"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 s.p.a.ce 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 gla.s.s. 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.