"But what about our prisoner—the crazy machinist?" asked Jack.

"Oh, I guess he will be all right. He had a good meal just before we landed, and he was asleep. We'll go with these queer people, and come back to-night to the projectile," said Mr. Roumann. "Come on."

They started to follow the leader, who beckoned them forward. He went off at a rapid pace, and the travelers found themselves being urged on just as speedily by that mysterious thought force.

"This is a great way of traveling," observed Jack.

"It suah does beat walkin'," commented Washington White, who, after his first fright, appeared to take it all as a matter of course. "But I hopes dat dey's got suffin' t' placate mah inner conscientiousness wid, 'case I'se gittin' mighty hungry."

"Oh, I guess these people have to eat, even if they are mostly brains," suggested Jack. "Anyhow, we've got plenty in the projectile."

"If dat air crazy man don't git loose an' cat it all up," added Washington. "I shorely hopes dat he doesn't hurt mah Shanghai rooster."

"Never mind about him. Look what a wonderful country we're in," said Mark.

And indeed they were in a strange land.



CHAPTER XXIII

THE RED LIGHT

At first glance Mars had not seemed to be much different from the earth they had left, but when the travelers had gotten over their first astonishment at seeing the strange people, they saw that there were many points of dissimilarity.

In the first place, there appeared to be a great deal of water about them. There were canals or broad rivers on every side, with only narrow strips of land dividing them. The Annihilator had landed on a broad, sandy plain, one of the largest on the planet, as it afterward developed, and so gentle had been the descent, that the projectile was not injured in the least. But leaving that vicinity, and following their guide, the travelers found themselves in the midst of a network of waterways.

"These must be some of the canals the astronomers see," observed Jack.

"Yes," assented Mark. "There isn't much land to spare. I should think the Martians would be a sort of water race. But they don't appear to have any boats."

"Yes, they do," put in Mr. Roumann. "Here comes one now."

Sure enough, there suddenly appeared on a broad river or canal, along which they were being moved by that mysterious force, a large open boat, in which were several Martians.

"Well, I wonder how that moves?" said Jack. "They're not rowing, they have no sail, and I can't see any engine."

"Maybe thought power moves the boat, too," suggested Mark.

"It certainly seems so," rejoined Mr. Henderson.

The travelers found themselves stopping, and their leader, turning, said something to the persons in the boat. There was a brief conversation in the strange language, and the adventurers found themselves moving into the craft, which stopped close to the bank of the canal. When they were seated the boat started off again, and though Jack and Mark, as well as the two men, looked closely to ascertain what was the motive power, they could not discover it.

"Unless it's in that small box," said Jack, pointing to one made of some shining metal, in the stern of the boat.

"Perhaps it is," assented Mr. Roumann. Then he made some motions to the guide, asking whether or not the substance in the box contained the motive power.

The man with the squared triangle on his head seemed to hesitate a moment, and then, with a motion to the Martian in charge of the boat, he said something, and the latter opened the box. Mr. Roumann looked eagerly into it, as did the others, and the German uttered a cry of surprise.

And well he might, for all the box contained was a lump of what seemed to be red clay. There were no wheels, no machinery of any kind, and there appeared to be no propeller on the boat with which the box was connected. Nevertheless, the craft continued to move along swiftly, and the Martian had indicated that the object in the box made it go.

"The red substance!" exclaimed Mr. Roumann in a low voice. "I wonder if this can be what I seek?"

Once more he looked at the crimson mass in the metal box. He reached forward his finger as if to touch it, but the chief Martian, with a warning cry, suddenly dosed down the lid.

"Humph! I guess they're afraid we'll steal it," exclaimed Jack.

"Maybe it's dangerous to touch," added Mark.

The Martians conversed among themselves in low voices, and from the glances they cast at the travelers every now and then, from their great, protruding eyes, it was evident that the little men were discussing the strangers.

"Has yo' folks any adequate perceptionability ob de exteriorness in de inverse ratio ob de objectiveness ob de transportation projection ob our destination?" asked Washington White, breaking a rather lengthy silence.

"Do you mean where are we going?" inquired jack.

"Dat's what I done axed yo'."

"Well, we don't know," went on the lad. "But we seem to be approaching some big city."

Off in the distance, on the side of a hill, which rose from the midst of a great lake or canal, were many glittering buildings. It was a city of large size.

"The question is, what are they going to do with us when they get us there?" spoke Mark. "Maybe they're cannibals."

"They are too highly an educated race for that," replied Mr. Roumann. "No, I fancy they will treat us well. They will want to know about the planet we came from, as well as we want to know about them. I think they will treat us with respect."

"They certainly have, so far," remarked Mr. Henderson. "I only hope none of them meddle with our projectile."

"I'm a little apprehensive about that myself," added Mr. Roumann. "And I trust that crazy man does not get loose. But we can't help ourselves, and we'll hope for the best."

They were now close to the water-front of the city, and they saw the shore lined with a great throng. Evidently their approach had been heralded, and they were being eagerly awaited.

"Looks as if we were going to have quite a reception," remarked Jack. "I hope it's a pleasant one."

"If it isn't, we can't help ourselves," went on Andy. "I can't use my gun in a land where the bullet has about as much force as a pea in a putty shooter. But if they attack us we can pick up stones and fire at them."

"Stones won't be much more effective than the bullets," said Mr. Roumann.

"Why not?"

"Because they'll be light, too. Things here will weigh only about a third as much as they do on earth. In fact, that is one reason why we are moved about so easily by their thought power. We are only a third as heavy as we were on earth, though we weigh more than the Martians, for all that."

By this time they were at the dock, and they found themselves being moved out of the boat, and up to the pier, through the crowd of people.

Their guide—the Martian with the squared triangle—called out an order, and the crowd opened up a living lane, through which the adventurers passed. They could not help noticing how polite the Martian inhabitants were, for there were no idle remarks on the appearance of the strangers, such as would have taken place under similar circumstances on earth. But the Martians made up for it by staring with their great eyes, listening with their great ears, and sniffing, the air with their long noses, though they kept a profound silence.

At the end of the pier the travelers found some queer carriages waiting for them. They were boxes, fitted up with soft cushions, and were on runners, like those of a sled. Jack looked and saw that the street was paved with a substance like glass, very slippery.

"We're going to have a sleigh ride!" he exclaimed; "but I don't see any horses to pull us."

"Maybe these are automobile sleds," suggested Mark.

"If they are, there's no motor in them," declared Jack, making a careful examination.

"Then they move by the same power as do the boats," was his chum's opinion. "Yes, see the metal box?" and he pointed to one in each vehicle.

The leading Martian motioned for Jack and Mark to get in one sled, Mr. Roumann and Professor Henderson were assigned to another, and Washington and Andy to a third. The leading Martian took his place in the vehicle with the two men, while two others of the queer people got in the remaining two sleds, which the boys dubbed the vehicles. No sooner had they done so than they started off as if by magic, sliding over the smooth, glass-like streets.

"Well, they certainly have the transportation problem down to a science," remarked Jack. "This beats a taxicab all to pieces."

"That's right," agreed Mark. "But say, this is a mighty fine city."

The boys looked on either side of them. The street, which was thronged with the queer feather and fur covered inhabitants, led between rows of stately buildings, all built of some light-colored substance. The designs were like those usually seen in fantastic fairy pictures—beautiful in the extreme.

The street led to a great public square, and as the vehicles swung into it, the boys could not repress a murmur of delight. For, at the head of the square was a great palace of glass, its walls so transparent that everything going on within could be seen from without.

"This must be their city hall, the palace of justice, the main administration building, or whatever they call it," said Jack. "Evidently the Martians don't believe in conducting politics in the dark."

"Well, it's going to be dark pretty soon," observed Mark, "for the sun is setting."

"And look at what a small sun it is," added Jack.

For the first time they noticed that the great luminary was much smaller than it appeared to them on the earth. It was about half the size, but, though Mars must have received considerably less heat from it than did the earth, it was not at all chilly, but, on the contrary, warmer than on the earth at the same time of year.

The little sun slowly sank down behind the distant hills, and when the sleds came to a stop in front of the glass palace, the boys and others found themselves being moved up the broad steps.

"Evidently there's going to be an inquiry concerning us," commented Jack.

They were taken into a vast audience chamber. At one end was a raised platform, upon which were seated a number of Martians. Each one had a golden circlet on his head, and in the center of each band was some geometrical figure.

In the middle of the throng on the platform was a Martian attired in a golden, shimmering robe. And on his head was a small circlet, made apparently of diamonds.

"He must be the high muck-a-muck," said Jack in a whisper.

"Hush!" cautioned Mark.

As the adventurers felt themselves advancing toward the raised platform, there came a shout from the throng. And the words sounded like:

"Silex Corundum!"

At this the Martian with the diamond circle on his head arose and bowed.

"That must be his name," whispered jack.

"Hush!" spoke Mark again, and he who appeared to be a sort of chief or king began to speak.

He made quite a lengthy address, and as he went on it grew darker, with the approach of evening.

Suddenly, from various points in the great room, there glowed a red light, until the apartment was as bright as day. And the boys, looking up, saw that the light streamed from the sides of small metal boxes fastened to the glass walls.

"The mysterious red substance!" murmured Mr. Roumann. "It is a source of power, it gives forth light, and what will it not do? I must certainly secure some of it!"

The red glow increased as it grew darker outside, and, looking through the glass sides of the palace, the boys saw that the palace was surrounded by a great crowd of Martians, who were watching what went on within.



CHAPTER XXIV

A MARVELOUS SUBSTANCE

"Say, that's a good way to have a building," observed Jack in a low voice to his chum. "Those who can't get in can see just as well what's going on as if they were here. But I wonder what he's saying?"

"Probably telling his people about us," replied Mark, and this seemed to be so, for Silex Corundum, as they later learned was the name of the ruler of Mars, frequently motioned toward the adventurers, who stood in a group in front of the platform.

Much interest was manifested by the throng, and even those on the platform, who seemed to be members of a sort of council or governing body, could not restrain their interest.

When the chief ruler had ceased speaking the Martian with the triangle on his head—the one who had first greeted the world travelers, stepped forward, and made an address.

"He's telling 'em how we got here," was Mark's opinion, and Jack nodded.

When this one had finished, the guide who had conducted them to the palace had his turn, and at greater length he described the strangers, the curious craft in which they had arrived on the planet, and many other details, which, of course, our friends could not comprehend.

This done, Silex Corundum made another address, and at its close a great blackboard was brought forward, some pieces of chalk were handed to Mr. Roumann and to Professor Henderson, and by signs they were invited to illustrate something of themselves and their wonderful journey.

"What shall we draw?" asked Mr. Henderson.

"First see if you can make them understand something of the earth where we came from," suggested Mr. Roumann; and the professor, who was a good draughtsman, soon placed on the board a sort of map of the universe, indicating the position of Mars, the sun, the other planets and the earth. To his surprise a delighted shout told him that he was understood. The chief ruler, with a rapid motion, pointed to a great telescope, located in one corner of the big audience chamber. He motioned for the travelers to look through it, and after it was adjusted he pointed to the drawing of the earth on the board, and indicated that the adventurers could see their own planet through the telescope.

Mr. Roumann looked first. Then he uttered an exclamation.

"Can you really see our earth?" asked Jack.

"I can! Look for yourself! This is a marvelous telescope! No wonder the Martians understand something about us. They can clearly make out the shapes of our continents."

Jack peered through the eyepiece. There, far off, shining in the light of the distant sun, which was now on the other side of Mars, he saw the earth they had left about two weeks ago. It was like looking at some map in a geography, and he could clearly make out the shapes of North and South America.

"Take a look, Mark!" he cried. "I almost thought I could make out the place where we live, and where we built the Annihilator!"

In turn they all gazed at the earth, distant thirty five millions of miles, but which was made very plain to them through the powerful glass.

Silex Corundum made a motion as of some body flying through space, and looked inquiringly at the travelers.

"He wants to know how we got here," interpreted Mark.

"I'll draw a picture of the projectile,"' said Mr. Roumann, and he put on the board one containing many details. So interested was the chief ruler and his cabinet, that they all came down off the platform to examine it more closely. They appeared to understand everything but the Etherium motor, but Mr. Roumann illustrated the force by which it was worked, by pointing to the metal boxes containing the red substance, which gave out light as well as power, indicating that some force like that worked the motor.

This appeared to satisfy the questioners, and after some talk among themselves they motioned that the travelers would be given a place to sleep.

"I'd a heap sight radder hab soffin' t' eat," said Washington, when it was made known that they were to retire. "I'd jest like to git back t' mah kitchen. I jest know mah Shanghai rooster needs some corn, an' as for dat crazy man, maybe he's broken loose."

"That's so," agreed Mr. Roumann. "If we don't get back, we can't give him anything to eat."

"Let's try to make them understand," suggested the professor, and, accordingly, with chalk, they pictured that they had left behind them, in the projectile, an enemy of theirs, who was bound and helpless. Silex Corundum appeared to understand, and he indicated that the unfortunate man would receive attention.

The travelers were then led out of the palace. They found instead of being urged along by the thought power, however, that they were now allowed to walk. And they also noticed that they could go very rapidly, with little exertion, due to the fact that they only tipped the scales at about a third of their usual weight.

"This is better," observed Jack. "I'd rather walk than be floating along the way we were."

"Yes, I guess they were so anxious to question us that they couldn't wait for the ordinary forms of locomotion," said the professor. "Now that they know something about us they will let us do as we please for a while."

One of the Martians, who seemed to be a minor official, led them out into the street. They found that it was lighted by means of the same metal boxes that were in the palace.

Overhead were the two tiny moons of Mars, but they gave but little light, and had it not been for the wonderful red substance the streets would have been quite dark.

"This stuff is what makes Mars seem so I red when we look at it with telescopes from our earth," observed Mr. Roumann. "It is a very marvelous chemical. I must get some to examine."

"I wonder where they'll put us?" asked Jack, but his question was answered a few moments later, when they were ushered into a finely built house of generous size, and by signs their guide indicated that they were to make this their home. It was nicely furnished, though in a different manner from houses in the world, and there were many scientific books and instruments in it.

"The Martians must study all the while," observed Mr. Henderson. "No wonder they have such big heads. All their intellectual faculties are wonderfully developed."

"At the expense of their arms, legs and bodies," said Jack. "I fancy I could fight half a dozen of their biggest men."

"But we're not going to," said Mr. Roumann. "At least, not as long as they treat us decently."

"And now for something to eat," added Henderson.

Their guide showed them a dining-room, where they found a table filled with food that looked very appetizing. The Martian motioned for them to eat.

"I want t' find where mah kitchen is goin' t' be," declared Washington. "If I'm goin' t' cook heah, I want t' see how I'm goin' t' do it."

The Martian seemed to understand what was wanted, for he led the way to another apartment, where it was evident that cooking was done, as there were pots, pans and what looked like a stove in it.

"But I don't see no coal," objected the colored man. "How I gwine t' cook without coal t' make a fire?"

The Martian opened the square iron box that seemed to be the stove. Inside was a small metal box, which he also opened, disclosing a lump of the red substance.

"They cook with it, too!" exclaimed Mr. Roumann. "And I have no doubt that they warm their houses with it in winter. A wonderful substance—most marvelous! It exceeds my wildest dreams—light, heat and power! Our fortunes are made! It is good that we came to Mars!"

"And it's a good thing they've got something to eat!" remarked Jack. "Come on, I'm half starved."

"I'll wait on table fo' yo'," said Washington, as they went back to the dining-room, and the Martian left. They sat down, and the colored man was about to pass the victuals, when, to the surprise of all, the center of the table began to revolve, and the dishes of food went with it, passing slowly in front of each one in turn.

"Good land a' massy!" cried Washington. "It's bewitched! Look at de table movin'!"



CHAPTER XXV

SEEKING THE TREASURE

They all stared at the strange sight. It was rather odd to see the entire middle portion of the table going around, while the outer part, at which the adventurers sat, was stationary. But the boys and men, with the exception of Washington, recognized it as very convenient.

"What are you frightened at, Wash?" asked Jack.

"At dat table, dat's what! It's a ghostest table."

"A ghost table?"

"Yep! Spirits am workin' on it! I ain't goin' t' stay heah. I'se goin' back t' de ship, where I kin move t'ings fo' mahself."

"Don't be alarmed," said Mr. Henderson. "It's all right, Washington. The table moves by some hidden mechanism, which doubtless was set in motion by the Martian who were just here, or the mere sitting down to our places may have started it."

They all got up to make an examination, and the table center at once ceased revolving, proving that some, connection existed between it and the chairs. But they could not discover the machinery. There was a small metal box underneath the table, but that was all.

"That must contain some of that marvelous red substance which gives light, heat and power," declared Mr. Roumann. "I must certainly get a supply of it. In fact, that is what I came to Mars for. That is the object of my trip, and if we can get a sufficient quantity of it, our fortunes are made."

"Is it so valuable?" asked Mark.

"It is the most valuable treasure in the universe," replied the German. "Long ago I suspected some such thing must exist on Mars, or else how, receiving only half the light and heat from the sun that we receive, can the inhabitants exist? And that they do live, and live well, we have seen. It must be due to the red substance, and if we could only get some back to earth it would be worth millions. Think of simply putting a bit of it in a stove and having heat, or hanging up some in a room and getting light from it. But, more than this, think of having it move machinery, I would not be surprised but what I could transform it into energy that would operate the motors of the Annihilator."

"But wouldn't you need a new supply every once in a while?" asked Jack.

"I think not. I believe it is like radium, and will last forever. In fact, you notice that the metal boxes it is contained in, except the ones in the boats, are securely sealed. If they had to be putting in a fresh supply every so often, they would make the boxes so they would open more easily. We must get some of that treasure."

"But how?" inquired Mr. Henderson.

"I don't know, but I will find out a way. When we have been here a few weeks we will be better acquainted with the Martians and their language, and can make a search."

"Well, if you folks is done talkin' about treasure, I'm goin' to eat," observed old Andy. "I'm hungry!"

"So am I," added Jack, and as they all sat down again the table began revolving. They found it a convenient arrangement once the novelty had worn off, and they were soon eagerly talking, over the meal, of the wonders they had seen, and speculating on what might be before them. Washington, having nothing to do, went to see about beds for the night, as the travelers were tired.

"Well, Wash," asked Jack, as the colored man returned, "did you find the beds making themselves, or waltzing around the room?"

"Nope, dey seemed t' be ordinary, respectable beds. But I ain't goin' t' take no chances in 'em. I'se goin' t' sleep on de flo'."

"Why?"

"'Cause I don't want t' wake up in de middle ob de night an' find mahself squashed inter a jellyfish. I believe de beds am bewitched same as de table is."

"Nonsense," said Jack. "They're all right. This is a fine place to live."

They found the beds good to sleep in, and nothing disturbed them. Washington, however, stretched out on the floor, and he arose early to prepare breakfast on the stove, which never needed to have a fire built in it, because of the marvelous red substance. By an arrangement of levers and valves the heat could be increased or diminished at pleasure.

The same Martian who had conducted the travelers to the house returned soon after breakfast, and by signs and motions indicated to them that the crazy machinist left in the projectile had been properly cared for. The Martian also indicated to the world-dwellers that they were free to go where they pleased about the city, which they learned was called Martopolis, and was the largest city on the planet.

"We'll take a walk," suggested Mr. Roumann, "and maybe we can find where they keep the red stuff, or where they get it from."

They strolled about the streets of Martopolis, noting many strange sights. The queer little people were hurrying to and fro, with a peculiar gliding motion, much faster than the ordinary walk, yet it was not a run. The peculiar lightness in weight of everything on Mars probably accounted for this, as the travelers themselves found they could move about very swiftly, and with little fatigue.

Nor did the world-dwellers attract as much attention as they expected they would. The Martians appeared to have satisfied their curiosity regarding the strangers the previous night, and now gave them but passing glances. Even the boys did not follow them.

Every one seemed to be busy, and the travelers noted many schools, in which the children were industriously studying, though it was early morning. Observatories, with great telescopes, were numerous, and astronomers were gazing at the sun or different parts of the heavens, even in daylight.

"They are a very learned people, and they never seem to cease from acquiring information," commented Mr. Henderson.

"Well, I'd like to acquire some information about where that red stuff is," said the German. "There is one of the metal boxes that contain some, up on that pole."

He pointed to one that evidently served as a street lamp at night.

"And there's a policeman near it," said Jack. "Ask him."

A Martian stood leaning against the light-pole, much as does an officer of the law on earth. That he was some sort of an official was evidenced by the uniform he wore.

Mr. Roumann approached the Martian, and made signs that he would like to see the light box. The officer shook his head vigorously, and said something rapidly.

"I guess they don't allow strangers to touch it," observed Jack.

"Evidently not," admitted Mr. Roumann. "I wonder if he knows where it comes from?"

He made more signs, asking, as well as he could, where the substance in the box was obtained. The officer pointed to the distant hills, but again shook his head in protest, and spoke for tome time very earnestly, as if warning his questioner not to venture after it.

"Guess they must guard it pretty closely," said Mark.

"Well, I'm going to have some, anyhow," declared the German. "We'll take a stroll over toward the hills."

They passed through the city, no one offering to stop them. On every side they observed something new or strange, and they were particularly struck by the absence of all noise. Everything was done silently. There were no trolley cars, no wagons or trucks, no puffing automobiles, and no confusion.

The Martians moved noiselessly about, and the sleds, with their queer motive power, made no sound. They seemed to be the only vehicles in use, save the boats, and these sleds were of many sizes, some as large as big trucks.

"Do you think it will be safe to leave the projectile so long?" asked Jack.

"I think so," replied Mr. Roumann. "These people will not bother with it. In fact, they all seem too busy. I want to get some of that valuable red stuff."

They kept on, until they found themselves out of the city and into the country districts. Here there was more water than land, great canals and lakes being scattered here and there, with narrow paths or roads winding in and out among them.

"It's always flood time here," observed Jack. "We must get one of those boats."

They approached the hills, which seemed to rise out of a great lake.

"There is where the treasure is—in those hills," said Mr. Roumann. "They're not more than a mile off. Let's hurry there and get some."

They came to a narrow strip of land connecting two lakes, and as they were crossing it, there suddenly appeared from a little hut, about half way over, several Martians, who opposed their progress.



CHAPTER XXVI

IN PERIL

"Well, I wonder if we can't go any farther?" asked Mr. Roumann, as he and his companions came to a halt, and noticed that the little men held what looked like small sticks in their hands.

"It seems as if they didn't want us to," observed Mr. Henderson. "Looks as if they were on guard."

"Let me get at 'em with my gun," spoke Andy. "I'll soon show 'em—"

Then he stopped suddenly, as he recalled how useless his firearm was on Mars.

"You'll have to get some stronger powder, and heavier bullets, to hunt here, Andy," said Jack.

"I wonder if they have guns?" came from Mark.

"They only look like sticks," said Jack.

Mr. Roumann, by signs and motions, indicated that he and his companions would like to travel along the narrow path to the hills. The leading Martian, who was dressed like the officer at the lamp-post, while the others were less elaborately arrayed, shook his head. His big mouth broke into a smile, however, as if he wanted to be good-natured about it.

"He doesn't want us to go," said the professor.

"Evidently not, but we're going just the same," retorted Mr. Roumann. "We're more than a match for twenty of these little creatures, and there are only ten here. Come on."

"Do you think it will be safe?" inquired Mr. Henderson.

"Of course. They can't harm us."

The German scientist took a step forward. The others were about to follow him when the leading Martian uttered a command, and his men pointed their sticks at the travelers.

"Look out! Dey's goin' t' shoot!" exclaimed Washington, stooping down.

"They can't shoot with those things," declared Mr. Roumann, for there seemed to be no mechanism about the sticks.

They all pressed forward, but to their surprise it was just as if they had met with an invisible stone wall. They could not advance a step farther. They were halted by some strange power, and it appeared to come from the sticks, which the Martians kept pointed at the strangers.

"Why—why! I can't seem to move!" cried Jack, pushing with all his might. But, though nothing could be seen in front of him or the others, they might just as well have tried to push over the glass castle in the public square.

"We can't go on," called Mr. Roumann.

The Martian officer said something to his men, and they lowered their wands. Instantly it was as if a stone wall had been taken down from in front of the world-dwellers. They were able to advance a few steps, and then, when at a command the wands were again pointed at them, they had to stop.

"It's those sticks!" cried Jack. "They contain some strange power. That's the queerest kind of a policeman's club I ever heard of. It would keep back any mob!"

Try as they did, they could not pass the invisible barrier, and they were forced to give it up. Seeing that the strangers realized that they could not pass, the Martian officer and his men lowered their sticks. He spoke to the travelers, and, though they could not understand what he said, it was evident from his gestures that he was advising them to return to the city.

"I think we'd better," said Mr. Henderson. "The red substance is too well guarded for us to get any of it. Evidently they don't want any of it taken away."

"I must get it!" insisted Mr. Roumann. "If not now, then later."

There was nothing for them to do save turn back, and the Martians tried to smile pleasantly at them, as if sorry for what they were obliged to do.

"We'll go back to the projectile," decided Mr. Henderson. "I am a little anxious to see that it is all right."

They found that it was, though quite a throng had gathered about to inspect it.

"Are we going to stay here, or go back to the house they let us have?" asked Mark.

"I think we will live in the city," decided Mr. Roumann. "We can learn more about the Martians there, begin to understand something of their language, and be in a better position to get some of that red stuff, than if we were out here. But we'll go inside and see about the crazy man, and also how the machinery is. I want to fix the motors so that if any one meddles with them no damage will be done."

It took some little time to adjust the machinery, and then the travelers took from their supplies some personal belongings, which they wished to have with them.

"Now to see to that crazy machinist," said Mr. Henderson, when they were ready to leave the projectile again. "I wish we could get rid of him. He's a nuisance."

They went to the storeroom, where he had been confined, but the man was not there.

"He's hiding again," declared Jack.

"No; he's got away!" exclaimed Mr. Roumann. "See, the ropes with which we bound him have been broken. When the Martians came out to feed him last night they could not have fastened them securely. Well, he's gone, and I don't know but what I'm glad of it."

But there came a time when they were all very sorry that the insane man had escaped, for he caused them much trouble.

As they left the projectile to go to the house provided for them in Martopolis, Mr. Roumann took with him several small iron boxes.

"What are those for?" asked Jack.

"To put that red stuff in," replied the scientist.

"I am going to make another try for some, but I'll take a different road this time."

For a week or more the travelers lived in their house in Martopolis. They were courteously treated by the Martians, and soon began to pick up the language, which was very simple when once the principles of it were understood.

Several times the travelers were taken before the Great Council, as it was called, and asked in regard to matters on the world they had left. In turn the adventurers learned much about Mars. Though it was much smaller than our earth, it was superior to it in many ways. One was the simplicity of life. The Martians never had any need of clothes, for they were born with fur and feathers, which were renewed by Nature from time to time. They had to contend with a large quantity of water, which covered most of the surface of their planet, but by ingenious means they got along nearly as well as if there was more land. In science they were far ahead of scientists of the earth, and they were fortunate in possessing the red substance, which they called Cardite, and which was their only source of light, heat and power. With it they accomplished much that the world-dwellers have to bring about by great labor.

By inquiry, after they had learned the language, the travelers found out that Cardite was regarded with much reverence, and there was a tradition that if any of it was taken away from Mars, the planet would disappear.

"No wonder they didn't want us to get any," said Mr. Roumann. "But I'm going to have some, for all that. It's all nonsense to think any harm can come from taking it. It will not injure their planet, and it will be a fortune to us. They must have a lot of it, for they told us that all the cities on Mars, and there are several of them, are lighted and heated by it."

"But how are you going to get it." asked Mark.

"By going a different route. I'm going to get a boat, and go by water. I've found out how to run one of their boats by means of the red substance, and some day we'll sail over the lake to the hills and get some Cardite."

They waited another week, and, as they found less and less attention was paid to them from day to day, they decided to make an attempt to get some of the treasure.

They started one morning in a large boat, which Silex Corundum, the ruler of Mars, had placed at their disposal, and in a short time were approaching the distant hills, at the foot of which was the great lake. The boat moved swiftly, the controlling mechanism consisting of three little knobs on the outside of the box containing the Cardite. One sent the craft forward, one reversed it, and the other stopped it.

"We're almost there," said Mr. Roumann, after about an hour's sail. "There are no guards this way, just as I hoped. We shall soon be enormously wealthy."

Nearer and nearer came the boat to the hills. When they were within a half mile of them Jack, who was in the bow, uttered a cry.

"A whirlpool! A whirlpool!" he shouted. "We're heading right into it!"

Mr. Roumann, who was steering, tried to turn the boat to one side, but the craft would not answer the helm.

"Shut off the power and reverse!" exclaimed Mr. Henderson, when he saw that the boat was still rushing into the dangerous swirl of water.

Mark, who was near the metal box, did so. But even the power of Cardite was of no avail against the awful suction of the whirlpool. The boat began to go around in a great circle, ever coming nearer and nearer to the black, swirling center.

"No wonder they needed no guards on the water side," gloomily observed Mr. Roumann as he stood up and looked at the hills. "The whirlpool is the best protector they could have."

In deadly peril, the adventurers watched their boat coming nearer and nearer to the terrible center of the angry waters.



CHAPTER XXVII

GETTING THE CARDITE

"Isn't there any way of escape?" asked Jack in a low voice, as he crouched in the bow and peered into the whirlpool, on the edge of which they were circling.

"I don't see any," replied Mr. Roumann. "I am very sorry I got you into this trouble. If I had not insisted on coming for the red substance we would not be in this danger."

"It's as much our fault as yours," declared the professor. "We were anxious to get some of the treasure also."

"And now none of us will have any use for it," observed Andy dryly. "When we slide down into that hole it will be all up with us."

They all shuddered as they saw the black hole, around which the waters raced in a circle.

"I wonder what's down there?" asked Mark.

"It isn't a good thing to think about," responded Jack. "I always was afraid of whirlpools."

The boat was now beginning to go around faster. The occupants were getting dizzy with the motion. They could hear a distant roar, and knew that it came from the water falling down some great depth, into which they seemed fated to be dashed.

"Did you turn on all the power of the boat?" asked Jack after a period of silence. "Seems to me we didn't come along very fast in this craft. The one we were in first went at a great rate. Maybe we don't understand how to make it go at top speed."

"I turned the knobs every way I could think of," replied Mr. Roumann. "But it would take terrific speed and power to free us from the suction of the whirlpool."

Jack moved back to the stern, where the box was, containing the red substance that furnished power to move the boat. He looked closely at it.

Meanwhile the boat was moving around in ever-narrowing circles, faster and faster. Jack noticed that twice in each revolution it went respectively lower and higher on the course, and always at the same places. That is to say, the whirlpool was on what might be termed a slant. At one time the boat would be at the lowest point, and at another at the highest point. At the low point the occupants of the craft were out of sight of everything, as when a ship is in the hollow of the sea. A little later they would be raised up on a crest of water so that they could look to the distant hills.

"If we could only get power enough to shoot the boat out at an angle when it gets to the high point, we could escape," thought Jack.

But how could he obtain this power? The mechanism seemed to be working at the greatest force, for, after an attempt had been made to stay the progress of the boat by reversing it, Mr. Roumann had again put on full speed ahead.

But was it full speed? That was what Jack wanted to know.

He examined every inch of the box. At first he saw nothing but the three knobs that had been used. Then, all at once, down underneath, he saw a small pin. It looked as if it could be moved. He took hold of it.

"I wonder what will happen if I pull it out or push it in?" he asked himself. Then he happened to remember that in an electric battery, to obtain more power, you must pull out a certain pin.

"Perhaps this works like an electric battery," he said. "I'll pull it out."

He did so, and a surprising thing happened. The boat shot forward at enormous speed, and as Jack happened to pull the pin out at a time when the craft was high up, it began to shoot across the water at an angle to the whirlpool. He had solved the problem of how to escape. As he afterward learned, the pin was just for the purpose for which he used it—to cause a sudden increase in speed.

The whirlpool did not give up without a struggle, but the boat was finally successful, and fought its way out to calm water.

"How did you do it?" asked Mark, and Jack told them.

"Well, we'd better start back for the city," proposed Mr. Roumann. "I guess we've had enough for one day. We'll try again, and take some other route."

"There's no need of that," declared Professor Henderson. "See, we are close to the hills now. We have crossed the whirlpool. Why not go on, and see if we can't find some Cardite? Going back now will be no easier than after we have made an examination. Let's explore the hills."

The boat had shot out on the farther side of the whirlpool, and there was nothing now between it and the shore. After a consultation it was decided to land.

"We can be more careful coming back," said Jack.

Half an hour later they had landed and started up the hills toward the summit. The place seemed to be deserted, but there were evidences that some sort of mining had been going on there, for great holes and shafts were dug in the ground, and there were remains of machinery.

"They must have dug up all the Cardite in this locality," said Professor Henderson, "and they've gone to a new place."

"Which we wish to find," added Mr. Roumann, "and that without being discovered. From the way in which the Martians guard this, it will go hard with us if they see us taking any."

They toiled up to the top of some of the lowest hills. There did not seem to be any of the treasure there, and they went farther. They were getting tired and hungry, and they sat down to rest and eat some food which they had brought with them.

"Let's try that hill," proposed Mark, pointing to a high one about a mile away. "It looks red from here."

There was a rosy hue about the little mountain, and after a brief rest they headed for the spot.

"There's nothing here!" exclaimed Jack in disgust, as he and Mark, in a final spurt, reached the base of it. "Nothing but ordinary dirt."

Mark looked down. He dug his heel into the sod. Then he uttered a cry of triumph.

"Here it is! Here it is!" he cried. "It's under the grass! We've got to dig it up!"

He knelt down, and began to tear away the sod with his hands. Jack did the same, and when they had lifted aside the tangle of roots and grass, they saw beneath it a dull gleaming red substance, like clay,

"That's it! That's it!" shouted Mr. Roumann. "We've found it!"

He stooped over, and with his knife began digging some up.

"It's neither warm, nor does it give any light," said Mr. Henderson in disappointed tones.

"No; it requires special electrical treatment," replied Mr. Roumann. "I know how to do it, though. Now we shall all be millionaires! There is enough here to make us wealthy for life!"

He began filling his iron boxes, the rest helping him. They were engaged in getting out the Cardite, all working with feverish haste, when Jack, looking up, saw a Martian officer regarding the actions of the world-dwellers with his great, bulging eyes.



CHAPTER XXVIII

THE ATTACK

"They've discovered us!" exclaimed Jack, as he stood up and watched the Martian.

"What?" cried Mr. Roumann. "Oh, it's only one of them," he added, "and he hasn't any of those electrical sticks. Go ahead and take some more of the Cardite."

But the Martian advanced on the travelers, and, by his voice and gestures, seemed to be warning them to stop taking the red material.

"Maybe he's a guard," suggested Mark.

"Very likely," assented Professor Henderson.

"I'll see if I can't scare him with my gun," remarked Andy. "I've put in more powder, and a heavier bullet."

He fired in the air, over the Martian's head, but to the surprise of the adventurers the weapon only gave a faint sound, like that of a pop gun, while the bullet rolled from the barrel and dropped at Andy's feet.

"Why, that's worse than ever!" he exclaimed. "I guess the red stuff must have taken all the power out of your gun, Andy," said Mark.

The Martian stood still for a moment. Then he spoke again, more earnestly than before, and waved the strangers away from the red hill.

"We're not going," said Mr. Roumann, and he added a few of the Martian words he had learned, endeavoring to state that they were going to take only a little of the Cardite.

The officer, with a last warning shake of his big head, suddenly turned and ran away.

"I guess he's gone for reinforcements," said Jack.

"No matter," spoke Mr. Roumann. "We'll soon have all we can carry, and then we'll hurry back to the projectile. When we get there we can defy them."

They continued to fill the boxes with the Cardite, and soon had a good supply. Then, taking a look to see if the Martian had summoned any guards, but finding that none was in sight, the adventurers made their way back to their boat, and set it in motion.

"How are we going to escape the whirlpool?" asked Mark.

"I think if we skirt down the shores of the lake for some distance, and then strike across to the city, we'll avoid it," replied Professor Henderson. "The pool is not very large, and seems to be only, directly in front of the red hill."

This they found to be the case, and they were soon safely beyond the swirling waters, and on their way back to Martopolis.

"We had better not land at a public dock," suggested Professor Henderson.

"Why not?" asked the German.

"Because the Martians may see that we have some of the Cardite, and take it from us."

"What would you suggest?"

"Why, there is a landing place farther down, and we might go there and make our way from it to the projectile unobserved."

This was voted a good plan, and was successfully carried out. Though quite a few Martians saw the adventurers land, they evinced no curiosity in what they carried, and that evening the little party was back in the Annihilator, where they determined to stay all night.

Mr. Roumann tested some of the red matter, and found, when he applied the proper electrical treatment, that it gave off light, heat or power, according to the adjustments.

"This is the most wonderful material in the world!" he exclaimed. "Yes, or in the whole universe. It is better than perpetual motion, for it is not only that, but perpetual light and heat. I believe I can use it in the Etherium. motor in place of the force I ordinarily employ."

He made some experiments, and found that this could be done.

"I wonder what's become of the crazy machinist?" asked Jack.

"Oh, maybe he's made friends with the Martians," said Mark, "and has told them he's a king, or something like that, and they're treating him with royal honors."

"More likely he's plotting mischief," declared old Andy. "I wish my gun was in working order. Somehow I don't like the way that fellow acted on the red hill."

"Why, you're not afraid, are you?" asked Professor Henderson.

"No, not exactly, but I was just thinking how we could defend ourselves in case they attacked us. My gun is no good."

"You forget that we have electrical cannons," said Jack.

"That's so," added Mr. Henderson. "And it might not be a bad plan to get, them in working order."

"Nonsense!" exclaimed the German scientist. "The Martians will never bother us. They are thinking too much about the stars, the sun, moons and other planets—they are too intent on studying to bother us. That is all they do—study. That's what makes their ears, eyes, nose and mouth so big. They use them to listen to scientific sounds, to look at scientific objects, smell scientific odors, and talk of scientific things. They'll never bother us."

"Maybe not, but perhaps the crazy machinist will," suggested Mark.

"I'll make some inquiries to-morrow, and see if the Martians know anything of him," promised Mr. Henderson.

But if the Martians knew anything of the insane man, they would not tell. When the adventurers made cautious inquiries on the morrow, they were only met with vacant stares from the big eyes.

The boys and their friends made several excursions about Martopolis in the next week, and even traveled in the big sleds to distant cities, which they found much the same as the one they were in.

They saw no signs of the crazy machinist, and began to believe that he had disappeared for good. They were making progress in the Martian language, and could converse with the people. No longer did the Martians cause the travelers to move about by the thought force, and our friends were allowed to go here and there as they pleased. They found traveling exceedingly easy, as their bodies were so light.

They had again taken up their residence in the house in the city, paying occasional visits to the projectile, which remained on the soft sand where it had landed, but tilted upward, ready for a flight.

One afternoon Jack and Mark, who had been out taking a walk, came back rather hurriedly. They found Professor Henderson and Mr. Roumann doing some scientific work, while Washington and Andy were discussing the many strange things on Mars.

"Professor," said Jack, "I think something is up."

"What do you mean?"

"Well, there's something unusual going on. The Martians are acting very queerly. There's a big meeting in the glass palace, and when we tried to go in we were stopped. Crowds in the street kept following us, and they haven't done that since we first landed."

"Yes," added Mark, "and I think I saw that same man who watched us taking the Cardite with a lot of other officers, following us, too. And, besides, no persons here seem as friendly as they used to. Did they, Jack?"

"No, indeed. I think they have discovered that we have taken some of the red stuff, and they don't like it."

Professor Henderson and Mr. Roumann looked grave. If this was the case, it might mean serious trouble for them all.

"But they're a long while finding out that we took the stuff," said Andy, who listened intently to what the boys said.

"Maybe they knew it all the while," suggested Jack; "but they are so interested in scientific matters that they didn't want to take any action on it until now."

"Well," remarked Mr. Roumann, "whatever it is, I think we will be safer in the projectile. Come, we will all go out there and spend the night. We can defend ourselves in case anything happens, though I don't believe it will."

They started at once, and there was a feeling of security when they had clamped fast the great steel doors in the side of the Annihilator.

Contrary to their fears, the night passed without incident. They were all at breakfast the next morning, when Mark, happening to look through a heavy plate-glass window in the living-room, called out:

"Look what's coming!"

They saw a vast throng of Martians advancing toward the projectile.

"See who's leading them!" called Jack. "The crazy machinist!"



CHAPTER XXIX

THE REPULSE

"Do you suppose they're going to attack us?"' asked Mr. Roumann.

"It looks very much like it," answered Professor Henderson. "But we will wait and see. Are the electric cannons in shape?"

"Yes, they are all ready to work. All that is necessary is to open the ports and fire them. They will not kill, but they will disable the Martians for a time, in case we have to use them."

"I hope we'll not have to," said Jack. "They have been very good to us, and I shouldn't want to harm them."

"There's a big crowd of them," added Mark. "I wonder how that crazy man came to be with them?"

"He must be leading them against us out of revenge," was Mr. Henderson's opinion. "He may have induced them to try to kill us, and they may be very willing to do so, because we have taken some of the Cardite."

"I hope not," murmured Mr. Roumann.

The throng approached nearer. In front was the insane machinist, who was leaping about, running to and fro, and shouting at the top of his voice. His words came faintly to those in the projectile.

"They seem to have a new leader," remarked Jack. "I understood that the ruler, Silex Corundum, always went at the head of the troops when there was to be a battle, but there's a different person now."

A little in the rear of the crazy machinist was a Martian enveloped in a scarlet cloak, which hung from his shoulders to the ground. And fastened on his head to the golden circlet, which seemed to be a common badge of office for all leading Martians, was a small metal box.

"I believe that box has Cardite in it," said Jack. "Maybe he's the keeper of all the Cardite on this planet, and he and his soldiers have come to get it back."

"They don't look like soldiers," commented Mark.

"No; but they all have some sort of weapons," said Jack. "They look like sticks with small boxes of Cardite on the end of them. They must he a new kind of gun."

"And probably very effective, too," commented the professor. "But they are evidently going to hold a parley with us. The machinist and the Martian in the scarlet cloak are advancing alone."

The main body of Martians had come to a halt a short distance away from the projectile, while the two strange figures, so greatly contrasted—that of the insane man and the little officer-advanced together.

"Open the window to hear what they say," suggested Mr. Henderson, and the German scientist did so.

"Hello, you in there!" called the machinist.

"Well, what do you want?" asked Mr. Henderson.

"We want you to come out and be killed. I'm going to pay you back for all the trouble you caused me. I couldn't wreck your airship that you stole from me, but I'll have my revenge now. These little fellows will do whatever I say, and I want you to come out and be killed."

"Suppose we refuse?"

"Then we'll make you! Oh, they've got the power to, all right. I'm going to be their king next week, and they'll do anything I say. Come on out!"

"I'm afraid we shall have to decline," answered the professor.

The machinist began a rambling talk, and the scarlet-cloaked figure stepped forward. He spoke slowly, using simple words in the Martian tongue, such as he knew the travelers could understand.

"My name is Zun Flor," he began. "I am the keeper of the Cardite, and I am told by one of my assistants that you have taken some."

"Well?" asked Mr. Roumann.

"You must return it at once. It is against our laws for strangers to have any of the Cardite."

"But we came here to get it. We only took a little, and you have so much."

"That makes no difference. You must return it at once, and then you must go away. We do not want you here."

"Suppose we refuse?"

"Then you will perish! Be warned in time. Give up the Cardite, and take your departure."

"What will happen if we do not?"

"You and your machine shall vanish from this planet and never more be seen. We cannot have any of our precious Cardite taken away to another world."

"We have only taken a little," repeated Mr. Roumann. "We desire it for scientific purposes, and as you are so fond of science, you ought to let us keep it."

"Give it back!" exclaimed Zun Flor, and he seemed to be very angry. His big, bulging eyes flashed. "Return it to me, and all will be forgiven."

"We will not!" declared Mr. Roumann firmly.

"Then we shall attack you!"

"And we shall defend ourselves. Now, let me warn you. We have powerful forces within this projectile. We will use them against you and your men."

"You cannot harm us," insisted the Martian in the red cloak. "Your machines of war will be powerless against those we have. Be warned in time. You must choose between the Cardite and death!"

"We will keep the Cardite, and we will also keep our lives!" retorted the German.

He slammed the glass window shut with a bang, and locked it. Then he closed an inner shutter of steel over it.

"We, can't see what's going on, and what they do," objected Jack.

"Yes, we can," said Mr. Roumann.

He pressed a lever, and a shutter made of strong steel slats, that was on the plate-glass window of the projectile, opened. This gave a view all about the Annihilator.

This done, the ports covering the muzzles of the electric cannons were let down, and four guns, two on either side, were aimed at the throng of Martians.

"They are going to fire, or something!" exclaimed Jack, as he looked outside. "They are pointing those sticks at us!"

Instantly every one in the projectile felt as if a thousand pins and needles were sticking into him.

"They're discharging an electric current, or something like it, at us!" cried Professor Henderson.

A moment later every one felt himself drawn against one side or the other of the projectile, just as a magnet draws steel filings to itself through a piece of cardboard.

"They're trying to pull us through the steel sides!" cried Mark. "I can't move."

Neither could any one else. They were stuck there like flies on the wall.

"Maybe they are going to keep us here forever!" cried old Andy, while Washington was too frightened to use any big words.

Mr. Roumann was near some levers. He managed to pull one, and instantly those in the projectile felt themselves free.

"How did you do that?" asked Mr. Henderson.

"I neutralized the electric current," explained the German. "I anticipated that in our flight through space we might meet with electric storms. I provided so that in such a case I could throw a counter current of electricity all about the projectile. That is what happened just now, though not exactly as I expected it. I have rendered their weapons useless—at least, for the time being."

"And we can now try ours on them!" cried Jack.

"Exactly! Get ready to fire the electric cannons!" called Mr. Roumann.

The Martians seemed to understand that something had gone wrong. They were running about, consulting among themselves, and pointing to the projectile. The figure in red and the machinist were talking earnestly together.

"He's probably telling them something about the machinery," said Jack.

"Man the guns!" cried Mr. Henderson.

He and the German were at the cannon on one side, and Jack and Mark on the other.

"Fire!" shouted Mr. Roumann, pulling the lever that worked the weapon. The others did likewise. There was a flash of sparks from the muzzles of the guns, and a powerful and disabling, though not deadly, current of electricity shot toward the Martians.

Score after score of the queer creatures went down, among the first to fall being the machinist and Zun Flor.

"Once more!" cried Mr. Roumann, and another volley was sent out, stunning hundreds.

Then came a third one, but this was enough. The remaining Martians, leaving their helpless comrades on the ground, turned and fled.

"We've driven them away!" cried Jack.

"For a time, at least," answered Professor Henderson gravely. "But I think they will come back."



CHAPTER XXX

THE ESCAPE—CONCLUSION

Nor was the professor mistaken. In less than an hour the Martians returned, in larger numbers than before, and, while the first throng had seemed to consist of only soldiers or police, the next attack was made by thousands of men, women and children. They all seemed anxious to destroy, the strangers.

Those who had been disabled by the electric guns revived, and were able to crawl away, but they were too weak to resume the attack.

"Well, we'll have to shoot at them again," observed Jack, as he and the others noted that the attack was to be resumed.

"Let 'em have it!" cried Mr. Roumann.

Once more the electric cannons were fired, and thousands fell at each discharge of the powerful current.

But, in their turn, the Martians brought into use new weapons. First they hurled great rocks and chunks of lead at the projectile, but, as the missiles weighed only a third as much as they would have done on the earth, they only dented the heavy steel sides.

Finding that this would not answer, the little people created clouds of noxious gases, that swirled around the projectile like a fog. But this was harmless, as the adventurers could shut themselves in tightly, and breathe air of their own making. The gases had no more effect on them than did the ether through which they had traveled through space.

Meanwhile, the electric cannons were constantly being fired, and the ranks of the attackers were constantly being thinned. But, ever as the Martians fell, new ones arrived to take their places. They seemed determined to drive the newcomers off the planet or destroy them.

There was a lull in the fighting. The Martians seemed to be waiting for something. At last a large crowd was observed coming from the direction of the city. They carried great bundles of wood and torches.

"They're going to try to burn us out!" cried Jack.

"Good land a' massy!" yelled Washington. "Let me go! I ain't ready t' burn yet! No, indeedy!"

With shouts the Martians piled fuel all about the projectile. Then they set fire to it, and tongues of flame leaped up.

"Don't be alarmed," said Mr. Roumann. "We have passed safely through greater heat than they can produce. The gas in the projectile will absorb all the heat."

And this was exactly what happened. The flames had no effect on the Annihilator, whereas the electric cannons continued to mow down the Martians.

The day was now well advanced, and the defenders were getting tired and hungry, as well as apprehensive, for there seemed to be no limit to the fury of the little people, and their scientific knowledge was such that it was probably only a matter of time before they would find a way to destroy the projectile.

During a lull in the fighting, when the fire that had been kindled died away, Washington White came around with some food he had prepared.

They felt better after the meal, but immediately there came a new apprehension, for they saw that the Martians were digging a great hole to one side of the projectile.

"What can they be doing that for?" asked Andy. "Maybe they're going to roll us into it," said Mark.

"No," spoke Mr. Roumann, after watching the crowd at work, "I'm inclined to think they're laying a mine, and are going to blow us up."

"Blow us up?"

"Yes. They evidently have some explosive over there, to judge by the manner in which they guard it."

"Can we stand being blown up?" asked Jack.

"I hardly think so. The projectile itself might not be harmed, as it is very strong, but the machinery and motors would probably be damaged."

"Then what can we do?"

"The only thing left for us to do is to escape."

"Escape? You mean leave the projectile?" asked Mr. Henderson.

"No, I mean escape in the Annihilator. There is no reason why we should stay here any longer. We have what we came to seek, and though I should like to make some further scientific observations, we will have to forego them. We will start the atmospheric motor, and leave Mars."

"That's the stuff!" cried Jack. "Back to earth for ours! It's nice up here, when you don't do something they don't like, but the earth is good enough for me!"

"That's what I say," added Mark.

The Martians were hurrying their preparations to blow up the projectile. Perhaps they guessed that they must act promptly, or they may have had an intimation that something was going to happen, when the ports of the electric cannons were closed.

The shutter of the observation tower was sealed, all openings were well fastened, and, just as the mine was completed and the explosive was about to be put in, Mr. Roumann started the atmospheric motor, and the projectile left Mars with a rush.

Of course, the travelers could not see the blank looks of astonishment on the great faces of the Martians, but they could imagine them, as they shot away from the queer little planet at the rate of sixty miles a second.

"Well," remarked Mr. Roumann as he went to the pilot house, after seeing that the motor was working well, "we got to the place we set out for, and we secured some Cardite, which is what I wanted. I am now able to repay you for building this projectile, Professor Henderson, you need never worry about money again."

"I'm glad of it, as I shall devote the remainder of my life to science, and I may write a book about Mars."

"Well, ob all de transmigatoriousness dat I eber seed," exclaimed Washington, "de continual exteriorosity ob de inhabitants ob dat planetary sphere am de mostest indisputatious!" Though what he meant by that no one knew. But it seemed to give the colored man great satisfaction.

In due time they passed beyond the limits of the atmosphere of Mars, and again were sailing through space, the Etherium motor doing good work. Mr. Roumann tried some Cardite in it, and their speed was increased by half, so they reached the atmosphere of the earth in much shorter time than they calculated.

They met with no mishaps, though they narrowly escaped collision with a great meteorite that was rushing through space, white hot.

"Well, in a few days we will be at home," remarked Mr. Roumann one night, as he set the atmospheric motor in operation. "And I must say I have greatly enjoyed the trip."

"So have I," admitted Jack, and Mark agreed with him.

"Maybe mah Shanghai rooster won't be glad t' git on terra cotta again," spoke Washington. "I'se glad I didn't let him out on Mars. Dem funny fellers might 'a' eat him up."

The rooster crowed as if glad to be nearing the earth.

Three days later they came in sight of their own planet, but as night came on, and they did not want to land in the dark, the projectile was kept up above until daylight, and a day later a landing was made near the machine shed where the Annihilator had been built.

"Well, here we are, safe home again," said Mark.

"All but the crazy machinist," added Jack. "I hope he likes it up there among the Martians."

"I wonder if we'll ever take another trip like this?" asked Andy.

"Perhaps, some day," replied Mr. Roumann.

"I have some other ideas regarding distant planets that I would like to prove. But we'll take a rest, and see what use we can make of the Cardite. I would also like to learn if my enemy, Forker, sent that crazy machinist to bother me," but he never found out.

As the German had predicted, the red material brought back was enormously valuable, and the projectile was more than paid for by a small part of it. The boys resumed their studies at school, and Professor Henderson devoted much of his time to writing a book describing some of the peculiar conditions on Mars, while Mr. Roumann invented a new motor to run with Cardite, he having revealed the secret of the Etherium one to Professor Henderson.

As for Washington White, he is learning new big words, while Andy says he is glad to be back on a world where a bullet is a bullet and a gun a gun.

THE END