"Yes. I wish you and Mark would go to the pilot house and turn on the power. Do it very slowly. Mr. Henderson and I will stay here and see how the motor behaves."

It was an anxious moment when the power was turned on the repaired machinery, but, to the delight of all, the motor again began to give out the mysterious force. The projectile ceased to fall, and once more was hurled onward.

"That's the stuff!" cried Jack, as he noted the needle of the indicator moving around, showing that they were again headed for Mars.

Once more they were shooting through the ether. The wonderful motor worked even better with the new plates, and Mr. Roumann said they had increased their speed about twenty-five percent.

"So we will soon make up for what we lost," he added.

They were all tired that night, for the work of making the repairs had not been easy, and Andy had gone over the whole projectile many times, looking for the hidden insane man.

"I don't believe he can be here," was Mr. Henderson's opinion.

"He certainly is," declared Mr. Roumann, "and we shall have more trouble from him."

"I hope not," ventured Professor Henderson.

It was on the second day after the accident, when the Annihilator was speeding along, that Jack and Mark, who were in the pilot house with Mr. Roumann, noticed a peculiar trembling of one of the needles on a dial designed to indicate the nearness of heavenly bodies.

"We're coming close to something," said Jack.

"We certainly are," admitted the scientist, with an anxious look at the instrument.

"Maybe it's Mars," suggested Mark.

"No, it can't be that planet."

"What is it?" inquired Jack. "Look, the needle went all the way around that time."

Mr. Roumann bent over the gauge. Then he consulted some charts of the sky, and made a few calculations.

"Boys, I am afraid we're approaching a large comet," he said gravely. "And, what is worse, it is attracting us toward itself.

We are in great danger!"

CHAPTER XIX

ESCAPING A COMET

The two boys looked at the German scientist. He was gazing, as if fascinated, at the swiftly moving needle of the gage that had told of the nearness of the comet.

"How far from it are we?" asked Jack.

"Many thousands of miles," replied Mr. Roumann. "But that distance is nothing compared to the rate at which we are traveling. We are almost certain to crash into it, or the comet will collide with us."

"And when it does, what will happen?" inquired Mark quietly.

"That is hard to say," was the answer of the German. "We know very little about the composition of comets. They may be composed merely of flaming ga.s.ses, or they may be a train of burning meteors, held together by attraction. The head may be some vast, blazing world, as large as our planet. In fact, comets are very baffling to astronomers."

"Well, if a comet is nothing but gas, it won't hurt if we run into it, will it?" inquired Jack.

"That's just the trouble. We don't know that it is gas," said Mr. Roumann. "It may be solid, and then to rush into it at terrific speed would mean that we would be demolished. Also, if the gas is flaming, you can easily imagine what would happen to the Annihilator. There would be nothing left of it--or us--in less than an instant."

"But isn't there some way of escaping it?" asked Mark.

"I'm going to try," responded Mr. Roumann. "Jack, ask Professor Henderson to step here. I wish to consult him."

Jack delivered the message, and it was overheard by Washington White. Something in Jack's manner told the colored man that there was trouble aboard.

"What's de mattah?" he asked.

Jack saw no reason for concealing the danger from the cook.

"We're heading into a comet," he, said.

"What? One ob dem tings wid long, fiery tails, Ma.s.sa Jack?"

The youth nodded.

"Am we gwine t' hit it?"

"I'm afraid so."

"Well, I hopes we does!" exclaimed Washington with great earnestness. "I hopes we knocks it clean outen de universe, dat's what I hopes."

"We're a great deal more likely to be knocked out ourselves, Wash."

"No, sah! Don't yo' believe anyt'ing like dat!" exclaimed the colored man. "I know dis airship. I helped build it, an' it's de strongest one de perfesser eber made. A comet won't be one, two, six wid it. We'll jest knock a piece of his tail off, at's what we'll do. I don't laik comets. Dey allers brings bad luck.

Onct, when I was a young feller, I had a ten-dollar gold piece.

Dat same year a comet was observed, an' de fust t'ing I knowed somebody done up an' stole mah ten-dollar gold piece. Comets brings bad luck, an' I knows it; Golly! I want t' see one ob 'em busted all t' pieces."

"I guess you don't appreciate the danger," said Jack gravely, as he followed Professor Henderson back to the pilot room, where the two scientists began to consult.

"We have decided on a plan, Mr. Henderson and myself," said Mr.

Roumann. "The fact that so little is certainly known concerning comets makes it difficult to know what to do. We might keep on our course and come to no harm, merely pawing through a gaseous ma.s.s which makes up the comet's tail. But there is a danger that we might strike the solid head of it, for that the head is solid, and of a glowing, fiery ma.s.s, which gives off a train of sparks, is my belief. To collide with a fiery ball, larger than the sun, would indeed be terrible. So we have decided to try to pa.s.s through the less dense part the tail of the comet."

"Can't we steer to one side, or above or below the comet?" asked Jack.

"Impossible," replied Mr. Roumann. "We have made some calculations, and have ascertained that this is Donati's comet--the one of 1858--and the head of it is two hundred and fifty thousand miles in diameter.

The tail is many millions of miles long, and as many thick. To pa.s.s entirely beyond it would consume much time. In fact, we could not move quickly enough to escape it, as we are now being attracted out of our course toward the comet."

"How far off is it now?" asked Mark.

"About seven hundred and twenty thousand miles."

"Then we'll be up to it in about two hours," went on Mark, making a rapid calculation.