Produced by Sean Pobuda

THROUGH SPACE TO MARS

Or the Longest Journey on Record

By Roy Rockwood

#4 in the "Great Marvel Series"

CHAPTER I

TWO CHUMS

"Mark, hand me that test tube, will you, please?"

The lad who had made the request looked over at his companion, a
boy of about his own age, who was on the other side of the
laboratory table.

"The big one, or the small one?" questioned Mark Sampson.

"The large one," answered Jack Darrow.  "I want to put plenty of
the chemical in this time and give it a good try."

"Now be careful, Jack.  You know what happened the last time."

"You mean what nearly happened.  The tube burst, but we didn't
get hurt.  I have to laugh when I think of the way you ducked
under the table.  Ha, ha!  It was awfully funny!"

"Humph!  Maybe you think so, but I don't," responded Mark with
rather a serious air.  "I noticed that you got behind a chair."

"Well, of course.  I didn't want broken glass in my eyes.  Come
on, are you going to hand me that test tube, or will I have to
come and get it?  We haven't much more time to-day."

"Oh, here's the tube," said Mark as he passed it over.  "But
please be careful, Jack."

Jack measured out some black chemical that resembled gunpowder,
and poured it into the test tube which Mark handed him.  Then he
inserted in the opening a cork, from which extended a glass tube,
to the outer end of which was fastened a rubber pipe.

He paused in his experiment to laugh again.

"What are you making--laughing gas?" asked Mark.

"No.  But--excuse me--ha, ha!  I can't help laughing when I
think of the way you ducked under the table the other day."

"Maybe you'll laugh on the other side of your countenance, as
Washington White would say," commented Mark; "especially if that
big tube bursts."

"But it isn't going to burst."

"How do you know?"

"Well, I worked out this experiment carefully.  I've calculated
just how strong the new gas will be, and--"

"Ah, that's just it.  It's a new gas, and you've never yet
succeeded in making it, have you?"

"No; but--"

"And it takes a different combination of chemicals to make it
from any you ever experimented with before, doesn't it?" asked
Mark.

"It does.  But--"

"Yes, and I don't see how you can tell, with any amount of
calculation, just how much force will develop from those
chemicals, as no one ever put them together before."

"Well, maybe I can't," admitted Jack.  "But this tube is very
strong, and even if it does break nothing very serious can
happen."

"Unless the gas you expect to generate is stronger than you have
any idea of."

"Well, I'm going to do it.  I've got half an hour before
Professor Lenton and his class comes in, and that's time enough.
Here, just hold this rubber tube under this jar, will you?  And
be sure to keep the edge of the jar below the surface of the
water.  I don't want any of the gas to escape."

He handed Mark the end of the rubber tube, and the somewhat
nervous student, who was helping his chum Jack in the experiment,
inserted it under the edge of a large bell-glass, the open mouth
of which was placed just under the surface of water in a shallow
pan.

The two lads were students at the Universal Electrical and
Chemical College.  They stood high in their classes, and were
often allowed to conduct experiments on their own responsibility,
this being one of those occasions.  Jack, who was somewhat older
than his companion, was of a more adventurous turn of mind, and
was constantly trying new things.  Not always safe ones, either,
for often he had produced small explosions in the laboratory of
the college.  Only minor damage had been done thus far, but, as
Mark said, one could never tell what was going to happen when
Jack mixed certain things in test tubes and placed them over a
spirit lamp, or the flame of a Bunsen burner.

"Have you got that tube under the jar?" asked Jack as he lighted
a large Bunsen flame.

"It's under," answered Mark.  "But say, what are you going to do
in case you prove that your theory is right, and that you can
make a new kind of gas?  What good will it be?"

"Lots of good.  If I'm right, this will be the lightest gas ever
made.  Much lighter than hydrogen--"

"Lighter than the kind Professor Henderson made for use in the
Flying Mermaid, in which we went to the center of the earth?"

"No, I'm afraid I can't equal his gas; but then, no one can ever
hope to.  I'm going to make a new gas, though, and I'll show you
that it will be much lighter and more powerful than hydrogen."

"More powerful, eh?  Then I wish you'd have some one else hold
this.  I'm afraid the test tube will burst."

"What if it does?  It can't hurt you--very much.  But here, since
you're so nervous, I'll put a pile of books all around the tube
and the burner.  Then, if it bursts, the books will prevent the
pieces of glass from flying all about.  Does that satisfy you?"
and Jack began heaping some books about the burner, over which he
was about to suspend the test tube containing the queer chemical.

"Yes," returned Mark doubtfully.  "I suppose it's all right--unless
the books will be blown all over."

"Well, I'll be jig-sawed!" exclaimed Jack with a laugh.  "There's
no satisfying you.  You're too particular, Mark."

"Maybe; but I don't want to get hurt."

"You'll not be injured in the least.  Look, you're quite a
distance away, and even if it does explode and the books are
scattered away, it can't hurt much to be hit by one of these
volumes.  There, I'm all ready now.  Hold the tube firmly."

He placed the test tube in a support, clamping it fast, so that
it would be held steady over the flame.  Then he turned on more
of the illuminating gas, which, coming through the Bunsen burner,
was made intensely hot.  A little column of flame now enveloped
the big test tube containing the powder.

There was a little crackling sound as the heat expanded the
powder, and the end of the test tube became quite red from the
flame.

"That tube'll melt!" exclaimed Mark, peering over the pile of
books.  "It's too near the flame."

"Guess you're right," admitted Jack.  "I'll raise it up a bit."

He turned down the flame and elevated the tube slightly.  Then he
took a position where he could watch the process of making what
he hoped would be a new kind of gas.  He wanted to be where he
could see the vapor beginning to collect in the top of the tube,
pass off through the glass in the cork, and then through the
little rubber hose to the bell glass held by Mark.  If the gas
was generated too quickly, Jack knew he would have to turn down
the heat slightly.

The crackling sound continued.  Then, as Jack watched, he saw a
thick, yellowish vapor collecting in the top of the test tube
near the cork.

"It's coming!" he cried.  "There's my new gas!"

"What's the name of it?" asked Mark.

"I haven't named it yet.  I want to collect it in the jar and
show it to Professor Lenton.  He said he didn't believe I could
make it."

The boys resumed their careful watching of the experiment.  It
was a nervous moment, for, from experience, Mark knew you never
could tell what would happen when Jack began to try new
combinations of chemicals.  He was ready to drop down on an
instant's warning, out of the way of flying missiles.

"See any bubbles in that pan of water yet?" cried Jack.

"No, not yet."

"That's queer.  The test tube is full of the yellow gas, and some
ought to be over to where you are now.  I'm going to turn on some
more heat."

He increased the Bunsen flame.  The crackling noise was louder.
The test tube became a fiery red.

"It's bubbling now!" suddenly called Mark.

"That's good!  The experiment is a success!  I knew I could make
it.  Is any of the gas coming up in the glass jar?"

Mark bent over to make a closer examination.  There were a few
seconds of silence, broken only by the roaring of the burner and
the crackling of the black powder.

"Yes, there is vapor in the jar," he said.

"Good!  That's the stuff!" cried Jack.  "Now I guess Professor
Lenton will admit that I'm right."

He turned the Bunsen flame up higher.  A moment later he uttered
a cry, for he saw the cork being forced from the test tube.  The
pressure of the new gas was too much for it.

"Lookout!" cried Jack.  "She's going up!"

Then followed a sharp explosion, and the laboratory seemed filled
with fragments of broken glass and torn books.

CHAPTER II

JACK MAKES OXYGEN

"There it goes!  There it goes!" cried Mark, making a dive for
the laboratory door, but slipping and sprawling on the floor.
"There it goes, Jack!"

"No; it's gone already!" cried Jack, who, even in the midst of
danger and excitement, seemed to remain calm and still to have
his appreciation of it joke.

"Come on!" cried Mark as he scrambled to his feet.  "We must get
out of here, Jack!"

"What's the use now?  It's all over."

There was a tinkling sound, as fragments of the broken test tube,
the bell-jar and other things began falling about the room.

Mark was fumbling at the door of the laboratory, seeking to
escape.

"Come on back," said Jack.  "It's all over.  There's no more
danger.  We'll try it again."

Just then one of the pile of books, that had been blown on an
upper shelf, came down, landing on Mark's head.

"No danger?" cried Mark, trembling from excitement.  "No danger?
What do you call that?" and he pointed to the books at his feet,
while he rubbed his head ruefully.

"Well, there aren't any more," observed Jack, with a look upward.

Just then the door opened, and an elderly gentleman, wearing
spectacles, entered the laboratory.  He seemed much excited.

"What happened?  Is any one hurt?  Was there an explosion here?"
he asked.

Then he saw the devastation on all sides--the broken glass, the
scattered and torn books--and he noticed Mark rubbing his head.

"There was--er--a slight explosion," replied Jack, a faint smile
spreading over his face.

"Are you hurt?" the professor asked quickly, stepping over to
Mark.  "Shall I get a doctor?"

"A book hit him," explained Jack.

"A book!  Did a book explode?"

"No, sir.  You see, I was making a new kind of gas, and Mark was
helping me.  He was afraid the test tube would explode, so I
piled books around it, and--"

"And it did blow up!" cried Mark, still rubbing his head.  "The
test tube, and the other tube, and the rubber hose, and the
bell-jar.  I told you it would, Jack."

"Then you weren't disappointed," retorted Jack, this time with a
broad smile.  "I don't like to disappoint people," he added.

"What kind of gas was it, Darrow?" asked Professor Lenton.

"Well, I hadn't exactly named it yet," answered the young
inventor.  "I was going to show it to you, and see what you
thought of it.  It's the kind you said I couldn't make."

"And did you make it?" asked the instructor grimly.

"Yes, sir--some."

"Where is it?"

"It's--er--well, you can smell it," replied Jack.

Sure enough, there was a strong, unpleasant odor in the
laboratory, but that was usual in the college where all sorts of
experiments were constantly going on.

"Hum--yes," admitted the professor.  "I do perceive a new odor.
But I'm glad neither of you was hurt, and the damage doesn't seem
to be great."

"No, sir.  It was my own apparatus I was using," explained Jack.
"I'll be more careful next time.  I'll not put in so much of the
chemical."

"I don't believe there had better be a 'next time' right away,"
declared Mr. Lenton.

"The next attempt you make to invent a powerful gas, you had
better generate it in something stronger than a glass test tube.
Use an iron retort."

"Yes, sir," replied Jack.

"And now you had better report for your geometry lesson," went on
the professor.  "I need the laboratory now for a class in
physics.  Just tell the janitor to come here and sweep up the
broken glass.  I am very glad neither of you boys was seriously
injured.  You must be more careful next time."

"Oh, Mark was careful enough," said Jack.  "It was all my fault.
I didn't think the gas was quite so powerful."

"All right," answered the professor with a smile as Jack and Mark
passed out on their way to another classroom.

The two lads, whom some of my readers have met before in the
previous books of this series, were friends who had become
acquainted under peculiar circumstances.  They were orphans, and,
after having had many trying experiences, each of them had left
his cruel employers, and, unknown to each other previously, had
met in a certain village, where they were obliged to beg for
food.  They decided to cast their lots together, and, boarding a
freight train, started West.

The train, as told in the first volume to this series, called
"Through the Air to the North Pole," was wrecked near a place
where a certain Professor Amos Henderson, and his colored helper,
Washington White, lived.  Mr. Henderson was a learned scientist
who was constantly building new wonderful machines.  He was
working on an airship, in which to set out and locate the North
Pole, when he discovered Jack and Mark, injured in the freight
wreck.  He and Washington White carried the lads to the
inventor's workshop, and there the boys recovered.  When they
were well enough, the professor invited them to live with him,
and, more than that, to take a trip with him North Pole.

They went, in company with Washington and an old hunter, named
Andy Sudds, and some other men, whom the professor took along to
help him.

Many adventures befell the party.  They had battles with wild
beasts in the far north, and were attacked by savage Esquimaux.
Once they were caught in a terrible storm. They actually passed
over the exact location of the North Pole, and Professor
Henderson made some interesting scientific observations.

In the second volume of this series, entitled "Under the Ocean to
the South Pole," Professor Henderson, Jack, Mark, Washington and
old Andy Sudds, made even a more remarkable trip.  The professor
had a theory that there was an open sea at the South Pole, and he
wanted to prove it.  He decided that the best way to get there
was to go under the ocean in a submarine boat, and he and the
boys built a very fine, craft, called the Porpoise, which was
capable of being propelled under water at a great depth.

The voyagers had rather a hard time of it.  They were caught in a
great sea of Sargasso grass, monstrous suckers held the boat in
immense arms, and it required hard fighting to get free.  The
boys and the others had the novel experience of walking about on
the bottom of the sea in new kinds of diving suits invented by
the professor.

On their journey to the South Pole, the adventurers came upon a
strange island in the Atlantic, far from the coast of South
America.  On it was a great whirlpool, into which the Porpoise
was nearly sucked by a powerful current.  They managed to escape,
and had a glimpse of unfathomable depths.  They passed on, but
could not forget the strange hole in the island.

Mark suggested that it might lead to the center of the earth,
which is hollow, according to some scientists, and after some
consideration, Professor Henderson, on his return from the South
Pole, decided to go down the immense shaft.

To do this required a different kind of vessel from any he had
yet built.  He would need one that could sail on the water, and
yet float in the air like a balloon or aeroplane.

How he built this queer craft and took a most remarkable voyage,
you will find set down in the third book of this series, entitled
"Five Thousand Miles Underground."

In their new craft, called the Flying Mermaid, the professor, the
boys, Washington and Andy, sailed until they came to the great
shaft leading downward.  Then the ship rose in the air and
descended through clouds of vapor.  After many perils they
reached the center of the earth, where they found a strange race
of beings.

One day, to their horror, an earthquake dosed the shaft by which
they had come to the center of the earth.  The boys were in
despair of ever getting to the surface again, but the professor
had been prepared for this emergency, and he had built a strong
cylinder, into which all the travelers placed themselves.  Then
it was projected into a powerful upward shooting column of water,
which Professor Henderson hoped would take them to the surface of
the earth.  Nor was he mistaken.  They had a terrible journey,
but came safely out of it.

They opened the cylinder, to find themselves floating on the sea,
and they were rescued by a passing vessel.  Of course, they had
abandoned the Mermaid, leaving the craft in the center of the
earth, but they had brought back with them some valuable
diamonds, which formed their fortune.

This ended, for a time, the experiments of the professor, who
decided to settle down to a quiet life, and write out the
observations he had made on the three voyages.  The boys wanted
to get an education, and, investing their share from the sale of
the diamonds, they took up a course at the Universal Electrical
and Chemical College.  Each had an ambition to become as great an
inventor as was Professor Henderson, with whom they continued to
live in a small city on the Maine coast.  Washington White and
Andy Sudds also dwelt with the professor, Andy going off on
occasional hunting trips, and Washington acting as a sort of body
servant to Mr. Henderson.

Jack and Mark had completed one term at the college, and were in
the midst of the second when this story opens.

They had not lost their love for making queer voyages, and one of
their greatest desires was to help the professor turn out a craft
even more wonderful than the Electric Monarch, the Porpoise or
the Flying Mermaid.  It was in this connection that Jack was
experimenting on the new gas, when the slight accident happened.

"Are you going to try that again?" asked Mark, as he and his chum
walked along to their geometry class.

"Sure," replied Jack.  "I want that to succeed.  I know I am on
the right track."

"You came near getting blown off the track," remarked his
companion, which was as near to a joke as he ever would come,
for, though Jack was jolly and full of fun, Mark was more
serious, inclined to take a sterner view of life.

"Oh, I'll succeed yet!" exclaimed Jack.  "And when I do--you'll
see something--that's all."

"And feel it, too," added Mark, putting his hand on his head, the
book having raised quite a lump.

It was several days after this before the boys had the chance to
work alone in the laboratory again, and Jack had to promise not
to try his experiment with the new gas before this privilege was
granted him.

"Want any help?" asked Dick Jenfer, another student, as he saw
Jack and Mark enter the laboratory.

"Yes, if you want to hold a test tube for me," answered Jack.
"I'm going to try a new way of making oxygen."

"No, thanks!  Not for mine!" exclaimed Dick as he turned away.
"I don't want to be around when you try your new experiments.
The old way of making oxygen is good enough for me."

"Well, I have a new scheme," went on Jack.

Soon he and Mark, whom he had again induced to help him, were
busy with test tubes, rubber hose, Bunsen flames, jars of water,
and all that is required to make oxygen.

Somewhat to his own surprise, the experiment Jack tried was a
success.  He collected a jarful of oxygen, generated in a way he
had thought out for himself.  It was much simpler than the usual
method.

Just as he concluded the test, some one opened the laboratory
door.  It was Professor Lenton.

"I have a telegram for you," he said.

"A telegram?"

"Yes.  It just arrived."

Jack tore open the yellow envelope.

"It's from Professor Henderson," he said.

"Is anything the matter?" asked Mark.

"I don't know," answered Jack.  "It says: 'Come home at once.'
I wonder what's wrong?"

"I hope nothing serious," said Professor Lenton.

"You may both prepare to leave this afternoon.  I am sorry.  Let
me hear from you when you reach Professor Henderson.  I trust
nothing has happened to him.  He is too great a scientist for us
to lose."

WASHINGTON MEETS THE BOYS

All thoughts of experiments were driven from the minds of Jack
and Mark by the telegram.  They imagined that something had
happened to their old friend, and it worried them.  If he was
dangerously hurt, as might be, for he was constantly experimenting
in a small way, it would mean that a great change must take place
in their lives.

"What do you suppose can have happened?" asked Mark, as he and
Jack went to their rooms to get ready to leave the college.

"I haven't the least idea.  Maybe he wants us to go on another
trip."

Mark finished packing, and Jack was not far behind him.  Then the
lads went to the railroad station, where they purchased tickets
for home and were soon on a train.  On the journey they could not
help but refer occasionally to the telegram, though Jack kept
insisting that nothing so serious had happened.  Mark was not
quite in such good spirits.

"Well, here we are," announced Jack, about three hours later, as
the train pulled into a small station.  "And there's Washington
on the platform waiting for us."

Jack hurried out of the car, followed by Mark.

"Hello, Wash!" cried the fat lad.  "How are you?  Catch this
valise!" and he threw it to the colored man before the train had
come to a stop.  Washington deftly caught the grip, though he had
to make a quick movement to accomplish it.

"I 'clar t' gracious!" he exclaimed.  "Dat suttinly am a most
inconsequential mannah in which to project a transmigatory object
in contiguousness to mah predistination."

"Whoa, there!" cried Jack.  "Better take two bites at that,
Wash!"

"Dat's all right, Massa Jack," answered the colored man.  "I'se
glad to see yo', an' I suttinly hopes dat de transubstantiationableness
ob my--"

"Wow!" cried Jack.  "Say that over again, and say it slow."

"Don't yo' foregather mah excitability?" asked the colored man
rather anxiously.

"Yes, I guess so.  What's the answer?  How's the professor?
How's Andy?  What's the matter?  Why did he send for us?"

"Wait! Wait!  Please wait!" begged Washington.  "One ob dem
interrogatorial projections at a time, Massa Jack.  Where am
Massa Mark?"

"Here I am," replied Jack's chum, as he followed him out on the
platform of the train, which had come to a stop.

"Dats right!" exclaimed Washington.  "Let me hab yo' extended
article ob transportation an' I'll jest expidite it in--"

"I guess you mean it, all right," interrupted Jack.  "But what's
up?  Why did the professor send for us?"

"I doan't know, Massa Jack."

"You don't know?"

"Nopy.  He jest done gone tell me to send dat transmigatory
telegraph, an' dat's all."

"But why does he want us?  He's not sick, is he?" asked Mark.

"Never felt bettah!" exclaimed Washington as he walked along the
street leading from the depot, a valise in either hand.  "His
state ob health am equal to de sophistication ob de soporiferousness."

"You mean he sleeps well?" questioned Jack.

"Dat's what I done meant to convey to yo', Massa Jack."

"Well, why don't you say it?" asked Mark.

"Dat's jest what I done.  I said--"

"Never mind," interrupted Jack.

"Then you can't tell us why the professor sent for us?"

"He's got company," went on Washington, as if he had just thought
of that.

"Company?" exclaimed both boys.

"Yyais."

"Who is it?"

"Why, his name am Santell Roumann."

"What an odd name!" commented Mark.

"Is he a doctor?" asked Jack.

"He speaks wid a Germannes aceetnuation," said Washington.  "He
suttinly uses de most ogilistic conglomerations--"

"If he can beat you, he's a wonder," said Jack.  "But where did
he come from?"

"I 'clar t' goodness I doan't know.  All I knows is dat he jest
comed.  One day he wasn't dere, and come next day he was."

"Does the professor know him?"

"Suah!  He's a friend ob de perfesser," added Washington.  "De
perfesser was pow'ful glade t' see him."

"'Then he must be some scientist," said Mark.

"Dat's it!  He's chock full obscientistical bombasticness an'
labiodentalisms," said the colored man.

"I guess the professor wanted us to meet him and learn something
that we couldn't in college," spoke Mark.  "Well, we'll soon be
there."

"Yes," assented Jack.  "I want to find out what it's all about.
Santell Roumann--that's an odd name."

"An' he's a mighty odd man," supplemented Washington.

They reached the house a few minutes later, and went in the front
door.  The sounds of two voices came from the library.  One of
them was that of Professor Henderson. He was saying:

"I tell you it can't be done!  It is utterly impossible!  It is
madness to think of such a terrible trip!"

"And I tell you it can be done--it shall be done and you are the
very man to accomplish it," insisted the other.  "You and your
young assistants will succeed.  I know you will.  You will go
with me, and we will make the longest journey on record."

CHAPTER IV

WONDERFUL PLAN

"I wonder what they can be talking about?" asked Mark of Jack, as
they paused outside the library door.

"I don t know, but it concerns us."

"What makes you think so?"

"Because, didn't you hear the stranger speak of us as the 'young
assistants'?  That's us."

"Very likely.  But who is the man in with Professor Henderson,
and what is the wonderful journey he is talking about?"

"Dat gen'man in wid de perfesser am also a perfessor." Explained
Washington in a whisper.  "He's Perfesser Santell Roumann.  Now I
'spects I'd better saggasiate mahself inter proximity t' de
culinary reservation."

"You mean you've got to go to the kitchen?" asked Jack with a
smile.

"Dat's what I approximated to yo'," replied the colored man.

"I wonder if we'd better go in now, or wait until Professor
Henderson is through talking to Mr. Roumann?" asked Mark.

"Yo' am to go right in," remarked Washington.  "Dem's de orders I
got when I went t' de statione t' meet yo'."

"All right," assented Jack.  "Come on, Mark.  We'll find out
what's wanted of us."

The two boys entered the library, whence the voices of Professor
Henderson and Mr. Roumann could still be heard in earnest
discussion.  Mr. Henderson looked up as his proteges advanced to
the middle of the apartment.

"Jack!  Mark!" he exclaimed.  "I am very glad you came so
promptly.  I have something very important to communicate to
you--something that I hope will make up for the loss you suffer
in being taken away from college in the middle of the term.  Or,
to be more correct, Mr. Roumann will impart most of the
information, for it is at his suggestion that I sent for you."

"Are these the young assistants of whom you spoke?" asked the
other man, and the boys noticed that he was a big, burly German,
with a bushy, gray beard, and penetrating, blue eyes.

"This is Jack Darrow," said the professor, indicating the stout
youth, "and the other is Mark Sampson.  They have lived with me
several years now, and we have had many adventures together."

"Ha!  Hum!  Yes!" murmured Mr. Roumann, then he said something in
German.

"I beg your pardon," he went on quickly.  "I have a habit of
talking to myself in my own language once in a while.  What I
said was that I did not know the lads were so young.  I am
somewhat apprehensive--"

"Do not be alarmed on the score of their youth," cried Professor
Henderson.  "I assure you that they have had a peculiar training,
and, in some scientific attainments, they know as much as I do.
You will not find them too young for our purpose, in case we
decide that the thing can be done."

"I tell you it can be done, and it shall be done," insisted Mr.
Roumann.

"I have my doubts," went on Mr. Henderson.

Jack and Mark must have shown the wonder they felt at this talk
between the professor and his friend, for their guardian turned
to them and said:

"Boys, you must excuse me for not telling you at once the reason
why I sent for you.  The truth is that Mr. Roumann has laid a
very strange proposition before me.  It is so stupendous that I
hardly know whether to consider it or not.  I want to talk with
you about it, and see what you think."

"They will go with us, will they not?" asked Mr. Roumann.

"That is for them to say," replied Mr. Henderson.

"Go where?" asked Jack, wondering if there was in prospect
another voyage to one of the Poles, or a trip to the interior of
the earth.

Professor Henderson looked at the other man.  They were silent a
moment.

"Shall I tell them?" asked Mr. Henderson.

"Surely," assented Mr. Roumann.  "It all depends on you and them
whether we go or remain on earth."

Jack started.  Then there was a question of getting off the
earth.  He began to think there might be exciting times for Mark
and himself.

"Mr. Roumann has proposed a wonderful plan to me," went on
Professor Henderson.  "It is nothing more nor less than a trip
to--"

"Mars!" burst out the blue-eyed man.  "We are going to make the
most wonderful journey on record.  A trip through space to the
planet Mars!  Such an opportunity for reaching it, and proving
whether or not there is life on it, will not occur again for many
years.  It is now but thirty-five millions of miles away from us.
Soon it will begin to recede, at the rate of twenty-eight
millions of miles a year, until it is two hundred and thirty four
millions of miles away from us.  Then we may never be able to
reach it.  Now, when it is but thirty-five millions of miles
away, we have a chance to get there."

"I still believe it is impossible," said Professor Henderson in a
low voice.

"Nothing is impossible!" exclaimed Mr. Roumann.  "We shall go to
Mars!  I say it!  I who know!  I who hold the secret of the
wonderful power that will take us there, and, what is more, bring
us back!  I say it!  We shall go!"

"Impossible!" said the professor again, shaking his head.

"Don't say that word!" implored Mr. Roumann.  "I will prove to
you that we shall go."

"Go to Mars!" exclaimed Mark.

"Thirty-five million miles!" exclaimed Jack with awe in his
tones.  "How can we ever cover that distance?  No airship ever
made would do it."

"Not an airship, perhaps," said Mr. Roumann, "but something
else.  I will tell you how--"

"Perhaps I had better explain from the beginning," interrupted
Mr. Henderson.

"Maybe it will be better," assented the other.

"Boys, be seated," spoke their guardian, and Jack and Mark took
chairs.  "Mr. Santell Roumann is an inventor, like myself," went
on Mr. Henderson.  "I have known him for several years, but I had
not seen him in a long time, until he called on me the other day
with his strange proposition.  We used to attend the same
college, but since his graduation he has been experimenting in
Germany."

"Where I discovered the secret of the wonderful power that will
take us to Mars," added Mr. Roumann.

"That is one point on which we differ," continued Mr. Henderson.
"Mr. Roumann believes we can get to the red planet, which, as he
correctly says, is nearer to us now than it will be again in many
years.  I do not see how we can get there through the intervening
space."

"And I will prove to you that we can," insisted the other.  "The
power which I shall use is strongest known.  But it depends on
you and your young assistants."

"On us?" asked Jack.

"Yes," replied Mr. Santell Roumann.  "If and Professor Henderson
can build the proper projectile, we shall go."

"A projectile!" exclaimed Jack.

"A projectile," said Mr. Roumann again.  "I have studied it all
out, and I think the projectile, shaped somewhat like a great
shell, such as they use in warfare, or, more properly speaking,
built like a cigar or a torpedo, is the only feasible means of
reaching Mars.  We shall go in a projectile, two hundred feet
long, and ten feet in diameter at the largest point.  That will
offer the least resistance to the atmosphere of the earth, though
when we get within the atmosphere of Mars, and are subjected to
its attraction of gravitation, we shall meet with even less
resistance."

"Why?" asked Jack, who wanted to know the reason for everything.

"Because," answered Mr. Roumann, "from my observations I have
proved that the atmosphere of Mars is much less dense than is
that surrounding the earth, and the attraction of gravitation
there is about two-thirds less.  That is, an object that weighs
one hundred pounds on the earth will weigh only thirty-three
pounds on Mars."

"That's the stuff!" cried Jack.

"Why?" asked Mr. Roumann in some surprise.

"Then I'll have a chance to lose weight," replied Jack.  "I'm
getting too fat here.  I weigh a hundred and eighty pounds, and
that's too much for a lad of my age.  When I get to Mars I'll
only weigh--let's see, two-thirds of one hundred and eighty--"
and Jack got out pencil and paper and began figuring.

"It's sixty pounds!" exclaimed Mark, who was quick at figures.

"How are we to get to Mars, Mr. Roumann?" demanded Jack.

"I will tell you," answered the blue-eyed man.  "When you and the
professor have constructed the projectile, after plans which I
shall draw, I will apply my new, wonderful, secret power, and--"

"If yo' gen'men will kindly project yo'se'ves hitherward, an'
proceed to discuss de similitodinariness ob de interplanetary
conjunction what am waitin' fo' yo' heah, de obverseness of de
inner constitutions will be expeditiously relieved," spoke the
colored man, suddenly looking in the room.

"Does that mean supper is ready, Washington?" asked Professor
Henderson.

"Yes, sah.  It suah do."

"Then why didn't you say so?"

"I did, perfesser."

"Well, perhaps you thought so.  Washington has a very peculiar
habit of using big words, just because they sound so imposing,"
went on the professor.   "He spends all his spare time consulting
the dictionary."

"I have noticed it," remarked Mr. Roumann, smiling.

"Well, suppose we go out to supper?" went on Mr. Henderson.  "You
boys must be hungry."

"I can eat," admitted Jack.

"You'll get stouter if you do," warned Mark with a smile.

"Can't help it.  Wait until we get to Mars."

"Oh, yes, you didn't finish telling us how we were to get there,
Mr. Roumann," said Jack.

"I'll tell you while we're at supper," said the scientist.  "I
confess that Washington's announcement came just at the right
time.  I am very hungry."

CHAPTER V

THE SECRET POWER

For a few minutes after they were seated at the table nothing was
heard but the rattle of the dishes and the clatter of knives and
forks.  Washington was a fine cook, and there was a plentiful
supply of just what the boys liked best.

When the meal was well under way, the dining room door opened,
and a strange figure entered.  It was that of rather an aged man,
who walked with soft, cat-like tread, and who leaned forward, as
if on the trail of some enemy or wild beast.  His eyes were
bright, however, in spite of his age.

"Andy Sudds!" exclaimed Jack.  "I was wondering where you were."

"Well, snap my gunlock, if it isn't Jack Darrow!" exclaimed Andy.

"Any luck?" asked Mark, for he knew the old man must have been
hunting.

"And Mark, too!" went on the old hunter.  "Well, this is a
surprise.  No, I didn't have any luck--that is, what you could
call luck.  There's been a weasel carrying off our chickens and
killing them, and I went out to shoot it."

"Did you cotch it, Mistah Sudds?" asked Washington anxiously.

"I didn't 'cotch' it," answered Andy with a grin.  "I killed it.
I guess the chickens will be safe now, Wash.  But I'm hungry.
I've been hiding out there by the chicken coop all the afternoon.
But what brings you boys back from college?"

"We came home because we are going to take a trip to Mars,"
explained Jack.

"Mars!  Mars!  Good land!  Where'll you folks go next?" exclaimed
Andy.  "Wash, pass me some of that cold ham."

"You said you would tell us now how we were to get there, Mr.
Roumann," said Jack, who was anxious, as was Mark, to hear the
particulars.

"And so I will," replied the scientist.  "You must know that I
have long been interested in the planet Mars, for several
reasons.  Some reasons I will tell you now, and the others I will
disclose at a future time."

"Mars, you know, is the fourth major planet, computing their
positions in distance from the sun.  First there is Mercury,
then--"

"I know," interrupted Jack; "Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus and Neptune.  I learned them at school."

"That's right," said Mr. Roumann.  "But, while Mercury is only
about thirty-six millions of miles from the sun at its nearest
point, the closest it ever comes to the earth is fifty-seven
millions of miles, while, as I told you, Mars is now but thirty-five
millions of miles away, a difference in favor of Mars of
twenty-two millions of miles, quite a distance when one has to
travel it.  Neptune, the farthest of the major planets, is two
billion eight hundred millions of miles from the sun, and it is
separated from this earth by--"

"By two billion seven hundred and eight million miles," said Mark
quickly.

"How do you make that out?" asked Jack in some surprise.

"By subtracting ninety-two millions of miles, which is the
distance from the earth to the sun, from the number of miles
Neptune is away from the sun," said Mark.

"That's right," admitted Mr. Henderson.  "You're very quick at
figures, Mark."

"Well, let's get to Mars," said Jack.  "Maybe Andy can find some
new kind of game there."

"Me?  I'm not going to any place so many millions of miles away
from here," answered the old hunter, looking up from his plate.
"It's good enough hunting here."

"Wait until you see," said Mr. Roumann with a smile. "I expect
to find many marvels on Mars."

"If we get there," added Mr. Henderson.

"We'll get there," declared Mr. Roumann confidently.  "As I said,
I have long been interested in Mars, and one reason is that I
want to prove that there is life on it--that it is inhabited by a
superior race of beings.  Another reason is that I expect to find
on it a supply--or at least specimens--of a most valuable
substance--"

Mr. Roumann stopped suddenly.

"Well?" asked Mr. Henderson questioningly, for there was an odd
manner about the blue-eyed scientist.

"That is something I do not wish to speak about at present," said
Mr. Roumann quickly.  "I will tell you my other reason for going
to Mars--when we get there."

"Now, as to the method.  As I told you, Professor Henderson, and
as I intimated to you boys, we will go in a long, torpedo-shaped
projectile, which, though it will not be very large in diameter,
will be long enough to contain all our machinery and ourselves,
with a sufficient store of provisions for a year or more.  But I
know what you are going to ask, and that is: How can I send the
projectile through space?

"Well, I'll tell you--that is, partly tell you, for some parts of
my secret can never be revealed.  I have discovered a wonderful
power, more wonderful than man ever dreamed of before.  I have
called it Etherium, for the reason that I expect it to carry us
through the ether, or space that exists outside of the atmosphere
of this earth and that of Mars.

"Now, professor, do you think you and your assistants can build a
proper projectile?"

"We built an airship that went to the North Pole, we constructed
a submarine that took us to the South Pole, and we had the Flying
Mermaid, in which we went to the center of the earth," said Mr.
Henderson.  "I think we can build you the torpedo-shaped
projectile.  But what will make it move through thirty-five
millions of miles of space?"

"I will!" exclaimed the other.  "I and my wonderful, secret
power--Etherium!  If you will build the projectile I will do the
rest.  I will give you the plans for the machinery at once, and
you can begin as soon as you are ready.  You have a large
workshop here, I understand."

"Yes, we have all the means at our command," admitted Mr.
Henderson.

"But it must be built in secret," stipulated Mr. Roumann.  "No
one must know about it until we are ready to leave.  Several
unscrupulous men have tried to steal my secret."

"We can construct the projectile and machinery so that no one but
ourselves, and one or two trusty mechanics, will ever know about
it," promised Mr. Henderson.

"Good!  Now, when can you begin?  As I told you, Mars is already
beginning to move away from us at the rate of twenty-eight
millions of miles a year.  That is over two millions of miles a
month, and every day counts."

"We will start at once," promised Mr. Henderson.  "That is, if
Jack and Mark decide they want to go.  I will let them choose.
Boys, do you want to try to go to Mars, or go back to college?"

"Mars!  Every time!" cried Jack.  "I want to begin to weigh
less."

"I'll go wherever Jack goes," said Mark.

"Very well, then," assented the professor.  "But you must
remember, Mr. Roumann, that I am still unconvinced that you
possess the secret of a power that will project a heavy object
through space to Mars--thirty-five millions of miles away.  I do
not say it can't be done, only I want to be shown.  I will aid
you all I can, and I will accompany you.  But I fear we shall
never get to Mars."

"And I tell you we will!" insisted the other.  "Come, I will
prove it to you by mathematics, and by illustrating some of the
force of my new secret power.  Let us go to the laboratory."

The professor took from a valise, which sat in a corner of the
room, a bundle of papers.  Then, followed by the professor and
the boys, he started for the private laboratory of Mr. Henderson.

As they left the dining-room they heard an unexpected noise at
one of the windows.  They looked quickly up, and Jack saw the
face of a man staring in.

Before he could cry out, there came the sound of Washington's
voice:

"Hey dar!  Git away from dere!  Skedaddle, now, or I'll
prognostigate yo' inter modicums ob transmigatory infatisamatisms!"

The face disappeared from the window, and the sound of footsteps
in rapid retreat was heard.

CHAPTER VI

BUILDING THE PROJECTILE

"Did you see that?" exclaimed Jack.

"What?" asked Professor Henderson quickly.

"Some one at the window," replied Jack.

"I saw the face," added Mark.  "It was a man looking in."

"A man?  What sort of a man?" inquired Mr. Roumann, and he showed
some excitement.

"I couldn't tell very well," answered Jack.  "I saw him for only
a second.  But the man was looking right in."

"Did he have a heavy black mustache?" asked the German, and
strode rapidly toward the window.

"No, he didn't have a mustache at all," said Jack.  "He was
smooth-shaven.  I'm sure of that."

"Then it can't be he," murmured Mr. Roumann.

"Who did you think it was?" asked Professor Henderson.

 "I--I thought it was an enemy of mine," was the answer.  "Some
one who has been trying to discover my secret.  But the man whom
I fear has a heavy black mustache, and this one, you say, Jack,
had none?"

"None at all."

"Then it's all right."

Jack thought of saying that the man might have shaved his
mustache off, but he did not want Mr. Roumann to worry.

"I guess he was only a tramp," said Amos Henderson. "Some one
wandering about looking for a chicken coop that isn't locked.
Or, perhaps, seeking a chance to rob."

Jack said nothing, but from the glimpse he had had of the man's
face, he did not believe the fellow was a tramp.  There was too
much intelligence shown.  The face was an evil one, and seemed to
indicate that the man had an object in peering into the window--a
motive that was not connected with a chicken coop.

"I'll tell Andy to keep watch for a while tonight with his gun,"
went on the professor. "I don't like prowlers around here.  I
have some valuable tools in my machine shop, and they might steal
them."

"Now, Professor Henderson," began Mr. Roumann, when he had taken
his seat at a small table and spread out his plans in front of
him, "I am only going to sketch briefly, for you and your young
assistants, what I propose.  As I have said, we will need a
projectile, two hundred feet long and about ten feet through in
the thickest part.  In that we will build sleeping and living
apartments, lacks to store the air which we will have to breathe
while traveling through space, other tanks for water, a
compartment for food, another for scientific instruments, and we
will need a comparatively large space for my machinery."

"Why will it take up so much space?" asked the professor.  "I
thought you said the new power required only a small machine to
generate it."

"That is true, but you see we will have to carry two kinds of
machines."

"Two?  Why is that?"

"Because we are going to travel through two, and perhaps three,
different mediums.  We are going to shoot through the atmosphere
of the earth; then through the vast region beyond that, filled
with what is called ether."

"And is that different from our atmosphere?" asked Mark.

"Much different," replied Mr. Roumann.  "There is no air to it at
all.  The secret power which I have invented is perfectly adapted
to project us through this ether.  That is why I call it
Etherium.  Then when we reach Mars, we will find a different
atmosphere, somewhat like this earth's, I expect, but which will
require still another kind of power to move us in.  I hope,
however, that the same force which sends us through the limits of
the atmosphere of this earth will take us through that of Mars.
So that is why I need so much space for machinery."

"Well, I guess we can build the projectile for you," said Mr.
Henderson.  "It will take us nearly a month, though."

"No longer, I hope," said the German.  "Every day is valuable.
Once the projectile is finished we will enter it, seal ourselves
up, and be shot through space.  When we get to Mars--well, there
are many things to do when we reach there."

"I shall be much interested in seeing if they have discovered a
way of conquering the air," said Mr. Henderson.  "If they are a
race of superior intelligence, as some authorities believe, from
the fact that Mars may have been inhabited for millions of years
before this earth was formed, they must have advanced very
greatly in science.  The mastery of the air--in making flying
machines--would be one of the surest tests."

"I think you will find the Martians a very learned race,
professor," said Mr. Roumann.

"I want to see if the boys there are like the fellows on earth--
playing baseball, football and so on," marked Jack.

"I shall be interested in the colleges," added Mark, "and in the
great canals of Mars."

"I believe there will be plenty to interest us on the planet
which glows so red at night," went on Mr. Henderson.  "But, Mr.
Roumann, it is only fair to tell you that the building of this
projectile will cost considerable money.  I do not hesitate
on this account, but, as you know, the Flying Mermaid, in which
we went to the center of the earth, had to be abandoned there.
That was quite a heavy loss.  I should not like--"

"You will suffer no loss in this case," interrupted Roumann.  "I
appreciate that the projectile cost a large sum.  I have no money
to advance you, but I can promise you that when we reach Mars you
will be amply repaid.  We shall be rich--rich beyond your wildest
dreams.  There will be gold in untold quantities--"

"I never heard that there was much gold on Mars," said Jack.

"Not in the form of gold," said the German, who was growing very
excited, "but something that can be turned into gold.  I am on
the track of the most wonderful substance--that which gives Mars
its red color--that which will--"

He stopped suddenly.

"I must say no more now," he added, calming himself by a strong
effort.  "Sufficient to state that you will never regret making
the trip to the wonderful planet."

"But now about your new force--how powerful is it?" asked Mr.
Henderson.  "You promised to demonstrate it to me."

"Yes, and I will do so."

Thereupon the German plunged into a mass of figures and
calculations, which were quite puzzling to the boys, but which
seemed very clear to Mr. Henderson.  The German drew several
rough outlines, and the discussion became quite technical. Toward
the close, the inventor of the-secret force gave a demonstration
of its power.  By means of certain chemicals and an electric
current he developed from the end of a wire a force sufficient to
knock over a heavy block of steel, weighing over a ton.

"That is only a small sample of what my force will do," he said.
"In the proper machine it will be ten times more strong.  The
conditions here are not exactly harmonious.  Now, are you
satisfied, Professor Henderson?"

"Yes.  I could not help but be after that demonstration, it is
wonderful."

"And you will make the projectile for me--for us?"

"I will.  I'll start at once."

"Good!  And I promise that you will come back from Mars even more
wealthy than you were when you returned from the center of the
earth."

"Most of that wealth is now gone," said Mr. Henderson with a
smile.  "I have enough left, however, to build the projectile,
and we'll start at once."

"Hurrah for Mars!" cried Jack.

"And the marvelous red substance!" added Mark.

"Hush!  Not a word about that!" cried Mr. Roumann warningly.
"That must be kept a profound secret!"

The next day the boys, Professor Henderson, Washington White, and
some trusty machinists began the building of the Annihilator, as
the projectile was to be called, because it was to annihilate
space.

CHAPTER VII

AT TERRIFIC SPEED

"Now, boys," remarked Mr. Roumann one morning about a week after
work had been in progress on the projectile, "I did not mention
it, of course, but I hope you will not let it become known in the
village that we are constructing a machine in which to proceed to
Mars.  It would not do to have a lot of curious people out here."

"Oh, you needn't worry about that," replied Jack.  "We have built
several things in the shop here, and no one ever knew about them
until we were ready to have them start off."

"We'll tell Andy Sudds to keep on guard with his rifle,"
suggested Mark.  "That will prevent curious persons coming too
close."

"That will be a good idea," declared Mr. Roumann.

"You need have no fear of anything being discovered," put in Mr.
Henderson, who was busy planning the engine-room of the strange
craft.

"When we first came here we used to be bothered by curious
persons, but I soon found a method of keeping them away."

"How was that?" inquired the German.

"Why, I ran a wire all around the shop, and charged the conductor
with a mild current of electricity.  Some people got shocked by
coming too close, and after that they gave my place a wide berth.
I'll do the same thing now."

"A fine idea," commented Mr. Roumann.  "But what about Washington
White?  He is so fond of talking, and using big words, that he
may disclose our plans."

"No, I can trust Washington," declared the professor.  "But, as a
further precaution, I have not told him what our object is.  All
he knows is that we are building a new machine, but he does not
know what it is for, nor where we are going."

"That's good."

"Maybe when he does find out he'll not want to go," added Mark.

"Do you intend to take him with us?" asked Mr. Roumann.

"I think so--if he'll go," replied Mr. Henderson.  "He has always
been with me, and he is very helpful on these trips.  But I shall
not tell him where we are going until we are almost ready to
start.  But now, Mr. Roumann, I'd like to consult with you about
the installation of the motor, or whatever we are to call it, by
means of which your secret force is to be used."

"A motor will be as good a name as any other.  We'll call it the
Etherium motor."

"What will we call the other one?" asked Jack.

"What other one?"

"The motive power by which we are to go through the atmosphere of
the earth."

"Well, we can call that the atmospheric motor," replied Mr.
Roumann.  "However, there is no hurry about that.  I want to get
the work in the engine-room under way first."

He and the professor were soon deep in the discussion, while Jack
and Mark, with the aid of the machinists, were busy constructing
the main part of the projectile.

The first thing to be done was to build the shell of the
projectile.  This consisted of plates of a new and peculiar
metal, invented by Professor Henderson.  The plates were riveted
together, in the shape of a great cigar, two hundred feet long.
This work took some time, but, as the professor had in his shop
the proper machinery for it, a small force could accomplish a
great deal of work.

The rear of the projectile was to be occupied by the mysterious
apparatus that was to drive it through space.  In this compartment
would be many strange machines, including the one which Mr. Roumann
had invented to use the terrific and secret force of which he was
the discoverer.

There were apparatus for distilling water from the atmosphere,
others for manufacturing oxygen, dynamos for furnishing light to
the interior of the Annihilator, motors for working the various
small machines, and a number of other appliances.

Forward from the engine-room was a space to be used in storing
away the food supplies, and the materials necessary for generating
the force used, as well as for making a new supply of air when
needed.

Amidships was a living-room, with a plate-glass window on either
side.  There was not much space to move about in it, as, owing to
the long and narrow shape of the projectile, economy of room was
enforced.  Still, the place was a lengthy one, with tables and
chairs, which could be folded up out of the way when not in use.
There was provision for a library of scientific and other books,
and a piano played by electricity and brass disks, somewhat on
the order of modern player-pianos.

"What are those apertures in the sides of the living-room?" asked
Jack of Mr. Roumann, as the lad glanced over a sheet of
blue-print paper, on which was shown a plan of the projectile.

"Those," said the German, "are for the guns."

"Guns!" exclaimed Mark.  "Why, they're too big for guns.  They
are large enough to put a cannon through."

"And that is just what is going to be put through them, my boy,"
went on Mr. Roumann.  "From those openings, and you will see that
there are four of them, will protrude the muzzles of my electric
cannons."

"Do we need them?" asked Jack.

"You can't tell what we'll need when we get to Mars," was the
slow answer.  "You must remember that we know nothing about the
inhabitants of the planet.  While I believe that the people there
are of a very high grade of intelligence, we must be prepared for
the worst.  We may find them terrible savages, who will want to
attack and destroy us.  With the electric cannon we can defend
ourselves."

"That's so," admitted Jack.  "We had to fight the Esquimaux up
north,"

"And the putty-men in the center of the earth," added Mark.

Forward of the living-room, and near what corresponded to the bow
of the projectile, were the sleeping-rooms, consisting of two
long, narrow compartments, with a passageway between them, like
the aisle in a sleeping-car.  The beds were berths against the
wall, much as in the Pullman cars of to-day.

In the very "nose" of the Annihilator was the pilot house.  Here
were grouped together the wheels, levers, cams, gears, pistons
and other apparatus that controlled the big projectile.  Standing
in it, and peering out through a heavy plate glass window, the
operator could guide the machine in any direction he desired, and
he could also regulate the rate of progress.

A number of scientific instruments were carried, for showing and
registering the speed and direction of the Annihilator, the
distance it was above the earth, and there was an indicator to
note how near the travelers came to Mars.  There was also a
powerful telescope, and a number of cameras so arranged that they
would automatically take pictures.

"We'll have to travel through space pretty fast in order to cover
thirty-five millions of miles," observed Jack, stopping in his
work of helping rivet some of the plates.

"About how fast will we have to go, Mr. Roumann?"

"I have it all figured out," replied the German.

"I hope our projectile will stand it," remarked Mr. Henderson.
"We did not have to make such terrific speed on our other
voyages."

"I think that the Annihilator, as we have planned it, will not
suffer from the strain of speed," when on Mr. Roumann, looking up
from his study of some blue-prints.  "You may be astonished when
I tell you we shall have to travel at the rate of one hundred
miles a second."

"One hundred miles a second!" exclaimed Jack.  "That's pretty
fast, isn't it?"

"It's at the rate of eight million six hundred and forty thousand
miles a day," came from Mark, who was a rapid figurer.

"And to cover thirty-five million miles would take us less than
five days," said Jack. "But such an enormous speed--"

"We must travel at about that speed," interrupted Mr. Roumann,
"though I fancy we will be nearer ten days than five in reaching
Mars."

"Why?" asked Jack.

"Because we will not dare travel at such terrific speed as one
hundred miles a second through the atmosphere of the earth.  We
would be burned into cinders by the mere friction of the air.
Therefore, I shall send the Annihilator comparatively slowly
through the earth's atmosphere, and perhaps I will find that I shall have
to do the same thing when we near Mars.  But while traveling through
the ether, or the space that is between the two        can go as fast
as we like, which will as Mark has said, eight million miles per day."

"But even that rate," began Jack, "is going to pretty fast."

"It is faster than almost anything except light," went on Mr.
Roumann.

"Light travels one hundred and eighty-six thousand miles a
second," stated Mark, who remembered his physics.  "That's more
than seven times around the earth in a second."

"Correct," said Mr. Roumann with a smile.  "But sound, as you
know, only goes a little over a thousand feet a second, at a
temperature of thirty-two degrees above zero.  In a warmer
atmosphere it travels slightly faster.  We are going much faster
than sound ever travels.  A cannon ball will travel about three
thousand feet per second, so we are even going to beat cannon
balls.  At least, we hope we are, when we get beyond the earth's
atmosphere."

"That's going to be terrific speed," remarked Jack dubiously, as
if there was some risk in it.

"You need not worry," said Mr. Roumann.  "You know we are building
the Annihilator with a double shell, with a space between the two
walls."

"Yes?" said Jack questioningly.

"Well, in that space I intend to put a new kind of gas, that will
absorb all the heat that may be generated by our flight through
space," went on Mr. Roumann.  "Now that you know you have
nothing to fear, let us go on with the work."

CHAPTER VIII

A MYSTERIOUS THEFT

"Would yo' kindly permit me t' prognostigate yo' attention fo' de
monumental contraction of impossibilitiness in de circomlocution
ob attaining de maximum nutrition ob internal combustion?" asked
Washington White about an hour later, as he poked his head into
the workshop, where the professor, the boys and Mr. Roumann,
together with the machinists, were busily engaged.

"What's that, Wash?" asked Jack with a wink at Mark.  "Would you
mind saying that over again?"

"Not in de leastest, Massa Jack," replied the colored man.  "What
I done intended to convey to de auditory sensibilities ob de
auricular nerves ob do exterior contraption ob de--"

"Hold on, Washington!" cried Professor Henderson with a laugh.
"That sounds as if it was going in be worse than the other.  Did
I understand you to say that you wanted us to come to dinner?"

"Dat's jest it, pertesser.  I done 'spress mahself in de most
disproportionate language what I knows how, an' yet it seems laik
some pussons cain't understand de appreciableness ob simplisosity."

"Simplisosity is a new one," murmured Mark, while Washington,
with an injured look at Jack, who was laughing, went back to his
kitchen to prepare to serve the meal.

"I wonder what we'll get to eat when we get up above?" asked
Jack, taking advantage of a lull during the meal, when Washington
was in the kitchen, for it had been agreed that nothing was yet
to be said to the colored man as to their destination, though
Andy Sudds knew of their plans.  But Andy could be depended on
not to talk too much.

"Eat?" repeated the professor.  "Why, I fancy that we will take
enough along from the earth to last us, eh, Mr. Roumann?"

"Not altogether.  I am positive that there is life on Mars, and
where there is life there must be things to sustain it.  Perhaps
the food there will not be such as we are used to, but when our
supply, runs short we will have to depend on what we will get
there."

"How long do you expect to stay?" asked Mark.

"It is hard to say.  When I get what I want I shall be ready to
return--that is, after having studied the inhabitants and made
some scientific observations."

"Maybe the Martians will like us so that they let us come back,"
suggested Jack with a laugh.

"Oh, I fancy we will be able to get away," said Mr. Roumann.
"But now I must get back to the shop.  I am having a little more
trouble with my Etherium motor than I anticipated."

"I don't exactly understand how that works," said Jack.  "The
plans don't call for any opening the stern of the Annihilator for
a propeller to project from, and there is no provision for a
tube, such as we used to send compressed air from the Flying
Mermaid.  Nor is there anything in front to pull the Annihilator
along."

"We need nothing like that," explained the German scientist.
"The powerful force which I discovered does not need a tube or a
propeller to enable it to be used.  The simplest explanation of
it is that it consists of waves of energy, which pass from
certain square surfaces attached to the motor.  The force flows
from the plates right through the stern of the ship, passing
through the metal without the necessity for any openings.  The
wireless waves, as they may be called, act on the ether, and, by
pushing against it send the projectile forward, just as if it was
a stream of compressed air acting on the atmosphere, or a
propeller in the water.  Of course, that is to be used when we
pass beyond the atmosphere.  In the latter space I shall use a
different force, as I also shall when we approach Mars."

"Then you can't see this force?" asked Mark.

"No more than you can see the wireless impulses that flow from
the wires of an aerial station."

"Yet it's there, just the same," spoke Jack.

"Indeed, it is," answered the scientist.  "But, now I must get
back to my motor."

"Yes," added Professor Henderson, "we must, all get busy.  What
are you going to do, Andy?"

"Well, I thought I'd go off hunting.  I'm no good at building
machinery.  I thought you might like something for dinner--say a
brace of ducks."

"Good!" cried Jack, who was fond of eating, which, perhaps,
accounted for his stoutness.

It was a fine day, just right for hunting, and Andy set off with
his gun over his shoulder.

"I wonder if there'll be any game on Mars," said Mark.  "I think
I'd like to hunt there with Andy."

"If other things are in proportion, the game there will be very
different from that on this earth," said the scientist.  "We may
find monsters there which you never dreamed of."

"That'll be just the stuff for you, Andy," cried Jack.

"Well, bring on your monsters," said the old hunter, as he walked
toward the little lake, where wild ducks abounded.  "I'll try and
shoot some for you."

"Andy takes everything as a matter of course," went on Jack.  "No
sort of animal seems to frighten him.  If he should happen to
meet a dinotherium, such as used to live ages ago, he'd shoot it
first, and wonder about it afterward."

"And we, are likely to meet with stranger beasts than
dinotheriums on Mars," said Mr. Roumann.

"What am dat dinotherium?" asked Washington, entering the room at
that moment and catching the word.

"Washington wants to work that into his conversation!" exclaimed
Jack with a laugh.  "But you want to be careful, Wash."

"Why so, Massa Jack?"

"Because the dinotheriurn was a fearful beast.  It was about
twenty feet long, lived in the water, and ate all sorts of
weeds."

"How long you say he was?"

"About twenty feet."

"He must eat a pow'ful sight ob weeds, den.  Wish I had one."

"What for?"

"Cause mah garden am jest oberrun wid weeds.  If I had one ob dem
dinnasorriouses--"

"Dinotheriums," corrected Jack.

"Dat's what I said," observed Washington with dignity.  "If I had
one ob dem, I wouldn't hab t' weed mah garden.  Where am one to
be possessed ob, Massa Jack?"

"I guess you were born a few million years too late," was the
lad's answer.  "They lived a few centuries before the flood."

"Good land!" exclaimed Washington, his eyes opening wide.
"Before Noah built de ark?"

"Yes."

"Landy gracious!  Dat animai'd be so old by dis time dat he
couldn't chew de weeds after he pulled'em.  Guess I'll hab t'do
mah own weedin'."

"I reckon you will," added Mark.

They went back to the machine shop, and for the next week were
very busy over the Annihilator.  It was beginning to assume
shape, and some of the machinery was installed.

One evening, after a hard day's work, when they 'were all seated
in the big living-room of Professor Henderson's home, discussing
the progress they were making, Jack suddenly held up his hand for
silence.

"What's the matter?"' asked Mark.

"I thought I heard somebody walking around the house," was the
stout lad's answer.

"Maybe it's Washington," suggested the professor.  "He generally
goes out to see if his chickens are shut up.  He is very proud of
his flock of hens, and seems to hate to kill any for pot-pie."

They all listened.  Plainly there was some one or some animal
moving about under the windows of the living-room.

"That doesn't sound like Washington," said Mr. Roumann.

Just then the colored man, who had been upstairs, attending to
some of the housework (for he was the only servant the professor
kept), came down.

"Were you just outside, Washington?" asked Mr. Henderson.

"No, sah.  I'se been upstairs, makin' beds."

"There it is again!" cried Jack suddenly.

The footsteps sounded more plainly, and one of the window
shutters rattled.

"Dat's somebody after mah chickens!" exclaimed the colored man.
"I'se gwine t' git him, too!"

He started for the door, but the professor held him back.

"Let Andy go," he said.  "He will make less noise than any of
us."

He looked at the old hunter and nodded.  Andy understood, and,
taking his gun from a corner, slipped out of a side door, making
no more noise than a cat.

The others, left in the living-room, waited in silence.  They
could hear the stealthy footsteps, which, however, seemed now to
be moving away.

"I wonder who or what it can be?" murmured the professor.  "This
is the second time some one has been sneaking around here.  I
don't like it."

"It does look suspicious," admitted Jack.  "Do you suppose the
man you spoke of, Mr. Roumann, who you thought might try to
discover your secret, has traced you here, and is endeavoring to
steal it?"

"No, I hardly think so.  I took good care to conceal my
movements, and not even my closest friends know that I am here
with Professor Henderson, making a projectile, the trip of which
will astonish the world.  No, I think this must be some other
person."

"It's a pusson after mah chickens!" insisted Washington.  "If
yo'll allow me, perfesser, t' project mahself inter de promixity
of his inner consciousness--"

"No, you just stay here," decided Mr. Henderson.  "You might get
into trouble if you went out and tried conclusions with a thicken
thief, which I suppose is what you are trying to say you want to
do."

"Dat's what I did say, perfesser."

They could no longer hear the footsteps, but the silence of the
night was suddenly broken by the report of Andy's gun.

"There!  He's shot at him!" cried Jack.

"I hope he disabled dat chicken stealer!" yelled the colored man.
"Anybody what'll steal chickens--"

"Hush!" commanded Mr. Henderson.

Another shot rang out, and then the sound of footsteps could be
heard.

"He's running past here," called Jack, hurrying to the door.

He caught sight of a dark figure rushing past, and was about to
follow, but the outline was immediately lost in the darkness, and
Jack that it would be a useless move.  Andy came up.

"Did you hit him?" cried Jack

"No.  I only fired over his head," replied the old hunter.

"Who was it?"

"I don't know, but it was some man prowling around, and for no
good purpose, I take it."

"Did he steal any ob my chickens?" asked Washington.

"No; he wasn't near the coop."

"I guess it was only a tramp," said Mr. Henderson.

"I hope he doesn't go near the machine shop," added Mr. Roumann.
"Still, if he did, the two machinists sleeping there would hear
him."

They returned to the room, and Andy stood his gun in a corner.
The weapon was seldom far from him.

"What was he doing when you saw him?" asked Mr. Henderson.

"Just sneaking along the window here as if listening."

"Maybe he was trying to hear what we were talking about,"
suggested Jack.

"Or trying to discover my secret," added Mr. Roumann quickly.
"Fortunately I never talk about the secret of the power.  But I
shall be anxious about the machine shop."

"Suppose we go out and take a look around it," proposed Mark.
"Ned and Sam will know if any intruder has been sneaking around
there."

They all went out where the Annihilator was in process of
building, but the machinists said they had not been disturbed,
and they were sure no one had stolen anything.

There was no further disturbance that night, but when Mr. Roumann
paid an early visit to the machine shop the next morning, he
uttered a cry of surprise.

"What is it?" asked Jack, who accompanied him.

"The plates--the plates of the Etherium motor!" cried the
scientist.  "They have been stolen!"

CHAPTER IX

A CRAZY MACHINIST

For a moment Jack stared at Mr. Roumann.  He did not appreciate
the seriousness of the announcement.  The scientist was hurrying
here and there, looking under benches and on tables for missing
plates.

"Do you mean the plates that make the motor go?" asked Jack.

"No, not those, but the plates from which the mysterious force is
projected into space--the plates that give the forward motion to
the projectile.  They have been stolen.  They were taken last
night, and the man Andy fired at stole them!"

"Will that prevent us from making the trip?"

"No.  I have duplicate plates."

"Then little harm is done."

"No particular harm is done to the projectile, but I am afraid
that, with the plates in his possession, the man may discover the
secret of the power that I use.  Oh, I should have locked them
up, but I thought they would be safe."

"What has happened?" asked Mr. Henderson, entering the machine
shop at that moment.  The scientist told him, and expressed his
fear.

"Do you really think there is any danger that the man, whoever he
was, will learn how to use the plates?" inquired the professor.

"Perhaps, and then, again, perhaps not.  I think it will be very
difficult for him to work out the secret of the power from the
plates, for they are only a small part of the mechanism.  Still,
he may do so.  I am convinced now that this man is either the
same one of whom I stand in fear, or he is some one hired by him
to steal my secret."

"Then we had better notify the police," suggested Mark.

"No, that would never do," answered Mr. Roumann.  "I would have
to describe the plates, in order to have the authorities identify
them in the possession of the thief, and I do not care to do
that.  No; the best plan will be to hasten work or the Annihilator,
and start for Mars before the thief can gain any advantage from the
plates.  If he should succeed in discovering from the plate how to
make the power that is discharged in wireless currents, it will take
him a long time, and we can be away before then.  Let us hasten our
work and start for Mars."

"You say you have duplicates of the plates?" asked Jack.

"Yes.  I was afraid lest something happen to one set, so I made
three.  Well, it will do no good to worry, but I wish I had the
plates back."

"I don't see how he got them," observed Mark.  "There doesn't
seem to be anything broken, to indicate how the thief got in, and
he certainly didn't touch Professor Henderson's live wire."

Not a window or a door had been forced, and the two machinists,
who slept in the shop, declared they had heard no suspicious
sounds during the night.  It was a mysterious theft, and there
seemed to be no means of solving it.

At Mr. Roumann's suggestion they all increased their hours of
work on the Annihilator.  They wanted to have it finished ahead
of the time set, and it seemed that this would be done.

Day after day, and far into the night, they labored.  Bit by bit
the machinery was installed, the supplies were gathered together,
the great water tanks were built, to provide a supply of the
fluid in case of any accident to the distilling apparatus.  The
Etherium motor was almost finished, and the other, motor, which
was to drive the Annihilator through the earth's atmosphere, was
nearly ready to install.  The steering apparatus necessitated
considerable labor, and when it was finished Amos Henderson
declared they had made a mistake, and would have to build it all
over again.

This lost them a week, and time was precious, as there was no
telling what the thief would do with the stolen plates.

"I tell you what, but we're going to have a better ship than any
of the others we built," remarked Jack one day, as he and Mark
were putting the finishing touches to the living-room.

"This isn't a ship," said Mark.  "It's a projectile."

"I guess I can call it a ship if I want to," was the retort.
"It's going to sail through the air, and it's an airship, of
course.  Wait until you see the one I'm going to build when I get
that new gas invented."

"I'll not go with you," said Mark.  "There's too much danger of
being blown up."

"There won't be, after I have it perfected.  But say, won't it be
fine when we're shooting through space to sit here in an easy
chair and read a book and eat sandwiches?"

"I guess you think as much of eating as you do of reading, Jack."

"Well, almost, that's a fact.  I must cut out some of my eating,
too.  I've gained five pounds this week, because of not doing any
studying.  But wait until I get to Mars.  Then I'll weigh less."

"I hope Mr. Roumann lets us help run the machinery," went on
Mark.

"I guess he'll have to.  He'll need help, and I understand that
he and the professor, you and I, and Washington and Andy are the
only ones going along.  He and the professor can't run the affair
all alone, and they'll have to have our help.  Wash and Andy
won't be much good at machinery."

"That's so.  My!  Think of steering a two hundred-foot projectile
through space, when we're moving at the rate of one hundred miles
a second!"

"Great, isn't it?" commented Jack.

"It would be a bad thing if it ever got away from us," said Mark.

"Yes; or if we steered into a comet."

"That's so.  We may run into one of those things--or a shooting
star."

"As long as we don't fall into the sun and get burned up we'll be
all right," went on Jack.  "And when we get to Mars I know what
I'm going to do."

"What?"

"Go for a sail on one of the big canals.  Mars is covered with
them, astronomers say."

"Maybe the Martians won't let you."

"Maybe not.  I wish we could start to-morrow."

"Well, we can't.  The Annihilator isn't near done.  We will be at
her for two weeks yet."

The boys were busy for some time fitting up the living-room.
They were in the midst of this occupation, and were conversing
about the strange experiences in store for them, when Jack was
startled by hearing a strange voice say:

"Say, don't you want some help building this airship?"

He looked up, to see a man standing near one of the entrances to
the projectile--an entrance that would be closed when the
Annihilator was finished.  The man was a stranger, and from his
appearance Jack judged that he was a mechanic.

"How'd you get in here?" asked Mark, for he knew it was against
the rules for any stranger to enter the machine shop, much less
approach the projectile.

"I walked," replied the man.  "I saw the door open, and I heard
hammering going on in here.  I knew it was a machine shop, and as
I'm a first class machinist, out of work, I thought I'd apply for
the job."

"How'd you get past the doorkeeper?" inquired Jack, for he knew
that Andy Sudds was supposed to be on guard with his gun.

"He wasn't at the door," went on the man.  "There was nobody
there, so I walked in.  Can't you give me a job on the airship?"

"How do you know it's an airship?" asked Jack.

"Oh, I know.  I know lots of things," and the man winked one eye
at the lad.  "I built a balloon once."

"Did you?" asked Mark.  He began to think perhaps the man might
be able to aid them.

"Sure I did.  I know about airships.  I'll work for low wages,
and I'll keep my mouth closed.  Oh, I know what patents mean.
Say," he went on in a whisper, "you'd be surprised to know where
I went in my balloon.  I'll tell you," and he looked around as if
to make sure no one was listening.

"Where did you go?" asked Jack.

"Up to the moon," was the surprising reply.  "And, say, it's all
a mistake about it being made of green cheese.  It's green
apples--that's what it's made of.  I know, for I was there, and I
ate some.  They gave me an awful pain in my head, too," and the
man passed his hand across his brow.  "A fearful pain," he went
on.

Jack and Mark looked at each other.  They did not understand the
man's strange talk and actions.

"You don't believe me, do you?" the stranger asked.  "Well, if
you want a good machinist, hire me.  I know all about airships
and traveling through space.  Why, I once did a dance on the tail
of a comet, only the comet got mad and shook me off. I'll show
you how I danced."

He threw a somersault, lighted on his hands, and began to waltz
about in the somewhat contracted space of the living-room of the
projectile.  Then he set up a loud shout as he regained his feet.

"That's how!" he cried.

The boys were alarmed.  The man was evidently crazy, or perhaps
he might be doing this for effect, in order to disarm their
suspicions, so that he could discover Mr. Roumann's secret.
They did not know what to do.

"Come on, we'll all have a dance!" cried the man.  "My name is
Axtell--Fred Axtell.  I used to live on the moon--tra-la-la!"

His loud voice attracted the attention of Mr. Henderson, who was
working at the far end of the shop.  The professor ran toward the
place where the strangely acting man was, the latter having now
emerged from the ship, followed by the boys.

"Here we go!  Off to the moon!" cried the man, and catching up a
big hammer he began to pound on the sides of the Annihilator as
if he would destroy the projectile.

CHAPTER X

WASHINGTON IS AFRAID

"Here!  Here! Stop him!  Grab that man!" cried Mr. Roumann, as
he rushed toward Axtell, who was hammering away madly.

Jack and Mark started for the fellow.

"Keep away!" cried the machinist, swinging the sledge toward the
boys.  "I want to work on an airship, and I'm going to do it.
I'll make some dents in it, and then I'll straighten them out!
Whoop!"

Mr. Henderson hastened forward.  He took in the situation at a
glance.

"That man is insane!" the professor whispered to the German
scientist.  "Let me deal with him."

"Do something quickly," pleaded Mr. Roumann, "or he will damage
the projectile."

"This is the way I work!" cried the insane man, and he brought
down the hammer with great force on the rounded sides of the
Annihilator.  He made quite a dent in it.

"Stop him!" begged Mr. Ronan.

Mark and Jack had retreated out of reach of the big hammer, the
professor and the German were consulting together, and in the
door of the shop appeared Andy Sudds with his gun.  He had gone
away for a moment, in which interval the crazy machinist had
appeared.

"Andy will scare him with his gun," whispered Jack to Mark.

Just then Mr. Henderson called out:

"If you want work, I can give it to you."

Axtell stopped his pounding of the projectile, laid his hammer
down, and asked in a mild voice:

"Can you give me work now?"

"Of course," answered the professor, as if it was the most
natural thing in the world to give work to insane persons.  His
calm manner and soothing words had a quieting effect on the
lunatic.  The glare died out of his eyes.

"Come with me," went on Mr. Henderson.  "I have some work
outside."

"What is it?" asked Axtell suspiciously.

"I want you to dig a hole so we can put this airship in it,"
whispered the professor.  "Come outside."

He wanted to get the man out of the machine shop, where he could
better deal with the fellow.

"That's just the kind of work I want," declared the unfortunate
person.  "I love to dig holes in the ground.  I once dug one
clear through to China.  Get me a shovel."

He seemed to have forgotten all about the projectile, and meekly
followed Mr. Henderson.  The latter led him some distance from
the shop, talking soothingly to the man, and promising that he
should soon have a shovel.  But there was no necessity for going
to these measures.

Axtell suddenly caught sight of Washington coming toward him, and
he exhibited the greatest fear.

"Hide me!" he exclaimed to the professor.  "Hide me in the
airship!  Here comes the king of the cannibal islands!"  And away
he ran at top speed and disappeared in the woods behind the
Henderson place.  A search was at once made, but he could not be
located.

Andy was rather worried lest he be blamed for not remaining on
guard, but no one thought of censuring him, as he was such a
faithful watchman and had only left the shop in answer to a call
from Washington, who thought he heard some strange animal after
his chickens.

"But I'll not desert my post again," declared the old hunter, as
he looked to the loading of his gun.

"If any other crazy men get inside, they'll have to answer to
me."

Work on the projectile was resumed, and for a week went on
uninterruptedly.  It was nearing completion, though there were
many details yet to look after.  Mr. Roumann was having more
trouble with his Etherium motor than he anticipated.

"The atmospheric motor is all right," he declared, "and it works
to perfection," which was indeed true, for in tests they made
they found that the motor, the force of which was only less
powerful and complicated than the secret power that was to hurl them
through space, would easily send the projectile through the
comparatively thin atmosphere of the earth.  They did not
actually move the Annihilator, since to do so would mean they
would have to take it out of the shed.  But they made tests and
experiments with heavy objects, applying the force to them, and,
by calculation, Mr. Roumann and the professor found that the
force would actually send the projectile on the start of its
journey.

"But there is one point about my Etherium motor that still
bothers me," said the German.

"Can I help you solve it?" asked Mr. Henderson.

"No, thank you.  I think I am on the right track.  I will have it
perfected in a few days, and then we will be off for Mars.  I can
scarcely wait until I get to that wonderful planet, thirty-five
millions of miles away, where I hope to get possession of a most
wonderful substance.  Once we are on Mars--"

"'Scuse me, Mistah Roumann," interrupted Washington White, who
happened to be in the machine shop at that moment, and overheard
what the scientist said, "'scuse me, but did I done heah yo'
promulgate de ostentatious fact dat yo' is gwine to de planet
Mars?"

"That's where we're going, Wash," replied Jack, for it had been
decided that the colored man could now be told of their
destination.

"Yo' means dat red star what shines in de sky?"

"That's the one, Washington."

"An' how far did yo' say it was from heah?" was the question
directed at Mr. Henderson.

"Well, it's about thirty-five millions of miles from the earth."

"And is yo' all goin'?"

"Yes, we expect to."

"Is dis heah contraption yo' done been buildin'?"

"Yes."

"And is I gwine, too, perfesser?"

"I calculated on taking you, Washington.  You went north and
south with me, and down into the center of the earth.  I thought
you'd like to go on this trip."

Washington laid down the hammer he had come in to borrow to fix
the chicken coop.  He looked around on the circle of smiling
faces.

"I--I 'spects I'd bettah be lookin' fo' annudder place,
perfesser," he said quietly.

"Why, you aren't afraid to go to Mars, when you went with us in
the Flying Mermaid down into the earth, are you?" asked Jack.

"'Scuse me, Massa Jack," said the colored man solemnly, "dis trip
am wuss dan any ob de udders.  It suah am.  Good land a' massy!
T' t'ink ob being projected transmigatorially in de obverse
tangent ob de parallelism circumdelegated on de inverse side ob a
duodecimo.  It's too altogether imparipinated fo' dis chile!
I'se afraid dat's what I is!  I'se too much afraid t' go," and
Washington started to run from the shop, as if he feared that the
big projectile would take after him.

CHAPTER XI

A STRANGE EXPLOSION

"Here, come back, Washington," called Mr. Henderson.

"No, sah! I ain't gwine t' entrust mahself 'n any sech t'ing as
dat!" cried Washington. "I ain't gwine t' be shot up froo de sky.
Why, good land a' massy!  'Sposin' we was t' hit a star, or land
on de moon?  I'd look purty, wouldn't I, hangin' on one ob de
moon's horns?  How's I eber gwinee git down?  I axes yo' dat.
How's I gwine f git down?"

"Well," said Professor Henderson with a laugh, "if you did get
caught on one of the horns of the moon, Washington, I guess it
would be a pretty hard matter to get down."

"Dat's what I done said," insisted the colored man.

"You could slide down a moonbeam," said Jack with a laugh.

"Yes, an' mebby git hit by a comet or be kamked sensible by a
piece ob star," objected Washington, as if Jack's plan was a
feasible one.  "No, sah, I ain't gwine along nohow.  Dis ole
earth am good enough fo' me.  I don't want to die an' go floatin'
through space.  When I dies I wants t' be buried decent-like.  I
ain't gwine wid yo' at all."

It began to look as if Washington's revolt was a settled fact.
Yet they depended on him to go.  However, Professor Henderson
solved the problem for him.

"Who will cook my meals for me, if you don't go, Washington?" he
asked solemnly.

"Is you really goin', perfesser?"

"I certainly am."

"An' yo' t'ink it's safe?"

"Yes, or I shouldn't go.  But I can't have much comfort if I
don't have my meals right, for I can't cook very well, and as for
Jack and Mark--"

"Hu!  Dem boys can't cook wuff a cent.  Is dey gwine t' go
'long?"

"We sure are," answered Jack.

"Hu!  Den I 'spects I'se got t' go," said the colored man,
scratching his head in perplexity.  "I can't let de perfesser go
alone, wid nobody t' do his cookin' fer him.  Well, I'll go,
but--but I'se mighty skeered, jest de same."

"You needn't be, Washington," said Mr. Henderson kindly.  "We
will be perfectly safe in the Annihilator, and when we get to Mars
I am sure you will like it there."

"I've got to, wedder I does or not," said Washington simply.
"Well, t' t'ink ob me seein' dis work goin' on, day after day,
an' me nebber suspectin' dat yo' was goin' on sech a transmigatory
flight in de direction ob an interplanetary sphere what transmits
effulgent rays transversely an' pyritiferilously changes 'em inter
crimson light most advantageously."

"I guess you're all right now, after getting that out of your
system," observed Mark.

It was two days after this that Jack and Mark, who were working
in the shop with Mr. Roumann, suddenly heard him utter a cry.

"Has anything happened?" called Jack, dropping his tools and
hastening to the engine-room, where the scientist was.

"Yes!" cried the German.

"What?"

He was pacing rapidly up and down the contracted space, waving a
piece of metal above his head.  Jack thought he might have hurt
himself.

"I have discovered what was the matter with my Etherium motor!"
exclaimed Mr. Roumann.  "I didn't bend this piece of metal
properly.  That was why the machine did not work satisfactorily.
Now it is all right.  We can start in a week."

"That's good!" said Mark, who had joined his chum.  "Are you sure
it will work now, Mr. Roumann?"

"Quite sure.  But we will have a test to make certain.  Send
Professor Henderson here, Please."

The other scientist came from the house, and the test was made.
To the delight of all the Etherium motor worked perfectly.  The
slight adjustment of the piece of metal had been all that was
needed.

"Now we can get ready to leave in a week," repeated the German
enthusiastically.

In fact, the projectile was finished, and all that was necessary
was to put in the stores and some supplies, turn on the power,
and they would be off through space.

The actual starting of the Annihilator was, of course, to be left
entirely to Mr. Roumann.  He had not disclosed to his companions
the secret of the force that was to make it move, nor had he told
them how to work the Etherium and atmospheric motors.  He would
start the machinery in operation, and he had promised to show the
professor and the boys how to control it, but the secret of the
wonderful power he kept to himself.

"I think we can let the two machinists go now," said Mr. Henderson
at the conclusion of the tests.  "We shall not need them any more if
we are almost ready to start."

"No, we can dispense with their services," agreed Mr. Roumann;
and, accordingly, Ned and Sam were paid off, and left, promising
to say nothing of the wonderful apparatus on which they had been
working.

The next week was a busy one.  Mr. Roumann spent most of his time
in the engine-room, assembling the machinery of the two motors,
and arranging the connections between them and the pilot house in
the "nose" of the projectile.  The strange gas had been forced in
between the two shells of the projectile, to absorb the heat that
would be generated by friction, and nearly all the stores had
been put aboard.

The electric guns were installed, ready to be run out of the
openings of the living-room to repel any attack of the Martians,
and then the ports were closed tightly.

Finishing touches were being put on the Annihilator, and Mr.
Henderson and his German friend were kept very busy.  As for the
boys, they helped wherever they could, and did considerable work,
for they had been well trained by their guardian.

Andy remained on guard at the door with his gun.  He said he was
going to take no more chances with the crazy machinist.

Nothing further had been seen or heard of the mysterious thief
who had stolen the plates, and it was supposed that he was unable
to make any use of them.

One afternoon, about three days before the time set to start for
Mars, Mr. Roumann was working alone in the machine shop.  The
boys and Professor Henderson had done all there was for them to
do, and the Annihilator was practically finished.

"Are you going to take along any extra-sized bullets, Andy?"
asked Jack of the old hunter, who was on guard, as usual, at the
door.

"I don't see why I should.  I guess the regular ones will do when
I get to Mars."

"I don't know about that," went on Jack.  "We may find bigger
game than elephants or sea lions there."

"If we do, I'll use a new kind of explosive electric bullet Mr.
Roumann told me about," declared Andy.  "It has a charge of
electricity in it, and he says it will kill the biggest animal
that ever lived, with one shot."

"Then you're all right," said Mark.  "Well we'll soon be on our
way now."

"I suppose Washington will want to take some of his chickens
along?" ventured Jack.

"Well, I don't see why he can't," said Andy.  "They take pigeons up
in balloons, and I guess chickens would live in the Annihilator--at
least, until we ate them."

They stood about the entrance to the machine shop, talking of
various topics, but they always came back to the subject of the
wonderful journey before them.

Suddenly Jack, who had strolled a little away from the door,
looked toward the rear of the big shed that housed the projectile,
and uttered a cry.  Mark heard him, and ran to his chum's side.

"Look!" exclaimed Jack, pointing to two men who were running away
from the shop.  "Who are those men?"

"One is that crazy machinist!" cried Mark.

"And the other is the tramp we saw looking in the window that
night!" added Jack.  "Come on!  Let's catch them!  They may
have done some damage!  Andy!  Here!  With your gun!  Quick!"

The old hunter hastened to join the boys.  He reached them in time
to see the two intruders making for the woods back of the shed.

"Hold on there!" cried Andy, quickly raising his gun and firing
over their heads.

But the men did not stop.  Hardly had the echoes of Andy's weapon
died away, than there sounded a loud explosion from the shop.  A
cloud of smoke poured from the windows.

"They've blown up the projectile!" cried Mark.  "Come on!"

They ran toward the place where the explosion had occurred.  As
they neared the end of the shed Washington came running out.  He
showed great fear.

"Come quick!  Come quick!" he cried.

"What's the matter?" shouted Jack.

"Somebody's blowed de place up, an' Mr. Roumann am killed!" was
the answer.

CHAPTER XII

THE ELECTRIC REMEDY

"Get Professor Henderson!" directed Jack, "Where is Mr. Roumann,
Washington?"

"In heah!" exclaimed the colored man, pointing to the shop.  "He
am all blowed to pieces!"

Jack and Mark were terribly afraid.  The smoke of the explosion
hung all about.  They rushed through it, and into the shop.  Part
of the side of the wooden building had been blown out.

"Where is he?" asked Mark.  "I can't see anything."

"Over here," called Jack, as he saw a huddled heap in one corner.
As the smoke cleared away he could see pieces of machinery
scattered all about.

"Is the projectile damaged?" asked Mark anxiously.

"Doesn't seem to be--at least, on the outside," answered Jack, as
he looked at the huge shape of the Annihilator looming up before
him.  "But I'm afraid it's all up with Mr. Roumann."

He bent over the German scientist.  The man seemed lifeless.
There was quite a cut on his head and his clothes were torn.

"He's breathing a little!" cried jack.  "We must get Professor
Henderson here.  He'll know what to do--if anything can be done
for him."

"They must have exploded a bomb in here," said Mark, as he looked
around at the ruin about, them.

"Something like that," admitted jack.  "Here, help me carry Mr.
Roumann out of the fumes," for there was a choking smell in the
shop.

The two boys found it hard work to carry that limp form out, but
they managed it.  Just as they got outside the shop they saw
Professor Henderson running toward them, followed by Washington
and Andy.

"What has happened?" asked the inventor, for he had not been able
to learn much from Washington's excited account.

"I don't know," answered Jack.  "We heard a explosion, just after
we saw two men running away from the shop, and we found Mr.
Roumann senseless."

Professor Henderson bent over, and placed his hand on the heart
of his friend.

"I'm afraid he's dying," he said.

"Dying?" cried jack in dismay.

"Yes; and if he expires, the secret of the wonderful power will
die with him.  We will never be able to get to Mars!"

The professor placed his ear against the breast of the unconscious
man.

"There is still a spark of life," he remarked.  "Perhaps I can
save him.  I will try my electric remedy."

He got up and hurried to the house. Mr. Henderson had invented a
number of medical appliances, not the least of which was an
affair, different from an electric battery in that it allowed a
current to be administered internally.  It was this that he now
decided to try on the unfortunate German.

He came back in less than a minute with a curious machine.  It
was shaped like a box, but on the outside had a number of shiny
knobs, and several wires ending in brass handles.

Professor Henderson placed a brass handle in each of the palms of
the German, directing Mark and jack to hold them there.  Then he
placed several of the shining knobs at the back of his head, and
ran a long wire around his waist.

"Now, Andy," ordered the inventor, "if you will take hold of this
rod and place the end of it on his tongue when I open his mouth,
I think we may be able to revive him."

This was done, and Mr. Henderson turned on the current.  There
was a buzzing sound from the box, and a slight tremor was visible
throughout the whole body of the unconscious man.

"It is beginning to work!" exclaimed the professor.  "He is
coming to!"

Mr. Roumann opened his eyes.

"Take the rod from his tongue, Andy," directed Mr. Henderson.

The hunter did so, and the German, looking curiously about him,
asked:

"Is the projectile damaged?"

"It doesn't seem to be," replied Jack quickly.

"Are you much hurt?" asked the professor.

Mr. Roumann passed his hand slowly across his head.

"I feel rather strange here," he said.  "There seems to be some
injury."

Mark silently pointed to the cut.  Mr. Henderson quickly examined
it.

"The skull is not injured," he announced.  "It is merely a scalp
wound.  Wait a moment now and I will give you something to make
you feel better."

From a small pocket case he took a spoon and a bottle.  He poured
out a strong-smelling liquid, and administered a few drops to the
German.  The latter's pale face at once became flushed.

"I think you will be all right now," said Mr. Henderson.  "But it
was a narrow escape.  Do you feel well enough to let us take you
to the house?"

"I think so.  But guard the shop well.  That crazy machinist came
back, and some one was with him.  Then came an explosion--and I
don't remember any more."

"I'll guard the place!" exclaimed Andy.  "And if any of those
chaps come around--well, they'll wish they hadn't," and he looked
significantly at his gun.

Mr. Roumann was getting better every moment, and was soon able to
stand.  He was assisted to the house, where Mr. Henderson
attended to the injury on his head.

Then, after some more medicine had been administered, and the
electric remedy had been applied again, the German announced that
he felt almost as good as ever, except for an aching head.

"How did it all happen?" asked Mr. Henderson, and Jack and Mark
told what they knew of the explosion.

"I was working over an extra air-pump that I wish to take along
with us," stated Mr. Roumann, "when I was startled by seeing two
strangers standing near my work bench.  One I recognized as the
insane machinist who was here before.  The other--"

"The other was the same one who looked in the window one night,
and who, I believe, stole the power plates," interrupted Jack.

"I wish I had known that," went on Mr. Roumann. "I would have
made him give them back.  But I did not have time to do anything.
Before I could stop him the crazy machinist had thrown something
at me, which I now know must have been a bomb.  Then came the
explosion, and knew nothing more until you revived me.  Is the
place much wrecked?"

"I think not," answered Jack.

"We will go look in a little while; just as soon as we see that
you are all right," announced the professor.

"Oh, I am all right.  Go now.  I am anxious to know."

Having assured himself that the German was able to walk to the
shop, Mr. Henderson an assent, and the two boys, Washington and
two scientists started for the place where Annihilator was kept.

"How did you happen to see it, Washington?" asked Mark.

"I was out fixin' a loose board on mah chicken coop," explained
the colored man, "when I seen dem two rapscallions come runnin'
out ob de place.  I knowed dey hadn't no right dere, an' I
hollered at 'em.  But dey didn't stop, an' de nextest t'ing I
knowed dere was a big bang.  I run in, an' I seed Mistah Roumann
all blowed to pieces."

"Hardly as bad as that," said the German with a smile.

"Well, almost," insisted Washington.

They reached the machine shop.  The smoke had all cleared away,
but the fumes from the bomb were still noticeable.

"I wonder what their object could have been?" said Jack.

"I believe they are urged on by some of my enemies," was the
German's reply.  "But let us see what damage has been done.  I
hope it is not much."

Pieces of broken machinery, twisted wheels, bent levers,
shattered cogs and smashed plates were all about one corner of
the shop.  But the great projectile was still in place.  It had
not even been jarred.

Mr. Roumann went to an opening in the side that led to the
engine-room.  No sooner had he entered than he uttered a cry.

"The Etherium motor is damaged!" he exclaimed, and with fear in
their hearts the others followed him inside the Annihilator.

CHAPTER XIII

AN ALARMING THREAT

The main machines in the engine-room were the two motors, one
designed to send the projectile through the atmosphere, the other
intended to propel it through the space filled with what is
called ether.

It was to these two massive machines that the eyes of all were
now directed.  The smaller one, the atmospheric motor, did not
appear to have been damaged, but several wheels and pipes of the
other were broken and twisted.

"Is it ruined?" asked Professor Henderson.

Mr. Roumann was anxiously looking at the apparatus to see what
damage had been done by the bomb.

"Can't we go to Mars?" inquired Jack.

"I think so," was the reassuring reply of the scientist.  "It is
not damaged so much as I feared.  The wheels and pipes are easily
replaced, and as long as the generator and the distributing
plates are not disturbed, I can easily repair the rest.  But it
was a fortunate chance that the bomb did not explode nearer the
projectile.  Otherwise we would have had to give up our journey."

"And we would have had to if you had been killed," remarked the
professor.  "I thought the secret of the power was going to die
with you!"

"It will," replied Mr. Roumann, "but not just yet.  I shall never
disclose the source of the power until I reach Mars, get what I
am after, and come back.  Then I may bequeath it to you,
Professor Henderson, in return for the kindness of yourself and
your young assistants."

"I will appreciate that.  But you had better go to the house now
and let me doctor you up."

"No, I feel well.  I want to get right to work repairing the
damage.  It will delay us several days, but we cannot avoid it.
I wish I could catch the men responsible for this outrage."

"Have you any idea who they were?"

"No; but I suspect they were in the enemy of mine.  A man who
used to work for me, but whom I discharged because of dishonetesty.
His name was Zeb Forker."

"One of the men who threw the bomb was same one who was at the
window one night," said Mark.  "Do you suppose he could be
Forker, Mr. Roumann?"

"No, I do not believe so.  But we will not discuss that now.  I
fancy the men will not bother us again."

"I'll tell Andy to keep a better watch," said Mr. Henderson.

"And we'll help him," added Mark.  "There is little for us to do
on the projectile now, and we can do guard duty, Jack and I
together."

It took Mr. Roumann several days to repair the damage done to the
Etherium motor by the bomb.  During that time Andy and the boys
were constantly on guard about the shop, but the crazy machinist
and his companion did not return.

Washington White agreed to stand guard part of one night, and, as
the others were tired, they agreed to it.  But a fox or some
animal got in among the colored man's chickens, and at the first
sound of alarm from his favorite fowls, Washington deserted his
post and rushed for the coop.  Jack, who was awakened by the
noise, looked out of the window.

"It is some one trying to get in, Wash?" he asked.

"Dat's what, Massa Jack."

Jack awakened Mark, and the two hurried down with their guns.
They found the colored maw making a circuit of his coop.

"I thought you said some one was trying to get in," observed
Jack.

"So dey was, Massa Jack.  I done heard de most, tremendousness
conglomeration of disturbances in de direction ob my domesticoryian
orinthological specimens, an' I runned ober to see what it were."

"You mean that something was after your chickens?" asked Mark.

"Dat's de impression I done endeavored to prognostigate to yo',
but seems laik I ain't understood," replied Washington with an
injured air.

"Oh, I understand you, all right," said Jack, "but I thought you
meant some one was gettin in the machine shop."

"No, dere ain't been no one dere, but I was skeered dat somebody
was after mah chickens, but I guess it were only a rat.  I'll go
back an stay on guard now."

"No, you'd better go to bed," decided Jack.  "Mark and I will
finish out the night."

"All right," agreed Washington, who, to tell the truth, was getting
sleepy.

There were no further disturbances, and Mark and Jack found their
tour of duty rather lonesome.

"Well, I suppose we'll start in a day or so," marked Jack, as
they paced about the big shed which housed the great projectile.

"Yes.  The motor seems to be in good working order again.  But
say, I've just thought of something."

"What?"

"Suppose something should happen to Mr. Roumann or to the motor
while we were half way to Mars?  I mean, suppose he should die,
why, we wouldn't know how to stop the motor, and we might keep on
going forever."

"Oh, I guess he'll tell the professor enough about it so that in
case anything happened we could start it or stop it.  It's only
the secret of the power that he wants to keep."

"I wonder what he wants to go to Mars for, anyhow?"

"Well, you know what he said.  That he wants to get possession of
some wonderful substance.  I guess it is the same stuff that
makes the planet seem red to us."

"What's he going to do with it?"

"I don't know."

"Wonder what it is?"

"I don't know that, either. Maybe it's some sort of a mineral,
like radium."

"Radium would be valuable, if he could get that.  Maybe that's what
he's going after."

"No, I think not.  If it was, he wouldn't be particular about not
telling us.  We'll just have to wait and see."

The following two days were busy ones, as many little adjustments
had to be made to the machine.  But at last Mr. Roumann announced
that all was completed.

"We will start day after to-morrow," he said.  "All the stores
are in the projectile, I have every thing arranged, and we will
begin our trip Mars."

"Are we going to go up like a balloon, through the roof of the
shed?" asked Jack.  "If we we'll have to take the roof off."

"No, we'll start out through the great doors," said the German.
"My plan is to elevate the nose or bow, of the projectile, point
it toward the sky, at a slight angle, by means of propping it up
on blocks.  Then we will get in, seal all the openings, and I
will turn on the power, and off we go.  We can shoot right through the
big doors at the end of the shed, and no one will know anything
about it, for we will leave the earth so fast that before any one
is aware of our plans we will be out of sight."

"That is a good idea," commented Mr. Henderson.  "Have you boys
put everything in the projectile that you'll need?"

"I guess so," replied Jack, "though it's hard to tell what you
really will need on another planet."

"All I want is my gun and some ammunition," declared Andy Sudds.
"I can get along with that."

"How about you, Washington?" asked Jack.

"'Well, I suah would laik t' take mah fowls along."

"I don't see how you can do that very well, Wash," objected Mr.
Henderson.  "We would have to carry food for them, and our space
is very limited at best.  I'm afraid you'll have to get rid of
your chickens."

"Couldn't I take mah Shanghai rooster?" begged the colored man.
"He's a fine bird, an' maybe dem folks on Mars nebber seed a
real rooster.  I suah does hate to leab him behind."

"Oh, I guess you could take him," agreed Mr. Roumann.

"I'll gib him some ob my rations," promised Washington.  "He eats
jest laik white folks, dat Shanghai do.  Golly!  I'se glad I kin
take him.  I'll go out an' make a cage."

"What will you I do with the rest of your fowls, Wash?" asked
Mark.

"Oh, a feller named Jim Johnson'll keep 'em fer me till we gits
back.  Jim's a cousin ob mine."

The next day was spent in jacking up the prow of the projectile
so that it pointed in a slanting direction toward the sky.

"Am yo' aimin' it right at Mars?" asked the colored man, pausing
in the work of making cage for his rooster.

"No; that isn't necessary," said Mr. Roumann.  "Once it starts
upward, I can steer it in any direction I choose.  I can send it
directly toward Mars."

"Hit's jest like a boat," observed Washington.

"That's it."

"Well, to-morrow we start," spoke Jack that night, as they were
gathered in the dining-room of the professor's house after
supper, discussing the great trip.

"And to think that in ten days we'll be on thirty-five millions
of miles away from the earth!" added Mark.

"It's a mighty long way," said Andy.  "Mebby we'll never git
back."

"Oh, I guess we will," declared Jack "We got back all right
from--"

His words were interrupted by a breaking of glass.  One of the
windows crashed in, and something came through it into the room.
It fell upon the floor--a square, black object.

"Dat's one ob dem bombs!" cried Washington.  "Look out,
everybody! It'll go off!"

There was a scramble to get out of the room, Washington falling
down on the threshold.  Jack, who was in a corner, behind some
chairs, found his way blocked.  This gave him a chance to take a
little longer look at the object that had been thrown through the
window.

"That's not a bomb!" he cried.  "It's something wrapped in black
paper."

The professor, Mark and Mr. Roumann stopped their hurried egress.
They came back and looked at the object.  As Jack had said, it
was something tied up in black paper with pink string.

"It doesn't look like a bomb," observed Mark.

"More like a brick," said Jack, and started toward it.

"Maybe it's an infernal machine," suggested Mark.

Jack hesitated a moment, listened to detect any possible ticking
of some hidden clock mechanism, and then, as no sound came from
the object, he picked it up. Rapidly tearing off the paper, he
disclosed a harmless, red brick.

"Some one wanted to scare us," remarked Andy.

"There's a paper wrapped around the brick--a white paper," said
Professor Henderson.

"So there is," spoke Jack as he removed it.  "There's writing on
it, too."

He held it up to the light.

"It's a message," he went on, "and not a very pleasant one,
either."

"Who's it from?" asked Mr. Roumann.

"It's signed 'The Crazy Machinist', Jack, and this is what it
says:"

"Beware, I am still after you!  I will yet blow you sky-high!"

"He threw that in through the window!" cried Mark.  "He must be
outside here.  Let's see if we can't catch him."

"That's right," added Jack.  "Andy!  Washington!  Come on!"

The boys, followed by the hunter and the man, hurried from the
house.

CHAPTER XIV

OFF FOR MARS

It was dark outside, and coming from the lighted room, the
searchers at first could discern nothing.  Then, as their eyes
became accustomed to the gloom, they could make out objects with
greater distinctness.

A movement in a tree, just outside the broken window, attracted
the attention of Andy.

"Here's something!" he cried.

He raised his gun, which he had caught up as he rushed from the
house, and fired high enough in the air, so as not to hurt
whoever was in hiding.  The flash of the weapon showed a man in
the act of sliding down the trunk.

"Catch him!" cried Jack.

They all made a rush for the tree, but the flash of Andy's gun,
while it revealed the man to them, also had the effect of
momentarily blinding the men and boys.  For an instant they could
see nothing, and when the effect of the flash passed away the man
was not in sight in the semi-gloom.  They could hear him running
through the underbrush outside of the garden, however, and took
after him.

But the crazy machinist, if indeed it was he, got away, and after
a vain search through the garden and about the machine shed, they
all returned to the house, Mr. Roumann and the professor having
joined in the hunt.

"What do you suppose he did it for?" asked Mark, when they were
again gathered in the dining-room, examining the strange message.

"He wanted to scare us," suggested Jack.

"No, I really think he means to do us an injury," said Mr.
Roumann.  "He has some fancied grievance against us, or he is
being used as a tool by Zeb Forker.  Perhaps the man who stole
the plates was with him, and he hoped to get some more during the
confusion.  I think we had better take a look at the machine
shop."

They acted on this suggestion, but an examination there showed
that nothing had been disturbed.  No one had been in the place.

"I'm going to sleep here to-night," said German scientist.  "I'm
not going to take chances at the last moment.  I'll stay here."

"So will I," decided Andy, and with his gun he mounted guard
outside, while Mr. Roumann made up a bed in the projectile.  They
were not disturbed, however, any more that night.

"Now for Mars!" cried Jack, as the sun rose the next morning, and
he jumped out of bed.  "Hurry up, Mark!  One would think you
didn't care about going!"

"Well, I guess I do, but I don't see what good it does to get up
so early. We aren't going to start until ten o'clock."

"No; but I couldn't sleep any longer," declared Jack. "I'm going
out to take a look at the Annihilator."

He quickly dressed, and was on his way down stairs when there
arose quite a commotion out of the garden. Washington's voice was
heard crying:

"Come back heah, yo' unregenerated specimen ob a ungrateful
bipedical ornithology!  What fo' yo' want t' distress mah
longanimity fo'?  Come back heah!"

"What's the matter, Wash?" asked Jack.

"Oh, dat Shanghai rooster got away jest as I were shuttin' him up
in de cage, an' I'se been runnin' all ober de garden after him.
'Pears laik he doan't want t' go t' Mars."

"Wait a minute and I'll help you," volunteered Jack.  "Come on,
Mark," he added.  "Washington's pet has got away."

The two boys went below, and, with their aid, the colored man
succeeded in catching the rooster, which, crowing a loud protest,
was shut up in a wooden cage and taken to the shop, ready to be
placed in the projectile.

There was little to do at the last moment.  Professor Henderson
had arranged for a relative to come and live in the house during
the time of the journey to Mars, and this gentleman arrived about
nine o'clock.

Meanwhile, the last of the stores and supplies had been put in
the Annihilator, a final inspection had been given the machinery,
and all the scientific instruments were in place.

Washington carried the cage containing his rooster into the
storeroom, where there was a large quantity of provisions,
sufficient to last for a year, in case, after reaching Mars, the
travelers should find on the planet no food which they could cat.

There was a plentiful supply of water, and machinery for
distilling more out of the atmosphere.  The gas that occupied the
space between what might be termed the two skins of the
projectile had already been pumped in, and nothing remained to,
do but for the adventurers to enter the great airship, as it
might be designated, seal up the ports, turn on the power and
start.

Mr. Roumann looked critically to the bracing up of the
Annihilator, to see that it was slanted just right.  Then he went
carefully over every inch of the great machine, to make sure that
there were no openings which were not closed.  As he reached the
port that communicated with the storeroom, he found it only
partly shut.

"Did any one of you open this?" he asked suddenly.

"I didn't," replied Jack.  "Why do you ask?"

"Because I was sure I closed and locked it from the inside early
this morning," was the answer.  "Washington, did you open it when
you put your rooster in there?"

"No, sah.  I went in de inside way.  I didn't tetch it."

"That's very strange," murmured Mr. Roumann, as he locked the
port, and each one, in turn, had denied meddling with it. "I was
sure I locked it."

The matter appeared to give him a little uneasiness, but, as he
had much to do to get the projectile ready for the flight, he had
to leave the solution of the matter until another time.

The great doors of the machine shed were thrown open.  They were
designed to allow such large bodies as airships to pass out, as
Professor Henderson had, in years previous, constructed a number
of aeroplanes and dirigible balloons.  So there would be no
trouble in speeding the projectile directly out of the shop.

The great question, now that all was finished, was whether or not
the projectile would move, and in the manner and with the speed
necessary to get to Mars.  There had been no chance for a trial
flight, and it all depended on whether or not Mr. Roumann had
correctly estimated the powers of his motors.

He was sure he was right, and, from calculations made, Professor
Henderson was also positive.  But it yet remained to prove this.

"Well, we may as well get in," said Mr. Roumann at length.
"Everything is done that can be done.  The next thing is to start
the motors, and--then we'll see what happens."

It was a nervous moment.  Once they were in, side the great
projectile, sealed up, would they ever be able to emerge again?
It was a momentous question.

"Well, here goes!" exclaimed Jack with a jerky laugh as he
stepped into the Annihilator.

"I'm with You," added Mark as he followed his chum.

"Come on, Washington!" cried Jack from within.

"Wait till I take one mo' look at terra cotta!" said the colored
man.

"You mean terra firma, I guess," spoke the professor.

"Yes, sah.  Dat's hit.  Terra flirma--de earth.  I wants t' bid
it good-by."

Andy Sudds, still carrying his gun, went in next.  Then followed
Amos Henderson, and finally the German scientist.  The latter
clamped fast the cover of the opening by which they had entered.
The interior of the Annihilator was brilliant with electric
lights.

Mr. Roumann made his way to the pilot house, to see that all the
levers and wheels that controlled the engines were in working
order.  Then he went to the engine-room, where he adjusted the
two motors.

"Well," he said a bit nervously, "we are all ready to start."

"Let her go!" cried Jack gaily.

There was no crowd on hand to see them off.  Professor
Henderson's relative was the only spectator.

 Mr. Roumann and Mr. Henderson went to pilot house again.  They
held a brief consultation.

"Come here, boys, if you want to see us start the motors going,"
called the professor.

Jack and Mark stood in the doorway.  Mr. Roumann grasped a lever.
He threw it over.  There was a spark as the electrical contact
was made.

"The atmospheric motor is now ready to start!" he remarked.
"Push that knob, Professor Henderson."

The professor pushed in a small, shiny knob.  Mr. Roumann turned
a small wheel, and closed another electrical switch.

Instantly there was a trembling through t whole length of the
projectile.  Would it move?  Would it leave the earth and go to
Mars?

There was a moment of hesitancy, as if the great machine had not
quite decided.

Then came a more violent vibration.  There was a humming,
throbbing, hissing sound.  Suddenly the boys, and all within the
projectile, felt it swaying.  A moment later it began to shoot
through space like a great rocket.

"Hurrah!" cried Jack.  "We're off!"

"Yes," added Mr. Roumann joyfully, "we are on our way to Mars!"
and he grasped the steering wheel and peered through the thick
plate-glass windows of the pilot house into the vast space before
them.

CHAPTER XV

SOMETHING ABOUT MARS

"Are we really in motion?" asked Jack, after a moment's silence.
"It doesn't seem so."

"We are certainly in motion," declared Mr. Roumann.  "See this
dial?"

He pointed to one near the steering wheel.  The hand on it was
gently vibrating between some of the figures.

"We are traveling that many miles a second," went on the
scientist.  "The atmospheric motor is not working as fast as I
hoped it would, but we are going fast enough.  When we start the
Etherium machine we shall go much more speedily."

"And when will that be?" asked Mark.

"I can't tell exactly.  It will not be until we have passed
through the atmosphere of the earth, and there is no way of
ascertaining in advance just how thick that stratum is."

"Then how will you know?" asked Jack.

"By means of my instruments.  When the hand on this dial points
to zero I will know that we are beyond the atmosphere, and that
it is time to start the Etherium motor."

"How do you know in which direction to steer?" asked Mark.  "Can
you see anything out of that window?"

"Not a thing," replied the German.  "Look for yourself."

Jack and Mark peered through the plate glass.  All they could see
was a sort of white, fleecy mass of clouds that surrounded the
great projectile.

"It's just like when we were above the clouds in the Electric
Monarch," said Jack.

"Exactly," agreed Mr. Henderson.

"But if you can't see anything, how can you tell where to steer?"
asked Mark.

"By means of this instrument," replied Mr. Roumann, indicating
another among the many on the wall of the projectile.  "This is
automatically kept pointed at Mars, and by means of a hand and
dial I can tell how to keep the Annihilator aimed directly at the
red planet."

"Even when it is on the opposite side of the earth from us?"
asked Jack.

"We are now far above the earth," was the answer, "and the planet
on which we lived offers no obstruction to my telescope being
pointed at Mars, even though it is daytime, when Mars is on the
opposite side of the earth."

"Have we traveled as far as that?" asked Jack in awestruck tones.

"We have come just thirty thousand miles since leaving the
earth," replied Mr. Roumann.

"But we don't seem to be moving at all," objected Mark.

"That is because we are shooting through space so fast, and
because you can see no stationary objects with which to make a
comparison, as when you are traveling on a railroad train,"
continued the German.  "And, as we are not dependent on tracks,
or roads, with their unevenness, there is no motion to our
projectile, save that of moving through space.  That is why it
seems as if we were standing still."

"But thirty thousand miles!" cried Jack.  "I thought the earth's
atmosphere was variously estimated at from only forty to two
hundred miles in thickness."

"The oxygen atmosphere may be," agreed Mr. Roumann.  "As a matter
of fact, the atmosphere we are now in would not support life for
you and me a single instant.  But it is atmosphere, nevertheless,
or my instruments would indicate something different, and my
atmospheric motor would not work.  No, I expect to be traveling
through the atmosphere for several days yet.  Then we shall reach
the true ether, and the Etherium motor will be put into
operation."

"Well," said Jack, "this trip isn't going to be very strong on
scenery, anyhow."

"No," agreed Mr. Roumann.  "We shan't be able to observe anything
but this fleeciness until we get to Mars."

"We can see the stars and moon at night, can't we?" asked Mark.

"There isn't going to be any night," replied the German with a
smile.  "We are now in the region of perpetual day."

"No night!" repeated Jack blankly.

"No.  Just stop to think for a moment.  We have left the earth,
and are many thousands of miles away from it.  You know that
which causes night and day on the earth is the rotation of it on
its axis.  Half the time the part we are living on is turned away
from the sun, and the other half of the time turned toward the
sun.  Now, the sun is fixed in space.  We are also in space, and
we are so comparatively small that there will never be any
shadows to cause night.  We are like a small point in space, and
the sun is constantly shining on us.  We do not revolve, so there
will no night, only day."

"Are we headed for the sun?" asked Mark

"No, for Mars.  But as we will take good care not to head for any
other planet, so as to get it between us and the sun, we shall
never have any darkness."

"But it doesn't look like sunshine out there," objected Jack,
pointing out of the window.

"No, because we are surrounded by a mass of vapor.  I think it
will presently pass and we shall see the sun.  The difference in
temperature between the projectile and the surrounding atmosphere
causes us to be enveloped in a sort of cloud.  When the outer
shell of the Annihilator is the same temperature as the
atmosphere through which we are flying, we shall emerge into
sunlight."

This happened a little later, and soon they could observe the
great ball of fire hanging in space.

"It seems to be smaller than when we were on the earth, doesn't it?"
asked Mark.

"It is seemingly smaller," replied Professor Henderson.  "We are
going away from the sun you know.  Mars is not as close to it as
we are on our planet--I mean the one we have just left--is
ninety-two millions of miles from the sun, while Mars is one
hundred and forty-one millions of miles away, though its orbit is
so eccentric that distance varies about thirteen millions of
miles.  That is, it may be thirteen millions of miles more than
its mean, or average, distance, so that at times it is as far
away from the sun as one hundred and fifty-four millions of
miles."

"My!  That's a good ways," observed Mark.

"Yes," went on Mr. Henderson, "and, in consequence, the light and
heat received by Mars from the sun is a little less than half of
that which our earth receives."

"Whew!  We'll be mighty cold in winter--if we arrive in winter,"
said Jack with a shiver.

"Unless the Martians have a means of making up for this loss of
light and heat," said Mr. Roumann.  "I believe they have."

"I shall be much interested in seeing how the great canals on the
planet are dug," said Professor Henderson.  "I have seen a map of
Mars, made by a scientist named Schiaparelli, and he has drawn a
number of large bodies of water, among which are intermeshed
continents and islands.  The surface of Mars must be a curious
one."

"I believe we shall find it so," spoke Mr. Roumann.  "Astronomers
tell us that the water on it is never frozen, except near the
poles.  There great ice caps are to be found."

"But what makes the planet so red?" asked Jack.

"That," said Mr. Roumann quickly, "is what hope to discover and
use for our benefit, but I not wish to discuss it now."

They talked of Mars for some time further, discussing the many
queer features, and during this time the Annihilator was shooting
through space at terrific speed.  Inside the projectile the
adventurers moved about, living and breathing, comfortably as if
they were on earth, for the great tanks of stored air provided
all the oxygen they needed.  Nor did they feel either heat or
cold thanks to the marvelous construction of the projectile.

"Isn't the year on Mars longer than the year on earth?" asked Jack
as he and Mark stood near the entrance to the pilot house,
interested in watching the various indicators record the speed
they acquired, the distance traveled, and the density the
atmosphere.

"Yes; it is about twice as long," answered Roumann.  "But I shall
tell you more about Planet--"

"If you'll kindly promulgate yo'se'ves in dis disrection yo' will
find sufficient condiments an' disproportionate elements to
induciate a feelin' ob intense satisfactoriousness," exclaimed
Washington White, poking his head in from the sleeping room
compartment.

"That means dinner is ready," cried Jack.  "That's the stuff!
Our first meal on the trip to Mars!"

CHAPTER XVI

THROUGH THE ETHER

"What's that, Washington?" asked Mark, as the colored cook put
something on the lad's plate.  "It looks like chicken."

"It tastes like chicken," added Jack, after making a test.

"It am chicken," declared Washington.  "I roasted some ob mah