say that, either. Finding

his wallet here doesn't prove that he was here. It might have

been brought here by one of the spies and dropped. But I'm sure

we're on the track of the men who damaged my airship, as well as

those who know something of the mystery of Mr. Nestor."

 

"I agree with you," said Jackson. "Of course there's a

possibility that the same peculiar metal you used in your

silencer case may have been used in some other machine shop, and

these files may have come from there, and have been employed in

perfectly regular work. But the chances are--"

 

"There's only one way to make sure," said Tom. "Let's take the

files with us and see if they fit in the grooves where the break

came. We'll take these back to where we left the Air Scout," and

he clinked the files he held.

 

"We can just about make it before it gets black dark," returned

Jackson. "But that won't give us any more time to look around

here," and he indicated the hut.

 

"I fancy we've seen all there is to see here," said Tom. "Mr.

Nestor isn't here, and whether he was or not is a question.

Anyhow, some one was here who had something to do with him after

his disappearance, I'm positive of that. And I'm sure some one

was here who damaged my airship. Now we'll run down both those

clews, find out who owns this place, who has been using it, and

all we can along that line. So, if you're ready, let's travel."

 

The two set out to make their way back to where they had left

the stranded airship. It was fast becoming dark, but they could

hurry along with more speed now, as they did not have to stop to

look for the marks of the peculiar automobile tires. They had

noticed the path along which they had traveled, and in half the

time they had spent coming they were back where the Air Scout

rested undisturbed in the meadow amid the trees.

 

Making sure that, as far as they could tell, no one had visited

the craft since they had left it, Tom and Jackson compared the

file marks on what was left of the broken silencer case with the

files they had found in the hut. They used a small, but powerful

electric lamp to aid them in this examination, as it was too dark

to see otherwise, and what they saw caused the young inventor to

exclaim:

 

"That settles it! These were the files used!"

 

"That's right!" agreed his assistant. "You've called the turn,

Tom. The next thing to do is to find who connects with the

files."

 

"Yes. To do that and find Mr. Nestor," said Tom. "We have

plenty of work ahead of us. But let's get nearer civilization and

send some word to the folks at home. They'll be getting worried."

 

"It doesn't seem as if there was a way out of here without

using an airship," remarked Jackson.

 

But he and Tom finally reached the seldom-used road which ran

along the field that contained the lonely shack, and, following

this, they reached a farmhouse about a mile farther on. Greatly

to their relief, there was a telephone in the place. True it was

only a party line, set up by some neighboring farmers for their

own private use, but one of the subscribers, to whose home the

private line ran, had a long distance instrument, and after a

talk with him, this man promised Tom to call up Mr. Swift and

acquaint him with the fact that his son and Jackson were all

right, and would be home later.

 

"And now," said Tom, after thanking their temporary host, a

farmer named Bloise, "can you tell us anything about an old cabin

that stands back there?" and he indicated the location of the

mysterious shack.

 

"Well, yes, I can tell you a little about it, but not very

much," said Mr. Bloise. "It was built, some years ago, by a rich

New Yorker, who bought up a lot of land around here for a game

preserve. But it didn't pan out. This cabin was only the start of

what he was going to call a 'hunting lodge,' I believe it was.

There was to be a big building on the same order, but it never

was built.

 

"Some say the fellow lost all his money in Wall Street, and

others say the state wouldn't let him make a game preserve here.

However it was, the thing petered out, and the old shack hasn't

been used since."

 

"Oh, yes, it has!" exclaimed Tom. "We just came from there, and

there are signs which show some one has been sleeping there and

eating there."

 

"There has!" exclaimed the farmer. "Well, I didn't know that."

 

"I did," said his son, a young man about Tom's age. "I meant to

speak of it the other day. I saw an automobile turn into the old

road that the men used when they built the shack. I thought it

was kind of queer to see a touring car turn in there, and I meant

to speak of it, but I forgot. Yes, some one has been at the old

cabin lately."

 

"Do you know who they are?" asked Tom eagerly. "We are looking

for a Mr. Nestor, who disappeared mysteriously about two weeks

ago, and I just found his wallet there in the shack!"

 

"You did!" exclaimed Mr. Bloise. "That's queer! You relatives

of this Mr. Nestor?" he asked.

 

"Not exactly," Tom answered. "Just very close friends."

 

"Well, it's too bad about his being missing in that way," went

on the farmer. "I read about it in the paper, but I never

suspected he was around here."

 

"Oh, we're not sure that he was," said Tom quickly. "Finding

his wallet doesn't prove that," and he told the story of his own

and Jackson's appearance on the scene, to the no small wonder of

the farmer and his family. Tom said nothing about the finding of

the files, nor the evidence he deduced from them. That was

another matter to be taken up later.

 

"Who were in the auto you saw?" asked Tom of the farmer's son.

"Was Mr. Nestor in the car?"

 

"I couldn't be sure of that. There were two men in the machine,

and they were both strangers to me. They were talking together,

pretty earnestly, it seemed to me."

 

"One did not appear as if he was being taken away against his

will, did he?" asked Tom.

 

"No, I can't say that he did," was the answers "They looked to

me, and acted like, business men looking over land, or something

like that. They just turned in on the road that leads to the old

hunting cabin, as we call it around here, and didn't pay any

attention to me. Then I forgot all about them."

 

"Neither of them could have been Mr. Nestor," decided Tom. "At

least it doesn't seem as if he'd talk at all companionably to a

man who had treated him as we think Mr. Nestor has been treated.

I guess that clew isn't going to amount to much."

 

"It may!" insisted Jackson. "They may have had Mr. Nestor in

the car all the while--concealed in the back you know. We've got

to find out more about these men and their auto, Tom."

 

"Well, yes, perhaps we have. But how?"

 

"Station some one at the shack, or at the beginning of the

private road. The men may come back."

 

"That's so--they may. We'll do that!" cried the young inventor.

"We must tell the police and Mr. Nestor's folks what we have

learned. How can we get back to Shopton in a hurry?" he asked

the farmer.

 

"Well, I can drive you to the railroad station" was the answer.

 

"Thank you," remarked Tom. "We'll accept your offer. And as

soon as we get back we must send some one from the shop to stand

guard over the airship," he added in an aside to Jackson. "Those

file fellows may come back."

 

"That's so, we can't take any chances."

 

The farmer soon had his team at the door, and, after they had

had a hasty but satisfying supper at the farmhouse, the son drove

Tom and Jackson several miles to a railroad station, where they

could catch a train for Shopton.

 

In due season Tom's home was reached. He intended to stop but a

minute, to assure his father that everything was all right, and

then get out his speedy runabout to go to see Mary, to tell her

the news.

 

But when Tom sought his father in the library, he was told that

there was a visitor in the house.

 

"Tom," said his father, "this gentleman is from Washington. He

wants to arrange for a government test of your silent airship. I

told him I thought you were about ready for it."

 

"A government test !" cried Tom. "Why, I didn't think the

government even knew I was working on such an idea!" Tom was

greatly surprised.

 

 

 

CHAPTER XXIV

IN THE MOONLIGHT

 

 

With a reassuring smile the visitor from Washington looked at

Tom Swift.

 

"The government officials," he said, "know more than some

people give them credit for--especially in these war times. Our

intelligence bureau and secret service has been much enlarged of

late. But don't be alarmed, Mr. Swift," went on the caller, whose

name was Mr. Blair Terrill. "Your secret is safe with the

government, but I think the time is ripe to use it now--that is,

if you have perfected it to a point where we can use it."

 

"Yes," answered Tom slowly, "the invention is practically

finished and it is a success, except for a few minor matters that

will not take long to complete.

 

"Our accident this afternoon had nothing to do with the

efficiency of the silencer," Tom went on. "It was deliberately

damaged by some spy. I'll take that up later. That I am

interested to know how you heard of my Air Scout, as I call it."

 

"Well, we have agents, you know, watching all the inventors who

have helped us in times past, and we haven't forgotten your giant

cannon or big searchlight. I might say, to end your curiosity and

lull your suspicions, that your friend, Ned Newton, who has been

doing such good Liberty Bond work, informed us of your progress

on the silent motor."

 

"Oh, so it was Ned!" exclaimed Tom.

 

"Yes. He told us the time was about ripe for us to make you an

offer for your machine. I think we can use it to great advantage

in scout work on the western front," went on the agent, and he

soon convinced Tom that when it came to a knowledge of airships,

he had some very pertinent facts at his disposal.

 

"When can you give me a test?" Mr. Terrill asked Tom.

 

"As soon as I can get my craft back to the shop and fit on a

new outer case. That won't take long, as I have some spare ones.

But I must help the Nestors," he went on, speaking to his father.

"I didn't mention it over the wire," he added, "but we've found

in the cabin a clew to the missing man. I must tell Mary and her

mother, and help them all I can."

 

"And allow me to help, too," begged Mr. Terrill. "Since this

affects you, Mr. Swift, and since you are, in a way, working for

Uncle Sam, you must let him help you. This is the first I have

heard of the missing gentleman, of whom your father just told me

something, but you must allow me to help search for him. I will

get the United States Secret Service at work."

 

"That will be fine!" cried Tom. "I wanted to get their aid, but

I didn't see how I could, as I knew they were too busy with army

matters and tracing seditious alien enemies, to bother with

private cases. I'm sure the Secret Service men can get trace of

the persons responsible for the detention of Mr. Nestor, wherever

he is."

 

"They'll do their best," said Mr. Terrill. "I'm a member of

that body," he went on, "and I'll give my personal attention to

the matter."

 

Then followed a busy time. Tom did not get to bed until nearly

morning. For he had to arrange to send some of his men to guard

the stranded airship, and then he went to see Mary and her

mother, taking them the good news that the search for Mr. Nestor

would be prosecuted with unprecedented vigor.

 

"If it isn't too late!" sadly said the missing man's wife.

 

"Oh, I'm sure it isn't !" declared Tom.

 

In addition to sending a guard to the airship, other men, some

of them hastily summoned from the nearest federal agency, were

sent to keep watch in the vicinity of the lonely cabin. They had

orders to arrest whoever approached, and a relay of the men was

provided, so that watch could be kept up night and day. Besides

this, other men from the Secret Service began scouring the

country around the locality of the cabin, seeking a trace of the

two persons the farmer's son had seen in the automobile.

 

"If Mr. Nestor is to be found, they'll find him!" declared Tom

Swift.

 

Mr. Damon, as might be expected, was very much excited and

wrought up over all these happenings.

 

"Bless my watch chain, Tom Swift!" cried the eccentric man,

"but something is always happening to you. And to think I wasn't

along when this latest happened!"

 

"Well, you can be in at the finish," promised Tom, and it was

strange how his promise was fulfilled.

 

Meanwhile there was much to do. During the time the Secret

Service men were busy looking up clews which might lead to the

finding of Mr. Nestor and keeping watch in the vicinity of the

hut, Tom had his airship brought back to the hangar, and a new

silencer was attached. While this work was going on the place was

guarded night and day by responsible men, so there was no chance

for an enemy spy to get in and do further damage.

 

An investigation was made of the Universal Flying Machine

Company, but nothing could be proved to link them with the

outrage. Gale and Ware were in Europe--ostensibly on government

business, but it was said that if anything could be proved

connecting them with the attempt made on Tom Swift's craft, they

would be deprived of all official contracts and punished.

 

All this took time, and the waits were wearisome, particularly

in the case of Mr. Nestor. No further trace of him was found,

though every effort was made. Tom began to feel that his boast of

his enemies having to get up early in the morning to get ahead of

him, had been premature, to say the least.

 

Tom Swift worked hard on his new Air Scout. He determined there

would be nothing lacking when it came to the government test, and

not only did he make sure that no enemy could tamper with his

machine, but he took pains to see that no inherent defect would

mar the test.

 

Jackson and the other men helped to the best of their ability,

and Mr. Swift suggested some improvements which were incorporated

in the new machine.

 

One of the puzzles the Secret Service men had to solve was that

of the connection, if any, between the men who had to do with the

missing Mr. Nestor and those who had damaged Tom's airship by

filing the muffler case so it was weakened and burst. That there

was some connection Tom was certain, but he could not work it

out, nor, so far, had the government men.

 

At last the day came when the big government test was to be

made. Tom had completed his Air Scout and had refined it to a

point where even his critical judgment was satisfied. All that

remained now was to give Mr. Terrill a chance to see how silently

the big craft could fly, and to this end a flight was arranged.

 

Tom had put the silencer on a larger machine than the one he

and Jackson had used. It held three easily, and, on a pinch, four

could be carried. Tom's plan was to take Mr. Damon and Mr.

Terrill, fly with them for some time in the air, and demonstrate

how quiet his new craft was. Then, by contrast, a machine without

the muffler and the new motor with its improved propellers would

be flown, making as much noise as the usual craft did.

 

"I only wish," said Tom, as the time arrived for the official

government test, "that Mary could be here to see it. She was the

one who really started me on this idea, so to speak, as it was

because I couldn't talk to her that I decided to get up a silent

motor."

 

But Mary Nestor was too grief-stricken over her missing father

to come to the test, which was to take place late one afternoon,

starting from the aerodrome of the Swift plant.

 

"First," said Tom, to Mr. Terrill, "I'll show you how the

machine works on the ground. I'll run the motor while the plane

is held down by means of ropes and blocks. Then we'll go up in

it."

 

"That suits me," said the agent. "If it does all you say it

will do, and as much as I believe it will do, Uncle Sam will be

your debtor, Mr. Swift."

 

"Well, we'll see," said Tom with a smile.

 

Preparations were made with the greatest care, and Tom went

over every detail of the machine twice to make certain that, in

spite of the precautions, no spy had done any hidden damage, that

might be manifested at an inopportune moment. But everything

seemed all right, and, finally, the motor was started, while Mr.

Terrill, and some of his colleagues from the Army Aviation

department looked on.

 

"Contact!" cried Tom, as Jackson indicated that the compression

had been made.

 

The mechanic nodded, gave the big propeller blades a quarter

turn and jumped back. In an instant the motor was operating, and

the craft would have leaped forward and cleaved the air but for

the holding ropes and blocks. Tom speeded the machinery up to

almost the last notch, but those in the aerodrome hardly heard a

sound. It was as though some great, silent dynamo were working.

 

"Fine!"

 

"Wonderful!"

 

"Wouldn't have believed it possible!"

 

These were some of the comments of the government inspectors.

 

"And now for the final test--that in the air," said Mr.

Terrill.

 

Previous to this he and his colleagues had made a minute

examination of the machinery, and had been shown the interior

construction of the silencer by means of one built so that a

sectional view could be had. Tom's principles were pronounced

fundamental and simple.

 

"So simple, in fact, that it is a wonder no one thought of it

before," said a navy aviation expert. "It is the last word in

aircraft construction--a silent motor that will not apprise the

enemy of its approach! You have done wonders, Mr. Swift!"

 

"I'd rather hear you say that after the air test," replied Tom,

with a laugh. "Are you ready, Mr. Terrill?"

 

"Whenever you are."

 

"How about you, Mr. Damon?"

 

"Oh, I'm always ready to go with you, Tom Swift. Bless my

trench helmet, but you can't sail any too soon for me!"

 

There was a genial laugh at his impetuosity, and the three took

their seats in the big craft. Once more the engine was started.

It operated as silently as before, and the first good impressions

were confirmed. Even as the machine moved along the ground, just

previous to taking flight into the air, there was no noise, save

the slight crunch made by the wheels. This, of course, would be

obviated when Silent Sam was aloft.

 

Up and up soared the great craft, with Tom at the engine and

guide controls, while Mr. Terrill and Mr. Damon sat behind him,

both eagerly watching. Mr. Terrill was there to find fault if he

could, but he was glad he did not have to.

 

"The machine works perfectly, Mr. Swift," he said. "My report

cannot be otherwise than favorable."

 

"We mustn't be in too much of a hurry," said Tom, who had

learned caution some time ago. "I want to sail around for several

hours. Sometimes a machine will work well at first, but defects

will develop when it is overheated. I'm going to do my best to

make a noise with this new motor."

 

But it seemed impossible. The machinery worked perfectly, and

though Silent Sam took his passengers high and low, in big

circles and small ones, there was no appreciable noise from the

motor. The passengers could converse as easily, and with as

little effort, as in a balloon.

 

"Of course that isn't the prime requisite," said Mr. Terrill,

"but it is a good one. What we want is a machine that can sail

over the enemy's lines at night without being heard, and I think

this one will do it--in fact, I'm sure it will. Of course the

ability of the passengers to converse and not have to use the

uncertain tube is a great advantage."

 

As Tom Swift sailed on and on, it became evident that the test

was going to be a success. The afternoon passed, and it began to

grow dark, but a glorious full moon came up.

 

"Shall I take you down?" the young inventor asked Mr. Terrill.

 

"Not quite yet. I thoroughly enjoy this, and it isn't often I

get a chance for a moonlight airship ride. Go a little lower, if

you please, and we'll see if we attract any attention from the

inhabitants of the earth. We'll see if they can possibly hear the

machine, though I don't see how they can."

 

And they did not. Tom piloted the machine over Shopton, sailing

directly over the center of the town, where there was a big crowd

walking about. Though the airship sailed only a few hundred feet

above their heads, not a person was aware of it, since the

craft's lights were put out for this test.

 

"That settles it," said Mr. Terrill. "You have succeeded, Tom

Swift!"

 

But Tom was not yet satisfied. He wanted a longer test. Hardly

knowing why he did it he sent the craft in the direction of Mary

Nestor's home. As he sailed across her lawn he saw, in the

moonlight, that she and her mother were walking in the garden.

They did not look up as the aircraft passed over their heads, and

were totally unaware of its presence, unless they caught a

glimpse of it as it flitted silently along, like some great bird

of the night.

 

"It is perfectly wonderful!" declared Mr. Terrill, and he spoke

in ordinary tones, that carried perfectly to the ears of Tom and

Mr. Damon.

 

"Wonderful!" cried the eccentric man. "Bless my chimney, but

it's the greatest invention in the world! Yes, it is! Don't tell

me it 'isn't!"

 

And no one did.

 

Passing the Nestor home, the saddened occupants of which were

unaware of the passage, Tom sent the Air Scout about in a circle,

intending to proceed to the hangar. And then, some whim, perhaps,

caused him to guide Silent Sam out toward the lonely hut. Mr.

Damon and Mr. Tenrill seemed perfectly content to sail on and on

indefinitely in the moonlight. Tom thought he would take them

over a lonely neighborhood, and then bring them back.

 

In a little while the craft was directly over the stretch of

country where the aeroplane accident bad occurred, and where Tom

and Jackson had found the deserted hut.

 

Rather idly Tom looked down, wondering if the Secret Service

men were on the watch and if they had discovered anything.

 

Suddenly Tom was aware of an automobile moving along the field

path toward the cabin. There were two men in the car, both on

the front seat, and as Tom looked down the brilliant moonlight

showed him the figure of another man, behind, and huddled in the

tonneau of the car. The aeroplane was low enough for all these

details to be seen by the moon's gleam, but the men in the car,

not hearing any noise, did not look up, so they were unconscious

of this aerial espionage.

 

"Look! Look!" exclaimed Tom in a low voice to his companions.

"Doesn't that seem suspicious?"

 

 

 

CHAPTER XXV

THE GOLD TOOTH

 

 

Eagerly Mr. Damon and the government agent leaned over and

looked down. In the moonlight they saw the same sight that had

attracted Tom Swift. The touring car, the two men in front, and

the huddled, bound figure in the back.

 

"Can you go down, Tom, without letting them hear you?" asked

Mr. Damon, using a low voice, as if fearful the men in the

automobile would hear him.

 

"I guess so," answered the young inventor. "I can land nearer

to the cabin than Jackson and I did, and then we can see what

these fellows are up to. It looks suspicious to me. That is,

unless they're some of the Secret Service men, and have made a

capture," he added to Mr. Terrill.

 

"Those aren't any of Uncle Sam's men," declared the agent.

"That is, unless the bound one is. I can't see him very well.

Better go down, and we'll see if we can surprise them."

 

"My plan," voiced Tom.

 

Quickly he shifted the rudder, and then, shutting off the

motor, as he wanted to volplane down, he headed his craft for an

open spot that showed in the bright moonlight. By this time the

automobile and its occupants were out of sight behind a clump of

trees, but Tom and his companions felt sure of the destination of

the men--the deserted cabin in the wood.

 

As silently as a wisp of grass falling, the big craft came down

on a level spot, and then, leaping out, the young inventor and

his two companions crept along the path toward the cabin. Mr.

Terrill was armed, Tom carried a flashlight, while Mr. Damon

picked up a heavy club.

 

As soon as he came near a place where he thought the marks of

the automobile wheels would show, Tom flashed his light.

 

"I thought so!" he exclaimed, as he saw the square, knobby tread

marks left by the tires. "It's the same gang, or some of them in

the same car. If we can only capture them!"

 

"The Secret Service men ought to do that," returned Mr.

Terrill, but, as it developed later, they were not on hand,

though through no fault of theirs.

 

On and on crept Tom and the two men, until they came within

sight of the cabin. They saw a light gleaming in it, and Tom

whispered:

 

"Now we have them! Work our way up quietly and make them

surrender, if we find they're what we think."

 

"Is there a rear door?" asked Mr. Terrill in a whisper.

 

Tom answered in the negative, and then all three, in fan shape,

crept up to the front portal. It was open, and silently reaching

a place where they could make an observation, Tom and his

companions looked in.

 

What they saw filled them with wild and righteous rage, and

brought to an end the mystery of the disappearance of Mr. Nestor.

For there he sat, bound in a chair, and at a table in front of

him were two forbidding-looking men.

 

"What do you intend to do now?" asked Mr. Nestor in a faint

voice. "I cannot stand this captivity much longer. You admit that

you don't want me--that you never wanted me--so why do you keep

me a prisoner? It cannot do the least good."

 

"There's no use going over that again !" exclaimed the harsh

voice of one of the men. told you that if you will promise to

keep still about what happened to you, and not to give the

police any information about us, we'll let you go gladly. We

don't want you. It was all a mistake, capturing you. You were the

wrong man. But we re not going to let you go and have you set the

police on us as soon as you get a chance. Give us your promise to

say nothing, and we'll let you join your friends. If you don't--"

 

"Make no promises, Mr. Nestor!" cried Tom Swift in a ringing

voice, as he leaped from his hiding place, followed by his

companions. "Your friends are here, and you can tell them

everything!"

 

"Up with 'em!" called Mr. Terrill to the two conspirators as he

confronted them with his automatic pistol ready for firing. He

had no need to mention hands--they knew what he meant and took

the characteristic attitude.

 

"Tom! Tom Swift!" cried Mr. Nestor, struggling ineffectually at

his bonds. "Is it really you?"

 

"Well, I hope it isn't any imitation," was the grim answer.

"We'll tell you all about it later. Jove, but I'm glad we found

you! If it hadn't been for Silent Sam we might never have been

able to."

 

"Well, I don't know who Silent Sam is," said Mr. Nestor

faintly. "But I'm sure I'm much obliged to him and your other

friends. It has been very hard. Tell me, are my wife and Mary all

right?"

 

"In good health, yes, but, of course, worrying," said Tom. "We

saw them in the garden a little while ago. Now don't talk until I

set you free."

 

And as Tom cut the ropes from Mr. Nestor, Mr. Damon used them

to bind the two conspirators, while Mr. Terrill stood guard over

them. And when they were safely bound, and Mr. Nestor had

somewhat recovered from the shock, Tom had a chance to examine

the prisoners.

 

"What does it all mean? Who are you fellows, anyhow, and what's

your game?" he demanded.

 

"Guess it--since you're so smart!" snapped one.

 

And no sooner had he opened his mouth and Tom had a glance of

something gleaming brightly yellow, than the young inventor

cried:

 

"The gold tooth! So it's you again, is it, you spy?"

 

The man shrugged his shoulders with an assumption of

indifference. And, as Tom took a closer look, he became aware

that the man was surely none other than Lydane, the spy he had

chased into the mud puddle some weeks before. His companion was a

stranger to Tom.

 

"What does it all mean, Mr. Nestor ?" asked Tom. "Have these

men held you a prisoner ever since you called for help on the

moor that night?"

 

"Yes, Tom, they have. And I did call for help after they

attacked me as I was riding my wheel, but I didn't know any one

heard me. I began to be afraid no one would ever help me."

 

"We've been trying to, a long time," said Mr. Damon, "but we

couldn't find you. Where did they keep you?"

 

"Here, part of the time," was Mr. Nestor's answer. "And in

other lonely houses. They bound and gagged me when they took me

from place to place."

 

"But what was their object?" asked Tom, concluding it was

useless to question the two captives. "Why did they make you a

prisoner, Mr. Nestor?"

 

"Because they took me for you, Tom."

 

"For me?"

 

"Yes. The night I called at your house, and found you were not

at home, I put back in my pocket a bundle of papers I had brought

over to show you. They were plans of a little kitchen appliance a

friend of mine had invented, and I wanted to ask your opinion of

it."

 

"These scoundrels must have followed me, or have seen the

bundle of papers, and, mistaking me for you, they followed,

attacked me in a lonely spot and, bundling me and my wrecked

wheel into an auto, carried me off. They first demanded that I

gave up the 'plans,' and when I wouldn't they choked off my cries

for help and knocked me into unconsciousness. Then they brought

me here, and kept me here for several days.

 

"They soon learned that the plans I had weren't those they

wanted, though what they were thin after I couldn't imagine.

Only, from what I laser overheard, I knew they mistook me for you

and that they were bitterly disappointed in not getting plans of

some new airship you were working on. They have kept me a

prisoner ever since, and though they offered to let me go if I

would keep silent, I refused. I did not think, to secure my own

comfort, I should let such men go unpunished if I could bring

about their arrest."

 

"I should say not!" cried Tom.

 

"Did they treat you brutally, Mr. Nestor?" asked Mr. Damon.

 

"Not after they found out who I was, by looking through my

wallet. Of course they didn't behave very decently, but they

weren't actually cruel, except that they bound and gagged me. Oh,

but I'm glad you came, Tom! How did it happen?"

 

Then they told Mr. Nestor their story, and how the test of the

new Air Scout had led to his rescue.

 

"But where are the Secret Service men?" asked Mr. Terrill, when

it became evident that none them was on guard at the cabin.

 

Later it developed that, by following a false clew, the Secret

Service men had been drawn miles away from the cabin. And only

that Tom and his companions in the silent airship saw the men.

Mr. Nestor might not have been rescued for some further time.

 

His version of what had happened was correct. He had been

mistaken for Tom, and the spy with the gold tooth and his

accomplice had waylaid Mary's father, under the belief that it

was Tom Swift with the plans of the new silent motor. Mr. Nestor

had been attacked while riding his wheel in a lonely place, and

had been carried off and kept in hiding, a prisoner even after

his identity became known.

 

"Well, this is a good night's work!" exclaimed Tom, when the

two rogues had been sent to jail and Mr. Nestor taken to the

Bloise farmhouse, to be refreshed before he went home. Word of

his rescue was telephoned to Mary and her mother, and it can be

imagined how they regarded Tom Swift for his part in the affair.

 

Little the worse for his experience, save that he was very

nervous, Mr. Nestor was taken home. He gave the details of his

being waylaid, and told how the men, for many days, were at their

wits' ends to keep him concealed when they found what a stir his

disappearance had created. The conspirators were well supplied

with money, and in the automobile they took their prisoner from

one place to another. They had usurped the use of the cabin and

had lived there nearly a week in hiding, leaving just before the

first visit of Tom and Jackson. The rifled wallet had been

dropped by accident.

 

And it did not take much delving to disclose the fact that,

Lydane, "Gold Tooth," as he was called, and his crony, were spies

in the pay of the Universal Flying Machine Company. As the men

went under several aliases there is no need of giving their

names. It is to be doubted if they ever used their real ones--or

if they had any.

 

Of course, there was quite a sensation when Mr. Nestor was

found, and a greater one when it became known the part the

Universal Flying Machine people had in his disappearance in

mistake for Tom. The officials of the company were indicted, and

several of the minor ones sent to jail but Gale and Ware escaped

by remaining abroad.

 

It came out that they both knew of the acts of Lydane and his

companion in crime, and that the two officials realized the

mistake that had been made by their clumsy operatives. It was

believed that this knowledge led to the visit of Gale to Tom, the

time the latter's suspicions were first aroused. Gale made a

clumsy attempt to clear his own skirts of the conspiracy, but in

vain, though he did escape his just punishment.

 

What had happened, in brief, was this. Gale and Ware, unable to

secure Tom's services, even by the offer of a large sum of money,

had stooped to the sending of spies to his shop, to get

possession of information about his silent motor. This was after

Gale had, by accident, heard Tom speaking of it to Mr. Damon.

 

But, thanks to Tom's vigilance, Bower was discovered. The man

tripped into the mud hole lost in the muck the plans Bower passed

to him. They were never recovered. Then Lydane tried again. He

managed, through bribery, to gain access to the hangar where the

new silent machine was kept, and, unable to get the silencer

apart, tried to file it. In doing so he weakened it so that it

burst.

 

The attempt to waylay Tom, and so get the plans from him, had

been tried before this, only a mistake had been made, and Mr.

Nestor was caught instead. Finding out their error, Lydane and

his companions did not tell the Universal people of their

mistake, though Gale and Ware knew the attempt was to be made

against Tom Swift.

 

Later, hearing that the young inventor was still at work on his

invention, Gale was much surprised, and paid his queer visit, in

an attempt to repudiate the actions of Lydane. At this time it

was assumed that Gale and his partner did not know that it was

Mr. Nestor who had been kidnapped by mistake or they might have

insisted on his release. As it was, Lydane had Mary's father, and

was afraid to let him go, though really their prisoner became a

white elephant on the hands of the conspirators and kidnappers.

 

And it was after all this was cleared up, and Mr. Nestor

restored to his family and friends, that one day, Tom Swift

received another visit from Mr. Terrill, the government agent.

 

"Well, Mr. Swift," was the genial greeting, "I have come to

tell you that the favorable report made by my friends and myself

as to the performance of your noiseless motor, has been accepted

by the War Department, and I have come to ask what your terms

are. For how much will you sell your patent to the United

States?"

 

Tom Swift arose.

 

"The United States hasn't money enough to buy my patent of a

noiseless motor," he said.

 

"Wha--what!" faltered Mr. Terrill. "Why, I understood--you

don't mean--they told me you were rather patriotic, and--"

 

"I hope I am patriotic!" interrupted Tom with a smile. "And

when I say that the United States hasn't money enough to buy my

latest invention I mean just that."

 

"My Air Scout is not for sale!"

 

"You mean," faltered the government agent. "You say--"

 

"I mean," went on Tom, "that Silent Sam is for Uncle Sam

without one cent of cost! My father and I take great pleasure in

presenting such machines as are already manufactured, those in

process of making, and the entire patents, and all other rights,

to the government for the winning of the war!"

 

"Oh!" said Mr. Terrill in rather a strange voice. "Oh!"

 

And that was all he could say for a little while.

 

But Tom Swift reckoned without a knowledge of a peculiar law

which prohibits the United States from accepting gifts totally

without compensation, and so, in due season, the young inventor

received a check for the sum of one dollar in full payment for

his silent motor, and the patent rights thereto. And Tom has that

check framed, and hanging over his desk.

 

And so the silent motor became an accomplished fact and a great

success. Those of you who have read of its work against the

Boches, and how it helped Uncle Sam to gain the mastery of the

sky, need not be reminded of this. By it many surprise attacks

were made, and much valuable information was obtained that

otherwise could not have been brought in.

 

One day, after the rogues had been sent to prison for long

terms, and Tom had turned over to his government his silent

aircraft--except one which he was induced to keep for his own

personal use--the young inventor went to call on Mary Nestor. The

object of his call, as I believe he stated it, was to see how Mr.

Nestor was, but that, of course, was camouflage.

 

"Would you like to come for a ride, Mary, in the silent

airship?" asked Tom, after he had paid his respects to Mr. Nestor

and his wife. "We can talk very easily on board Silent Sam

without the use of a speaking tube. Come on--we'll go for a

moonlight sky ride."

 

"It sounds enticing," said Mary, with a shy look at Tom. "But

wouldn't you just as soon sit on a bench in the garden? It's

moonlight there, and we can talk, and--and--"

 

"I'd just as soon!" said Tom quickly.

 

And out they went into the beautiful moonlight; and here we

will leave them and say good-bye.

 

 

 

 

 

THE END

 

----------------------------------------------------------------

 

 

 

THE TOM SWIFT SERIES

 

By VICTOR APPLETON

 

 

 

These spirited tales. convey in a realistic way, the wonderful

advances in land and sea locomotion. Stories like these are

impressed upon the memory and their reading is productive

only of good.

 

TOM SWIFT AND HIS MOTOR CYCLE

TOM SWIFT AND HIS MOTOR BOAT

TOM SWIFT AND HIS AIRSHIP

TOM SWIFT AND HIS SUBMARINE BOAT

TOM SWIFT AND HIS ELECTRIC RUNABOUT

TOM SWIFT AND HIS WIRELESS MESSAGE

TOM SWIFT AMONG THE DIAMOND MAKERS

TOM SWIFT IN THE CAVES OF ICE

TOM SWIFT AND HIS SKY RACER

TOM SWIFT AND HIS ELECTRIC RIFLE

TOM SWIFT IN THE CITY OF GOLD

TOM SWIFT AND HIS AIR GLIDER

TOM SWIFT IN CAPTIVITY

TOM SWIFT AND HIS WIZARD CAMERA

TOM SWIFT AND HIS GREAT SEARCHLIGHT

TOM SWIFT AND HIS GIANT CANNON

TOM SWIFT AND HIS PHOTO TELEPHONE

TOM SWIFT AND HIS AERIAL WARSHIP

TOM SWIFT AND HIS BIG TUNNEL

TOM SWIFT IN THE LAND OF WONDERS

TOM SWIFT AND HIS WAR TANK

TOM SWIFT AND HIS AIR SCOUT

TOM SWIFT AND HIS UNDERSEA SEARCH

TOM SWIFT AMONG THE FIRE FIGHTERS

TOM SWIFT AND HIS ELECTRIC LOCOMOTIVE

 

 

 

 

SIX LITTLE BUNKERS SERIES

 

By LAURA LEE HOPE

 

Author of "The Bobbsey Twins Books,"

 

"The Bunny Brown Series,"

 

"The Make-Believe Series," Etc.

 

Delightful stories for little boys and girls which sprung into

immediate popularity. To know the six little Bunkers is to take

them at once to your heart, they are so intensely human, so full

of fun and cute sayings. Each story has a little plot of its own

-Äone that can be easily followed-Äand all are written in Miss

Hope's most entertaining manner. Clean, wholesome volumes which

ought to be on the bookshelf of every child in the land.

 

SIX LITTLE BUNKERS AT GRANDMA BELL'S

SIX LITTLE BUNKERS AT AUNT JO'S

SIX LITTLE BUNKERS AT COUSIN TOM'S

SIX LITTLE BUNKERS AT GRANDPA FORDS

SIX LITTLE BUNKERS AT UNCLE FRED'S

SIX LITTLE BUNKERS AT CAPTAIN BEN'S

SIX LITTLE BUNKERS AT COWBOY JACK'S

 

 

 

 

THE MOVING PICTURE BOYS SERIES

 

THE MOVING PICTURE BOYS

THE MOVING PICTURE BOYS IN THE WEST

THE MOVING PICTURE BOYS ON THE COAST

THE MOVING PICTURE BOYS IN THE JUNGLE

THE MOVING PICTURE BOYS IN EARTHQUAKE LAND

THE MOVING PICTURE BOYS AND THE FLOOD

THE MOVING PICTURE BOYS AT PANAMA

THE MOVING PICTURE BOYS UNDER THE SEA

THE MOVING PICTURE BOYS ON THE WAR FRONT

THE MOTION PICTURE CHUMS SERIES

THE MOTION PICTURE CHUMS' FIRST VENTURE

THE MOTION PICTURE CHUMS AT SEASIDE PARK

THE MOTION PICTURE CHUMS ON BROADWAY

THE MOTION PICTURE CHUMS' OUTDOOR EXHIBITION

THE MOTION PICTURE CHUMS' NEW IDEA

THE MOTION PICTURE CHUMS AT THE FAIR

THE MOTION PICTURE CHUMS' WAR SPECTACLE

 

 

 

End.