The Air Ship Boys

CHAPTER I - THE DEPARTURE OF THE OVERLAND LIMITED
The Overland Limited, aglow with lights, stood in the Dearborn Street station in Chicago waiting for eight o'clock and the last of its fortunate passengers. Near the entrance gates, through which perspiring men and women were hurrying, stood the rear cars of the train. Within these could be seen joyous passengers locating themselves and arranging bags and parcels.

In fifteen minutes the long journey of Ned Napier and his chum Alan Hope to the far southwest was to begin.

At the other end of the big shed, where the cars of the long train seemed to fade almost out of sight, four persons were anxiously awaiting the approach of the hour of departure. One of these, the conductor of the train, consulted his watch, as he had done several times already, holding it close within the glow of his green-shaded lantern.

"It's getting pretty close to time, Major Honeywell," he said with some concern. "You're sure he'll be here?"

The man addressed, who stood leaning lightly on a cane and whose soft dark hat and clothes indicated his military calling, showed similar concern, but replied confidently:

"We have nearly fifteen minutes. Young Napier has a reputation for never failing. I'm sure he'll be here in time."

"Here's the telegram," interrupted young Alan Hope, as he drew a yellow sheet from his pocket. "It is from Youngstown, Ohio, and says Ned's train is on time. He left Washington yesterday and if everything is all right he reached the Union Depot a half hour ago. He'll be here."

"Well, you know we can't wait, much as I'd like to," replied the conductor. "You'd better have everything ready."

"She's dat, sah," interrupted the fourth person of the group, a young negro, who, as he spoke, placed his hand on the side door of the car, and moved it on its easy running bearings.

"You see, there isn't much time left," continued the sympathetic train official. "We're coupling up." And he nodded toward the gloom beyond the train shed out of which the big compound locomotive was already emerging. The military man with the cane became more apprehensive.

"What shall we do if Ned fails to get here?" he said suddenly after peering down the long platform toward the busy end of the station.

"Oh, we didn't go into this to fail," cheerily responded the youth by his side. "If we 'fall down' it won't be on a simple thing like this. He'll be here. It won't take us but three minutes to transfer the stuff when it gets here. Never fear. I'll just take another look in the car to make sure."

As he did so the colored boy exclaimed:

"It's all right. Here's de screws as he done tole us to git and here's de screw-driver outen de box as he done writ us to have ready and dar's de door all ready fur to fly open."

To prove it the lad gave the wide door in the side of the car a shove, and as it ran back on its track a portion of the inside of the car was exposed. It was a peculiar car and worth description, for in it, next to the big engine and ahead of all the other cars of the almost endless train, Ned Napier, his friend Alan Hope, and their servant, Elmer Grissom, were to be the sole passengers on a most mysterious and, as it proved, most eventful journey. In railroad parlance the car was what is known as a "club" car. Half of the interior was bare and unfinished, like the compartment in which, on special and limited trains, baggage is carried. This part of the car, now exposed to view, was dimly lighted with one incandescent bulb. In the half-light it could be seen that the space was almost wholly filled with tanks, boxes, casks, crates and bundles, all systematically braced to prevent jarring or smashing. It was plainly not the luggage of ordinary travelers. Except for a narrow passageway in the center of the car and a space about five square next the open door, every inch, to the very ventilators of the car, was crowded with bound or crated, numbered and tagged packages. In the open space next the door Alan Hope now appeared.

"Coming yet?" he asked with apparent confidence as he peered outside.

The colored boy Elmer shook his head.

Just then the conductor returned and again his watch.

"Eight minutes," he said; "time's getting along and I've got to go back and see about my train. I don't want to make you nervous, but do you want us to take this car if fails to get here with the stuff?"

"I suppose there's no need," replied the military man, beginning to show irritation. "But there's eight minutes yet."

"I know," replied the conductor, "but after we are coupled up and it is time to leave we can't stop to cut this car out. We've got to have five minutes for that. At five minutes of eight you'll have to decide whether it is go or stay. I'm sorry—but you'll have to decide in a minute or two."

"Decide it now," interrupted Alan from the open car door. "We're going and he'll be here."

The Major appeared to be in doubt as to the wisdom of this, but before he could say anything Alan continued:

"Couple up whenever you want to, Mr. Conductor, we'll be ready," and he sprang out of the car, his face set with determination.

By that time the throbbing engine had silently moved up next the car and two grimy depot men with smoky torches had swung off the footboard to make the connections.

"Got to know," repeated the sympathetic conductor. "Only five minutes." He looked at the Major for the final word.

The latter peered down the long almost vacant platform. There was no one in sight but the late arrivals being helped aboard the cars in the far end of the station. Then he gave another look of appeal at his own watch as if in doubt what to say. To send a special car half way across the continent was no inexpensive project. And to send it without the person or the precious material that it was intended seemed not only a waste of money but foolish. Although the anxious man had both confidence and nerve it could be seen that he was in a quandary.

"Five minutes," exclaimed the railway official. "Does she go or stay?"

Before the man could answer, Alan faced him and with a hand on the Major's arm exclaimed:

"Ned will be here, he can't fail; tell him we're going."

The Major smiled. "That's it," he exclaimed suddenly. "Take her along. It's up to us to take care of ourselves."

"Good," said the conductor, "I hope he'll make it."

With a signal to couple on the engine he hurried away for a final inspection of his train.

For a moment the three persons left behind stood in silence. There was a hiss of the engine as it pushed the connecting blocks together and then those waiting so anxiously could hear the jar of connecting valves as the brake hose were snapped. Confident as Alan was, it gave him a sinking feeling. Then, as the swish of tests sounded and the gnome-like figures of the depot men crawled from under the car, the Major looked again at his watch in despair.

"Four minutes—"

Before he could say more Alan caught sight of a movement among those gathered around the last car at the far end of the depot.

"There he is!" he shouted and darted forward.

"He sho'ly is," exclaimed Elmer, his white teeth showing, "and Yar's de screw driver and yar's de screws all ready."

A slowly moving truck had carefully turned the end of the waiting train and, drawn by two baggage-room employees, was making its way along the platform. By its side walked a boy—a lad of about seventeen. One of his hands rested on the truck and his eyes were carefully fixed on the load it bore. This was a black, iron-bound case about four feet long, three feet deep and perhaps a yard in height. On each side in red letters were the words:

"Explosive; no fire." Beneath this ominous legend were two large iron handles.

When the men drawing the truck quickened their pace the boy spoke to them sharply and they fell again into a steady walk. For the curious onlookers through whom the strange little caravan passed the lad by the side of the truck seemed to have no concern. A traveling cap was pushed back from his young face and his keen and alert eyes and the tone of his voice indicated a quality that goes with those born to command.

"Hello, Ned," came a ringing greeting from Alan as he ran forward. "They were afraid you wouldn't get here. But I knew you would. It's only a minute or two. Hurry."

"Four," said the new arrival cheerfully and confidently.

He gave his left hand to Alan and a better welcome in a cheery word of greeting, but his right hand did not leave the truck. Nor did his eyes leave it except for a moment.

"And the Major?" asked the new arrival as the truck rumbled on.

"Waiting to bid us good-bye."

"Everything aboard and shipshape?"

"Everything but this," and Alan glanced at the black case on the truck.

"I've carried it a thousand miles like a baby," laughed Ned. "Rode with it all the way in the express car."

"Then you didn't sleep last night?"

Ned laughed. "It was too interesting," he answered, "and I can sleep to-night. But I'm glad it's here with no one killed and not a drop spilled."

Advancing leaning heavily on his cane, the military man had hurried forward, his face radiant.

"Welcome, my boy, and congratulations. But for goodness' sake hurry," he began hastily.

Ned smiled again. "I think we had better not hurry this," and he pointed to the truck load. "That's the reason I'm late. I walked the horses from the Union Depot. You see we can't afford to spill our supplies. It was too hard to make and cost too much."

In another moment the truck was abreast of the open car door.

"Back her up," exclaimed Ned giving a hand himself to the tongue of the truck. Then, as the top of the truck came up flush with the car door and floor he sprang lightly on the truck and motioned the men to do likewise. For a moment they hesitated, but being reassured, Ned and Alan and the truck men lined up on either side of the big case. Slowly and carefully, with a brawny truck man on each side to help the less stoutly muscled lads, the case slid forward and with a "yeo-ho" or two from Ned it was soon in the car. Without a pause it was pushed at once into a space outlined on the floor.

"And about two minutes to spare,"' cried the Major from the platform jubilantly and thankfully.

"Not quite," laughed Ned, "but it'll be a half a minute and that's as good as an hour. The screws, Elmer."

The colored boy, who had been busy keeping out of the way, sprang forward to perform his part of the apparently ticklish job. It was then seen that each bottom corner of the mysterious box had an iron flange. In the center of' each of these was a small hole.

"Major," called out Ned as the truck men climbed out of the car, "these men were very obliging and careful."

The Major understood him, and as he began searching his pockets for a bill Ned quickly inserted four screws in the waiting holes and with a few sharp turns of the screw driver made the case hard and fast to the floor of the car. Almost as quickly he threw the door into place and bolted it, and then with Alan hurried out for a last word to the friend who was so much interested in his success.

"Was I right?" he exclaimed. "Half a minute?"

"To the dot," enthusiastically answered the Major. "Now, boys, good-bye. Everything in that car is exactly as you planned and asked. From now on it is subject to your orders alone. What mine are you know. God bless you both and good luck to you!"

As the boys took his hand Ned handed him a letter. "I'm sorry I couldn't have seen my mother again, but please send her this. I wrote it to-day on the train."

Far down the line of cars came the words, "all aboard," and Elmer, cap in hand, sprang onto the steps.

"Good-bye," exclaimed Alan, "and thank you for the great chance you're giving us."

"Good-bye," said Ned, "if we fail in our work it won't be your fault, Major."

And then, as the train began to move, the boys stepped aboard, off at last, after six weeks preparation, in search of the lost Cibola and the treasure of the Turquoise Temple.

CHAPTER II - NED'S MEETING WITH MAJOR BALDWIN HONEYWELL
Six weeks before Ned Napier and Alan Hope had set out on this trip Ned had been the surprised recipient of a mysterious note. In this message, written on the stationery of the Annex Hotel, he was urged to call on the writer the next morning at ten o'clock. With his mother's approval he had kept the engagement. The events which followed will explain how Ned came to take his momentous journey to the far southwest.

Promptly on the hour Ned presented himself at the office desk. A clerk with a handful of letters gave him a half glance and turned away.

"I say," began Ned in a voice that made the clerk turn quickly, "I want some information."

The man stepped forward, leaned over the counter far enough to get a full view of his questioner, and answered:

"All right, sonny. What can I do for you?"

"You can tell me if Major Baldwin Honeywell is staying here."

"Friend of Major Baldwin's?" asked the clerk, his smile broadening.

"If Major Honeywell is stopping here I suppose he is paying well for his entertainment," replied Ned after a moment's pause.

"Sure," answered the facetious clerk, "regular rates."

"Perhaps that ought to include civil attention to those he has business with. I have an appointment with him at ten o'clock. I wish you would see at once that he knows I am here."

The clerk's smile was not quite so broad now but he was still amused.

"What name shall I give, son?" He was about to repeat the "sonny" that had grated a little on Ned's sense of the proprieties but he stopped short—and added: "Have you a card, Mr.—?"

"I have no card and I don't call myself 'Mr.'," answered Ned, "but you can say that Ned Napier is here and will be glad to see Major Honeywell whenever it is convenient."

At the mention of "Ned Napier" the clerk's airiness disappeared. A certain respect seemed to take its place. Then he leaned forward and said a good deal more politely: "You are not the Ned Napier?"

"I never heard of any other one of that name," answered the boy. "But I think we are losing time. Please say I'm here."

A moment later a page announced that Major Honeywell, in suite 8 A, desired Mr. Napier to be shown up at once. Reaching the apartment the page knocked and there was a quick "Come in."

Hat in hand, and with all the manliness and dignity his seventeen years afforded, Ned stepped into the room. At a table a man had just risen as if from work on some papers. As the man turned to come forward and his eyes fell upon the lad he paused as if surprised. Ned Napier was neither large nor small for his age. But his circumstances had been such, financially, that his attire was plain and perhaps old fashioned—much of it the handiwork of his frugal and fond mother; and the absence of smart and up-to-date ideas in clothes and shoes made him look, perhaps, even younger than his years. Other lads of his acquaintance—those in his classes in high school—aped their elders. Ned's time and interests were too much given up to his boyish ambition to permit this.

Ned saw a man of about sixty years, with snow-white moustache, dressed in blue. The man had every appearance of being both a soldier and an officer. His face was tanned as if by much exposure to the sun, but the line of white at the top of his forehead, where his hat gave protection, suggested that the color was both recent and transitory. Major Honeywell's hair, which was yet dark and only slightly streaked with gray, was too long to suggest present active service, as Ned at once concluded. His face, too, had something of the student in it, and this effect was increased by a pair of large gold spectacles with double lenses. The man's contracted eyes gave the youth the uncomfortable feeling of being microscopically examined, and Ned was for a moment ill at ease. The manner of the scrutiny was that of a scholar who had before him a strange new specimen. Ned, still with hat in hand, felt more like a dead bug than a very live boy. Then the white-mustached man smiled, took off his heavy-lensed glasses, and stepped forward with his hand extended.

"I am Major Honeywell," he began in a low voice, "formerly of the regular army and later detailed on ethnological work for the Government. You are—"

"Ned Napier," responded his youthful caller.

"You must take no offense if I am a little surprised," exclaimed Major Honeywell; "I had supposed you would be older. Perhaps your surprise came first on receiving my note?"

"It did," replied Ned; "I was surprised and so was my mother. But she thought I ought to come, although we could not imagine what you wanted."

Major Honeywell smiled and motioned Ned to a chair with a graciousness that made the lad more comfortable. It had taken but a passing glance to reveal to the boy that he was in the presence of no ordinary man. The articles scattered about the room, which apparently were part of his host's traveling outfit, confirmed this. Of three leather cases or trunks in front of the mantel and within Ned's view, one was open. On the extended top of this, still partly covered with the folds of a light Indian blanket, were several flat and dull plates or dishes of Indian design, more or less broken and chipped. From the case came a pungent aromatic smell such as Ned had noticed in the "Early American" room of the museum. He was not quite sure what "ethno" meant, but he made a guess that it related to old Indian things, and this theory he confirmed to himself when he noticed on the table that Major Honeywell had just left another piece of pottery and by its side a large reading or magnifying glass.

"A collector," thought Ned, more puzzled than ever.

"I thank you for coming," said Major Honeywell finally. "It was good of you to do so. But I had supposed you were older—at least a young man," and he smiled again as if in some doubt.

"Perhaps," replied Ned with just a shadow of resentment in his voice, "if you will tell me why you sent for me I can help you in making up your mind as to whether you were wrong in doing so. I'm seventeen."

Major Honeywell arose, took off his glasses again and walked to where Ned was sitting.

"I hope you'll not take offense, my boy. But my business with you is most important. It is possibly the most important thing that has ever come to me. Fate, or chance more properly, of course, seems to have brought us together. If what I have in mind and have partly hoped could be brought about, is brought about, you will have no reason to regret my sending for you. We must be sure of ourselves. So far we know almost nothing about each other. Since our acquaintance may mean a great deal to us let us be sure of ourselves. Therefore, you will pardon me if I ask you if you are the Ned Napier?"

Ned laughed good-naturedly.

"That's what the clerk down stairs asked me few moments ago—if I were the Ned Napier. Well, I never heard of any other Ned Napier. But boys don't carry credentials, you know, Major Honeywell. I'll take your word for it that you are Major Baldwin Honeywell, formerly of the United States Army, and now of the—what do you call it—ethno—?"

"Ethnological survey," laughed the Major. "Then, since we know each other, I want to congratulate you, my young friend, on being one of the brightest, nerviest, and most promising young men of America. I've read about you and that's why I sent for you."

Ned could only conclude one thing and it made him blush. "You mean my dirigible balloon experience last summer?" he asked with growing embarrassment.

"I do," replied Major Honeywell with what Ned thought was wholly unnecessary warmth and enthusiasm, "and I want to shake the hand and congratulate the youngest, most daring and most promising balloon navigator in the world."

CHAPTER III - THE RELATION OF MIGUEL VASQUEZ
It may be well to recount how such a young lad as Ned had become so famous.

Ned's father had been a consulting engineer with a fondness for aeronautics. When Mr. Napier died, a year before Ned's meeting with the Major, it was discovered that he was making in his little shop a small dirigible balloon to be used at an amusement park. Mr. Napier's death was sudden. Manufacturer's bills for the balloon bag and engine came due and Ned, young as he was, knew that he must pay them. Putting on all the dignity that his sixteen years would permit he called on the manager of the amusement park.

"I hear your father is dead," said the manager. "I suppose we have lost the twenty-five per cent we advanced on the air ship."

"Why do you suppose that?"

"Because he had complete charge of the work and we have no one to take his place."

"I mean to do that myself," said Ned.

The manager smiled and shook his head. "No doubt you would try—you look it—but we don't care to experiment."

"But you want the air ship, don't you? You've advertised it."

"Yes, it was ordered—through your father. Since he is dead and cannot contribute his services, our agreement is void."

"Very well," replied Ned. "Good day."

"Look here," interrupted the manager, "what do you mean to do?"

"I'm going out to sell an air ship."

"You mean our air ship?"

"You said the contract is void."

The manager laughed again, but not as jovially.

"You ought to get on," he exclaimed.

"I've got to get on, and I'm going to do it by being on the square."

"I guess you're right. What's your proposition?"

"Since you've thrown up the contract I'm going to sell the balloon at a profit. The price is now $3,000. And I want a contract as operator for six weeks at $100 per week."

The manager stared at Ned and then exclaimed. "I'll do it. You are the very youngster we want."

That was how Ned Napier came to finish the air ship his father had planned, and how it happened all that summer that the papers printed news stories and Sunday specials with pictures of his daring flights, and how Major Baldwin Honeywell and other happened to speak of him as the Ned Napier.

To return to the scene of Ned's meeting with the Major—

"My name is Ned Napier," the boy began as soon as his host's cordiality gave him a chance, "and I am the young man the newspapers wrote about."

"I certainly made no mistake in sending for you," exclaimed the soldier. "But, before I say more I want you to realize that this is, to me, a most important matter."

"You mean it is—"

"A solemn secret. I want secure your services in a desperate and daring adventure that will mean a great deal to me—and a great deal to you."

"Certainly," was the boy's response. "I give you my pledge on that."

A look of relief came into the old soldier's face.

"If I furnished you the money," went on Major Honeywell suddenly, "could you produce in a short time a practical and manageable balloon?"

Before the boy could answer the old soldier continued: "I don't mean one of those affairs in which ascensions of an hour or so are made. I mean one in which you could travel for several days—perhaps a week?"

"No," said Ned, "it can't be done. No one has yet remained in the air in a balloon over fifty-two hours."

Major Honeywell said nothing, but Ned could see that what he had told the Major had dashed some budding hope.

"That is," Ned hastened to explain, "you couldn't do it unless you periodically renewed your supply of hydrogen. I really believe," continued Ned, "that I ought to know more about what you are planning to accomplish."

Again the white-mustached man was silent a few moments, and then he told without reserve the great secret. He began with an account of himself. Until three years before he had been an officer in the United States cavalry, stationed in the southwest. Then the President had assigned him to ethnological work. His special work was in the ruins of the Sedentary Pueblos. While scaling a cliff in this work he fell and permanently injured his left knee.

Resigning from the army, he traveled for a year and then went to visit an old friend, Senor Pedro Oje, whose immense sheep herds in Southwestern Colorado had made their owner a millionaire.

While here, hearing of an ancient nearby pueblo, just south of the Mesa Verde, Major Honeywell and his friend drove to the settlement. To Major Honeywell's surprise he found an old friend in Totontenac, the chief. As the two white men were about to leave, old Totontenac presented to his soldier friend an ancient funeral urn.

Major Honeywell was almost paralyzed with astonishment when he saw that the vessel was sealed and that it bore on its side, instead of the conventional Aztec design, this inscription in black: "Miguel Vasquez, 1545."

"What was in it?" asked Ned quickly when the Major came to this part of his narrative.

"That man was undoubtedly a soldier who marched out of Mexico in 1539 with Friar Marcos, the great explorer," went on Major Honeywell, ignoring the question, "and when others gave up the search for the famed seven cities of Cibola and the wealth of the Aztecs that every Spaniard believed rivaled the treasure of the Incas, this man kept on. Either by accident or design Miguel Vasquez was left by the expedition and six years later he wrote on cowhide and concealed in that vase one of the most valuable historic records extant in America to-day—confirmation that there was a real basis for the tales that lured the Spaniards to this region in quest of treasure."

Stepping to a trunk Major Honeywell took from a compartment a tin tube. From this he extracted a stiff sheet of parchment-like material.

"It's writing, isn't it?" exclaimed Ned.

"Yes, and Spanish. It is Miguel Vasquez's last will and testament, written over three hundred and fifty years ago. And here is a translation of it. You may read it yourself. That is my secret— and yours now!"

And these are the words that turned the current of Ned Napier's life:

"A relation of Miguel Vasquez soldier of Spain made in the year 1546 concerning the hidden city of Tune Cha. Coming out of Saint Michael in the Province of Culican I journeyed with Captain Marco de Nica in 1539. At Vacupa I departed from him and remained now six years among those of this land. Three years I dwelt in the town of Acuco and heard often of the city of Tune Cha wherein is to be found the Temple of Turquoise than which none more beautiful is to be found, not even in Castile itself. Such I have seen with my own eyes. It standeth within a palace of five hundred rooms or more wherein are to be found priestly vessels of gold and silver. And this same palace or City of Priests is compassed about by a massive wall. And in the center of the palace standeth the Temple, facing the sun which is the sacred place of al Quivera, Arche and Guyas. And the walls of this Temple are naught but precious Turquoise even to the height of forty feet or more, and the pillars thereof are of gold and silver alternate. Knowledge of this hidden and beautiful city hath not been reported unto Spain nor even unto Nueva Espana. From Acuco it lieth thirty day's travel west of north and as I estimate in 36 degrees latitude in the mountains of Tune Cha. From the Rio de Chuco it lieth west six days' travel. Nor may it be discovered but by those who have knowledge of it. Miguel Vasquez"

"What I had hoped to do," said Major Honeywell at last, "was to make the most perfect balloon ever built and discover through you this hidden temple of turquoise treasure. You say you cannot do it."

Something he had never felt before shot through Ned's body. His face flushed and then grew pale under the spell that was on him.

"Major Honeywell," he said suddenly, "I don't know of a balloon that can be made to fly for a week. But if it is necessary to have one to do what you wish I'll make it and I'll find Vasquez's Turquoise Temple."

CHAPTER IV - THE CONTRACT, AND LIQUID HYDROGEN
"I knew you'd do it," exclaimed Major Honeywell, beaming. "Now we'll have my friend Senor Oje up and get right at the details."

"One moment, Major Honeywell. It is easy to say what I just told you. But it means I've got to do something no one has ever done. I've got to take with me—in the balloon, of course—the material to replace the gas I lose."

"Well, that's easy, isn't it? For you—" qualified the old soldier.

"I guess you don't know much about ballooning," laughed Ned.

"Will money enable you to do it?"

"I hope so! Other experimenters have tried to carry materials to make gas. I'm going to take the gas itself in a glass jar."

"In a glass jar!"

"Precisely. Liquefied hydrogen gas."

At that moment Senor Pedro Oje, who had been summoned by Major Honeywell, entered the room. An almost Indian complexion and cast of countenance indicated his Mexican origin. What had taken place was related to Senor Oje, and he left no doubt that he was thoroughly in sympathy with the project. He soon put matters on a business basis.

"We are to share alike in what is found, I understand," he said. "Major Honeywell will have a third interest because the secret is his. This young man is to have a third because the risk is his. And I am to have a similar portion for furnishing the capital. And that brings us to the real starting point," the Mexican capitalist continued. "What is it to cost?"

"Ten thousand dollars at least," answered Ned instantly.

"Phew!" exclaimed Major Honeywell.

Senor Oje, not unused to speculative investments, gave no sign of surprise.

"How shall it be arranged?" was his only comment.

"Put that amount to my personal credit in the First National Bank— if you care to trust me."

"We are trusting you with more than that," replied Major Honeywell with earnestness.

"It will take me six weeks to make my arrangements. In that time, as I need the money, I will draw on the account," said Ned.

"Very good," said Senor Oje; "I will draw up the agreement."

"Now," continued Ned, addressing Major Honeywell, "what is your interpretation of the message of the Spaniard?"

"Of course Vasquez's words must be modernized. What he termed the Tune Cha Mountains begin in New Mexico and extend northwesterly into Arizona and Utah. In many places their plateaus rise eight thousand feet above the sea. Their thousands of peaks and canyons are fit rivals of the wonders of the Grand Canyon of the Colorado. Nowadays they are known by many names—the Sierra Chusca, the Lokaeboka, the Carrisco. 'Thirty days' travel west of north' is not very definite, but it certainly locates the palace in the far northwestern part of these mountains.

"The Rio de Chuco can only mean the Chusco river. The only place in its winding course that is six days' journey from the mountains is where it joins the Amarilla. This is south and east of Wilson's Peak, which is our landmark."

"Very good," exclaimed Ned, briskly. "Now, what is the nearest point in civilization?"

"Clarkeville, Arizona."

"Then that is my starting point. This is June twentieth. I shall be ready by the last day of July. Of course I shall need a special car."

"Very well," responded the capitalist. "I see you know what you want."

"Incidentally," exclaimed Ned, "I shall, of course, be permitted to carry my own assistants."

"Assistants? Yes, of course," replied Major Honeywell, "but they must be persons of discretion."

"My chum, Alan Hope, who will make the ascension with me, will be one, and a colored boy, Elmer Grissom, who has helped me prepare for all my flights, will be the other."

There was no dissent.

"When shall I make my report?" Ned added.

Major Honeywell and his friend conferred a moment.

"Will five weeks be enough time for your exploration?"

"I think so; perhaps less."

"Then we will meet you at the Coates House in Kansas City on the first day of August."

Senor Oje arose and lit a fresh black cigar.

"It will be well for you and Major Honeywell to talk over these things while I see my Chicago banker," said he. And with a good- natured "Adios, Senores," he left the apartment.

"Now, about this liquid hydrogen?" began Major Honeywell at once.

"Well," said Ned, "instead of ballast, I'm going to carry reserve hydrogen with me."

"And is that so difficult?" asked the Major.

"Impossible, if you try to carry material to make the gas," answered the boy.

"And so you are going to carry it in liquid form?"

"I'm going to try, although the making of liquid hydrogen is, so far, pretty much a theory. It has been made only under tremendous pressure and at minus 423 degrees Fahrenheit."

The Major whistled.

"That is so cold that ice is red hot comparatively," explained Ned. "This work must be done, in Washington."

They discussed the balloon itself, and the car and the engine for propelling it; where these were to be made in the East, and how they were to be forwarded to Chicago as they were completed. Ned himself was to go East at once and remain there until the last thing was accomplished.

Ned's chum, Alan Hope, had just taken employment for the school vacation in a large sporting goods store not far from the hotel. A few minutes later Ned walked leisurely into this store and sought out the fire-arms department, where Alan was on duty.

"Hello, Ned," exclaimed Alan, "what do you think of this?" And with a smile he handed him an automatic pistol he was inspecting.

Restraining himself, Ned looked it over carefully.

"It holds ten cartridges and it's a beauty," declared Alan.

Ned weighed it carefully in his hand. "What's it worth?" he asked with dignity.

"Eighteen dollars."

"I think we'll need three of them!"

Alan laughed.

"And there are a good many other things I think we shall need," went on Ned, soberly.

"This hot weather is pretty bad on some people," laughed Alan. "But, by the way, who are 'we?"'

"You and Elmer Grissom and I," answered Ned carelessly.

"And where are we going?" continued Alan, who was not unused to Ned's joking.

"On a little run in a private car down into New Mexico."

Alan looked at him a moment and then determined to have the joke out.

"Then what are we going to do?" he asked, still laughing.

"Make a trip through an unexplored mountain region in the best dirigible balloon ever built."

Alan wondered just where the joke came in. "And then?" he continued.

"Discover enough hidden treasure of jewels and silver and gold to make us rich."

"Shall I get you a cabbage leaf and some ice water?" asked Alan.

"Get your father's consent that you can go; that'll be all," announced Ned and then, breaking into a laugh, he relieved the perplexed Alan by explaining what had just taken place. In ten minutes Alan had secured permission to be off for the remainder of the day and the two boys hurried away for luncheon, to revel in dreams of their great opportunity.

By night Mrs. Napier had consented, though with tears, to Ned's going, and later Alan's father reluctantly did the same. As Ned was to leave the next afternoon and had to see Major Honeywell and Senor Oje in the morning it was a busy evening that the two boys spent in Ned's workshop.

At one o'clock in the morning Alan's work in Chicago was outlined and Ned's needs in the East were all listed.

"And now," exclaimed the tired but exuberant Alan, "it is all arranged but the name. What are we to call the air ship?"

"The 'Cibola,'" answered Ned without hesitation, "the dream of the Spanish invaders and our hope of success."

CHAPTER V - A DINNER PARTY ON THE PLACIDA
The long, heavy, limited train on which the young air ship boys were at last embarked on their extraordinary mission pulled slowly out of the station.

Ned made a quick survey of the Placida. Coming out of the baggage end he passed first into a drawing room. In this were two sections that opened up into four berths. Beyond the berths a passageway led to a private stateroom. When the boys reached the stateroom, Elmer was standing at the door with a happy smile on his face.

"Fo' de captain," exclaimed the colored boy.

"Where are you to bunk, Alan?" Ned asked, quickly.

"Oh, the crew is in the main room."

"Not much," exclaimed Ned. "We're partners in this enterprise. I don't have any better than the rest."

And in another moment he had dropped his valise alongside Alan's berth.

"We'll keep the little room for consultations," he said with a laugh, "when we don't want Elmer to hear us talking about the Indians."

The colored lad grunted.

"Can't scare me wif no Injun talk," he said. "I specs I ain't half so 'fraid o' Injuns as I is o' dat stuff in de black box."

"And it's time to attend to the 'stuff,'" interrupted Ned.

They returned to the baggage room.

"Now," Ned began, "the door to this car must be kept locked except when the train crew are compelled to come through. We, in turn, must be careful about fire and lights. But, for fear of accident, I have taken some precautions."

Alan and Elmer then saw that the top of the case was fitted with a lid the edges of which were bound with rubber. In the center of the covering was a short spout.

"What's the use of an air and gas proof top with a hole in it?" asked Alan, inspecting it curiously.

"Maybe dat's to let de air in and de lid's to keep de hydrogum from gettin' out," volunteered the colored boy.

Ned was too busy to answer the one or to laugh at the other. He had unlocked the lid and thrown it back. About six inches beneath the top of the case stood eight iron boxes—two rows with four boxes in each. These boxes, six inches square, were each about three feet in height and in each could be seen the neck of a glass vessel. Securely packed in their iron jackets to prevent breaking, stood the glass receptacles, open-mouthed and apparently empty. But down below the shadowed rims were soft clouds of gaseous vapor, beneath which reposed the precious contents that had cost Ned over a thousand dollars—the liquid hydrogen.

On top of the square iron buckets was coiled eight or ten feet of rubber hose. Taking it out Ned closed and locked the lid. He then screwed one end of the hose onto the open spout and, springing to the top of the case, passed the other end out of the open ventilator.

"Now," Ned explained, "we are in less danger. Difficult as it is to condense hydrogen, it is more difficult to keep it in liquid form. It constantly seeks to return to gas. In a closed place it might make trouble."

Elmer had already disappeared, with popping eyes and mumbles of protest. Alan proudly exhibited to his friend the results of his share of the work of preparation. Every crate, box, barrel and package was numbered and labeled and securely fastened in place.

On one side of the car stood five large oak tanks, looking like the famous beer tuns of Germany.

"I can make more hydrogen in those than you've got in your black box," Alan exclaimed jokingly.

"I'll have a better look at them in the daylight," finally said Ned; "and now those easy chairs in the other car would feel pretty good."

"Aren't sleepy, are you?" asked Alan, forgetting that his chum had not slept the night before.

"No," said Ned, "only happy. But I'd be happier if I had had time to get a good hot supper."

"All ready, sah, in de stateroom," announced Elmer's cheerful voice.

Both boys turned—Ned in surprise.

"Supper's all ready, sah!" continued the colored boy, "and waiting fo' you all."

In the stateroom was a sight to arouse a sleepy boy and to delight a hungry one. In the middle of a small table was a bunch of pink roses. On either side, in a dish of cracked ice, was the half of a luscious cantaloupe. Silver knives, forks and spoons, sparkling glass-ware and snowy napkins at once revealed the resources of the Placida's pantry.

"Well, I'll be jiggered!" exclaimed Ned.

"Pretty nifty, eh?" laughed Alan.

"Well, if this isn't the last straw!" exclaimed Ned as they seated themselves. "But I want to thank you both. I didn't know how hungry I really was—"

He was about to plunge a spoon into the fragrant, cool melon when he saw a folded note by his plate. Opening it he read:

"Dear Ned: Good luck and good voyage. The roses are from my own garden. Bring me a turquoise ring. MARY HOPE."

It was from Alan's sister.

"Shall we do it, Alan?" he cried.

"Shall we?" answered Alan wringing his chum's hand. "We'll do it or—"

"Is you all ready for dis?" asked the young chef suddenly appearing with a smoking broiled steak. "It can't wait no longer."

And it did not have to.

An hour later the two happy boys sat on either side of the table in the drawing room of their car.

"Are you getting nervous?" began Alan.

"About what?" asked Ned.

"Oh, about everything. The responsibility for this car and the setting up of your balloon, and the trip itself."

"Are you?" exclaimed Ned.

"My, no, I'm not. But then I'm not the captain. But I thought you might be."

"Aren't we getting along all right?"

"Perhaps too well," Alan answered.

"Never talk that way," interrupted Ned decisively. "Everything is happening as it does because we planned it just that way. Things can't go too well. That is a foolish idea. The good fortune of careful preparation should only confirm your judgment."

This was the sort of advice Alan had to take now and then from his friend; but it always did him good.

"Then you don't believe in good luck?" rather sheepishly suggested Alan.

"I believe in it, yes," replied Ned, "if it comes—and I never put it aside. But I never count on it."

Sleep seemed to have fled from Ned's eyes. Although Alan suggested that it might be well to turn in early and be up early, Ned insisted on seeing Major Honeywell's chart of the country they were to explore, saying that he had another night on the journey in which he could sleep.

The chart was really only a rough pencil sketch. The instructions were more in detail.

"This country, now a portion of the reservation of the Navajo and Southern Ute Indians, is a wilderness," Major Honeywell wrote. "White men do not visit it because the Indians will not permit them. Mining prospectors who have tried to do so have been murdered."

"Cheerful, isn't it?" interrupted Alan.

"This jumble of mountains has no connection with our two great western mountain ranges. The towering plateaus, cut with yawning canyons, are plainly the result of some special volcanic action. This unknown region extends over a hundred miles northwest and southeast, and on all sides drops suddenly into the sandy deserts. At Clarkeville the desert begins at once. If you will start a little east of north and locate the Indian village of Toliatchi, twenty miles away, you will be on the Arroyo Chusco. Although the bed of this stream may be dry it can be traced northward sixty-five miles, where it unites with the Amarilla, eighty-five miles from Clarkeville. At the juncture of these water courses, if you face west, the roughest part of the Tunit Chas will confront you. At your right will be Wilson's Peak. That portion of the Tunit Chas to the southwest forms the Lu-ka-ch-ka mountains. To the northeast lie the Charriscos. Somewhere in these mountains lie the temple and the treasures we seek."

CHAPTER VI - BOB RUSSELL OF THE KANSAS CITY COMET
When the Overland reached Kansas City at nine o'clock the next morning the air ship boys were just finishing an appetizing breakfast of fruit, omelet, pancakes and coffee. The Placida, their special car, came to a stop at the far end of the station train shed, and, covered with dust as it was, and almost hidden among hissing engines and baggage and express cars, there seemed little reason for it to attract attention. Of course it was not ignored by the railway officials. No sooner was the train at rest than the depot master and the division superintendent were knocking at the door. They had special orders concerning the car, and immediately wheels and brakes were being tested and ice and water were being taken aboard.

The railway officials made a quick inspection of the car, asked if anything was needed, and were soon gone. A few minutes after they had left a young man suddenly appeared, dodging among the cars. He sprang on to the rear step of the Placida, but before he could enter the car, the door of which had been left open by the departing officials, the vigilant form of Elmer Grissom blocked his way.

"Who's in charge here?" demanded the stranger. "I'm a reporter and want to see him in a hurry."

The railway officials had been admitted through the baggage portion of the car, but Elmer knew that this way was not open to everyone. He understood the need of secrecy, and politely forcing the reporter out of the door on to the platform he led him to the front of the car.

"If you'll give me yo' card," he then said with dignity, "I'll take it in, sah."

As he was about to do so, Ned and Alan emerged from the car for a few mouthfuls of fresh air.

"Hey!" exclaimed the impatient young man, "I'd like to see the man in charge of this car. It's important and I'm in a hurry. I'm a reporter for the Comet."

The boys smiled.

"We are in charge," answered Ned. "What can we do for you?"

The reporter seemed taken somewhat aback at seeing two youngsters directing a special car. His bearing changed at once.

"I've been sent to get a story about where you are going and what you are going to do," he said with a little more consideration; "that is, if you care to tell."

Ned puckered up his lips and thought. He had met reporters before and he knew what a "story" meant.

"I think we don't care to say," he replied in a moment. He did not even care to say it was a secret. Even that admission, he knew, would be a basis for something that might interfere with his plans,

"Our correspondent in Chicago says you left there last evening with a carload of new and powerful explosives."

"Was such a story printed this morning?" asked Ned, eyeing the reporter closely.

"I think not," said the reporter, "but we are an afternoon paper, you know. We have a report that you are on your way to Mare Island, California, and that you have a carload of explosives for the navy."

"Was such a story printed this morning?" repeated Ned, smiling again.

"No, it wasn't. But it will be this afternoon," answered the young man impatiently.

"If such a report had been known in Chicago last night," replied Ned sharply, "it would have been in every newspaper in that city and this city this morning. No correspondent sent you such a story. You are a poor guesser."

The reporter was at least four years older than Ned and Alan. Therefore, he gave a little start of surprise. He had been trapped in a trick that he had often worked successfully on many an older person. For Bob Russell, easily the brightest and quickest-witted reporter in his city, thus to be turned down by two "kids" would never do. Without wasting time to deny Ned's charge, he tried a belligerent role.

"Do you deny you have newly invented ammunition in that car?" he exclaimed brusquely.

"I deny nothing and refuse to be put in the attitude of doing so," calmly answered Ned. "Although it happens you are wrong again."

The young man laughed and again changed his tactics.

"Well, look here, boys, what's the use of getting mad about this? You're working on something, just as I'm working on a newspaper. You've got a good story somewhere about you and I'd like to have it. What's the matter with being good fellows and loosening up?"

"Because it is purely a business matter in which the public would be too much concerned if it knew what we were doing."

"Well, whatever it is, it's good—I know that," replied the young journalist, laughing, "and I'm sorry I'm not in it with you—special car—flowers—traveling like railroad presidents. I'm on. But, say, when this thing breaks I'd like to be in on the yarn. I was lying. I never heard of you before the train pulled in. But you know the railroad people are on. They told me you had a black case marked 'Explosive.' That's all I know. Say, couldn't you tell me this—are you going through to the coast?"

Ned relented a little.

"Perhaps," he said smiling, "we might go to the coast."

"You might?" interrupted the reporter eagerly.

"Or we might stop in the mountains."

The reporter looked perplexed.

"Then you've got something to do with mining?" interrupted the impulsive journalist, "and it isn't the navy yard. But you came from Washington! I know that, you see."

"Yes," volunteered Ned, "but we might be from the Hydrographic Office."

"Cloud breakers," quickly interrupted the reporter again. "How's that for a guess? Are you rain makers?"

"What are they?" innocently asked Alan.

The reporter saw he was wrong.

"I give it up," he said shrugging his shoulders. "You are two wise lads."

"Not wise," suggested Ned, "but attending strictly to our business."

"Right you are," answered the reporter.

"I've got to leave you to have a look through the train. Sorry I'm not in on this. Where ever you're going, it looks good to me. When you come back, don't forget me. Save the story for me, Bob Russell of the Comet."

Handing his card to the boys with a cheery "So long!" he was gone. The boys felt a little relieved. They had done what they could to protect the interests of their patrons and themselves by keeping their mission a strict secret. So far as Ned knew, the only persons who had knowledge of what they were doing and where they were going were his mother and sister, Alan's family, and Major Honeywell and Senor Oje. Not even Elmer Grissom's parents knew where he was bound—it was sufficient for them to know that he was with Ned. Of course the railway people knew where the car was to stop. Beyond these it was necessary for no one else to know what was being done— not even the manufacturers who made the balloon, the engine and their precious gas. But what the young air navigators desired and what Bob Russell wanted were two different things.

CHAPTER VII - THE MAKING OF A NEWSPAPER STORY
Let us see whether the young reporter was baffled by the reticence of the secretive boys.

"Every one to his trade," murmured Bob Russell, as he hastened from Ned and Alan, "and now, me to mine."

Bob was what was known on his paper as the "depot reporter." It was not the most important assignment, for usually his work consisted only in describing such notable personages as passed through the city and now and then in interviewing the more important of these. But this day he was confronted with a mystery and it was his business to solve it. He acted quickly.

Hurrying after the depot master, with whom of course he was friendly, he persuaded that official to go at once to the conductor of the train and ascertain the names of the boys. This was a simple thing, done in that manner, for even the passengers in a special or private car must have regular tickets. The conductor at once revealed the identity of the three passengers. Although Bob knew the conductor, he realized that he stood a chance of being refused even thin information if he asked for it personally.

While his friend the depot master was getting this information, Bob quickly, but apparently carelessly, approached the head brakeman who had helped bring the train from Chicago. It was Tom Smithers—also a friend of Bob's, who made a point of knowing every employee running into the station.

"I see you've got the Placida with you?" began Bob indifferently.

"Yep," answered Tom, "and loaded to the axles. All except passengers. She's running light on them. Two boys and a coon."

"I just had a talk with them," remarked Bob, carelessly offering the brakeman a cigar. "Pretty dusty, eh?" After a moment's casual talk Bob returned to the subject.

"I guess those kids must be next—running a car with locked doors."

"Locked doors!" snorted Tom, putting his cigar away for a surreptitious smoke. "Not on your life. Not against me. You bet she was open whenever I rang."

"But it might just as well have been locked," said Bob. "The place is so jammed full of stuff. I couldn't make out what it was, but there was a wad of it."

The unsuspecting brakeman then gave Bob what he was hoping to get.

"Well, I stopped and saw it," he confessed. "I roused up the coon after midnight to have a look at the ropes and when I came back I took my time. They got a case of powder or dynamite in there marked 'Explosive.' I didn't bother that but the rest was plain. Half the boxes in the car were labeled 'balloon works' or 'motor works.' It's a balloon show—nothing else."

"Where is the car going?"

"They ain't consulted me," laughed Tom.

A few moments later Bob was in the office of the division superintendent. When he left he knew that the Placida would be dropped on the only siding at the little town of Clarkeville in New Mexico. He had also looked over the best map in the offices and fixed in his mind the topography of the adjacent country.

Before half past nine Bob had presented these scattered facts to his city editor.

"It's a story, all right, Bob, and a good one. Go to it," said the editor. And Bob did the best he knew how—in a newspaper way. On the suggestion of the editor he telegraphed to the representative of the Comet in Chicago: "Who is Ned Napier?" In a little over an hour he had a hundred and fifty word telegram outlining Ned's aeronautic career and concluding: "Why? What do you know? Napier not here. Family won't talk."

Then Bob began his story. It was, for a reporter of his experience, brilliant, with good deductions, good guesses and good ambiguous generalities. It seemed to tell more than it really did.

At four o'clock that afternoon Ned and Alan were speeding over the green and fertile prairies of middle Kansas in blissful ignorance of what Bob Russell had done. Under striking headlines appeared the following story:

"Ned Napier, the famous young aeronaut of Chicago, passed through the city this morning on his way to the southwest to execute the most daring and important balloon journey ever undertaken in this country. Accompanied by an assistant, Alan Hope, and on board a special car packed with $50,000 worth of apparatus he will proceed to Clarkeville, an insignificant town in New Mexico, from which place he will make his hazardous flight over the mountains lying to the north. The aerial journey may possibly extended over the Sierra Nevadas as far as the Pacific Coast.

"The details of the expedition are not made public, as young Napier has been retained by the authorities at Washington and is operating under a strict pledge of secrecy. The knowledge that such an expedition is under way was made known for the first time to the representative of the Comet by Mr. Napier at the Union Station this morning. While slow to discuss the ultimate object of his trip Mr. Napier talked of his plans in a general way.

"'I represent the Hydrographic Department,' he said to the reporter, 'and the journey I am about to make may extend from Clarkeville as far as the Pacific. I hope it will accomplish what the department has planned, but you know that we who are in this profession are always prepared for failure. My assistant and I may easily have our lives crushed out on the rugged peaks of the mountain chain we are attempting to cross.'

"Mr. Napier suggested that some might conclude that he had been sent out as a 'rain maker,' or 'cloud breaker' in an attempt to secure rain for the arid plains, but he laughed at this idea.

"In the government's special car, carefully safeguarded, is carried a large can of a new and powerful explosive. In exhibiting this to the reporter Mr. Napier good-naturedly said:

"'I am sorry I cannot tell the public the exact character of this new explosive. But the secret belongs to the government.'

"When it was suggested that the explosive might be destined for certain elaborate experiments in the unpopulated wilderness of the region to which the expedition is now hastening on the Limited, Mr. Napier would only answer;

"My lips are sealed. I can say no more. But I compliment the Comet in discovering what all the eastern papers have missed—that a stupendous thing is projected and that I have the honor, with my friend, Mr. Hope, to attempt it."

Then followed an elaborate rewritten version of what had been telegraphed from Chicago concerning Ned. After this was a detailed account of the car, not omitting little Mary Hope's bouquet of faded roses, which in Bob's story became "a wealth of cut blossoms, the tribute of Mr. Napier's scientific friends."

What Bob wrote was in type by twelve o'clock. Three hundred words of it were telegraphed to the Chicago evening newspapers. Sharp at six o'clock that evening the Chicago correspondent of the New York World sent advice to his paper that he had a story on the mystery of what Ned Napier was about to do for the government. Word came back at once to send on the story.

At ten o'clock the telegraph editor of the World in New York took the account just received to the managing editor of the paper.

There was a minute's consultation, a nod of the head, and at twelve o'clock that night Bob Russell was awakened to respond to a telephone call. It was his own managing editor who read him this telegram:

Managing Editor, Comet, Kansas City

Send man at once to follow Chicago balloon man and discover mission. Advance funds and draw on us. Will share story with you.

Managing Editor, New York World.

It is hardly necessary to say that Bob Russell was a passenger on the Limited leaving the next morning. He was just twenty-four hours behind in the race, but he meant, if he could, to execute his orders, and was already smiling delightedly in anticipation of what he knew would be a contest of wits.

CHAPTER VIII - THE HOSPITALITY OF NEW MEXICO
Clarkeville was even smaller than the boys had imagined it. The little depot was far more pretentious than any other building in sight. Beyond this was a wide and exceedingly dusty street. On the far side of this unpaved roadway was a row of one- and two-story frame buildings. Here and there was a cheaper structure of little else but corrugated iron sheets, while to the left, where a similar street crossed the railroad at right angles, there was a one-story cement building proudly labeled "Bank." Both streets suddenly disappeared in a sandy, treeless plain.

Wooden awnings in front of the buildings extended over the sidewalk. At the edge of these awnings were a few teams and many saddled horses, some of them hitched to posts, and others standing with their bridle reins dropped to the ground. Not many persons were in sight. The deep and cloudless blue sky was brilliant with the noonday sun while a hot breezeless haze hung over all.

The Limited had made its usual daily pause and then to the surprise of the agent had run down beyond the water tank with one car, switched it back onto the one siding until it stood opposite the musty smelling freight shed, and, quickly coupling up again, had gone.

Ned and Alan had alighted when the train stopped. Around them the boys could detect the first signs of the real West. At one end of the station a big-hatted Mexican squatted by a hot tamale can. Among others idling near were some high-heeled and sombrero-topped cow-boys, whose easy and loose clothing made Alan envious at once. Even the depot attendants, with their belts and loosely knotted neckerchiefs, seemed gayer and freer than their brother laborers back in the East.

With coats off and collars loosened the two boys filled their lungs with the tonic air, for, in spite of the heat, a certain dryness seemed to give life and vigor to the atmosphere.

"There it is, Alan," exclaimed Ned finally, pointing away to the north and the distant mountains, "beyond those peaks and somewhere under that sapphire sky is our land of promise. We'll be in it in a few days."

The brilliant sky, the exhilarating air and the new life about them filled both boys with enthusiasm.

"Whoopee!" almost shouted Alan finally, throwing out his arms as if to embrace his friend. "All we need is an Indian or two and I guess we'd be out West for sure."

"You may not be so anxious to see them before we start back," remarked Ned. "Anyway, I promise you enough of them in this country."

With the departure of the train, the two boys became the center of some attention. Strangers were not plentiful in Clarkeville, and when the news spread that a special car was standing behind the freight shed on the far side of the tracks there was an instant rush of idlers in that direction. Ned and Alan returned with them and smiling good-naturedly right and left took stand at the forward car steps.

It was about two o'clock in the afternoon, but so anxious had the boys become in the last stage of their journey that they had ordered Elmer to put off the noonday meal until they reached Clarkeville. The colored boy, troubled over the notion of a good dinner spoiling, was waiting on the car platform for it chance to get his "bosses," as be delighted to call them, into the car.

Before he could do so, and while the two chums were answering idle questions as to whether they were a "show," Ned's quick eye caught sight of a more important personage. A middle-aged man, not quite so western in appearance as the others, but plainly as much at home in the saddle, rode up with a clatter and sprang from his pony.

Ned advanced quickly, spurred on by the new arrival's quick "Howdy, strangers!"

"My name is Ned Napier," explained the lad, "and this is my friend, Alan Hope."

The rider held out his hand.

"I'm Curt Bradley, and I'm the mayor of this town," he replied by way of introduction.

"Glad to meet you," answered Ned. "You've just saved me the trouble of looking you up, for that would have been my first business."

"Not to be over cur'ous," laughed the Mayor as his eyes took in the big expensive car and then returned to the two boys, "might I inquire the nature o' yer business."

Ned laughed.

"Certainly," he answered, "but come aboard first. Elmer," he said to the waiting cook, waiter and porter, "another plate for Mr. Bradley."

And in spite of the wholesome-looking but bronzed Mr. Bradley's protest that gentleman was soon sitting with the boys before what was perhaps the most elaborate meal he had ever eaten. His protest came from the fact that he had already had his dinner, but the fresh fruit and vegetables and spring chicken were temptations too strong for him.

When Ned saw that their new acquaintance was at his ease and rapidly becoming satisfied he lost no time in coming to the point.

"Our visit here, Mr. Bradley, is, in part, a secret. I hope you will accept my assurance, however, that it can in no way operate against or damage your town or its residents or the country round about. I want your assistance."

"Ye can hev that," came the quick answer, "and if your lay is no one's business, why, it ain't none o' ours."

"I'm glad to hear that," answered Ned. "But there may be some who will not be so considerate."

"When I pass the word I guess they'll all think about like me," interrupted the Clarkeville official. "Ye jest tell me what it is you want."

"First I'll explain to you that in the other part of this car we have the material to make a dirigible balloon."

"A what!" exclaimed the Mayor, his mouth full of chicken.

"A balloon that you can guide through the air."

Curt Bradley dropped his knife.

"One o' them flyin' machines?"

"Exactly."

"And kin we all see it fly?"

"Certainly," answered Ned, "if you will just see that no one interferes with us. I shall be glad in time to show you, I hope, the most perfect dirigible balloon ever put together and to explain just how it is to be operated. But in a few days, when it is ready, we are going to sail away on business that is our own. And when that time comes curiosity must stop. If anyone attempts to ascertain where we are going or what we mean to do I sound warning now that we will do all we can to prove to him that it is none of his business."

The Mayor looked at them in surprise.

"Why," he began, "I suppose ye must be on a mighty partic'lar job. Are you—?"

"There!" interrupted Ned. "You see you are beginning to ask questions. Since we can't answer them we'd rather not hear them."

"Right," exclaimed the Mayor. "Give me yer word it's all fair and square and that ye ain't violatin' no laws and I'll give ye my word they won't be no more questions asked."

"I'm glad to do that," answered Ned, "we want certain accommodations for which we are willing to pay. But we want the confidence of Clarkeville that we are all right, even if we are a little young."

"Clarkeville is yours," laughed the Mayor, getting up from the table, "and now what do ye want first?"

In another hour the two boys, guided by Mayor Bradley, had examined the entire settlement. A little way down the railroad track they found a rather ramshackle building, mostly tin roof, and behind it a large plot of ground surrounded with a high corral or fence. The sign read "Buck's Corral." In the East it would have been called a livery stable. The air navigators engaged the place at five dollars a day for a week or more, and put a half dozen Mexican laborers at work removing the few horses and cleaning out the building and corral. The proprietor, who owned one of the few wagons in the town, they also hired as a drayman at $2.50 a day for himself and team.

Work began at once. Through Mayor Bradley three reliable men were employed as watchmen, and these, in eight-hour shifts, undertook the duty of seeing that nothing in the corral was molested in the absence of Ned and Alan. Then the work of transporting material began, the first task being the removal of the five large generating tanks.

Alan had been thoughtful enough to foresee the need of special clothing, and it was not long before he and Ned and even Elmer Grissom were enjoying the freedom of wide-brimmed hats, stout shirts, thick-soled shoes, and belts. Elmer's duty was the constant care of the Placida, which he only left on special permission. Ned and Alan were free to devote themselves wholly to the agreeable and long anticipated task of at last "getting ready."

Help was easily hired and with Buck's wagon in service the wide-opened doors of the baggage car seemed to give out more boxes, crates and bundles than a full freight car. When strangers were on the car the colored boy stood like a sentinel over the black case which was made less conspicuous by being covered with a blanket. And his constant injunction "No smokin', sah," soon won him a sobriquet, Mexicans and cow-boys alike calling him "Smoky."

Elmer was relieved from picket duty in time to prepare an extra supper to which Mayor Bradley, Buck, and Jack Jellup, the town marshal, were invited. It was extra work for "Smoky," who took his new name with a mild protest; but when he called the crew to the meal it was apparent that he harbored no resentment. Jack and Buck took their seats gingerly, but the boys soon made all at home.

"There ain't agoin' to be no pay took fur this day's work," suddenly exclaimed Buck as he finished a generous portion of cold sliced ham and potato salad.

The boys laughed in protest.

"I ain't seen real food in ten years," continued Buck, "and what I said goes. This meal's worth a week's work to me."

"All I got to say, young uns," interrupted Jack Jellup, the marshal, "is that this 'ere town is yours."

Jack's idea of hospitality was an invitation to the boys to visit the town saloons as his guest, but Ned arid Alan laughed and thanked him, pleading weariness as a reason for declining. The final tribute of the three guests, however, before they left, was to push the Placida along with crowbars until it was free of the freight house and stood where the evening breeze could freely find its way through the windows. Then with hearty "buenos noches," ("Good night") and promises to see that every one was on hand early in the morning, they left.

For some time Ned, Alan and Elmer sat in camp chairs on the car platform reveling in the glorious starlit night. From somewhere in the little town came the sound of low singing and a Spanish air played on the mandolin. It was all so different from the life the boys had known that it seemed like a dream. And when their real dreams did come it was of the not far distant Tunit Chas.

CHAPTER IX - "CALIFORNY KID" GETS A JOB
Old Buck's horse-corral had blossomed over night into a modern balloon factory. And the proprietor, with his bronco team, and the superintending Ned and Alan made big gaps the next day in the precious freight of the Placida. By noon the five casks for generating hydrogen, the cooling and purifying box, and the lead pipe and other equipment, had been transferred to the old horse yard. Three tons of iron turnings, forwarded by freight in advance, were found in the keeping of the railroad agent. It took Buck six trips to move this, and that consumed the afternoon.

A special trip was made by the wagon just after luncheon. This was to transport the tool chest—practically two chests, for it was a large one containing both wood and iron-working tools. With it rode the two boys, both in overalls and ready to begin the setting up and adjustment of the generating tanks.

After their arrival at the corral, the rest of the afternoon, in spite of the heat, slipped quickly away. But by night a foundation had been leveled in a corner of the yard and the five barrel-like generators were firmly anchored and connected by lead pipes with the cooling and purifying box.

"Looks purty much like a distillery," commented Buck, who had just made his last trip with the iron shavings, which were now piled close by the casks.

"And is," laughed Ned, "in a way."

But he volunteered no more. In fact the whole matter was a mystery to every one in the town, except Mayor Curt Bradley and Marshal Jack Jellup.

In the morning the first work accomplished was the removal, one at a time, of ten casks of sulphuric acid, each weighing four hundred pounds. It was a delicate job and not unattended with danger in case of a cask breaking. The boys began to realize the need of help of a higher grade than that of the "greasers" who had been thus far their only assistants except Buck.

Their usual good luck seemed to be with them, however, for just in the middle of the work of sliding a heavy carboy of acid from the wagon a stranger stepped from the group of onlookers, and without words gave a hand to the job.

Alan was about to thank him hurriedly, when the stranger said: "Wot's the game, son? Wot's doin'?"

Alan was at first inclined to resent this "tough" familiarity. Then he realized that the language of the man was in his natural manner of speaking, and he said:

"Who are you and where are you from?"

"Give you one guess," laughed the stranger. "No! Can't tell a 'bo'? Well, just tramp. Wot's dew name? I lost me card case. Me nom de plumb is Kid, Californy Kid. And me address is—well wot's de name o' dis munificent metropolis?"

"Clarkeville, New Mexico," answered Alan smiling.

"Well, den me address is dat. Wot's de nex' inquiry?"

The man was young. His clothing was worn and greasy, his shoes were patched, and those parts of his face and hands that could be seen between smears of coal dust were red from exposure and the sun.

"How do you happen to be here?" continued Alan.

"Well, cul—beg pardon, son—de fact is I lost me purse and de brakeman on de fast freight wouldn't take me check. I was dumped. And I can't get away exceptin' I walk."

"Then you wouldn't care to work?"

"Will dis beautiful city give me coin and chuck widout work?"

"I'm afraid not," laughed Alan.

"Den' it's work for yours truly," answered the tramp with a sort of cheery humor. "But, say, boss, ye couldn't stake me to a drink and some chuck afore I loosen up me muscles?"

"Your pay will be two dollars a day," said Alan, "but no drinking goes. Here's a note that will get you something to eat." And writing a message to Elmer the tramp was soon hurrying to the car for a meal. A half hour later, with his sleeves rolled up, he returned, riding alongside Buck on the wagon.

Ned had given the new hand little attention.

Now he looked him over and asked:

"What's your real name?"

"Gus, boss; or, spellin' it out, Gustave Lippe. How's dat for a handle—Lippe?"

Ned looked at the young man long and sharply.

"One name, they say, is as good as another out here. But I didn't know tramps got this far west."

"Sure," answered the tramp, "It's long jumps and hard ones. It's me last excursion dis way."

"Well," said Ned slowly, "you can work for us as long as you are not too inquisitive."

"Dat's me, boss. I'm de clam till me two dollars per will git me to de next whistle."

"Then you'd better arrange to board with Buck."

"Dat's me lay, boss, already booked. Now show me some work. Me trunk was checked t'roo and I ain't nuttin' on me mind but me job."

"Well, you had better spend the rest of the afternoon in cleaning up a bit," suggested Ned. "Here's five dollars in advance. Report early in the morning."

"Tank's, boss," said Gus, the tramp. But he took the bill slowly.

"But, you can't spend it on beer and whisky and work for us," added Ned.

Gus shifted uneasily.

"You'd better have a bath and a shave. And if you need clothes and can get them here," continued Ned, "I'll advance more to-morrow—if you show up all right."

"I kin work widdout a shave," the man said, "ain't der nuttin' doin' to-day?"

Assured that to-morrow was when he was wanted the tramp slowly and apparently reluctantly turned and slouched away toward the stores.

"What do you make of him, Ned?" asked Alan as the two toys resumed work.

"Too slangy, I think," commented Ned.

But the final stowing of the acid soon drove the tramp from the minds of the boys.

When the young aeronauts finally closed the corral and returned to the car, the sun a great red ball, was just dropping behind the serrated mountains of the western horizon. On the car steps, Ned turned and pointed to the north. Far away the dusky gray of the plains deepened into darker and darker shadows that ended in a low black mass. But here and there from the black wall rose irregular spires, their tops pink-tipped by the red sun.

"Yes," exclaimed Alan, "the Tunit Chas—our mountains."

And even though the vigilant Elmer called from within, the boys stood and gazed in silence until the last glow had died away and the land of their hopes was lost under the stars.

Important as was the work to be done in Buck's corral, there was another vital thing to be accomplished while this progressed. That was the creation of a base of supplies near the navigator's field of work. This was preferably to be at the junction of the Amarilla and Chusco rivers, and that point lay just eighty-five miles to the north. Between Clarkeville and that spot there were no roads and, at this time of the year, perhaps, no water. With the best wagon and team they might be able to get, this trip over the desert would require not less than five days.

It was impossible for either of the boys to go on this important errand, as both were needed on the spot to set up the balloon. So it had long since been decided that Elmer was to have charge of this secondary expedition. And since it was Elmer who would have to conduct the expedition safely to its destination and establish a relief camp, the colored boy had been thoroughly coached in his coming task.

"Kin I?" the boy had said more than once. "When de Cibola gits dar I'll be dar. And ain't no Indians nor rattlesnakes nor hot weather goin' to break up dat camp."

And the camp meant gasoline, water, food and a stepping stone back to civilization, whether the expedition ended in failure or success. As the boys had already planned that Buck should furnish the wagon and horses and guide Elmer's caravan, they had asked him to call that evening to talk it over.

"I'm ready to start, yes, right now," Elmer had said as he served the good supper over which he had been laboring, "but I does jes nach'elly hate to turn you young gemmen over to dese greaser cooks."

The boys laughed. "You don't think we can keep this up all summer, do you?" exclaimed, Ned. "Even 'greaser' cooks are better than having nothing to eat. And up there," nodding toward the north, "there won't be any cooks."

"Don't forget," interrupted Elmer, "camp—camp—well, my camp. When you get dar dar'll be a good meal waitin' you and when you git outen de mountains I'll still be dar waitin' wid eatin's."

The boys laughed again.

"Like as not," suggested Alan, "if you get all that truck up there. You'll certainly have enough. But don't you bother about the eating. You just watch the water and the gasoline."

"Till de snow flies," exclaimed Elmer with emphasis.

"Which, right there," dryly remarked Ned as he disposed of the last of a generous slice of melon, "is rather indefinite."

When Buck, whose real name they had discovered to be William Bourke—easily corrupted into "Buck"—appeared, the boys had a delicate job before them. Inquiry had quickly shown them that Buck's twenty-five years on the old Santa Fe trail as guide and an active service in the army as scout easily made him the man to conduct Elmer to the north.

To all their long explanations and reasons Buck listened in silence. When there seemed nothing more to be said, Buck smothered the still glowing end of a cigarette between his dark weather-beaten fingers and said slowly:

"When do we start?"

It was arranged that on the second morning Buck should be ready for a journey of uncertain length; that the general direction should be north; that the final destination should be revealed by Elmer on the second morning out.

"Soldier-like," Buck had commented, "and that's the way I like it."

Buck and an assistant were to take an outfit of two wagons, each drawn by four horses. In the lighter wagon six barrels of water were to be carried for use in case the usual "water holes" were dry. In case of an accident, the lighter wagon and horses were to be sent south by the second man and Elmer and Buck were to make a quick dash forward with what water and supplies could be carried on the other wagon.

Old Buck made rather light of the matter.

"Injuns ain't nothin' nowadays," he had explained, shrugging his shoulders, "ye jest want to keep yer bearin's and git used to drinkin' atmosphere and ye'r all right."

The contract with Buck called for thirty dollars a day in money and food for himself and a helper. Both parties to the contract were satisfied and after Buck's fresh cigarette disappeared in the direction of the town the boys lost no time in turning in for a good night's rest.

CHAPTER X - AN ERROR IN CALCULATION
While Buck was busy getting his wagons and horses and water casks ready the next morning the boys were not surprised to see Gus, the tramp, drive up just after breakfast with the moving team.

"Have you had breakfast?" asked Alan by way of a greeting.

"Have," retorted Gus, pulling up his team awkwardly. "It's me wrappin' meself around tortillas till I feel like a bag o' corn meal."

"I can't see that you've spent any great amount of that five dollars on yourself," interrupted Ned, noticing the tramp's unshaven face and the still visible traces of coal smoke.

"Well, boss, ye'r right. Dead right. But, ye see, de barber o' dis growin' city only works on Saturday and me friend Buck's bat' tub has a leak. Anyhow, de ladies hereabouts is scarce and few. Think wot a swell I'll be when Sunday comes."

"Come in the car. We've plenty of water, and soap too," suggested Alan, smiling.

'"Well, boss, don't tempt me. I'm working. I can't soldier away no time dudin' meself up on do bosses' time."

"All right," replied Ned, laughing, "every one to his taste."

There was plenty of work to be done, and in a few minutes all were at it. The chief task this day was the unloading of the materials yet on the car. That had to be done by night, except in the case of the boxes marked "Overland," all of which had been carefully and specially crated for wagon transportation. Of these there seemed a great many, and they were all put in one pile in the space made vacant by the removal of the gas generators. The hydrogen case, covered with a blanket, stood always under Elmer's watchful eye. This was to be removed last.

As the boys meant to stay close by their valuable outfit, they planned to load Elmer's caravan early the next morning and to see it start on its trying and dangerous trip. Then they intended to remove the hydrogen cask to the corral and take up their own abode in the same place. The Placida—with no little regret—was to be surrendered to the railroad and returned to Chicago.

For that reason this was a busy day. Load after load of crates, boxes, and bundles were carried to the big corral, the teams stirring up the dust of Clarkeville's main street on their way. It was heavy work, and required care. Smoky-faced Gus was earning his pay. So skilful and adroit was he in executing tasks assigned him that Ned commented on it to Alan.

While the boys were at their noonday lunch Buck appeared to report progress. The big wagon was to come from a sheep ranch, ten miles to the south. A man had gone for it and would arrive with it that night. The wheels of the smaller wagon were being soaked in water and the axles had been greased.

Ned could not resist asking:

"How's your new boarder, Buck?"

"Ain't seen much o' him. Purty poor feeder fur a tramp. Can't get a tortilla down him nohow."

Ned looked at Alan significantly.

"Hasn't any baggage, has he?" continued Ned.

"Not a stitch. Lessen you allow fur a extra suit o' underclothes."

"Under clothing?" exclaimed Ned. "Two suits?"

"Yep. And fine, too. My old woman washed a suit to-day and she 'lows as how it cost more than the rest o' his outfit."

"Don't you think that funny?"

"'What?" responded Alan sleepily.

"Why, a tramp with two suits of fine underwear?"

"Probably he stole them."

"And probably be didn't. A real tramp might steal them, but he wouldn't wear them."

"Well, what do you care," laughed Alan, "whether he's a tramp or not so long as he's useful?"

Ned was silent a few moments.

"Tramp or not, that fellow will bear watching."

"All right," conceded Alan, "I guess we can do that."

By night the barn and horse yard of the corral looked like a combination manufactory and hardware store. The seven sections of the skeleton-like car stretched across the old horse yard like a disjointed snake; crated aeroplane guides, and the propeller and the rudder leaned against the fence, looking like the frame work of a house; the more compact engine, motor, radiator and fan stood ready for unpacking under the shelter shed, while shafts, connections and boxes of small parts filled a large part of the empty stalls. The tins of gasoline for experimental flights and the first trip to Elmer's camp were in a far corner of the yard, and in the wagon shed stood the two immense special trunks containing the gas bag and the Italian hemp netting.

The evening meal was not as cheery and chatty an affair as the preceding ones had been, although Elmer had done his best in honor of their farewell. And the boys insisted that at this last meal the waiter should be dispensed with, and Elmer was put at the head of the table.

"Yo' make me feel as if I was a startin' fo' do norf pole," exclaimed Elmer. "I don't see what's de use of so much fussin'."

"Well, anyway," exclaimed Ned, holding up a glass of iced tea, "here's luck to you, Elmer."

"And de same to you," answered Elmer. "And to all of us."

Rising bell was to ring at four o'clock the next morning; so the boys all turned in at once after they had cleaned up the kitchen.

It was about twelve o'clock when a sudden call sounded through the car.

"Alan!".

It was Ned, who, clad in pajamas, was shaking his chum. The latter, dazed for a moment, sprang upright, soundly whacking his head on the upper berth, in which Elmer was snoring loudly.

"What is it?" he exclaimed, rolling out on the floor. "Who hit me? Indians?"

"Not yet," laughed Ned, shaking his "pal" into wakefulness. "Listen!"

He struck a match, lit a candle and sat down on the edge of the berth.

"You're a bum calculator," he began, eyeing Alan.

"I didn't calculate where that berth was," answered Alan ruefully, rubbing a lump on the top of his head.

"And you didn't calculate where we are now," somewhat excitedly added Ned. "And I didn't think of it until just now."

"Go on," interrupted the still sleepy Alan. "If it's a riddle I give it up."

"I suppose you know what the air pressure is to a square inch," answered Ned, like a school teacher rebuking a slow scholar.

"Why, 14.7 pounds, of course."

"Where?" exclaimed Ned again, sharply.

"Where?" echoed Alan.

"Why, at the sea level-that's where. Not out here. Do you know how high we are above sea level right here?"

Alan began to see the point and a smile came over his face. He had no chance to answer:

"We're a little short of seven thousand feet up in the air right here in Clarkeville," continued Ned in about the same tone of exultation he might have used had he found a gold mine. "Now, listen. How many cubic feet of gas does our balloon hold?"

That question was easy. The boys knew that as well as the multiplication table.

"Sixty-five thousand, four hundred and ninety-three feet."

"And how much weight is it going to carry?"

"Three thousand nine hundred and thirty-five and a half pounds."

"Exactly," went on Ned. "That's the weight we are going to carry figured at sea level. Did it ever occur to you that our sixty-five hundred feet of hydrogen can lift more way up here seven thousand feet in the air, than it can at sea level? Did it ever occur to my special engineer and calculator that as the weight and pressure of the air grows less our hydrogen will lift just that much more weight.

"By the great horn spoon!" exclaimed Alan. "Give me that candle."

In another moment he was at the drawing room table with a pencil in his hand. It did not take him long to make his calculations.

"Live and learn," he exclaimed finally. "I'm certainly all you said was a 'bum calculator.' Our altitude here is 6,875 feet, for I took it to-day just for practice. And we can carry in our balloon just exactly 693.6 pounds more than we figured."

"I thought so," laughed Ned. "It came to me in a dream, I guess. But you don't need to feel badly. You say I'm the boss, yet I never thought of it. You see, the trouble is that all the balloon ascensions ordinarily are made from the large cities of America or Europe. Who ever thought of ascending a mountain to get a start? But since we have done so we must figure accordingly."

"And what is the first thing you are going to add?" asked Alan.

"First thing?" exclaimed Ned. "First and last and in the middle, gasoline. We may find water in the mountains and we might even find food, but we're not going to find gasoline. Now we'll do part of our work whether Elmer meets us or fails."

The incident showed the essential difference between Ned's mind and Alan's. Alan was careful, precise, and adept in detail. Ned had the "dreams" and inspirations of an inventor.

CHAPTER XI - A DISGUISE PENETRATED
The boys, in spite of their broken slumbers, all turned out promptly at four o'clock the next morning. They found this hour the pleasantest of the day in this hot and dry region. The late moon was just disappearing, and over the plains swept a breeze that hinted of snow on some mountain peak not far away. Not a sound broke the stillness but the occasional cry of a skulking coyote.

"Hear it, Elmer," said Alan, as the boys got busy in the baggage car. "You want to look out for those fellows."

"I ain't feared o' no cutes and I ain't feared of no Injun," solemnly answered Elmer, "jist so dem rattlers gives me de go-by. Dat's all I ast."

Buck's big wagon had arrived and was backed up to the car and now, by the light of a lantern hanging above the door, the work of loading began.

With their improved gas bag the boys had figured on a record flight without renewing the gas supply. They had hoped to be able to stay at least seventy-two hours in the air. But during a large part of this time they expected to drift without the engines, for they could not carry enough gasoline to last for more than twenty-four hours of engine work. By their new calculations they had more than enough gasoline, and according to Ned it seemed probable that the decreased air pressure on the bag might extend the period of flight another twenty-four hours, or to four days.

After that all would depend on the liquid hydrogen. The remarkable qualities of this unique product were to be tested for the first time in the history of ballooning. When the gas in the bag had diminished by leakage through the valves and elsewhere so that it was no longer sufficient to carry the car, the liquid hydrogen was to be turned into gas which was to take the place of that lost. Ned had left Washington with sixteen cubic feet of the liquid in eight delicate Dewar bulbs, or casks. He figured that one-quarter of it would be lost by evaporation, leaving twelve cubic feet. This seems a small supply until one understands that the hydrogen increases in volume 880 times as it returns into gas from the liquid form. The twelve cubic feet of liquid, therefore, would give them a little over ten thousand cubic feet of new gas. And this, with the loss of ballast and provisions in three or four days, Ned calculated, would give the balloon a new life of a day or so.

Therefore, the secret plan was a direct journey to Elmer's camp, a flight of eighty-five miles, which would bring the Cibola near to the foot of the mountains of mystery. After this camp had been located and more gasoline taken aboard the boys were to head their craft toward the Tunit Chas mountains. What would follow they could not foresee. With good luck they might be able to hover birdlike over the peaks, canyons and plateaus for five days. With bad luck they might have to come down sooner or fall. Then, if the Cibola failed them, they would have to find their way to the treasure temple and the ruined palace on foot in a rugged wilderness, infested with unfriendly Indians and reptiles, or struggle back, in some manner, if they could, to Elmer's relief station, and thus to civilization.

Should the worst happen and the balloon fail them, the boys might be lost in a desolate region that is even now uncharted by the government. The only resources they would have would be the Cibola equipment and their own ability to take care of themselves. In any event, the knowledge that Elmer and Buck were in camp ready to succor them meant a good deal. And that was why the loading of the overland outfit had so much interest for the boys.

Of tins of provisions there were many: condensed foods—German erbswurst, or army rations of ground peas and meat; dried potatoes; eggs in powdered form; preserved and salt meats; hard tack; tea and coffee; flour; and evaporated fruits. The water was already arranged for and the wagon containing the casks was at Buck's adobe house.

On the floor of the wagon, packed in bunch grass, were the precious gasoline casks. On top of all came the silk waterproof tent and the camp equipage. Stowed under the seat was the box containing spare flags, a heliograph, part of a wireless telephone outfit (the other part was to be carried in the balloon) and compass. Two magazine rifles and ammunition were included in the outfit, and Elmer donned for the first time in his life a belt and holster to carry one of the magazine revolvers that Ned had bought on the day when he first told Alan what he had undertaken to do.

By the time this work was done it was day. Then came breakfast, which Elmer insisted on preparing. He even demanded that he be given time to make hot biscuits. These, with thick slices of broiled ham, the last of their oranges, and hot fragrant coffee constituted the last meal on the Placida.

As the meal came to an end the clump, clump of horses' feet in the sand announced that Buck had arrived and that it was time for breaking the "special car" camp. Alan and Elmer hastened to clean up the little kitchen that had given the boys so many savory meals and to pack up the remaining provisions, and Ned jumped off the car to see Buck.

To the lad's surprise he found Gus, the tramp, just as dirty and just as cheerful as ever, proudly mounted on one of the newly arrived horses. Buck noticed the surprise in Ned's face and explained:

"The helper I thought I could get fell down on me. My boarder's goin' with us. I guess he'll do."

"You understand you don't know where you're going," said Ned, approaching Gus as he rolled off his horse, "nor when you're coming back?"

"I knows dat we ride and dat dere's chuck a-plenty," smiled Gus, "and whichever way it is," he added lowering his voice and chuckling, "can't be no worse dan Buck's place—fur me."

"Do you want to go?"

"Well, I ain't a settin' up nights a longin' to, but to oblige a friend, Mr. Buck, I allowed meself to be persuaded."

"Well, we'll see," said Ned.

Ned rather wanted to watch this young man. Something suggested that the tramp was too quick witted to be made a party to their plans. Ned didn't exactly know what harm the stranger could do them, but he decided to talk it over with Alan. While Buck was hitching up the horses Ned turned to go into the car.

They were loading from the far side opposite the hydrogen cask and as Ned passed the corner of the car he almost ran into the station agent. The agent, who was also the telegraph operator, had a telegram for Ned, which the boy took eagerly. Ned had sent a message to Major Honeywell, telling of their safe arrival, and did not doubt that this was some important afterthought of the Major's. The address ran: "Mr. Ned Napier, Private car Placida, Clarkeville, New Mexico." Tearing open the envelope Ned read:

"Just learned Kansas City Comet has story mysterious trip for government starting Clarkeville. Real object not known. Look out not followed.

"Baldwin Honeywell."

With three jumps Ned was in the car and had pull Alan into the drawing room portion. The telegram was read again and the two boys looked at each other in astonishment.

"How could they?" began Alan.

"No matter how," answered Ned, almost out of breath. "They did and that's enough. Now I know!"

"Know what?"

Ned pushed his chum to the side of the car and pointed outside where Buck and his helper were at work.

"Look at him," he exclaimed.

"At Buck?"

"No. At the tramp who won't wash his face, who has a gentleman's underclothes and who is so anxious to work for us!"

"Well, I see him. But—"

"Haven't you ever seen those sharp eyes before?"

"You don't mean—?"

"I do. If that isn't Bob Russell, the Comet reporter, I'm a goat."

CHAPTER XII - NED TO BOB RUSSELL'S RESCUE
It was a time for quick and fast thinking, and Ned and Alan did it. Alan's instant suggestion that they denounce the disguised tramp was almost as quickly voted down.

"So long as we didn't know who he was he had the advantage of us. Now that we know—" and neither of them now doubted the fact for an instant. "We have the advantage of him," argued Ned. "Let's turn that knowledge to profit. We can easily guess what he is trying to do. Major Honeywell's message says our real object is not known. This reporter has learned something, and I suspect he could have found quite a lot from the train crew. On that he has written a good enough story to attract attention. That shows he is no fool. And he wouldn't come out here unless he had been sent. Who would send him? Why, his paper, of course, to discover our real mission."

"What can we do to head him off?" mused Alan.

"There are two ways," suggested Ned, "and we've got to make one of them effective. I don't know how he has guessed but he must not have another guess. And he's seen a good deal."

"We might have him arrested," suggested Alan.

Ned thought awhile.

"I'll tell you, Alan," he said finally. "The young men of the press to-day may write fanciful stories, and they may even 'fake' where it injures no one, but personally they won't lie. Let's call our tramp in here, confront him with his imposture and give him his choice of writing nothing or of being drummed out of town."

"Who'll make him leave town?"

"Marshal Jack Jellup wouldn't need two suggestions on that score. And more, he'd see that the order was obeyed. I don't like to do it, but I think we're justified. He's taking that chance."

Again the thing was gone over, with arguments for and against, and then Elmer was hastily dispatched to find Jellup and bring him to the car.

"And Buck will lose his helper," laughed Alan.

"Better that than a second expedition on our heels," answered Ned

"Gus!" he called, throwing open a window. "Come in here!"

The tramp soon stood before them.

"Geel Dis is a swell joint," were the tramp's first words as with apparent awkwardness he entered the car.

Ned acted as spokesman.

"You say you've promised Buck to go with him without knowing where you are going?"

"Dat's about de cheese."

"Well, we are willing. But I may as well tell you that this is a secret expedition. If you go you must promise that you will not tell anyone what you see or hear."

The tramp's face suddenly took on a peculiar look, but it was gone as quickly.

"I gives me woid. I won't open me trap to no one."

"Meaning you won't say anything about it?" smiled Ned inquiringly.

"Dat's it. Mum's de woid. I won't open me trap."

"Nor write anything?"

The furtive look came back, this time more pronounced.

"Me to write! Wit wot? Me new typewriter?"

"That isn't an answer. Do you promise, if we send you with Buck, that you'll neither tell nor write nor make known in any way what you learn about what we are doing?"

"Say, look here, boss. Quit yer kiddin'. Me name is Lippe and mebbe I shoot it off a bit too frequent now and then, but you don't need to be afeered o' me peachin' to de udder'Bos.'"

"I'm not afraid of that," continued Ned. "We don't care what you tell all the tramps this side of Kansas City. But we don't want you to print anything more about us in the Comet."

Hardly a flush came on the tramp's face. There was a quick movement of the lips as if he were about to make protest and then he laughed outright.

"Bob Russell," said Ned, also laughing, "would you like the use of our bath tub for a few moments?"

"Would I!" laughed the young reporter rubbing his tinted and smoke begrimed hands together as if to wash them. "Well, I guess I would. My hands are up. What's next?"

"Wash up and we'll see," exclaimed Ned.

The young reporter was still laughing. "And if it isn't too much trouble," he asked, "would you mind if Buck took his check over to the depot and got the suit case that it calls for? Then we'll talk business."

In less than twenty minutes the sun burnt, dirty Gus Lippe had been transformed into the dapper Bob Russell. When be reappeared in fresh linen, outing clothes and a natty straw hat, he was still laughing. Approaching the group in the drawing room, where Marshal Jack Jellup had now arrived, the young reporter took out his pocket book and a five dollar bill.

"I'll pay that back first," he began; and then noticing one of his cards he politely handed it to the marshal. It read:

ROBERT RUSSELL KANSAS CITY COMET

"Ye'r a purty fresh kid," sneered Jellup.

"At your service, Mr. Officer."

Jellup had already received an explanation of the whole affair and was aching to exercise his authority.

"Ye'r an impostor," he began, "and ef ye hadn't been caught, ye'd have taken money on false pretenses. I was onto ye."

"Oh, now," interrupted Bob, "at two dollars Mex per day I'd have given good value."

"Mebbe," retorted the marshal, "but these gentlemen hev come here on particular business and they came like gentlemen. The officials o' this city hev give their word that there shouldn't be no interferin' with their plans. And thet's what you're a-doin'. Now git!"

Ned broke in:

"One moment, Mr. Marshall"

"Oh, that's all right, Mr. Napier," exclaimed the reporter, "he doesn't mean just that. He knows I don't have to leave here so long as I obey the law."

"Ye don't, don't ye?" retorted the marshal. "Well, there ain't no back east law down here. Our law books mebbe got all burnt up. And mebbe I happen to be purty much o' the law myself. Ye'll git and git quick."

Again Ned interfered.

"I suppose if we ask you to permit Mr. Russell to stay here he can," he asked.

"Well, I reckon that would be so. Ef ye ask it I reckon I'll have to," he replied surlily.

Ned and Alan held a brief consultation.

"We have decided to ask the authorities to permit you to remain here on one condition."

The, intelligent face of Bob took on a quizzical air as he waited to hear the condition.

"That is," went on Ned, "that you give us your word that you will not make known anything you have seen here, or of our plans so far as you may know them."

Bob's answer was immediate.

"I can't do that," he said, "I was sent here to do just that thing, and as quickly and as fully as I can. You ought to understand, and do, I think, that I have a duty to perform. I've taken the trouble to come all the way out here to get a story. I've got it and of course I'm going to use it. I should be false to my duty, to my employers and to myself if I promised not to do this."

"But you don't know our story."

"And I'm sorry. But I should have known it all if I had had a little better luck."

"Then you won't promise?"

"Decidedly not."

The boys showed that they were as stubborn as he.

"Then we'll see that you learn no more," Alan exclaimed angrily.

Bob smiled. "You can't take away what I already know, and it will take a pretty long story to tell all I am going to guess from what I have seen."

As he spoke his eyes were on Major Honeywell's chart of the Tunit Chas Mountains, which had carelessly been left lying on the table where it had been in use during breakfast in the last explanations to Elmer.

Ned's face reddened in new anger. He did not resent what the young reporter was doing; he even realized that he might do the same thing himself; but he was chagrined to find himself caught in such a simple manner. That was a big piece of additional information for Russell to have, and Ned knew it. Hard as the thing was to do he would at least put the young man out of the way of further discoveries.

"All right," he exclaimed, "we've tried to do the fair and decent thing, and if you want to be stubborn Marshal Jellup can do as he likes."

"Git!"

It was the marshal who spoke and he did so as if it were a pleasure.

"I'll take the Limited west to Gallup at noon," said Russell, "if I can stop it and catch the eastbound train there to-night."

"Then ye'll flag it along the road," shouted Jellup, "fur ye'll get out o' here on foot and in a hurry."

"On foot?" exclaimed Russell in surprise.

"That's what I said an' ye heerd me."

Russell looked in appeal at the two boys.

Ned was mad, and mad all over.

"You are so quick to have your own way," he said, "you can't blame us."

"All right," was the cheery response, "it'll lend a bit of local color to the story. Goodbye, boys. And good luck to you. I'll see you when you come back."

"Remember," said Alan relenting a trifle, "we'll let you stay until we leave if you'll promise to write nothing."

Bob laughed again.

"What good would that do me? No experience means anything to me that I can't turn into copy. And as for walking—I'd walk from here to Kansas City or crawl before I'd lie down on my shop like that."

"Come on, kid, get busy," exclaimed Jellup again. "An' when ye start, don't bother about lingerin', because I'll be hangin' around and I'm good with this at some distance."

As he spoke he drew a Colt 44 and tapped it.

"Never fear, Mr. Jellup," laughed Bob. "I suppose I can express my suit case to the next town?"

"Ye can't do no business in this city, d'ye hear? Now, come on."

"Say, partner," interrupted Bob with his usual good humor, "if you will let me take a snap of you I'll make you celebrated. 'Famous gun man' of New Mexico. It'll be great."

In another moment the nettled marshal had Bob by the shoulder and was whirling him out of the car. On the steps he threw the suit case onto the sandy plain and then pushed the reporter roughly down the steps. Ned and Alan stood, with flushed faces, watching the reporter pick up his hat and suit case. Then young Russell made a remark they could not hear and the marshal's revolver flashed in the air. They could see the boy's face grow pale at last, but as he straightened up the two men disappeared around the freight house.

Like a flash Ned was on the ground and after the marshal and his victim. Alan and Buck came running in the rear, for the alert Buck saw that something was in the air. It was early day and only a straggler or two was in sight at the depot. The sun, already mounting high, foretold a day of depressing heat. The steel lines of the railway stretched interminably eastward toward the first stop forty miles away.

Bob Russell, pale but defiant, stood in the middle of the track, his heavy suit case in his hand.

Suddenly there was the crack of a revolver and the dust flew about the young reporter's feet.

"Jist as a sample!" roared the angered Jellup. "The next one'll be higher up." And his trembling finger pointed down the hot sandy track.

There was nothing more to be done. The pale-faced but nervy reporter turned toward the east and started slowly down the track.

Ned ran forward.

"Russell!" he shouted, "Russell!"

As the reporter paused and turned, hearing his name, there was a second report of the marshal's revolver and Russell's suit case flew from his hand, ripped and torn ragged by a forty-four bullet.

The smoke of the explosion puffed upward and, where it had been, the marshal saw Ned Napier's automatic magazine revolver under his nose.

The boy was white with indignation. The possible serious results that might come to him and his plans meant nothing in his anger at such a dastardly act.

"It isn't a Colt," he said with dry lips, "but, if you make another move like that it's got ten shots and they come out all together."

CHAPTER XIII - QUICK JUSTICE IN THE WEST
Jack Jellup, marshal and "bad man," was never more surprised in his life. But Jack was no fool, and something in Ned Napier's eyes made the westerner conclude instantly that he had unexpectedly and unquestionably "barked up the wrong tree." For a few moments the marshal and the young aeronaut stood facing each other and then Jellup sneered:

"Do you reckon you'd better run this town?"

"No, nor you," quietly answered Ned, "and if that's the way you are going to do it you can settle with me right now. I'm going to stand on my rights."

He was conscious that Russell had hurried back and was behind him. Another second and there was a sharp click. Both Jellup and Ned turned to see the nervy young reporter with the torn suit case open on the ground at his feet. A snap shot camera was in his hand. His face was white, but there was a trace of his usual smile on it. Ned wanted to laugh too, but the situation was too serious.

"I've got you both," said Bob, a little nervously, "and if it's a good one I've got a dandy—'shooting up the town or the bad man covered'—"

Had it not been for Ned's lightning-like action these might have been Bob's last words. Jellup's pistol had flashed once more, but as it dew into position Ned's own weapon rose with it under Jellup's right hand and the marshal's shot passed over Bob's head. Before Jellup and Ned could recover themselves Bob's camera was on the ground and the reporter had his own revolver, which he had grabbed quickly from the suit case.

In the center of this group now stood, unarmed, Alan Hope and old Buck. Almost at the same time a dozen men, attracted by the melee, had also intervened and had taken charge of the three excited combatants.

Pushing the crowd right and left appeared the stalwart form of Mayor Curt Bradley, weaponless, but with the stern face of one who gives orders that cannot be ignored.

"Put 'em up, every one of you," he exclaimed; "do ye hear? Put 'em up."

"Ye'r both under arrest," shouted Jellup to Ned and Bob.

There was a quick explanation and then Mayor Bradley, still very stem of face, ordered everybody across the street to his office above the drug store. Men seemed to spring out of the ground, and the room was instantly packed to suffocation. Marshal Jellup made a formal charge against the two boys of "resisting and interfering with an officer" and then each told his story. The decision was immediate. Mayor Bradley ordered that both boys be released and the court be instantly cleared.

Jellup made his way noisily toward the door, his face white with rage. Apparently a number present were his friends and cronies, for the looks of sympathy that he got turned into open murmurs of dissent.

Mayor Bradley was on his feet at once.

"What's the matter?" he began incisively. "Is there some one here who wants to appeal from my decision?"

The hubbub subsided but there wag no response.

"The time to make any complaint about my decision is right now and to me," went on the tall Bradley, looking over those in the room.

But no one apparently cared to take up Jellup's cause. When the spectators had gone the Mayor, who had sternly watched the slow exit of the last loiterer, turned to the boys.

"I thank you, Mr. Bradley," exclaimed Ned earnestly.

"And I want to thank both of you," quickly added Bob Russell, taking the hand of each. "I'm the cause of this and I'm sorry. I guess you saved my life twice," he added, wringing Ned's hand. "If it hadn't been for you the Comet certainly would never have heard from me again. I guess that, puts all my obligation up to you."

"No," said Ned, "I can't let you say that. You have your own duty just as I have mine. We'll go over to the car and wait for the two o'clock Limited. Then you are at liberty to go and write your story and do its you like."

"He don't have to leave," interrupted the Mayor; "this is a free town and it's going to be an orderly one."

"And I'm not going to," broke in Bob. "You've got yourself in a muss over me and some of these soreheads may try to make you more trouble. If you'll let me, I'll stay to the end and if it comes to a mix-up I'm going to be right there with you."

Mayor Bradley smiled and old Buck slapped the reporter on the back.

"But how about the story you say you are going to write about us," asked Alan.

"There wouldn't have been any story if it hadn't been for Mr. Napier," replied Bob. "And there isn't going to be one until he tells me to write it. It's up to him."

Ned was looking out of the window at the curious loungers standing in the street. He was thinking of the work yet to be done and of all the difficulties that the discomfited marshal might put in his way. It wasn't a "picnic proposition." He didn't fear for himself, but the thought of his expensive and delicate outfit and of how easily it might be irreparably injured was not reassuring.

"Russell," he said finally, "I think we need you. If you care to stay with us we'll be glad to have you. It isn't because I don't want to be bluffed by Jellup, but because you are game. If you'll go with Buck and Elmer, I'll try to make it worth your while—some time—and you shall be the historian of this expedition—when the time comes to write its story."

Am hour later the delayed overland expedition was on its way toward the desert. There had been a quick shopping expedition in the stores of Clarkeville and Bob Russell, in a new hat and boots and various other articles of clothing, most of them too large for him, sat proudly on the driver's seat of the second wagon. Around his waist was a new cartridge belt and holster carrying Ned's gift, a 44 revolver—"for game or rattlesnakes," as the boys expressed it, but the weapon was not concealed when the little cavalcade traversed the main street of the town, and if Jellup was an onlooker Ned felt sure that the outwitted marshal would think twice before again molesting the expedition.

"All set," laughed Bob, as the final farewells had been said, and he held up his camera, "now for the real thing."

Ned and Alan were now alone. To tell the truth, the excitement of the morning had been rather trying for them, but if it left them a trifle nervous they soon forgot their apprehension in making the last of the transfer. There was now another reason for abandoning the car. With headquarters established in the corral they would be near the balloon and its equipment, and if Jellup should permit his ill will to develop into some overt act, they would be in a position more easily to protect themselves. For that reason a number of their "greaser" assistants were taken to the car before noon and the hydrogen cask was loaded on the small wagon and carefully freighted to the corral. Then followed the remainder of the provisions and the personal belongings of the boys. Early in the afternoon the Placida was closed and turned over to the railway agent.

CHAPTER XIV - BUILDING AN AIR SHIP
When Ned announced to Alan that they would at once unpack and test the motor—"for we might as well stop if the engine isn't right," as he put it—all thoughts of the troubles of the early day vanished. And the motor certainly was a beauty. Though some expert had recommended the French motor, Ned had preferred to use one made in America, not only because he had been able to get it quicker but because he believed it as good as the foreign make.

The engine had eight air-cooled cylinders, in two sets of four, placed at an angle of ninety degrees to each other. The crank case was of aluminum and the shaft of vanadium steel, hollow, and specially treated to insure toughness. All the studs or bolts were of the same steel. Complete, with balance wheel, it weighed two hundred pounds. The ignition was accomplished by six dry batteries and a single-wire vibrating coil. It was rated at fifty horsepower.

So exactly had the preliminary work been done at the factory that in two hours the boys were able to have the engine bolted to the section of the car where it was to be used, and before evening the radiator tubes and pump of the cooling system were also in place. Temporary connections were set up and the sparking wires attached, and then the reservoir was filled with gasoline. A little jar as the wheel was turned, then a couple of sharp explosions, and the engine fell to its work as if it had been running for weeks.

Ned shut it off after a moment's critical inspection.

"Let her flicker!" pleaded Alan. "We've waited so long for a real one that I like to hear her buzz."

"We'll let her buzz when we can use the buzz," laughed Ned. "Gasoline is gasoline, you know."

Night did not stop the work of the eager lads. As soon as they had eaten a light meal, Ned and Alan, with a couple of lanterns and a half dozen of candles, began to adjust the sections of the car. These, seven in number, when joined, were 54.12 feet in length. The American spruce frame and the aluminum joints were all intact. This work finished the day.

Blankets on the rough floor were good enough for the explorers that night. The luxury of the Placida's mattresses and fresh sheets was missed, as was Elmer's skill as a chef when it was time for breakfast the next morning. The boys were not so indifferent about this meal as they had been about that of the evening before. They had no stove, but they took the time to arrange a regular camp in a comer of the corral. A little fire was soon burning, at which they made coffee and toasted some bacon. This, with hardtack and some preserved fruit, they thought was enough, for they were determined not to disturb the carefully packed provisions that were to be carried in the balloon.

"Have you had enough?" asked Ned as the last piece of scorched bacon disappeared.

"Enough?" answered Alan. "A regular banquet!"

Just then there was a loud thump on the closed door of the barn.

"The hands are arriving," explained Ned, and he hastened to open the door.

A few of the workmen were there, but the knocking had been done by a pleasant faced woman—apparently a Mexican. A black shawl covered her head and one arm. It was Mrs. Bourke, Buck's wife.

"I thought," she said smiling, "hungry."

Without further words she threw back the shawl and revealed a small tin pail. The appetizing odor made Ned's mouth water. In the bottom of the bucket were frijoles, or boiled and fried Mexican black beans cooked in pepper, and on top of these were a half dozen smoking hot tortillas or corn cakes.

"Mrs. Buck," exclaimed Alan, "you have saved our lives!"

All recollection of his recent banquet seemed to have disappeared, and so did Mrs. Bourke's bucket of beans and cakes, in double-quick order. The reward was a bright silver dollar for the thoughtful woman and a contract that she should come three times a day and prepare the boys' meals. It would have been easier to have gone to Buck's home, only a short distance away, but the boys were now determined to stay in the corral, or leave it only one at a time. However, they soon developed a taste for Mrs. Bourke's peculiar hot wholesome dishes and these, with what provisions they had on hand, were a fair substitute for Elmer's cooking.

The frijoles having been disposed of, Ned at once went out, and was fortunate in finding a load of rough lumber and a sort of jack- carpenter. With the help of the boys a four foot-high series of "horses" or frames was set up in the center of the corral. This was for the car to rest on while it was being assembled. It was elevated so that the propeller and aeroplanes and rudder could all be tested after being set up. The propeller, 11.48 feet in length, revolved in bearings four feet above the bottom of the car.

After noonday refreshment the middle section of the car, to which the engine was already attached, was carefully lifted into place with the aid of the workmen, and then the laborers were paid off and dismissed—all except the watchmen. From now on there was nothing that the boys could not do themselves, and they wanted to be undisturbed and alone. The putting together of the car was a treat of which they had long dreamed and they were happy in their work.

The remaining sections were easily laid on 'the "horses" and then came the bolts and the bracing with piano wire. When brought together the fifty-four foot long skeleton was in shape much like a cigar. The main frame was six feet high, tapering to five feet at each end. In depth the dimensions were the same. The engine rested on the floor of the middle section and was accessible in all its parts from that compartment. An elevation of the floor in the forward part of this section made it possible for one to stand high enough to have an outlook in all directions through openings in a hooded elevation that projected above the top of the section.

This hood was of a waterproof silk, coated with powdered aluminum, that metal being used because of its semi-incombustibility. This silk also covered the sides of the central compartment, making a wind-, rain- and waterproof cabin. The lookout windows on all four sides were covered with isinglass. The bottom of the framework of the car forward and aft of the engine compartment had a ladder-like flooring of spruce, inserted more for strengthening the car than for service. But on top of the car, reaching from end to end, was a continuous runway two feet wide which could be used in hurriedly visiting either propeller or rudder. This runway was protected by guide ropes of Italian hemp running through posts extended upward from the sides of the car. The top of the engine compartment was completely floored, making a platform 6 x 6.12 feet square. This was surrounded by a protecting network, and Alan named it the "bridge."

A light rope-ladder extended into the engine cabin from an opening in the roof, making the top floor space or bridge and the upper runways quickly accessible. The gasoline reservoir, just forward of the engine, was connected with the bridge by a copper supply pipe. The extra supply of gasoline was to be carried on the bridge in the open air, and lashed to the netting instead of being stored in permanent reservoirs as is the usual practice. This was in order that the empty vessels might be thrown overboard when it was necessary to lighten the balloon.

The other sections of the car were each 8 feet long and decreasing in height from 6 feet next the cabin to 5 feet at the end of the car. In the two sections just forward of the cabin and in the two just aft provision had been made for attaching the eight liquid hydrogen casks—four at each end. As this liquid was reconverted into gas the light sheet-iron casings might likewise be cast overboard to lighten the balloon. As needed, the liquid hydrogen jars, coated with mercury, were to be taken from their casings and carried to the bridge where the reconverter was located.

Aft of the engine cabin was the store room for water and provisions. The grooves and rods for the counterweights and equilibrium adjuster ran in the middle of the upper footway and the propeller shaft rested on the bottom of the forward section of the car.

At ten o'clock that evening all the work on the car was finished except the buckling on of the aluminum silk sides and the hanging of the propeller, the rudder and the aeroplane sides. It was as long and as hard a day's work as either of the boys had ever done. They were dead tired, but happy, and after a sousing wash-up they got into their pajamas and, throwing their blankets on the floor of the little office, were soon fast asleep.

CHAPTER XV - HOW JACK JELLUP LOST AN ARM
In spite of his fatigue Ned did not sleep soundly. It had been threatening a thunder storm all evening and the increasing oppressiveness of the air made the young, aeronaut wakeful. The long whistle and jarring stop of the midnight local train finally fully aroused him. In the west the thunder was rumbling and great sheets of heat lightning promised a storm in a short time. After slipping out into the corral and seeing that the waterproof silk sides of the car were securely buttoned around the engine Ned returned and again tried to go to sleep.

But his restlessness continued. In his early sleep he had had a vivid dream about the wagon expedition. In this he thought that Marshal Jack Jellup had followed Elmer, Bob and Buck and set fire to the wagons while his friends were asleep in camp. It was a relief to awaken and find that the flash of light was lightning and not, as he had imagined in his dream, an explosion of the gasoline carried in Buck's big wagon. He lay awake awhile regretting the quarrel with Jellup, and then he sank into a doze again.

But his active brain would not rest. Again he fell into a dream. This time the picture was very real. The big balloon had been finished and launched. A thrill ran through him as he felt the monster craft poise and waver and then slowly rise above the corral. He could hear the cheers of those gathered about. But in the midst of them be heard the sudden crack of a revolver. Jack Jellup had put a bullet through the silken bulk of the bag. The cold perspiration broke out on Ned's forehead.

The dream was so real that he thought he could hear the taunting voice of Jellup. In feverish excitement Ned sprang upright, to find a pair of strong arms clasped about him. He did not cry out. A wave of cold fear seemed to benumb his tongue and brain. He knew this was no dream.

Forced onto his back, his face and eyes partly covered by the shoulders of his sudden captor, Ned's returning consciousness made him aware that there was a dim light in the office.

"It's Jellup, Ned," exclaimed in a whisper a sudden voice which Ned instantly recognized as Alan's.

"No more from you," exclaimed a rough voice in quick reply. "Here's the rope, Domingo."

The man on top of Ned knew his business. Almost before the boy realized what was being done his hands and feet were caught in dexterous knots and he was helpless.

"Now," continued the other voice, "let's have a few minutes' talk."

Ned's assailant had arisen, and for the first time the boy could look about. In the center of the room, with a sputtering candle in his hand, stood the revengeful Jellup. His companion Ned at once remembered as one of the noisy court room spectators of the day before. Between the two, clad in his pajamas and similarly bound, was poor Alan.

"Ye can stand or set, jist as ye like," began Jellup. "Me and me deputy hev made this little visit to ye fur a purpose. The citizens of this town is tired of yer carryin's on and they've just delegated me to ascertain what it all means. We got a purty good idee."

"Well, what is your idea?" interrupted Ned, slowly regaining his composure and his natural defiance.

"My idee is that ye don't need no flyin' machine anywhar except to git away quick and what we want to know is what air ye goin' to take with you when ye fly away?"

"Nothing that doesn't belong to us," answered Ned, "if that is what you mean."

"Ye ain't, eh? I suppose ye don't know that thar's enough cow money in our bank to be worth stealin'?"

Both Ned and Alan looked at each other astounded.

"You don't think we look like safe robbers, do you?" began Alan.

"Ye look just slick enough fur that and more," retorted the marshal who had placed the candle on the table and roughly pulled Ned to his feet. "But I didn't come here to argy. Ye began by vilatin' the law and ye didn't come the way down here for no fun. Ef that ain't yer game, and we don't put it above ye, what's yer lay?"

"There's only one answer," said Ned. "None of your business."

The marshal shoved Ned nearer the table.

"Mebbe ye want to apologize fur that little bluff of yers yesterday—"

"No," said Ned, "but I'll accept yours."

Jellup's right hand was on his revolver.

"I ain't hyar to make no threats," he exclaimed, "and ye don't need to be afeered that I'm going to shoot ye. But I've got just one other little proposition. Ef ye don't cotton to that, why, thar ain't agoin' to be no Fourth o' July balloon ascension around hyar."

Ned straightened up.

"Your proposition can't be a fair one or you wouldn't come like a thief at this time of night—"

Jellup's pistol flashed in the air but fell back again as the marshal's left hand shot upward and struck Ned full in the face. Even as the tears sprang into the bound boys eyes and pain and anger flushed his pallid face, the cowardly Jellup fell backward and stumbled to the floor. Alan, standing just behind the man, had shot his knees forward, striking Jellup's legs in the hollow of his knees, and, thrown off his balance, the westerner lay sprawling on the floor. Before the marshal's confederate could interfere, Alan, tightly as he was bound, had flung himself on top of Jellup and with all the power he could throw into the act had butted his head into the marshal's face.

Am oath and a cry of pain indicated how true the stroke had been. Both Ned and the companion of Jellup sprang forward at the same time and the four fell in a silent distorted heap. But the encounter was unequal. In another moment both boys were lying side by side on the floor and their captors stood over them. Even in the half light of the little room both boys could see the blood-smeared cheek of the marshal.

Jellup's hand was on Domingo's arm holding him back from further attack on the helpless boys and the marshal was restraining his anger as a snake withholds its venom until it strikes.

"Purty good," sneered the marshal, "and the funny thing is ye hain't got a bullet through ye fur it. But my business ain't with dead ones. Onct more, air ye goin' to say what ye'r a plannin' to do?"

"Since it doesn't concern you in the least," said Ned, slowly, "no."

Jellup was silent a moment.

"Fur kids ye seem to have plenty o' money. Ye'r purty free spenders. I'll give ye one more chance. Ef ye've got a thousand dollars handy fur a kind of a bond as it were I guess that'll sort o' protect us."

"You mean for bribery?" exclaimed Alan.

"No, just instead of stealing," angrily added Ned. "We haven't a thousand dollars and if we had you couldn't get a cent of it. And to save you some trouble I'll say that what we have is in your bank."

Another half-uttered oath sounded on Jellup's lips.

"In thet case," retorted the marshal, "we'll jest show you that we mean business. That's a lie about the bank. Produce or take the consequences."

"Help yourself," replied Ned, "if you think we are lying."

"I ain't no pickpocket," retorted Jellup, "this is official. I tell ye it's a bond and this is yer last chanct to make good."

The boys remained silent.

But Jellup's companion was already busy. Leaving the marshal to stand guard over the boys he made a quick search of their clothing. But Ned was not so used to money as to be careless in the handling of it and the six hundred dollars that he had in gold was in a belt carefully concealed in the top of the liquid hydrogen crate, which, for safety, had been stored in a corner of the room.

When the silent Domingo threw down the working garments of the boys he took up the candle and began a tour of the room. The big black liquid hydrogen crate attracted his attention and he approached it. The red "Explosive—no fire" letters of warning apparently meant nothing to him, but Jellup halted him with a sharp warning, followed by a few words in Mexican. Domingo handed the candle to Jellup and the latter stepped toward the box.

"That means what it says," exclaimed Ned quickly and sharply.

The crate stood as it had been carried from Washington with the top on and the connecting hose extended upward through a hole made in the low roof in order that the slowly accumulating reconverted gas might escape in safety.

"Mebbe," said Jellup, "mebbe yes and mebbe no. I guess they ain't nothin' agoin' to explode that ain't set afire."

Ned noticed with satisfaction that the lid was properly locked. Jellup noticed it too. Without a word, he turned and easily found Ned's keys. Again he approached the crate, looking over the keys.

"Jellup," exclaimed Ned in alarm, "there's gas in that box, and if you go near it with a light you'll blow us all up."

"Gas, eh?" answered the eager Jellup. "Don't run no sich bluffs on me."

"I warn you," cried Ned as the man approached the box, "it's taking your life in your hands."

Something in the tone of Ned's voice must have alarmed Jellup, for he paused. Then he retreated a few steps and handed the almost burned out candle to the vigilant Domingo.

"I allow I kin jest hev a look without no light to oblige you. I've been purty curious about this precious package ever since I see it. And ye'r a sight too anxious consarnin' my safety."

What might really happen Ned did not exactly know. The gas generated from the liquid hydrogen was highly inflammable and explosive when confined. But the evaporation was exceedingly slow and the exhaust hose should easily carry the forming gas in safety to the air. But even a small accumulation might be in the partly depleted bulbs or the top of the crate and a fire would certainly ensue even if there was no violent explosion. And besides, just beneath the lid was their money—the cash Ned had secured for their further expenses and the return home.

"We are anxious for all of us," explained Alan.

"And mebbe anxious fur something else," sneered the marshal. "I reckon a peek in the dark ain't agoin' to hurt no one—an' it may help some."

"Drop on your face, Alan," whispered Ned, "and lie flat."

It was the only precaution they could take. Both felt that all their plans might end in a moment. But Ned could not resist watching—even though his face was close to the floor. He saw Jellup examine each key, guess the right one at once and then insert it in the lock. Yet, despite his assumed bravado, it was apparent that the man had considerable apprehension. For, before he turned the lock, he motioned to Domingo to retire further with the candle.

Finally, as if summoning his courage, the avaricious marshal snapped the key, threw back the catches on each end of the crate and then slowly and gingerly and at arm's length began to lift the lid. With the top an inch ajar he paused, waited a moment or two, and then began sniffing as if searching for an odor.

Ned saw him.

"It doesn't smell," he explained quickly, "but it's there. Look out!"

"Don't smell!" retorted Jellup. "Gas as don't smell? Well, that's agoin' some, I guess."

Nevertheless, he had dropped the lid.

But as quickly recovering himself he reached forward again and with a quick motion threw the top up and sprang back.

To Ned's relief nothing happened. Either the light was too far away or the gas had all been removed by the hose. But this relief was quickly succeeded by another alarm. There had been no explosion, but their financial means were now at the mercy of two thieves, and he and his churn, bound and helpless, were powerless to protect either themselves or their funds. There was nothing to be done but to grin and bear it. For Ned's new leather money belt, containing six hundred dollars in gold was stretched out conspicuously and at full length on top of one of the two rows of glass bulbs in the case.

"Lyin', as I thought," exclaimed Jellup. "Gimme' the light, Domingo." And the chuckle that followed almost instantly was indication enough that he had discovered the boys' small fortune.

"Dangerous, eh!" he laughed. "Now, we'll see if the city gits its bond."

Then he paused as if a thought had entered his head.

"But, jest to keep the record clean, I reckon ye'd better give it to me yerself, young 'un. Jack Jellup ain't no burglar. Loosen him up, Domingo. And fur fear ye might need persuadin' jest take a peek at this," and he drew his revolver.

When Ned had been liberated, Jellup pointed to the money belt.

"Jest be good enough to hand me whatever's in that," he exclaimed, "without no hesitation. Then we'll have a little talk about what else is agoin' to happen."

It was hard to surrender so easily but the risk of attacking two armed men single-handed was great. Ned walked slowly toward the crate.

"Get busy," ordered Jellup; "we've got other business yit to talk of."

Ned had a sudden impulse. The thing flashed on him and taking hold of the belt in the middle he lifted it until the two ends were just over an open-mouthed bulb of hydrogen, and then as if by accident dropped the belt into the jar. The clear, watery liquid splashed and the belt disappeared.

"Water," shouted the eager Jellup, "Jist plain water." And as Ned sprang back the gold-fevered marshal sprang forward and plunged his hand into the liquid.

He did not immediately know that his hand was in the depth of a liquid whose temperature was 423 degrees below zero. But the thin film of gas that instantly formed and protected his naked flesh dissipated in a moment and then one benumbing, paralyzing shock swept over Jack Jellup's body.

With a cry wrung from him by pain such as few mortals have ever experienced and survived, the stricken man fell unconscious to the floor—his arm frozen as solid as crystallized steel.

CHAPTER XVI - READY TO "LET GO ALL"
In the confusion that followed the sudden extinction of the candle, while Ned was freeing Alan and Jack Jellup was uttering heartrending groans, the marshal's confederate lost his nerve and made his escape. When a lantern had been procured, immediate attention was given to the stricken man.

Ned hastened to secure a bucket of water. Wrapping the corner of a blanket about the handle of a tin dipper he ladled out a spoonful of the liquid hydrogen and, although the numbing chill ran through his fingers and up his arm, he managed to pour the hydrogen into the contents of the bucket.

The pail of lukewarm water became almost instantly a cake of solid ice. As Ned dropped the tin dipper to the hard adobe floor it flew into a hundred pieces. The inconceivable cold had crystallized the metal until the slightest shock was sufficient to break it into pieces.

At the sound of the crashing tin Ned instantly thought of the belt of gold yet in the hydrogen jar. But a human being was in pain, and he gave his first attention to the suffering marshal. He had made the ice to use in drawing the frost out of Jellup's frozen arm. In a few moments he had mashed a portion of the ice into small bits, and using a blanket to make a pack, he soon had Jellup's rigid arm encased in the fine ice. This he applied for the same reason that snow and ice water are applied to frozen ears and noses. But his treatment was of no avail.

The rain was now falling steadily and it was dark, but Ned found that it was nearly day—a little after four o'clock. Jellup's suffering was so extreme that the boys had given him a hypodermic insertion of morphine, using their "snake-bite" outfit, and in a few minutes the man's ravings ceased and he quieted into a deep sleep.

While awaiting this, attention was given the gold. Feeling free to approach the now open jars with a light it was seen that a portion of, the belt protruded above the liquid. A cord with a sailor slip knot was lowered over the extended bit of leather, drawn taut with a jerk and the belt was slowly lifted out. A folded blanket had been placed on the floor to receive it. As Ned expected, the leather crumbled and broke like glass as the belt fell on the soft blanket.

"If you want change for a twenty-dollar gold piece just tap one of those with a stick." said Ned, laughing and pointing to the gold pieces scattered among the broken fragments of the belt.

"Not I," exclaimed Alan, "not after what happened to the tin dipper."

Leaving Alan to watch over the unconscious Jellup and the frozen gold, Ned dressed himself, and in spite of the rain hastened out in the just perceptible dawn to carry out a plan he and Alan had agreed upon. An hour later, with the assistance of Mayor Bradley, the marshal, now somewhat easier, was placed in a bed in his own home. Unless the silent Mexican told it no soul in all Clarkeville other than Mayor Bradley and the air ship boys knew why Jellup was absent from his haunts and his post of duty that day. Nor did many of them ever know, when Jellup reappeared on the streets after weeks of suffering, how he had been injured. They only knew that his right arm was gone and that he was no longer marshal.

The rain ceased with the coming of the day.

"If we don't get away pretty soon," suggested Alan, as Ned was getting into dry clothing preparatory to tackling another of Mrs. Buck's meals, "this thing will be getting on my nerves."

"Well," answered Ned philosophically, "there is mighty little worth having in this world that isn't hard to get."

If all went well that day the boys hoped to be ready to make their departure that night or the next morning. Therefore they went to work with a vim. Both felt more comfortable when, after finding that the gold coins had returned to their normal condition, they had again concealed them. The propeller, rudder and aeroplane guides were now put in place and tested.

As the engine, with a speed of 1,400 revolutions but geared down to 800, began to turn the shaft and the twelve-foot propeller began to revolve, Ned swung his hat in the air. Without a break the speed increased to 500, 600, and then 700 revolutions a minute.

"Shut her off," exclaimed Alan joyously, as the white arms flew round and round and the air shot backwards on both sides of the long car. At 750 revolutions the car was rocking and lurching as if it would soar birdlike into the air. At 800 the powerful pulling propeller began to overcome the rigidity of the framework on which the car rested and as Alan caught and held the car, fearful that it was about to fly away under the propeller power alone, Ned shut off the engine.

The next instant the two boys, with clasped hands, were doing an Indian war dance in their glee.

It was not long until the rudder wires and the aeroplane shafts had been attached to their proper guide wheels in the lookout or pilot portion of the engine cabin. Then came the preparation of the balloon bag itself. Here again Ned showed what he had accomplished in the six weeks he had spent in the East.

Clearing a space near the generating tanks, they placed the one hundred sand bags, weighing forty pounds each, in parallel rows. These sacks, with convenient loops on each for attaching the rigging of the bag as it was being filled, had already been prepared by the "greaser" laborers, but the placing of the two tons of dead weight was not a joke, and the boys regretted that they had not kept a few men around. But by noon this was done, and then the great waterproof fiber trunk containing the silk bag was rolled out between the retaining bags. The boys could not carry it, as the balloon itself weighed seven hundred and twenty pounds, but they improvised rollers and with many a laughing "yo he ho" finally accomplished the task.

The bag had been made by one of the leading aeronautical engineers of America, whose factory, strangely enough, was in one of the small inland towns of New York State. In a spirit of humor the manufactory had been termed the "Balloon Farm," and so famous was it that Ned had even planned to spend a part of his summer vacation visiting it. When Major Honeywell gave him the opportunity, Ned was at once determined to utilize every advanced idea of the skilled owner, whatever the cost.

The result was a machine-varnished and, as nearly as such a thing was possible, hydrogen gas-proof bag. In the construction of this the experienced manufacturer and engineer, who was no other than Professor Carl E. Meyers, the hero of hundreds of ascents, had used a new machine which applied simultaneously to both sides of the bag fabric several thin films of elastic varnish. The bag itself consisted of two layers of Japan silk between which was a layer of rubber, all being sewed together and then vulcanized.

But the balloon trunk was not opened at once. The pipe to convey the gas from the cooler and purifying tank had been brought in four-foot lengths of light wood, cemented and shellacked. Eight lengths of these were laid to the center of the cleared place and then the joints were wound with binding cement tape. When these things had been satisfactorily adjusted it was mid-afternoon. Everything now seemed ready for the filling up of the generating tanks, the inflation, the flight, and "good-bye."

Therefore, a final consultation was held. Wind tests conducted each day had shown the prevailing breezes favorable, or at least not against the aeronauts. The inflation would require approximately ten hours. If begun at once this would make the departure possible about midnight. This was not undesirable as the absence of the hot southwestern sun would make the gas easier to control. But another thing had to be taken into consideration. Only four days had elapsed since Elmer and Bob and Buck had started. Were they yet at the rendezvous?

"I don't see what difference that makes," said Alan. "We expect to sail directly north and east of the foothills. If they have not reached their camp they must be nearly there and on the way. We've got to locate them with our glasses anyway. Let's start and pick them up where we find them."

"True enough," answered Ned. "The way the engine is working, in this light favoring wind, we ought to make eighteen miles an hour anyway. If we leave at midnight, by five o'clock in the morning we can be ninety miles north. The only trouble is in the handling of the bag. It's going to take at least twenty men to move the inflated bag from the retaining weights to the car and we can't make the rigging fast in the dark. We'd better begin work at four o'clock to-morrow morning, as soon as it begins to be light, and get away about two in the afternoon. I think we'll see our friends about seven or just at dark, if we do."

CHAPTER XVII - AN INTERRUPTED FLIGHT
And so it was arranged. The young aeronauts thus had all afternoon to store provisions, water, gasoline and the instruments. The altitude barometer, the recording thermometer, the statoscope and recording hygrometer, together with the telescopic camera were each given a place on the bridge and lashed to the netting. The twenty-five-foot rope-ladder, strong but light, that was to hang below the car, and the anchor and drag rope, were attached, the name pennant of white with the word "Cibola" resplendent in blue, "turquoise blue," explained Ned—was unfurled on its little staff just abaft the big propeller, and a new silk American flag was laid out it the stern of the car to be run up on its halyards as soon as the bag was attached.

Then came the careful transfer of the liquid hydrogen. One at a time the cast iron eases were carried from the building, hoisted aboard the car and lashed in place. Before supper Ned had time to go to the depot and send a telegram to Major Honeywell, who was yet in Chicago. It read:

"Ready for inflation. All O. K. Sail at 2 P. M. to-morrow, August 11."

He then visited "Saloon Row" and arranged for twenty men to report at four o'clock the next morning. No chances were to be taken that night. Dividing the hours up to four A. M. into two watches, the two boys had supper and Ned was soon fast asleep on the floor of the car "trying it out."

At the first blush of dawn the corral gates were thrown open and in a short time all the men engaged reported. Some of them were put to work dumping the heavy iron filings into the big oak gas generators and Ned and Alan began the delicate work of laying out the bag, bottom side up the thin silken folds of the golden shell were slowly lifted and laid on the ground. When the bottom filling valve had been attached to the wooden gas conduits the mammoth sections of the long gas receptacle were stretched out on top and then carefully smoothed until an even inflation was assured.

This done, the rigging trunk was opened and the seine-like mass of delicate hemp cords laid over the bag. No "greasers" were permitted to assist in this. Ned and Alan, in bare feet, laboriously but carefully drew the silk folds of the bag into the net. When this was completed the suspension cords reached out in all directions like skeleton fingers. In a quarter of an hour these had been attached to the retaining bags with slip knots and then the boys were surprised to find that it was already after six o'clock. At their best they could not now hope to reach the relief camp before nine o'clock and after dark.

Mrs. Buck came with a huge pot of coffee for all, and then followed the last step. One by one, borne on the shoulders of the curious workmen, the dangerous carboys of sulphuric acid were emptied into the generating tanks. The boys guided each step of the men, explaining the danger, and the work was finally completed without hitch or accident.

At the first bubble of gas the boys felt like doing another war dance. But they were "business men" now and had to put on dignity in the face of their employees. In two hours the reaction of the bubbling acid had sent enough hydrogen through the purifier to raise the bag shoulder-high and everything was going splendidly. The boys had removed their working clothes and were now in the light but warm canvas suits and caps they meant to wear in their flight.

Ned stole away a few minutes and at the bank secured bills to pay off the men. On his way back he stopped to invite Mayor Bradley to lunch with them on the Cibola and to be present at the "let go." By noon the men had been paid and the articles of baggage and tools that were to be left behind had been packed, tagged with shipping directions and turned over to Buck's wife.

The cigar-like bag, 98.4 feet long and 17.4 feet in diameter, which was to hold over 65,000 feet of gas, was now so far inflated that it was nearly off the ground. Then Mayor Bradley came. With pride the boys bade him climb into the cabin of the Cibola.

"You won't find anything hot in a balloon, Mr. Mayor," laughed Ned, "except the reception. Make yourself at home."

On the bridge of the craft the two boys and their guest had luncheon. Cold potted chicken and baked beans served on wooden plates with hardtack and water, and sweet chocolate for dessert, was the simple meal, but it tasted like a feast.

"Have you christened the craft yet?" finally asked the Mayor who had absorbed some of the enthusiasm of the young aeronauts.

"That's for you to do," politely answered Ned.

The luncheon was hurried to a finish, for the boys could see that the bag needed final attention. It had risen higher and higher and was now swaying and tugging at the suspension ropes. Both boys alighted and at once began straightening the extension ropes. Here and there where the cordage net was out of place they pulled down the bag and adjusted the rigging. Finally a little after three o'clock, the great case had filled out until its smooth glistening sides resembled the skin of a fat sausage.

"All ready!" ordered Ned as he shut of the valve of the cooling and purifying box. "Now, every man bear a hand."

One at a time the extension cords were untied from the retaining bags, and each of the workmen was given four of the light but strong lines. The Mayor himself passed among the men with stern injunctions to hold fast. As the last cord was loosed the great tugging bag was held wholly by the scared men. Then, with slow and measured steps, the double line of assistants advanced to the car and along each side of it.

"All steady," commanded Ned when each man had been placed; "now hang onto her."

Then he and Alan, springing into the car, began the work of making it fast to the bag. There was a place marked for each of the extension ropes, and the air ship builders, beginning at each end of the car, carefully adjusted and tied the end of each rope to the frame of the ship. As the cords were taken from the attendants the men took hold of the lower framework of the car, and to make doubly sure each man was cautioned to throw his entire weight into the work.

At last the final rope was made fast, and three thousand pounds of human flesh and muscle were holding the tugging balloon. Ned, covered with perspiration, and nervous but happy, was hastily connecting the compensating balloon tube with the hand blower on the bridge, and Alan had run astern to tie the new national colors to the halyards swinging from the end of the bag.

"Hold on," cried Ned seeing that Alan was ready to run up the stars and stripes. "Just a moment. Are you all ready, Mr. Mayor?"

"All ready," came the answer from the town official, as he stood on a box, his hat off and a revolver in his hand.

"With a western salute I christen this balloon the 'Cibola,'" he exclaimed, and a shot punctuated his speech. "Good luck and goodbye!"

As the shot sounded Alan's flag ran fluttering upwards. Ned's eyes took one final look fore and aft and then he leaned over the car for the last words for which all were waiting.

They were on his lips and the eyes of twenty straining men were fixed on him to hear the command, "Let go." One nervous attendant, apparently thinking the order had been given, threw up his arms with a shout.

At that instant there was a second sharp pistol shot, and a quick cry from the street outside the corral.

"Hold on there, all of you!" shouted Ned. His dream had rushed back to him with a sickening chill. Had some one shot at the towering bag? "Hold on!" he yelled.

At that moment there was another shout and Bob Russell, his face red with the sun and his shirt wet with perspiration, walked into the corral. In his right hand was gripped a revolver and in his left a repeating rifle. In front of him, and prodded on by Bob's pistol, was the Mexican, Domingo, Jack Jellup's tool and fellow thief.

CHAPTER XVIII - FREE AND AFLOAT AT LAST
This is what had happened.

At the time of the rain storm, two days before, Buck and his cavalcade were in camp on the bank of the dry Chusco, sixty miles north of Clarkeville. The experienced scout knew that a water supply was now assured, and he at once followed prearranged orders by instructing Bob to return with the smaller wagon. This was a sad blow to the young reporter, but it was a part of his contract and he knew that it was his duty to obey. And with necessity before him, he acted promptly. Emptying the heavy casks, Bob started on the back trail at five the following morning, and by night had made thirty miles with the light wagon. All day he wondered if it might not be possible to reach Clarkeville again before the Cibola sailed.

The next morning, spurred on by the hope that he might do this, he started at daybreak. By the middle of the morning he was on the old wagon trail and making better time. Some time after two o'clock he came up over the rise of the last foothills and saw, eight miles away, the glistening shape which he at once knew was the inflated balloon. He hesitated a moment and then, unhitching the horses, mounted one bareback and began a dash for the town. The animals were tired and worn, and progress was slow, but it beat walking, and Bob urged them on.

As the young reporter came nearer and the balloon grew more distinct he knew that it would be a close call. From time to time as the winded horses dropped into a walk Bob wondered why he was making such a race. "I can't go with them," he argued. But, like the trained reporter, be decided that no effort was wasted that gave him new information. And it was something out of the ordinary to see the most complete balloon ever made start on a mysterious flight into the wilderness.

So he spurred up the horses anew. The hot sun reflected from the yellow sands burnt his face and his muscles were sore, but he stuck to it. When half a mile from the town he could see the boys on the bridge of the Cibola. When a quarter of a mile away he decided that he could beat the horses by going afoot, and, throwing himself to the ground, he ran onward, knowing that the tired animals would follow. Out of breath he reached the edge of the town and stumbled on toward the corral.

With head down he plunged forward. Almost at his goal he threw his head up for breath just in time to notice a kneeling man with a rifle at his shoulder.

"Hey!" yelled Bob with what breath he had.

Then he saw that the man was aiming directly at the balloon swaying above the nearby corral fence. He also recognized the man instantly as one of the sullen court spectators, and Jellup's crony. The rifleman dropped the muzzle of his gun and turned.

"I guess I am something of a gun man," explained Bob later to the boys, "for I had that new revolver of mine on the 'greaser' before I knew what I was doing myself. I didn't even then realize what he was about to do. But I had the drop on him and when I figured out that he meant to put a hole in the balloon, why, I just had him right. And here he is."

Alan looked at Ned. Both boys were puzzled. A few moment's talk with Russell explained the whole situation. The balloon was ready and the relief expedition was undoubtedly now in camp awaiting them. It needed only the words and they would be off with the inquisitive reporter left safely behind. And yet the word did not come. Ned and Alan stood looking at Bob, and the reporter gazed in turn at the beautiful straining car. Bob's face was a study. He had now made some return to Ned for possibly saving his own life, but none of the boys was thinking of that. In Bob's fine young face was the longing of a child. In Ned's and Alan's faces were the traces of boyish sympathy.

The young aeronauts were very close to each other and all were silent. Then Alan turned slowly to Ned and with a little quaver in his voice whispered, "Shall we?"

Ned made no answer. A smile lit up his face and he sprang down the little ladder into the engine cabin followed by his chum. Almost instantly the trap door in the floor of the car dropped down. A moment later three fifty-pound sacks of ballast tumbled through the door to the ground beneath. The bag tugged and strained as Ned reappeared above.

"Hurry up, Bob, if you're going with us," he said quietly, leaning over the net of the bridge, "and close the door as you come up."

Bob hesitated, as if he had not heard aright, but then he understood, and with tears in his eyes be sprang forward. There was a jar and Ned knew the new passenger was aboard.

"All ready?" he called sharply from the bridge.

"Aye, aye, captain," came in a choking but jubilant voice from the inside of the cabin.

"Stand by, everybody," sharply ordered Ned. And then, as Bob's shoulders appeared through the hatchway, the commander of the air ship gave a final look about.

"Let go all," he cried sharply. "Everybody!"

For a moment only one clinging workman careened the buoyant craft and then, straight up, the Cibola bounded like a rubber ball.

"Good-bye, all," came from Ned, cap in hand, as he leaned from the bridge.

There were cheers from below and the Cibola was at last free and afloat.

"Sit down here and keep quiet," sharply ordered Ned as Bob crawled out on deck. Then the commander of the balloon disappeared below.

There were almost immediately several sharp, muffled explosions, and then the white propeller began to turn. The balloon was drifting quickly toward the northwest and rising—Bob could see its shadow following on the sandy plain. Then the arms of the propeller turned faster and faster and a velvet whirr in the cabin showed that the engine was falling to work. As the propeller blades settled into a steady hum the vibration of the car indicated increased speed. This Bob could also detect from the more swiftly flying shadow.

The shadow was also growing smaller, and this meant that the Cibola was still ascending. Now the shadow paused and turned. Alan had thrown the rudder over and the balloon had responded instantly. The aeroplane arms stretched out horizontally on each side of the car. Ned, reappearing, took a quick look at the altitude gauge and again disappeared. The aeroplane arms dipped in front almost forty-five degrees and the current, blown back by the propeller, struck them with a jar. The craft again responded and slowly took a downward slant.

Propeller, rudder and aeroplane being at work, Ned again appeared.

"Go below," he ordered sharply, "and bear a hand when needed."

Bob did so. Alan was on the pilot platform with his hands on the wheel controlling the rudder wires. His eyes were fixed straight ahead.

"See that lever," he said, jerking his head to the left.

Bob quickly discovered the aeroplane guider control and sprang to it.

"Wait for orders," added Alan.

CHAPTER XIX - THE FIRST FLIGHT
The balloon was still sliding downwards and swiftly forward. For several minutes the three boys stood in silence. Only the steady whirr of the engine and a musical humming of vibrating wires could be heard. Bob wondered if they were headed earthward again, for he could see the approaching foothills widening out beneath. At last, when they could not have been over five hundred feet from the ground, came the quick order:

"Right the planes."

Bob was almost caught napping, for he was busy looking through the window. But his hands responded instantly, and he almost choked with chagrin to find that he had started to throw the lever the wrong way. But his recovery of himself was instant and with a desperate pull he forced the guiding planes back horizontally. The glide downward stopped and the Cibola shot forward with renewed speed.

On the bridge Ned held a fluttering chart before him.

"How is she heading?" he called to Pilot Alan at the wheel. With a glance at the compass before him Alan promptly responded:

"Nor'nor'east."

"Make it north by east."

A quick slight movement and a strain told that the alteration had been made.

"North by east it is," sang out Alan.

"Keep her there," was the echoing response.

Bob was thrilled. Every word was to him a joy. Everything had happened so quickly that he hardly knew what it all meant, but he was happy. Even the sudden discipline pleased him and he was glad to be a part of it. The knowledge that a younger boy was giving him orders did not bother him. He had skill in his own line, but he saw and realized that in the Cibola Ned Napier was in charge and meant business.

For some time then no word was heard. The Cibola, speeding, swiftly onward, had crossed the low foothills and was pulling herself through the almost breezeless air like a modern liner, five hundred feet above the ground. She was holding her course beautifully. Then Ned appeared and tested the gas exhaust and oil feed of the engine.

"Were you ever in a balloon before?" he said when he had finished, turning sharply towards Bob.

"Never," answered Bob, glad enough for a chance to say something.

"Have you any matches?" somewhat sternly asked the commander of the Cibola.

"Sure," replied Bob reaching in his pocket and finding one.

"Any more? All of them."

Surprised, Bob searched his clothes and discovered a few more which he obediently handed over to his superior officer. Noting the look of surprise in the reporter's face Ned laughed.

"The first rule in a balloon is 'No fire.' But beginners forget, sometimes; we can't take this chance with you."

"Take anything I have got," answered Bob with his old smile, which had now been in eclipse for some time, "and if I can speak at last I want to say that you boys are white, clean white, through and through. Didn't you need that ballast?"

"We may need it badly," said Ned, laughing. "If it should become necessary I suppose you won't mind if we throw you overboard."

"No," retorted Bob, "not if it is a little at, a time. But you're bricks—both of you—if I thank you I'll cry." The tears were again in his eyes.

"Well, it wasn't the thing to do, I suppose," said Ned turning away, "but you looked so hungry to go, and I knew what it meant. So I thought we'd just give you a little ride up to the camp."

"Yes, of course," answered Bob slowly as his hopes fell. "Put me out wherever you like," he added.

"You can go up now and have a look around," said Ned at last, "both of you. I'll take the wheel."

The relieved boys scrambled onto the bridge deck. Night was coming on and the mountains to the west were already black. Evening shadows were lengthening on the sloping plains beneath and a gentle, rising breeze flapped the flag and pennant and swayed the bag above them. Beneath, the Chusco wound its half dry course and off to the east a blue haze, melting into the unending sand, told of a treeless and waterless waste.

"And there," exclaimed Alan at last, pointing off to the northwest where snow-capped, ragged peaks rose out of a black jumble of mountains, "are the Tunit Chas and the land of our dreams. To-morrow—"

"One moment," interrupted Bob quickly. "I think you are forgetting. That is your secret and not mine."

Alan flushed. "I forgot," he said with a stammer, "and I thank you."

"I can't afford to make you sorry you brought me," added Bob, "and you are not going to be."

There was a little jar. The propeller slackened a trifle, and Alan explained that Ned had headed the Cibola another point into the freshening breeze.

"Steward," said Ned from below, "it's seven o'clock and I'm hungry. Besides, it's getting pretty dark down here."

Alan and Bob looked at each other and laughed.

"That certainly means me," exclaimed Bob, and both boys clambered below. With Alan's help Bob made his first examination of the store room.

The meal was rather haphazard, as the boys, carried away by the excitement of their new flight, had neglected to eat when it was light. But water and hardtack were easily accessible, and Alan, taking the first two cans at hand, found happily that they contained sardines and veal loaf.

"We'll eat on deck," suggested Ned, as he set the wheel and had another look at the engine, which had not missed a revolution.

The night that greeted them was magnificent. The moon was not yet up, but the stars were scintillating in the inky sky and the deep silence of the clouds and desert was about them. Bob gazed as if spellbound. The charm of the night appealed to him as it did to Ned and Alan; but with it his brain formed phrases—"cloudland by night," "a dash to the stars." The reporter in him was thinking "copy."

"Hey, there, wake up!" cried practical Ned.

Bob flew to his task; with a turn he had the veal loaf can open and had dumped its contents in the wooden plate held by Alan.

In another moment he would have thrown the empty can overboard but the watchful Ned, ready for another lesson in aeronautics, caught his hand.

"Don't you like the route we are taking?" laughed Ned.

Bob's face showed he did not understand.

"The loss of the weight of that can might send us sparing upward a thousand feet," explained Ned dryly, "so don't cast over ballast until you get orders."

Bob shook his head. "Well doesn't that beat all," he exclaimed.

As night fell and the air grew heavier, the barometer showed that the Cibola had a tendency to rise. The aeroplanes were readjusted and then for an hour the craft sped on untouched. At eight o'clock Ned said:

"We haven't traveled over eighteen miles in an hour and we've been afloat four hours. If we are still over the Chusco and Elmer and Buck are at the appointed place we may be within ten or twelve miles of them."

"They are going to burn three small camp fires set in a triangle, you remember," remarked Bob.

"Therefore," suggested. Ned, "all keep a sharp lookout."

At half past eight Ned showed some concern. No lights had been sighted and the reckoning showed that they must be within two or three miles of the probable location of the camp. Another fifteen minutes went by, and yet no signal fires were seen. They had now passed over the junction of the two rivers, if their calculations were right, and Ned and Alan were in a quandary.

"It's no use to go on," commented Ned; "so we'll just make a wide circle and see what we can find."

It was also useless to look below. In the darkness there was no sight of either river or desert.

"It we don't pick them up in that way," continued Ned, "we'll descend and tie up for the night."

Both Ned and Alan went below, and with the engine shut down to half speed the Cibola was turned on her course in a wide sweep. Bob alone watched with anxious eyes, until he was joined in a short time by Ned. There was no sound but the soft chug-chug of the engine, and for some time neither spoke. The breeze of the early evening had died and there was not a breath of air. Alan in the dark cabin below held the wheel and Ned and Bob alone, hanging over the side net, watched and listened in vain.

CHAPTER XX - FIGHTING INDIANS WITH A SEARCHLIGHT
"Stop her!" It was Ned's voice in quick command. The young aeronaut, peering over the side of the car of the Cibola into the black night, had suddenly seen something that prompted the order. It was a distant flash of light. This was followed by an echoing explosion. The other boys heard the explosion and all instantly knew that it was a shot from a firearm. Almost before Alan could shut off the power Ned had disappeared into the cabin to help head the balloon in the direction of the spurt of fire. The Cibola slackened speed and they waited, drifting slowly toward the east. Then, suddenly, and almost together came two streaks of fire and two more explosions.

"One of them might mean a signal," said Ned gravely, "but they were not from the same spot. If it were Elmer he would have the three fires. If it is Elmer and Buck and they can't make a fire and are shooting I am afraid it means trouble."

"It may mean Indians," suggested Bob, "and they may have put out their fires for safety."

"They might even be holding off an attack of some kind," added Alan anxiously.

Just then there was another crack of a firearm now a little nearer. The Cibola was drifting directly toward the sound, but very slowly, and would soon have lost all headway.

"I don't want to be presumptuous," said Bob in a low voice, "but can't we land and find out what the trouble is?"

"We can find out without landing," replied Alan.

It was so dark in the cabin that the boys could only dimly see each other, but Ned was groping about near the silent engine. In a moment he had secured from the ammunition case a storage electric light, and cautiously shading the lens with his cap he asked Bob to hold it. Then he turned to his chum.

"I didn't know just how we would use our little drop light," he began; "but it seems that the idea wasn't half bad. There is a tribe of Indians not far from here that would steal a horse or cut a man's throat quickly enough—the renegade or Southern Utes." As he spoke he was digging in a chest extracting various small parcels. "Not even the other Indians have any use for the Utes. And there is only one thing to do. We must first find out if our friends are below."

With the help of the flashlight Bob could we that Ned held in his hand a large, high candle-power incandescent bulb and was adjusting it in a silver reflector.

"With an electric light?" exclaimed Bob.

"Why not?" replied Ned. "And the help of our little dynamo."

Ned took the flashlight, held it under his coat, and crawled around in front of the silent engine. "It's here," he explained for Bob's benefit, "and I am just throwing the gear onto the propeller shaft."

"Well, if you are afraid to show this little light why aren't you afraid to show a brighter light?" asked the observing reporter.

Alan answered him.

"We are only afraid because it might draw an attack from some observer. Balloonists are never safe from meddlesome persons or worse. But there isn't the same danger if the light isn't on the balloon."

"Sure," said Bob. "I understand that. But you can't hold it very far away."

"No," answered Ned, "that's why we braided two good copper wires in our drag rope." As he said this he opened the trap door in the floor of the cabin and feeling about in the dark soon had hold of the coiled drag.

"I guess I'm dull," began Bob.

"No," interrupted Alan, "only you haven't given two or three years to figuring out the possibilities of an air ship."

Ned was attaching the bulb, reflector down, to the end of the rope.

"That rope is three hundred feet long. A light at the end of it is quite a way from our bag.

"Oh, I see," exclaimed Bob at last. "If we find Indians and they shoot at our searchlight they are pretty sure to miss us."

"That is the theory," answered Ned.

And then the plan in Ned's mind was explained. The engine was to be started at quarter speed, which meant that the sound would be imperceptible; and, lying on the floor of the cabin, Ned was to direct the movements of the ship, with Alan at the rudder wheel and Bob at the aeroplane guider.

"A quarter to ten o'clock," said Ned glancing at his watch as he shut off the concealed flashlight, "and now start her up."

As Alan started the engine and it began to turn the propeller they could tell by the light breeze that the car was moving again, but very slowly. The other boys could also hear Ned delicately paying out the long drag rope. At last it was all out. Then Ned crawled forward again to the dynamo and up to the partly open floor of the car and whispered that he was ready. The multiple gear was already speeding the little generator swiftly.

"Lie down on the floor and watch," murmured Ned softly, "I'm going to turn her on."

Alan and Bob did so. As their two heads filled the open trap in the cabin floor there was a click and then, as if some necromancy had focused the sun on a part of the darkened world, a circle of light seemed to spring out of the desert beneath. Yellow, with here and there a ragged rock and a sage brush or two, the shadows of the rocks and brush black like spilled ink, and the sand glaring back at them with almost quivering brightness, the circle shot back and forth as the light followed the swinging rope. But no living thing was in sight. A click and all was black again.

"Nothing doing," exclaimed Bob.

"Wait," suggested Ned, "persons we couldn't see may have seen them."

Almost as he spoke there was another quick report.

"Did you see the flash, Alan?" asked Ned eagerly, for he had been busy with the dynamo.

But Alan was already at the wheel, and again the car swung from its course.

"Wait," he exclaimed, "turn it on again when I give the word."

After perhaps two minutes he gave the signal and again Ned flashed the gleaming bulb. Again the circle sprang apparently out of the black ground. As the car drifted forward the black blotched golden sand ran the opposite way like a whirling panorama. A coyote sprang, dazed, from a clump of bushes and back again, but that was all.

"Give him another chance," whispered Alan, and the light flashed out.

"Listen," exclaimed Bob breathlessly, "wasn't that a cry?"

Another moment and the sound came again.

"Elmer!" exclaimed the two air ship boys together.

The Cibola swung instantly at Alan's quick touch. Again the light flashed. Sand and rock and brush. The brilliant circle of light shot here and there, but the anxious watchers saw sign of neither friend nor foe. Then like a flash the level plain dropped into the sudden slope of a coulee and the darker shadow of water blotted out the glare of sand.

"The river," whispered Ned. "Now watch sharp."

As the light was blotted out this time Alan swung the wheel again. He knew instantly that they were on the wrong track, as they were going east and crossing the Chusco. Elmer and Buck would not cross the river. The camp was to be on the west side.

"Follow the river," ordered Ned quickly; "the west shore."

In order that the Cibola might be laid on the new course Ned threw on the light switch again. As he did so and the light flashed there was the sharp crack of a rifle and the light was gone.

"Turn her on," exclaimed Alan; "I want to get a line on the river bed."

Ned laughed. "I'll need a new bulb first. Some one down below turned it off."

"What?" exclaimed the other boys together.

"Shot out," calmly retorted Ned.

CHAPTER XXI - A CORDITE BOMB AND ITS WORK
In a moment the boys were hauling in the rope and Ned was back in the cabin after a new bulb which he secured and attached in the dark.

"Now give her a swing," he said as Bob again lowered the rope. "It will make it harder to hit."

When Bob announced that all the rope was paid out Ned snapped the switch again. In spite of the gravity of the situation all the boys were tempted to laugh. A brilliant green glow shot down. An emerald circle of light flooded the ground beneath.

"If anyone sees that they'll sure think it's a drug store," suggested Bob.

"'Or a sign of the Great Spirit, perhaps," added Ned soberly, "it may help us in more ways than one, if Indians are—"

"Look," hoarsely shouted Alan, "there, over there!"

But his words were superfluous. The three boys saw the same thing. And then as the wide swaying of the bulb swept the gnome-like picture in green from view Ned threw himself over and shut off the engine.

Not a hundred feet beneath the brilliant bulb the precipitous bank of the river had again shot into the circle of light. At the very edge of the cliff stood the big freight wagon. Behind it, between the wagon and the steep river bank, stood two horses. At one end two more lay prostrate on the ground. In front a light barrier of boxes and barrels rose a few feet from the ground. And there, a rifle at his shoulder, knelt Elmer Grissom, their friend and servant. Buck was nowhere in sight.

Their worst fears were realized.

As the dramatic picture flashed from view each boy knew that it was time to act.

"What's to be done?" exclaimed Alan, his voice choking.

"There can't be many of them," answered Ned finally, as if thinking, "or they would pushed their attack. If we could locate them the rest would be easy. Let Bob take the wheel and try to get over the wagon again; I have an idea."

The Cibola again answered the rudder and circled, Ned flashing the bulb until the river came beneath them. This required but a few moments, but, before the craft had gathered momentum on the way back, there were four shots almost together about three hundred yards to the right of where they supposed the wagon stood, and a quick reply from the river bank.

"Our light did it," exclaimed Alan, "they are rushing the barricade."

"Indians don't rush together, if it is Indians," replied Ned. "Keep on up the bank, Bob. It's risky for Elmer," he added with a husky voice, "but we've got to take chances."

Again the light flashed. Ned and Alan hurried to the bridge.

Within its circle and almost together, sealing the seamed and hard bank of the river, were five dark figures. As the powerful light encircled them the crouching figures sprang backwards. But they were not quicker than the alert and prepared Ned Napier. A small round object shot downward from his hands. The glare of flame as the missile struck true and the thunderous roar that hurled the big bag of the Cibola sideways told that the cordite bomb had done its work well.

Bob was speechless. Ned and Alan were already in hurried consultation. They could not count on fortunately finding the other besiegers all together, "'and there are at least four more," said Ned. The rescue of the lone besieged lad was not an easy problem. The boys believed themselves now just above the wagon again, but they were afraid to draw possible fire to the barricade by showing another light.

The hurling of the bomb overboard had shot the Cibola heavenward like a bird. Before they realized it the aeronauts had mounted up at least two thousand feet. They then began maneuvering to regain their position. But this was not so easy. A flash of the suspended searchlight gave them not a trace of their bearings and it was plainly apparent they would have to use time and patience in recovering the location of the besieged wagon. Using their best judgment, they put the aeroplanes to work, and, circling slowly, the Cibola gradually came nearer and nearer to the ground. After ten minutes or more the car gave a sharp bound upward.

"The drag has touched the ground," exclaimed Ned.

The aeroplanes were righted, the engine was stopped, and again the balloon was drifting. There was not a sound to guide the aeronauts. The contact with the ground had broken the bulb and it was not replaced. For aught the rescuers knew they might be again directly over the wagon. Not a shot had been fired since the roar of the explosion, but there was no reason to believe that the yet living besiegers had withdrawn.

"More likely planning a final attack," suggested Alan.

Again a council was held.

"We've got to take the risk," said Ned at last in desperation; "we can't do anything up here."

And then, with Alan's approval, the propeller was set turning again, but so slowly that the big balloon was just moving under control. The aeroplanes were also set to bring the craft nearer the ground and, as a precaution, Bob was sent onto the bridge with an open knife to cut away ballast if sudden ascent were needed. The drag rope had been brought in. There were no means of knowing how near the car might be to the earth and the suspense was decidedly trying.

"I guess I can come a little nearer finding out," exclaimed Ned finally to the others in a whisper.

Alan did not know what he meant, but he resumed his place at the wheel. Ned had disappeared in the dark.

"Where are you, Ned?" asked Alan anxiously at last.

The answer came from beneath the car.

"Only down here, but I'm going lower," Ned replied, again in a whisper. "Be ready with that ballast."

A perspiration of fear broke out on Alan's body. He sprang to the open trap door.

Just discernible in the darkness was Ned's slowly retreating form.

He was climbing down the twenty-five-foot rope landing ladder with only his own strong grip and the spruce rungs to save him from death.

There was nothing to be said or done. Bob did not know what was going on below, but he knew that he had a task set for him, and in the long silence that followed while the Cibola settled lower and lower and drifted on and on in the dark he stood, knife in hand, at the ballast bags.

CHAPTER XXII - A THRILLING RESCUE IN MID-AIR
Buck, the guide, and Elmer Grissom had reached their appointed rendezvous at two o'clock that afternoon. The hot journey had been tedious and uneventful. Only at the half-breed settlement twenty miles north of Clarkeville had they seen a human being. Therefore, after they had been in camp about an hour, even the vigilant, experienced Buck was startled to observe suddenly a solitary Indian—his horse as statuesque as himself—watching them from a knoll some two hundred yards distant.

As the old scout raised both hands in signal of peace the Indian rode forward. The man was not in the Indian panoply of the old days, except that he wore moccasins and had two bands of red and yellow paint on his broad, dark face. A black wide-brimmed hat, a faded blue shirt and trousers completed his outfit.

"How?" exclaimed the Indian.

"Navajo?" answered Buck.

"Ute!" came the answer. "Where go?"

"Right here," said Buck good-naturedly, pointing to the ground.

"Ute land!" retorted the Indian without a trace of expression in his face.

"No," retorted Buck sharply, "not Ute land. Ute land there," pointing north, "in Colorado."

"Ute land!" exclaimed the red man again, this time scowling.

Buck only shook his head.

Then the Indian suddenly threw himself from his horse, strode to the wagon and threw up the tail curtain. Safely stored therein he saw the protected tins of gasoline.

"Whisky?" he exclaimed.

"No," laughed Elmer, "not whisky."

"Whisky," repeated the stranger turning towards Buck; "drink!"

But Buck shook his head.

With out another word the Ute walked haughtily to his horse, threw himself upon it, and, clasping his heels to its sides, rode quickly away.

"I'm sorry," exclaimed the veteran at last.

"I had no idea that there were Utes around here."'

"He doesn't seem dangerous," commented Elmer.

"No," answered Buck, "men who'd cut your throat for a horse never do. The chances are he isn't alone."

Elmer looked up in surprise.

"We'll just make sure," exclaimed Buck, making as light of the affair as possible. "I don't want to lose my horses and you don't want to lose your freight. We'll make ourselves ready in case our friends come back to make us a little visit."

And as night came on and Elmer helped Buck draw the wagon close to the river bank, where approach from the rear would be difficult, the boy began to realize what it meant to get away from the telegraph and policemen and law and order. And when the experienced scout unloaded a portion of their heavier freight and began to build a small barrier Elmer's usual joviality cooled into silence. The three piles of brush and driftwood from the river were laid out some distance in front of the camp in preparation for the agreed signal fires and then, before the sun went down, the scout and his companion made their camp fire and had supper.

"What do yo' expec' deyll do?" asked the colored lad at last.

"Well, you can't tell. Injuns are puzzles. When they steal they steal in the dark. When they fight they fight at daybreak."

"What do yo' suggest?"

"To tell the truth, son," answered Buck, "there ain't much to do but keep yer eyes open and pop it to the first red horse thief ye see crawlin' around in the night."

"Hadn't we better light our signal fires?" asked Elmer.

"There won't be any signal fires to-night," replied Buck, slowly, "if you want my advice. It's one thing for a bluffin' Ute to walk up in the daylight when you've got a fair chance to give him as good as he sends, and its another thing for him to get a bead on you a sittin' in the light o' yer camp fire—him in the dark."

Elmer saw and understood.

So night fell in silence with Buck and Elmer keyed up and ready to meet any possible attack.

Nothing happened until several hours had passed. Neither Elmer nor Buck were any the less alert, however. The old scout was pacing up and down in front of the barricade and perhaps a hundred feet from it. Elmer could just hear his soft footfalls in the sand. Suddenly these ceased. Almost at the same moment there was the crack of Buck's rifle, a groan and a moment later the scout was inside the barricade.

"I guess I got him all right," he whispered, "he was makin' too much noise."

This was the shot Ned heard miles away in the Cibola.

Again for some minutes there was no sound and then, suddenly and from the left, came a spit of flame in the dark. Almost before Elmer heard the explosion Buck's gun had spoken in reply. Both bullets went wild, but Buck explained that it was necessary to give shot for shot, "and right at 'em," said Buck, "as it takes a little o' the ginger out o' them."

But the besiegers had undoubtedly widened out. The next signs of them were two shots, almost together. Elmer's rifle made quick reply, but, to the boy's surprise, Buck failed to fire in return. The scout had disappeared from his companion's side. Before Elmer could call out he heard a rush at the end of the barricade, and then two explosions almost together and not ten feet away. He could not describe the sound that followed, but he knew that it meant the convulsions of human beings in agony. He whispered his companion's name, but there was no answer—only a gasp.

In the black darkness the colored boy, revolver in hand, crawled forward. At the end of the barricade Buck's body was lying. As the boy's hand fell on the old man's breast he knew that it was blood he felt.

"Buck," he whispered, "Buck! Is yo' hurt?"

He put his arm under his friend's head. For a moment the unconscious form yielded and then convulsively straightened. Elmer knew that his companion and protector was dead.

With strength that he did not know he had Elmer laid Buck's dead body behind the little wall of freight boxes.

Then, as if by intuition, he sprang forward and found what he suspected—the unmoving form of an Indian. Unable to see, Elmer quickly felt over the adjacent ground with his hands and discovered the dead Ute's rifle. The revolver was gone. In the same manner he recovered both Buck's rifle and revolver, and then prepared to do his duty—to protect his employer's goods so long as he could.

He was scarcely entrenched again, with the three magazine rifles laid on the barricade before him, when his straining ears heard a new sound. Far away and faint, but meaning only one thing, the soft chugging of a motor. The Cibola! There could be no doubt of it. The instant feeling of relief was shattered even as it gave Elmer new courage; to attempt to light the signal fires would probably mean instant death. And without them how would his friends know his position or peril? But one thing he could do; and even knowing that it would mean an answering shot from the skulking horse thieves he discharged his revolver into the air.

Then the sound of the motor died away and the long minutes dragged by. When it began again, and more softly, the sound was nearer. Nearer, and nearer it came and then the circle of light fell on the wagon and was gone. "At least they know where I am," thought Elmer to himself, and settled down courageously for renewed attack, determined to hold out to the last. At this moment came the shot that put out the Cibola's light.

The nervy boy had been tempted to abandon the wagon and follow the light, but his second judgment was against this. "If they can, the boys will come back," he argued, "and I'll only get out of this when I have to."

To Elmer's surprise the attackers had been strangely silent for some time. With more experience he would have known that this meant even greater danger, but he only hoped it was due to the distracting and mysterious flying light. Then the sepulchral green light burst out in its funnel-like volume. It was coming back. It flared, went out, shot over the distant sands again like a searching' eye and then began moving straight up the river bank towards the wagon. Then came the earth rending explosion. Nor could the besieged boy know even then that Ned's well-aimed bomb had sent five Utes to their last sleep.

When the sound of the explosion had died away and Elmer had recovered himself—for the shock had thrown him forward on the barricade—the whirr of the Cibola's motor was again far away. But it was directly above him!

As if the attackers had been paralyzed by the explosion, the long interval continued without a shot. Then suddenly, from the right and left and front, the real attack began. One shot sounded as a signal, and then from a half circle before him half a dozen bullets tore their way towards the boy and his barricade. Most of them went wild. Two hit the boxes and half stunned the lone guardian behind them. The assailants did not know that one of the two white men was dead, and Elmer, in hopes temporarily to deceive them, fired two of the rifles at the same moment.

But his enemies were closing in; the half circle was growing smaller and the crash of the bullets in the wagon above him and in the barricade in front told the boy that the end could not be far away. To the right in the direction of the explosion there was a gap in the fast closing circle. It was folly to delay longer. If escape were possible, it was in that direction. He would make one desperate attempt. One shot remained in his rifles. Putting it where he thought it would do the most good, and catching up the two yet full revolvers, the colored boy crawled under the wagon and crept hastily along the river bank.

And yet he did not dare to attempt to pass the end of the Indian semi-circle. It was one chance in a thousand. Throwing himself on the ground, he waited. "Crack!" It was the rifle of an Indian, not fifty feet away and coming nearer. The stealthy footfalls told Elmer that his foe was heading straight for the river bank and that he was in the Ute's path. Then he could hear the Indian's deep breathing. Detection was inevitable.

One last thing remained to be done—to kill the Indian and make a dash forward down the river bank. And he must act before his foe discovered him. Elmer's revolver flashed fire and he saw his foe of the red and yellow face bound into the air and then topple forward with a cry of anguish.

The boy turned, but too late. Directly in front he heard the sudden shouts of other Indians. The river at his back! Flight down its cement-like bank was impossible. He might plunge forward and pray that the water was beneath.

The death cry of the man he had shot and the echoing yells of the Indians behind him had been taken up by others. He knew the determined savages were making a final rush. Indian cries seemed to come from the very ground at his feet. He hesitated no lodger.

As he turned to the river a sudden and strange wave of cool air struck down on him from above. Without reasoning he paused. That pause saved his life. In that swift moment he heard the low creak of something straining. His eyes pierced the black about him. Was it a shadow? Something was brushing by him like a great bird asleep on the wing. Then it was on him.

"Ned?" It was only a whisper but it was enough.

"Elmer, here, quick!"

Even the whisper had brought an instant shot, but the colored boy had hurled himself toward the voice and an instant later a strong young arm was about the besieged lad.

It was Ned Napier on the swaying ladder of the Cibola.

"Cut away," came the low quick order and before even the nearby besiegers could locate the sound Bob Russell, high above, had slashed the lashings of a bag of ballast. The big balloon sprang forward, Elmer dangling in the air, and then settled again to the earth as the desperate colored boy found the last rung of the ladder and clung fast opposite his rescuer.

"Another, another," called Ned springing up the fragile length of the doubly laden ladder.

A thud on the ground told where another bag of ballast had fallen. The crash of the fallen fifty-pound bag of sand probably saved the Cibola. Shot after shot poured in the direction of the sound, although the Cibola, dragging forward, yet refused to rise. Elmer, at the bottom of the ladder, was helping the car onward in low bounds by touching the ground with one foot.

Then the air craft settled again. Elmer's weight was too much. A mad thought came into the boy's brain. The Indians had located the new invader and yells nearby told that hot pursuit was already being made. Then the spit, spit, of new shots showed the risk the boys had taken. Elmer realized it. Should he hang on and endanger the lives of his friends, or should he let go?

There seemed no time to think, but the boy's hand had already loosened when out of the black came the hot breath of the foremost pursuer. As the savage sprang forward Elmer's free arm gave him a blow full in the face. At the same instant the Cibola sprang upward like a bullet. A volley of shots rang out below, but they were too late. The balloon had saved Elmer's life, and even before the lad had made his way up the swaying ladder into the cabin it was a thousand feet in the air.

CHATER XXIII - CAMP EAGLE IN THE MOUNTAINS

It seemed too wonderful to be true. But words were proof enough that Ned Napier and Alan Hope had found a new use for dirigible balloons. Faithful Buck's death was more than the loss of a companion. In the short time the boys had known him he had shown that under his rough frontier bearing he was a brave and honest man.

"We can't go back now," explained Ned, "and we can't afford to land and wait for day. We can't all stay in the Cibola, and those of us who are landed must be left in a safe place. Our work," he continued turning to Bob, "is in the Tunit Chas Mountains, thirty miles west of here. It seems as if you had to know it. We'll go there to-night and land, if we can, on some isolated and inaccessible plateau. We'll make that our new relief camp and you and Elmer must take charge of it. To-morrow Alan and I will return in the Cibola to our abandoned wagon, bury Buck and bring away such of our stores as may be left. It's going to be a great loss, for I suppose the Indians have stolen everything. If the gasoline is gone it will cut short our work in the mountains."

"I don't think it will be lost," said Elmer, quietly. "We tried to save it. We rolled it into the river."

"But it will float away," exclaimed Alan.

"Unless de tins caught on in de drift in de bend jes' below," answered Elmer. "I seen four ob de eight tins dar befo' dark."

"That's what I call genius," exclaimed Ned. "Elmer, you're a brick! And now our course is due east at half speed. By daybreak we'll be over the Tunit Chas. Until then, the rest of you turn in. I'll run the ship."

Fifteen minutes later, despite the nerve-racking experiences of the momentous day, Alan, Bob and Elmer were wrapped in their blankets and sound asleep on the bridge deck of the Cibola.

The night passed slowly, but Captain Ned stood the long trick at the wheel, happy and content. To feel the Cibola, the product of his youthful genius, at last moving forward in obedience to his slightest touch drove all thought of fatigue and sleep from him.

But, above all, the early light of the coming day was to reveal to him a sight of the land of his hopes. There, before him, were the Tunit Chas; peaks and chasms of unsolved mystery wherein the centuries had held close their secret. Many trials had blocked his way. Was he now about to reap the reward of his labors? Did the hidden city of Cibola lie somewhere below him? Or were the Palace of the Pueblos and the Turquoise Temple but empty myths?

The young aeronaut's present plans were simple enough. The Cibola had now been afloat twelve hours and nearly half her gasoline was exhausted. More than once in the night Ned had noticed that the balloon was settling lower and he had been forced to maintain his level by casting over ballast. It was apparent that they were already losing gas.

In boyish impulse and sympathy they had made Bob Russell, the young reporter, a third and unexpected passenger, and accident had forced them to add Elmer Grissom, their colored friend and servant. And these extra occupants of the car must be landed at the earliest opportunity.

This became imperative now because, the relief and supply station on the Chusco river having been destroyed, the Cibola must add enough ballast and gasoline to make its exploring tour in the mountains in one journey. The original plan had been to make quick dashes to the camp on the Chusco for gasoline and then return to the mountains. To provide for this new weight the two new passengers and a good portion of the air ship's stores must be landed. And the most feasible plan seemed to be to set up a new emergency camp in the heart of the mountains.

Many things might happen to the now perfectly working balloon. And, even if cast away in the mountains, it was no part of Ned and Alan's plan to cease searching for the temple of treasure until dire necessity drove them from it. In case wreck and privation came it would be comforting to know that somewhere in the same wilderness food and friends awaited them.

The first glow of the sun painted for the ever watchful pilot a picture beyond the possibilities of brush and canvas. Here and there out of the blackness below sprang rosy points, the sun-tinted peaks of the Tunit Chas. Down the mountain sides, like rivers of silver pink, fell the sun's light. Then the valleys began to open out of the chasm of night-dark canyons wrought in the wilderness of the mountain sides. Here and there, oases left by the devastating hand of time, rose high plateaus, tree-crowned and verdant. And then, higher up among the white peaks, sentinel-like, stood giant tables whose brown tops and precipitous sides told of inaccessible and arid wastes. "And somewhere," said Ned to himself, "in this Titanic chaos lies the object of our search."

Starting at half speed, Ned had soon reduced the engine to quarter speed. When he aroused his sleeping companions Wilson's peak, their chief landmark, was just in sight far behind. His calculations placed the present location of the Cibola thirty miles from the Chusco river and just over the eastern Tunit Chas Mountains.

"All hands turn to," shouted Ned cheerily, "and stand by to make a landing."

There was a scramble, a rubbing of yet sleepy eyes and then an outburst of admiring wonder. The Cibola had sailed over two broken ridges enclosing an irregular, broken valley and was now looking down on a shelf-like plateau abutting on the second ridge and west of it. On three sides the plateau dropped precipitately into a lower rock-strewn, valley. On its eastern side it joined the still higher ridge. A pine forest crowned the top of the shelf-like mountain side and then ran up to the higher slopes until the carpet of green faded into the brown wastes of the timber line. In the very center of the wilderness of trees glistened a little lake of mountain water. From it the silver thread of a rivulet wormed its way for a mile or more among the trees and then trickled over the side of the cliff in a vapory waterfall.

Ned had swung the Cibola into a wide curve and the balloon and car were soon directly over the mountain creek. He threw the aeroplane guides downward and the slowly moving car drifted lower until it was but four hundred feet above the water and the overhanging pines. Then, following the water course beneath, the air ship floated back into the woods and the little lake widened out beneath them. Two deer, at the water's edge, stood unalarmed. On the south of the lake a grassy opening indicated Ned's destination.

"Here," he explained, "we can make a safe landing. It is an ideal place for a camp, with plenty of firewood and water."

"And meat, too," interrupted Alan, pointing to the deer.

"Venison and bear meat too, no doubt," laughed Ned.

From the top of a dead pine tree an eagle rose and soared lazily away.

"It's like the camping out places you read about," exclaimed Bob. "That eagle nest completes the picture."

"It does," interrupted Ned, "and I hope you won't forget the picture. That high, barren tree is your landmark. Some day you may need it. Remember; from the valley below your camp can be found by locating the little waterfall on the cliff. From the timber line above you will know it when you see the eagle's nest. And now let go the anchor. We have no gas to spare, and can't afford to open the valve."

To make a landing in a balloon without throwing open a valve and wasting precious gas is almost impossible. The craft could only be kept near the ground by keeping it in motion or by causing the propeller fans to depress currents of air on the aeroplanes. Therefore, as soon as the engine stopped, the Cibola would mount higher. But resourceful Ned had long since thought out this problem.

The engine's speed was reduced and the anchor was quickly lowered until it caught hard and fast in a strong pine tree. The contact shook the fragile car and sent the bag bounding, but when it was seen that the iron had fixed itself firmly three of the boys, pulling on the anchor rope, gradually drew the great buoyant car down until it floated just above the tree top. To drag it lower was, impossible, for one sharp branch might injure the bag beyond repair.

When the ship was safely anchored just above the tree, the twenty-five foot landing ladder was lowered and Ned himself made his way down its fragile rungs into the tree. .

"Hold on tight," he continued, "I'm getting off."

As he did so and found footing in the tree branches the Cibola tugged to free itself, as if, overjoyed to be rid of Ned's one hundred and forty-five pounds of weight. As soon as the young commander was safely on the ground he ordered the other boys to pay out the anchor rope and again the Cibola rose in the air.

"Now," ordered Ned, "start your engine and head the car over the opening."

While Ned stood below directing, with hands to his mouth, trumpet-wise, the Cibola strained at her anchor rope and then, obeying her rudder, moved directly over the open space, her nose pointing skyward at an angle of forty-five degrees.

"Hold her," yelled Ned, "and haul back."

The boys again strained at the taut anchor rope until the car stood just clear of the trees and some two hundred feet in the air.

"Now lower your drag rope and an empty ballast bag," called Ned.

While this was being done the navigator of the Cibola was busy carrying chunks of broken rock from the margin of the little lake, and in a short time the boys above were hauling away on the rope and lifting aboard new ballast. With each bag of it the Cibola sank lower and lower, until finally, when it was almost balanced in the air, Ned easily drew the balloon to the ground.

But the landing was not yet finished. Not a passenger in the craft could step ashore until Ned had added more stone. But when enough of this had been lifted up to the hands above, and Elmer could alight, the two willing workers on the ground soon made it possible for the other boys to spring overboard. Then the four of them loaded enough more rock on the bridge to take the place of the stores to be landed.

There were not many things that could be left: water, and half the provisions and, preserved goods; a few cooking utensils; blankets, an extra compass, two revolvers, a hatchet and saw; a light silk tent; matches and candles, a medicine case, ammunition, and, to make way for the gasoline that it was hoped might be recovered, all the extra oil on board—for the reservoirs yet contained an ample supply to make the trip back to the scene of Elmer's attack.

At a safe distance from the balloon Elmer had returned to his favorite occupation. He got a fire going and while the other boys replaced the rocks on board with bags of sand from the margin of the lake the colored lad made hot coffee and broiled some bacon. It was a luxury after the cold, dry food of the long night.

"When you come back this evening," exclaimed Bob jovially, "I'll try to have a juicy venison steak."

"An' hot biscuits," chimed in Elmer.

"And a good bed of balsam boughs," added Bob, "and a fine camp fire, and we can sit round it and talk it all over."

"And if we don't get back to-night you'd better have your camp fire anyway," said Ned,

"Ain't you goin' to git back to-night?" ruefully interrupted Elmer, as he poured the smoking coffee.

"You never know what you are going to do in a balloon," answered Ned. "If we can we will. If we can't we won't. If we are not back to-night we may not be here for several days. We've got work ahead now, and plenty of it."

"We'll be here when you come," replied Bob earnestly, with a smoking bit of bacon in his fingers, "whenever that is."

"No," replied Ned, "if we are not here in six days you must make your way out to civilization. You have food enough but you can't wait longer than that. As for directions, all I can say is that from this ridge back of us you can see across the half desert valley to the higher range of mountains. Should you cross the valley bearing almost due east and be able to get over or through that second ridge you will be able to see the top of Mount Wilson, thirty miles further east. From Mount Wilson it is fifteen miles southeast to the camp Elmer made. There you should pick up the trail of Buck's wagon back to the railroad eighty-five miles south."

Bob's eyes opened.

"Is it as bad as that?" he said half laughing. "We'll certainly have to get busy if the Cibola breaks down."

"Or," went on Ned, "any strewn in the valley below here flows finally into the San Juan River to the north. If you can make your way to this river and then succeed in following its banks eastward until you reach the plains, some time or other you'll find a frontier settlement."

"Or Utes," interrupted Alan.

"Gib me de mountain road," exclaimed Elmer quickly. "Nomo'Utesfo'me!"

"Yes," added Ned, "that's the trouble. The route to the San Juan is not only through a barren, broken mountain region, but it gets you finally right into the Southern Ute reservation. And, remember, too, that this is Navajo land. Your safety with them, should you be discovered, will be in diplomacy. And now good-bye—until we meet again."

"And if we don't," replied Bob, huskily, taking the hands of the two boys in turn, "I just want to say again that you boys have done for me what I can't forget and what I can't repay. I don't know why you are here, and I don't want to know. What I've seen will never be revealed, when I get back to Kansas City and the Comet, until you tell me I am free to tell it. And you'd know what that means to me if you knew what a cracking good yarn my experience has given me already. Good-bye and good luck!"

Ned and Alan clambered aboard; the rocks were cast overboard, and as the Cibola shot skyward the boys could hear Elmer calling:

"Member, boys—we all'll be at Camp Eagle an' supper will be awaitin'."

CHAPTER XXIV - A GRAVE IN THE DESERT
But Ned and Alan did not eat with their friends that night, nor for some days to come. And when they saw each other again one of Elmer's juicy venison steaks would have seemed to all of them the sweetest morsel ever eaten by man.

Ned only waited to help inflate the balloonet in the big balloon with the little hand blower for the Cibola showed quite perceptibly the loss of gas after her twenty hours of inflation. Then, the course having been laid, he left the wheel and engine to Alan's care and turned in for his long needed rest.

Alan had determined on a record flight. He allowed the Cibola to rise higher than it had yet flown, about 5,000 feet, and then setting the aeroplanes on a slight incline he headed the car on a down slant for Mount Wilson's just visible peak, thirty miles away.

There was no economy in half speed, for time and the utilization of their gas were more precious than gasoline. "We can always float without gasoline," the boys had said to themselves, "but we can't move without gas." Therefore the Cibola was soon at its maximum and the enthusiastic Alan knew that Ned would have a short sleep.

In an hour and twenty-one minutes the swift dirigible was abreast of the peak of Mount Wilson, and then, without slackening speed, Alan altered her course southeast toward the scene of the previous night's hair-raising experience. Long before he reached the place he was able to make the juncture of the two rivers his landmark, and the ship pointed her course as straight as a railroad train. After thirty minutes sailing from Mount Wilson, Buck's rendezvous could be made out, three miles beyond.

One glance told the whole sad story. Two dead horses alone marked the spot where their freight wagon had stood. Alan aroused Ned, and as the Cibola sailed low over the place the boys saw that the thieving Utes had gone—with the wagon, horses, freight and their dead companions.

Poor Buck's body was lying where the brave escort had fallen.

"We can't make two landings," suggested Ned. "We'll find the gasoline and then come back and bury our friend."

Disappointed, although they had really in their hearts expected nothing less, the young navigators turned the Cibola and sailed slowly down the river in the hope that the gasoline would be found where Elmer had described it as lying.

They were as richly rewarded here as they had been previously disappointed. The drift, a tangled jumble of small mountain wood, had caught and preserved seven of their eight tins of gasoline.

It was now noon, and broiling hot, but luncheon was not thought of and the difficult work of recovering the heavy packages was begun. This presented a new difficulty, for again the boys were determined not to lose any gas in making a landing.

The drift was too light to hold their anchor although two trials at this were made. Not a bush or tree was to be found nearby. In despair at last, Alan was about to suggest opening the valve—for it was imperative that they secure the gasoline—when Ned turned the bow of the craft down stream.

"Perhaps we can find anchorage further down," he explained.

"But if will be pretty hard work carrying these tins," Alan began.

"They floated where they are, didn't they?" smiled Ned. "What's the matter with letting them float a little further?"

His hope was realized. But the solution was fully a mile away. On a sandy bar, half buried in the sand, the stout end of a cottonwood trunk, the flotsam of some extraordinary freshet, had come into view. The experience of the morning was repeated, but on a smaller scale, for here were no dangerous tree limbs to threaten their delicate silken bag. After two trials and much pulling and hauling the car of the Cibola was tied fast to the snag, half over the shallow water and half over the sand.

Then, naked as when they were born, and suffering not a little from the pitiless sun, the boys started afresh. Alan made his way back up the river and began to prod out the stranded tin casks. All were soon bobbing along in the slow current, with Alan behind them like a lumber driver of the northwest dislodging logs left in the shallows. Ned below soon had all of them in shallow water.

By means of a coil of the drag rope, looped in turn about the tins of recovered fuel, Ned lifting below and Alan pulling above soon transferred the gasoline to the bobbing Cibola. As each cask ascended, a portion of the extra ballast was dumped overboard.

Then, dressing themselves and improvising what tools they could, the boys made their way sorrowfully to the scene of the previous night's tragedy. Buck's body was carefully removed and decently buried. A mound of boulders was made over the grave to designate the spot, and with the hope that some day they might return and suitably mark the desert tomb the boys took a mournful farewell.

CHAPTER XXV - BARTERING STORES A MILE IN THE AIR
"And now," said Alan, "it's ho, for Camp Eagle and our search at last."

"I don't know about all that sentiment," answered Ned, thoughtfully. "I've been—"

But he was interrupted. The boys, aboard the Cibola again, were just about to cast off when Alan cut short Ned's remark with an exclamation.

"Isn't that a balloon?" he exclaimed pointing to an orange-like object high in the heavens toward the west.

Ned caught up the binoculars and had a quick look at the rapidly moving ball which was rushing toward them from over the distant Tunit Chas Mountains.

"No question about it," answered Ned, handing Alan the glasses; "a balloon, and a big one."

"And out here, too!" commented Alan in surprise. "I guess the world is pretty small after all."

"Everything ready?" asked Ned eagerly. And then as the retaining rope was untied from the frame of the car and slipped down and out from under the cottonwood snag the Cibola shot upward.

"I have an idea," continued Ned, "and please don't object until you think it over. Let's make a little social call on the stranger!"

"A call!" exclaimed Alan, plainly showing his astonishment; "a call on a balloon five thousand feet in the air?"

"Certainly. We are going that high anyway. And we have the means of going where we like. If we go up until we strike the same, stratum of air the stranger is moving in we have our propeller and aeroplanes to check and guide ourselves. When it passes we can easily run alongside!"

"Well, if that isn't the limit!" laughed Alan. "And I suppose we'll exchange greetings and messages like ships long at sea."

"And," added Ned, "we can send some word to Major Honeywell. You can see our fast flying friend isn't going to stop around here."

The Cibola was rising fast and the two air craft were coming closer and closer. As the dirigible reached the altitude at which the free balloon was sailing Ned put the aeroplane in operation, stopped the ascent of the Cibola and then, sweeping his own car into the same direction with the other balloon he reversed the propeller and held his own craft against the breeze until the stranger swept by.

Then, throwing on the propeller again at full speed, Ned made the Cibola bound after the other craft, and in a few minutes, aided by the favoring wind, they were within hailing distance.

Ned was on the bridge, his face flushed with the novelty of the race. A mile above the earth, the two air ships came closer until, as if running on parallel tracks, they were nearly together and abreast.

"Balloon ahoy!" exclaimed Ned at last and in true maritime style.

"The Arrow of Los Angeles, bound across the continent," came the sharp answer.

"The Cibola from Clarkeville, New Mexico," called Ned in reply, "exploring. Please report us over Mount Wilson."

Then the two ships of the sky came closer. The boys could see that the Arrow was well equipped for its purpose. Two determined looking aeronauts were leaning from the heavily laden car.

"Need anything?" shouted the Arrow cordially.

"In good shape," answered Ned, "but a little short on provisions."

"Plenty here," came quickly from the Arrow, "glad to exchange fifty-pound emergency rations for ballast."

"All right," responded Ned, "stand by to make a line fast."

Alan, at the engine, brought the air ship up as skillfully as a pilot might a vessel, and as the two cars almost touched Ned passed the end of his drag rope, and the occupants of the Arrow with a quick turn made her basket fast to the bridge of the Cibola. There were handshakes, mutual congratulations and quick explanations. The Arrow, the property of a wealthy amateur balloonist, was attempting to sail, from the Pacific to the Atlantic and was, so far, beating the best calculation of her owner. In reaching the desired height that morning, however, much ballast had been used and the possibility of a renewed supply was jumped at.

"These extra provisions were packed with the idea of possibly using them as ballast and we don't really need them. And, so," they explained to the boys, "if you do you had better take them and give us sand."

The exchange was quickly made, and then, having stored their new food supply safely on the bridge, they said hasty farewells.

Ned had scribbled this note on a page from his note book: "Major Baldwin Honeywell, Annex, Chicago. By courtesy of Balloon Arrow. Bourke, escort, killed by Indians. Search begins at once. Camp established on plateau, second range Tunit Chas Mountains, thirty miles due east Wilson's Peak. Greetings. Written 5,600 feet above San Juan River, New Mexico. Ned Napier and Alan Hope."

The case of provisions weighed a trifle more than the ballast given in exchange, and as the line holding the two cars together was cast off the Cibola sank slowly below the level of the Arrow. Then, as the Cibola's engines began to push the car ahead in a wide turning circle, Ned called up to the disappearing Arrow:

"Great country, this New Mexico, where you can buy food with sand. Good-bye and success to you!"

The answer was lost in space as the ships parted.

"And now," said Ned, after lashing the now case of provisions to the bridge netting, "we've wasted some more precious time. Do you still think we had better lose a night at Camp Eagle? We have all the fuel we can carry."

Alan saw what was in the wind.

"We have extra provisions, water and gasoline. My own judgment is we had better make at once for our starting point."

"I guess you are right," answered Alan after long thought; "I don't know what is to be gained by the trouble of a landing at the camp by the lake."

"Nothing but that hot supper," smiled Ned, "and we'll have to put that off a few days, I think."

"All right," agreed Alan, "set your course and with luck we'll do a little treasure hunting before dark."

This being settled, the prow of the Cibola was pointed a little west of northwest, and, dropping to a lower stratum to escape the lively eastern breeze at the higher altitude, the boys started at last directly for the and arid broken mountains of Northwestern Arizona.

This region, bordering on the great sand dunes lying beyond the Chelly River, was to be the beginning point of their arduous and momentous search. From that place to a point nearly one hundred miles to the southeast lay the secret fastnesses of mountain, canyon and mesa wherein, somewhere, according to the Spanish soldier's record, was the secret city of a dead race and the treasure that had brought Ned and Alan half way across a continent.

What such a search meant one glance at the monotonous and unending rock easily told. On foot, only the compass could lead a man forward in such wilderness of abrupt heights and winding chasms. As the boys meant to manage it, the attempt had possibilities, but it might mean days of drifting, of watching, of doubling back and forth over every possible site. And that was now their task.

So far as they could, Ned and Alan meant to begin at the extreme northern end of this unknown land and, sailing back and forth from east to west, cover every foot of exposed ground with their powerful glasses.

Both boys had long since agreed in this conclusion: the "city" meant no more than one large structure similar to but on a larger scale than those found in the Chaco Canyon at the extreme southern end of the Tunit Chas Mountains. This would be indicated now by nothing more than rectangular lines of wall stones, probably in piles, outlining the shape of the "city" or palace. Prominent among these ruins should be the more elevated temple, the object of their search. And beneath this should be found the underground "khivas" or religious chambers.

That this "city" was secret or hidden was proof to Ned and Alan and Major Honeywell that it would not occupy a prominent place such as an exposed plateau or a high level mesa. Only one other location was left, the abutting shelf of some canyon. And the young navigators had pictured to themselves that, if this should prove to be the location, the shelf would be so elevated as not to be visible from the front or below and that it would be concealed from above by an extended and overhanging cliff.

"Look for it as you would look for a bird's nest in the cliff," suggested Ned. And that was the plan of search.

It was nearly three o'clock when the boys had bade farewell to the Arrow and about half past five when the Cibola sailed over the second ridge of the Tunit Chas. But the course was far to the north and there was naturally no sign of the waterfall plateau or Camp Eagle. For a time they thought of passing over the camp and dropping a message, but this pleasant idea was given up.

"Although," as Alan expressed it, "one of Elmer's hot suppers and a soft bed of balsam boughs to-night wouldn't be bad."

Ned thought of the four nights of hard floor and agreed, but he said:

"You'll have to forget soft beds if we're ever going to find Cibola. We'll come down to-night, though, and make a camp of our own with a fire and a pot of coffee, and at daybreak we'll be off."

The boys had taken a light luncheon just after starting on the return trip, and now, soaring over the Tunit Chas again, they began to be anxious for night and supper.

At seven o'clock the peaks and ridges below them had begun to drop into foothills and as the great sandy deserts of distant Utah and nearer by Arizona came before their eyes the boys decided that it was time to anchor for the night. They were sailing over the eastern slope of the last low ranges of hills, barren of trees or vegetation. The aeroplanes being given the proper depression, the Cibola shot earthward and then, the propeller coming to a pause, floated gently along above the jumble of rocks. Making fast the anchor in a ragged pile of these the boys soon drew the Cibola to the ground and lashed her fore and aft to heavy boulders.

The firm ground felt delicious to the tired boys and they refreshed themselves with a brisk race over the open space between the rock piles. Then came Alan's camp fire, a hot supper and preparations for a good night's rest. There were no pine needles of balsam boughs, but fatigue made a fine mattress, and it was not long before the tired boys, rolled up in their blankets, were fast asleep on the soft sand.

"I hope," said Ned drowsily as they were dropping off to sleep, "that we won't have any Jack Jellups or thieving Utes to-night. My nerves need rest."

Then the boys got eight good hours of health and strength giving sleep in the tonic air of the Arizona Mountains.

CHAPTER XXVI - THE SECRET TUNNEL IN THE MESA
At five o'clock Ned and Alan were astir. With regrets that they were not at Camp Eagle for a plunge in the cool mountain lake, they prepared another hot meal, ate it, and boarded the Cibola.

The balloon had now been inflated thirty-eight hours and was noticeably showing the loss of its gas. While the top of the bag was yet round and firm in the heat of the sun the lower sides had become a trifle flabby as the cool evening had come on. Up to this time all records for balloon flight had been broken a fact due to the renewed buoyancy caused each day by the hot, Southwestern Sun. And, exploration in and quick ascent from the canyons before them would before long call for the use of ballast. The boys agreed that the time had arrived to utilize their liquid hydrogen. The shrinkage that night had been quite perceptible.

They regretted that but two-thirds of this remained—about eleven cubic feet. This when reconverted meant nearly twelve thousand cubic feet of new gas at their present altitude. As the work of converting the gas involved care, preparation for it was made before the Cibola was cut loose.

The reconverter, a reduced inversion of the apparatus used in making liquid air, was made ready. When the muffled explosions and the heat of the tubes told the boys that the reconverter was working perfectly and pumping new and needed gas into the shrunken Cibola's long bag, the lashings were loosed and once more the faithful dirigible mounted skyward.

With Major Honeywell's map of the region spread out on the deck of the bridge and the binoculars in hand Ned began the long anticipated search for the lost city.

All day the process of turning the liquid hydrogen back into buoyant gas went on. And all day the Cibola wound her devious course over the peaks and chasms beneath. By night half the hydrogen jars were empty and Ned and Alan saw the evening close in on them without a sign of the object of their search. When darkness stopped further work the balloon was brought to earth and camp made again.

The following day, as uneventful as the first, gave no indication of the secret city. The rest of the liquid hydrogen was transformed into gas. The sun seemed to enfold the craft in a fiery embrace. When camp was made again that night the Cibola had been afloat eighty hours.

"I think she is good for another forty-eight hours," said Ned that night. "If we find nothing in two more days we'll have our choice of going out on foot or of quitting in time to pick up Elmer and Bob and make a dash to civilization. What do you say?"

"I don't know," replied Alan, "I'd hate to give up as long as we can fly. I think the boys can care for themselves. Let's stick to it. We have provisions and there is water in some places."

"Well," answered Ned, "we'll have two more days time in which to decide."

The next morning the Cibola showed plainly that her gas was rapidly escaping. New life was given to the balloon by casting overboard some empty hydrogen casks. The fourth day broke hotter than ever. In all the wilderness examined by the tired and strained eyes of the searchers, not a human being had been seen—not even a wandering Navajo. This day they began the search with renewed vigor, but with the same monotonous result—miles of hopelessly desert rock and sand beneath them, with a little vegetation now and then, but so sign of Indian remains.

At noon Ned said:

"If we were not in a balloon with a compass and sextant I should say we were lost. And if Indians ever lived and died hereabouts they certainly left so signs of their bones."

By six O'clock, with the sun gratefully low, Alan expressed discouragement.

"To-morrow at this time," he said, "if we see no indication of the old palace or city or whatever it was—if it ever was—I think I'll vote to try to find Camp Eagle and get out."

"We'll see to-morrow," answered Ned stoutly.

That night at dark, a landing was made on the ledge of a point of land ending in a rounded cliff pointing south, selected because the place was open to the breeze and cool. The Cibola had approached the height from the west, and the boys believed that the promontory projected from yet higher ground beyond. On those portions of the cliff that they could see there was neither shelf nor projection of any kind. The walls rose almost like cut stone and were apparently about three hundred feet high. As the Cibola was about to descend, Alan, who was taking a last survey from the bridge, called Ned's attention to the fact that even the far side of the supposed promontory was separated from the mountains beyond, and that a chasm at least a half mile wide separated the two heights.

"It's a mesa," replied Ned with renewed enthusiasm, "and it will be a good thing to look over it to-morrow. These high and almost unapproachable islands of rock were favorite dwelling places for the Indians."

"But a temple up here wouldn't be a secret very long," replied Alan. "We've seen this point all afternoon. It's prominent enough."

"That's so," answered Ned, "but we are here, so let's make a landing and eat, and dream over it."

The balloon had now lost so much gas that a landing was easy, and, tired with four days' profitless search and its strain, the young aeronauts were soon beyond even dreams.

It was with no small alarm that the boys saw, when they awoke with the first rays of the sun, that the car of the Cibola, which had been anchored fore and aft to heaped up rocks during the night, was now resting on the ground. Gas, was rapidly escaping. But fortunately the aeroplanes and propeller had been left properly in a horizontal position and no damage had been done.

The boys knew that by throwing over enough ballast and stores the Cibola could be made good for one more flight, but that probably it would be the last. Therefore, the inevitable seemed forced upon them. They would fortify themselves with a good breakfast, look over the mesa, make one more circling flight and then attempt to find Camp Eagle. While Alan made haste to prepare breakfast, Ned determined first on an examination of the mesa point by daylight.

The rock had a top area of perhaps forty or fifty acres. It had a rolling surface and was coated with a carpet of dusty sand, except in the northwest corner. The northern end of the mesa, Ned could see, widened and ended in a sharp rise almost wall-like in form. At the western end this wall-like elevation turned the corner and extended south a short distance, finally dropping down to the general level of the mesa. In this protected comer grew a strange grove of gnarled and twisted pines, ill nourished and apparently very old. Between this comer of the mesa and the sharper promontory whereon the Cibola had come to anchor, was a wide, sandy, barren depression.

The narrow portion of the rocky island where the boys had made camp drew in abruptly to make the point that marked the southern end of the mesa. Ned turned first toward the point.

When he had advanced, making his way slightly upward all the time, to where the narrow mesa was not over four hundred feet wide, the lad was astounded to suddenly discover a deep and narrow fissure or chasm. It was dark, with sides as abrupt as the cliffs of the mesa, and too wide to jump across. A cold air was already rising from the opening into the warmer atmosphere above.

In his astonishment Ned called to his chum.

"What surprises me," exclaimed Ned, "is the character of the opening. If it extended from cliff to cliff I should say that the same freak of nature that made this solitary island of rock also split off this end at some time. But it is closed at each end."

Alan hastened to the end of the fissure, near the side of the mesa.

"It looks to me," he said, "as if it had extended entirely across at some time and the ends walled up later."

The boys made a closer examination.

"You're right," said Ned when he discovered that each end of the rift had been filled with closely fitted rock, "and human hands did it."

Alan sprang up in excitement.

"That's the first sign we've had," he exclaimed. "Do you suppose it means anything?"

The edge of the cliff was so abrupt that the boys had to lie down to look over in safety.

"It does," Ned answered. "The reason you can't see that chasm from below or from in front is because the face of it is walled up. And it is walled so skillfully that you can't detect it from even a short distance."

"That's to hide something," quickly replied Alan, "but I don't see— "

Ned was standing on top of the short filled-in portion of the chasm.

"Look!" he exclaimed, suddenly interrupting his friend. "These stones are steps, and, they are worn!"

CHAPTER XXVII - THE TURQUOISE TEMPLE DISCOVERED
In another moment he had sprung forward and was quickly descending into the narrow, dark pit, with Alan close behind. A cave-like smell and a rapidly, cooling air greeted them. They were soon in almost complete darkness. When the walls had narrowed to but a few feet, a thin ribbon of blue sky was all that could be seen above.

The steps had come to an end. An ascending elevation began just in front of them. This they made out by the light of a match, which flickered uncertainly in the bad air. Bats dashed against the walls and every movement was followed by a cloud of dust.

"Do you feel anything?" suddenly exclaimed Alan. "Seems to me like a current of air on my feet."

Ned lit another match.

Before them they again made out an ascending slant such as they had come down. But the base of it was hollowed out in the form of a small cave. As the light went out both boys stooped to look further into this opening.

"Light!" they exclaimed almost together.

They were looking through a tunnel made, as they afterward found, in the base of the filled-in portion of the chasm. Reptiles, bats and dust were forgotten now. Plunging forward on their hands and knees, the two boys advanced without difficulty to the distant mouth of the tunnel.

It ended abruptly in the face of the mesa cliff, one hundred feet above the valley below. There was not the slightest ledge below it and the side of the mesa dropped so precipitately that access to the tunnel mouth from without seemed impossible. The possibility of a climb to that entrance to reach the mesa above was out of the question.

The boys, panting for breath, lay on the floor of the tunnel with their heads just out of the opening.

"Some one has used this place, but how did they ever get up here?" asked Alan.

"I don't know and I don't care," said Ned with excitement. "But I do know that this entrance is concealed. Why, you couldn't even see it from below—it's so small. And it was made that way for a purpose. That must mean Cibola. Let's get busy."

There were one hundred and thirty-five steps to mount, and each was about a foot and a half high. When Ned and Alan were on top of the mesa again they were out of breath and their clothes were white with dust. They were also choked, thirsty and hungry.

"Eat heartily," laughed Ned, when they began breakfast over again; "we are going to have a busy day, I hope."

"What is your theory?"

"That our treasure is right here if it is anywhere," exclaimed Ned.

Alan laughed. "The place is barren as a barn floor," he said; "I don't see any very large palace or temple hereabouts."

"I don't either. That's why I'm going to look for it—and look hard."

"And our gas slipping away at a lively rate!" interrupted Alan again.

"Let it all go," said Ned. "We know how we can get down within a hundred feet of the ground, anyway. That's some consolation."'

"First we will make a circuit of the north end," continued Ned, after breakfast, "and if nothing comes of that—no unseen hollows or new crevices—we'll try this sandy hollow, even if it is smooth as a plain."

The circuit of a fifty-acre area requires time and it was an hour before the boys had traversed the edge of the precipitous cliff. At every few yards they examined the face of the mesa for gaps or shelves, but there seemed hardly a resting place for a bird.

Tired and hot, the sun being now high above them, the young aeronauts finally reached the north-eastern corner of the mesa without finding a sign or suggestion of Indians, or even of animal remains.

Alan had thrown himself on the ground at this point for a rest, when with an exclamation Ned darted from his side. As Alan's eyes followed him he saw the cause of the exclamation. From where they stood—directly east from the ancient grove—they could see for the first time that the trees stood in a wide double semi-circle, and, directly in the center, perhaps fifteen feet in height, arose a column of masonry. It was snow white in color and glistened like glass.

There was no question about it.

The fabled Temple of Turquoise, its deep blue glaze lost in the whitening sun of three centuries, stood before them. Almost overcome with the emotion of success the two boys stood as if transfixed. Then cautiously, as if afraid the wonderful pile might dissolve itself into a dream, they moved forward.

In this protected corner of the mesa where the winds of ages had gradually deposited a thin sandy soil, the hand of man had planted two almost complete circles of trees. Therein, and generally agreeing with the record of the long dead Vasquez, were the plain outlines of a stone structure. At places, where the walls crossed, and at some of the corners, the masonry yet rose to the height of a man. And again, it fell into long irregular piles of jumbled blocks. Sifted sand filled each corner and crevice.

In the center of the ruins rose the turquoise column. From this, and in a line with the true east to where the boys stood, extended an open approach. Almost reverently Ned and Alan advanced up this walk.

It was easily seen that the structure had contained a maze of rooms—over three hundred, they afterwards discovered—and that the white column stood in a hollow square.

"It's white," almost whispered Alan.

"Yes," answered Ned; "it ought to be blue."

They were now at the foot of the column. Directly in front stood an opening or door. Bordering this was a framework of brick-like squares or tiles, black, and ornamented with white figures.

"Just like pottery," said Alan, noticing the true geometrical design and the still cruder outlines of animals.

"Look," exclaimed Ned, pointing to the top of the door.

Here, the small tiles were replaced with a large square of black tile, in the center of which shone a dull yellow radiating design.

"A symbol of the sun," explained Alan, "and of gold!" he added excitedly.

"Then it certainly is our secret city," said Ned.

As he said this he was busy with his knife, digging at the glistening white bits with which the column was coated. Finally one came off. It fell into his hand and the back of it came into view.

The two boys broke out in an exclamation of delight. The protected portion of the piece was a deep sky blue.

"The Turquoise Temple!" they both cried together. "Hurrah!"

When night came again Ned and Alan were almost too excited for rest or sleep. Nor did they taste food again until the dust of the ruins warned them temporarily to abandon their search. To walk into a treasure house that the daring adventurers of two races had overlooked for three hundred years was enough to turn the heads of any two boys.

The "Doorway of the Sun" as Alan called it, led into a chamber about fifteen feet square. The walls of this were lined with smooth clay squares of black tile, undecorated. Eight feet above the floor, which was also of clay tile and half buried under sand, rose a ceiling of arched stones. There was no opening in this, but steps on the outside of the temple and in the rear led to a chamber above, in the front of which, and also facing the sun, was another opening about two feet from the floor. In front of this window was a stone bench or altar. The meaning of it the boys did not know. This room was barren of either decoration or utensil and it was half full of the debris of what had apparently been another arched stone roof. Only the front or eastern side of the structure was coated with the precious turquoise; the other sides of the column were of plain, fairly well fitted, mortarless stone blocks.

CHAPTER XXVIII - THE COLLAPSE OF THE CIBOLA
An opening in the paved court in the rear of the Temple, half filled with drifted sand, led into a "khiva" or secret religious council chamber beneath. Herein the young adventurers discovered their wonderland and the reward for all their labors.

Hastily returning to the balloon, they procured candles and improvised scoops out of the sides of the tin emergency ration case obtained from the Arrow. Major Honeywell had warned the boys that the floors of all closed chambers of this sort were covered with the accumulated dust of ages.

The first examination of the "khiva" resulted in disappointment. The immediate impression that the boys received was one of cave-like barrenness. In the half-light only a gray monotony met the eye. Yet under this ghostlike pall, forms soon began to appear. In the center of the chamber stood what was apparently an altar. In spite of its burden of dust an elevation could be seen about eight inches high and seven feet in diameter, on which was a boxlike structure about three feet square and four feet high. On top of this was a dust-covered figure. Beyond, in the deepest gloom, the mouths of four radiating tunnels leading still further into the ground could be seen. The roof was supported by irregular round columns, apparently of wood, arranged in two circles.

Before beginning an exploration of the chamber the boys decided to ascertain the depth of the dust covering the floor, into which they had already sunk over their shoe tops. This was stifling work, for the soft powder ran back as fast as it was dug away. A half hour at least was consumed in reaching the bard surface beneath. The coating of dust was nearly three feet deep.

As Ned climbed out of the little excavation Alan held the candle down. To the astonishment of the boys a beautiful blue sheen met their gaze.

"Turquoise flooring!" shouted Ned.

It was true. The entire "khiva," so far as the boys subsequently uncovered its floor, was a crude mosaic of the most perfect turquoise, the pieces, varying in size, being laid in a lime-like cement.

A general survey of the room and its connecting tunnels showed that each radiating arm led, with about twenty feet of passageway, into a smaller room. In each of these rooms were nine column placed in a rectangle. The main chamber was circular in form, forty-eight feet in diameter, and the smaller apartments were twenty-four feet square.

Ned while at work examining the floor, suddenly ceased and rushed to one of the columns.

"You remember," he exclaimed, "the Spaniard said these columns were of gold and silver."

But in this the ancient record was wrong. The inner six supports were painted a faded yellow and the second row, twelve in number, was colored red, as the boys discovered later when they brushed and cleaned some of them. Around each of the inner columns, however, there were two metal bands about two inches wide and thirty inches apart. The lower ones were six feet from the floor. They were of heavy gold with loops or hooks extending from each side, as if festoons or connecting bands had once extended from pillar to pillar.

"Not a bad substitute!" exclaimed Ned.

The second line of twelve columns had similar rings of silver, as the boys discovered in good time. The movable contents of the room were not easily examined, as each object on the floor was buried under a mound of heavy, suffocating dust. Bats had made the place an undisturbed refuge, and the repulsive flutter of these creatures was disconcerting.

A preliminary examination of the four lateral passages and the rooms at their far end showed that these were probably store rooms, excepting the one on the east side. Here, on shelves, fixed on columns or posts similar to the colored supports in the principal chamber, were eight oblong forms. Even the dust and refuse could not disguise the nature of these—they were unmistakably mummies, the embalmed bodies of either chiefs or priests. At the head and foot of each were various dust covered receptacles and utensils.

The afternoon was too short for the boys to accomplish the removal of anything.

"I feel like a grave robber," panted Alan, soberly, as the two boys clambered out into the fresh air, finding, to their surprise, that it was already night.

"Well, I don't," said Ned. "These things are so old that they seem to belong to Time itself. I feel more like a gold miner who has at last struck a rich vein—and it's our vein."

But, as so often happens, ill luck came close on good fortune. The first glance of the young aeronauts at the camp and the Cibola was enough to chill their new happiness. The big gas bag had settled so low that it half concealed the car, which was resting flat on the ground. The buoyancy of the air ship was gone. Without more gas the Cibola could not make another flight. It was a severe blow to Ned and Alan; but they met the issue squarely.

"There is no use in worrying," said Ned, finally, when they realized the exact situation, "and we've got to make the best of it. Besides," he said, laughing, "we are not ready to go."

"That's right," replied Alan, thinking of the yet unexamined contents of the Treasure Temple, "and when we are ready I guess we'll be no worse off than Bob and Elmer. I suppose we can manage the one hundred foot descent some way."

Ned pointed to the hundreds of yards of net cordage.

"Right," exclaimed Alan, "that'll be easy—a rope ladder."

It was almost dark and the boys were covered with the penetrating grime of the long undisturbed "khiva." A meager wash up and supper and rest were in order. But Ned said:

"By morning the Cibola will be in collapse. It is a valuable machine, and it ought not be left out here on this point unprotected from the seasons. We shall probably never see it again, but while we can move it let's tow it over in front of the temple and put the bag and engine and instruments in the protected room."

It was not a difficult task. With no great effort the car was half carried and half dragged down the slope and then to the clearing in the pine grove where the boys soon made a new camp. To complete their work the big bag of the balloon was untied from the car and drawn, half inflated, into the pathway leading to the temple door. Then, with no small regret, the boys opened the escape valve, and in a few minutes the collapsed Cibola was stretched like the cast off skin of a snake along the sandy pathway, ready to be rolled up and compactly stored away.

CHAPTER XXIX - THE GOLDEN EAGLE OF THE AZTECS
In the morning the boys went at their task with renewed vigor. Inventory was first taken of the stores and provisions. There was enough food for about six days, if used with care. Of water there was a supply apparently for a little longer period. But the choking dust of the "khiva" made bathing almost a necessity, and, used in this way, even sparingly, the supply would not last over two days.

"No more baths until we go down into the valley," ordered Ned. "Cleanliness would be a comfort, but we'll have to be uncomfortable."

Permanent camp was made in the cabin of the dirigible. In arranging this all the machinery, the engine, the blower, the dynamo, the reconverter and the aeroplanes, the rudder and the propeller were unmounted, and the smaller articles made ready for storing in the temple entrance. There were four casks of gasoline left unused. As these were being carried to the temple Ned suddenly exclaimed:

"Why not rig up the engine and dynamo and use an electric light down in our cave of Mystery."

"Good," answered Alan, "and while we are at it, why not hook up the balloonet blower with the engine and get fresh air?"

The stowing away of the machinery, the packing of the gas bag and the setting up of the engine and dynamo and blower afforded plenty of work until noon; and then, while the trusty little engine was pumping volumes of good sweet air into the hot, almost suffocating chamber below ground, the boys had luncheon.

Then began the real exhumation of the long buried articles in the secret religious chamber of the almost forgotten race. As revelation succeeded revelation in the next two days the paralyzing wonder that first came to Ned and Alan was succeeded by the dullness of fatigue. At intervals of not more than an hour they came above ground for fresh air. The absence of water soon converted them into bronze-like human statues. They could feel that their lungs were becoming clogged with the almost impalpable dust. But they persevered. The prize was too rich to be abandoned because of mere physical discomfort.

By means of the wired drag rope the powerful incandescent light was carried to all the chambers. And one after another, as the blower gave the boys air and helped sweep away the clouds of dust, the remains which had lain buried for over three centuries were uncovered and brought above ground.

Of the pottery itself, vases, jars, and religious ceremonial utensils, perfect in shape and displaying ornamentation that would have delighted Major Honeywell, the excavators could take little note. After removing the twelve gold hoops or bands from the supporting columns and twenty similar silver rings from the second row of pillars, the boys penetrated the elevation in the center of the "khiva."

As the end of the blower pipe was directed against this square column, the sediment of centuries disappeared. Then the brilliantly penetrating glare of the reflected electric light fell on the elevation and both boys burst out in an exclamation of amazement.

On what had been a ceremonial dais stood the treasure of the secret city of Cibola—an image of the sacred Golden Eagle of the Aztecs. The revered bird of the Aztecs stood upright, its extended head peering east. The body of this aboriginal work of art, crude in form, was of massive silver. And to it were attached overlapping plates of gold in the similitude of feathers. The unfolded wings were also of gold. The head, beak and talons were of gold, and the eyes were two polished bits of quartz. The idol, for such no doubt it was, stood forty inches in height and weighed about three hundred pounds.

The base on which the precious eagle stood was completely covered with the deepest blue turquoise. At its foot and covering the dais were the crumbled traces of many articles of cloth, feathers, bits of wood and pottery, and the like, all, no doubt, fragments of priestly utensils of worship. The most ornate and best preserved of these was a large flat bowl covered on the inside with skillfully cut mother-of-pearl. This was still iridescently beautiful, and the more striking because its milk white exterior was unmarked by decoration.

Each mummy, when hauled into the open air and examined, gave more positive proof of the riches that had been collected in this sacred retreat. The funeral bowls placed at the feet of the bodies varied in form and material. Some of these were of plain black and white pottery, others were coated with gold, silver, or mother-of-pearl. The bowls apparently had once contained food. In all there were two golden bowls, four of silver, one of pearl and one of pottery.

Each mummy was wound with as much care as was ever bestowed on the Egyptian royal dead. The woven wrappings were coated with pitch and beneath them were colored cotton cloths, affording proof of a high civilization. The richest treasures of the dead were the breastplates and necklaces found on each. These astounded the young investigators.

These plates and beads had been strung on deer sinews, which, not having been protected by pitch, were now only lines of dust. But, lying on the breast of each there was invariably a "body scraper," (as Major Honeywell afterwards termed them) of gold, silver or mother-of-pearl. Mother-of-pearl discs were the commonest neck decoration. Of these the boys discovered four.

On three of the bodies were pierced pearl bead necklaces. On the most elaborately wrapped figure, that of a head priest or high chief, came the crowning discovery. This was a necklace of pierced amethysts. And on the breast of this figure was a flat plate of gold with sixteen radiating points, each of these terminating in a large luminous unpierced and polished amethyst.

About the waist of this shriveled figure were the remains of a jeweled belt. The foundation or back of this had dissolved into dust, but careful unwrapping of the cerements revealed the priceless ornamentation. This decoration was of alternating squares of mother-of-pearl, in each of which glistened a perfect amethyst, and of matchless turquoise squares set with great pearls.

CHAPTER XXX - A QUARTER OF A TON OF TREASURE
It was impossible for the boys even to venture an estimate on the value of the immense mine of turquoise, although they realized that the increasing scarcity of the jewel made the beautiful and unique specimens everywhere about them worth a great deal of money. Nor had they any idea of the value of the mother-of-pearl bowls, nor of the hundreds of beautiful and unique ceremonial and funeral urns and vases. Least of all, could they put even an approximate price on the amethyst and pearl necklaces. Even their most sanguine hopes of discovering the hidden city of Cibola had not led the adventurers to investigate the current prices of precious stones.

Knowing, however, what the prices of gold and silver were, they could form some estimate of the worth of this part of the treasure.

By comparison with the known weights of certain articles in the car the two boys made the following list of metal pieces discovered:

GOLD POUNDS

Twelve bands. Weight each 2 lbs. I oz. 26 Two bowls. Weight each 6 lbs 12 Two "body-scrapers." Weight each 9 oz 1 1/2 Wings, head and talons of Sacred Eagle 82 Breastplate 3 Radiating sun over entrance 12

Total, 136 1/2, or 1,638 ounces.

SILVER POUNDS

Twenty-four bands. Weight each I lb. 8 oz 40 Four bowls. Weight each 5 lbs 20 Four "body-scrapers." Weight 10 oz.. 3 1/3 Body of Sacred Eagle. Weight 218 Ninety-six miscellaneous rings, bands, anklets and wristlets, many set with mother-of-pearl and turquoise 16 1/3

Total, 297 2/3, or 3,580 ounces.

The market value of these precious metals was easily computed. The silver at sixty cents an ounce was worth $2,148. The more valuable gold, at twenty dollars an ounce, was worth $32,760. Together, the 484 pounds were worth $34,908.

"And one-third of that," said Ned with a smile—almost discernible beneath his dust—begrimed face, "is nearly $12,000. And that is $6,000 for each of us."

"But how about the amethysts and pearls?" said Alan.

"I suppose," answered Ned, "that they are worth a great deal more, but I don't know. I should think that those that have no holes in them would be very valuable."

All this figuring was intensely interesting, but the boys, as the revelation progressed, knew that they were now facing a new problem. They could not possibly carry that gold and silver, to say nothing of even a portion of the exquisite mother-of-pearl bowls or the finest samples of the turquoise. When, in the end, nearly a quarter of a ton of the metal treasure alone lay in a heap in the corner of the temple vestibule they could come to but one conclusion.

This portion of the treasure would have to be removed at another time.

"It has lain here undisturbed for over three hundred years," said Ned hopefully, though sadly, "and we'll have to take a chance that it can be left a while longer."

Sorrowfully enough Alan agreed. It was to be no easy work getting out of the wilderness, and food must be carried. That might be more precious to them than gold before they saw a railroad again. The boys agreed to take at noon the next day the exact latitude and longitude of the mesa. The latitude, on one slip of paper, was to be carried by one boy and the longitude, on another piece, was to be in the possession of the other. This was a precaution against accidental revelation of the treasure mesa.

The set jewels were removed. There were two hundred and ninety-four pierced pearls and ninety-eight pierced amethysts. Among the whole gems, eighteen magnificent pearls were extracted from the jeweled belt. Eighteen unpierced amethysts were also taken from the alternating turquoise squares of the belt and sixteen magnificent amethysts from the gold breastplate.

It was then that the sewing kit supplied by Alan's sister Mary came into service. A small piece of aluminum waterproof silk cabin covering was converted into two flat bags and in these the stones, equally divided, were enclosed and concealed under the clothing and beneath the right arm of each lad. In addition, each boy took half of the mother-of-pearl and turquoise belt plates as the finest specimens of each material.

"And to show that there is gold too," suggested Alan, "we might as well take along, these gold 'scrapers,' which won't bother us much," So these two pieces were strung on cords and suspended about the necks of the young treasure seekers.

"And to-morrow," exclaimed Ned joyfully when all this was done, "we'll get down from here and get a bath."

"Amen," added Alan earnestly.

Until it was twelve o'clock, the time to take their observation, the boys spent the next morning in last preparations and making everything shipshape. The framework of the car was left intact, but weighted by stones to prevent injury by the wind. Everything movable was stored in the entrance room of the temple, including three and one-half cans of gasoline. The engine was oiled and covered with blankets. Underneath the smoothly folded balloon, in the folds of which dry sand had been liberally sprinkled to prevent possible adhesions of the varnish, lay nearly thirty-five thousand dollars' worth of curiously wrought gold and silver. This was first completely covered with sand.

The two provision packs for the retreat to civilization had been carefully arranged. How long the journey might take the, could not estimate. They had decided to their way east, in hope of falling in with Elmer and Bob, and this meant the crossing of at least two mountain ranges and thirty miles of barren foothills to Mount Wilson. Then, if they turned south, they would traverse eighty-five miles of sandy plain in which water was infrequent.

Their own provisions were exhausted. What they now depended on was the emergency case secured from the Arrow. This supply was intended to be enough for two men for two weeks.

"It certainly ought not take us that long,"' complained Alan. "Why not leave half the supply and take a little gold?"

But Ned was obdurate. He explained that they might fall in with the other boys, and that if they did Elmer and Bob might be wholly out of supplies.

"We can come back if we get out in good shape," explained Ned, "and if we don't get out what'll be the use of a back load of gold?"

That settled it. The food packs were made up of the following supplies: Flour, 12 lbs; corn meal, 5 lbs; beans, 5 lbs; bacon, 7 1/2 lbs; rice, 5 lbs; oatmeal, 2 lbs; baking powder, 1/2 lb; coffee, I lb; tea, 1/2 lb; sugar, 5 lbs; lard, 2 1/2 lbs; salt, 1/2 lb; pepper, 1/8 lb. Each provision pack weighed twenty-one pounds. In addition there was an aluminum frying pan, a coffee pot and two aluminum plates. A water canteen, a blanket, a revolver and belt of ammunition and a knife apiece completed the equipment. Alan carried in addition the "snake bite" case, the compass and small hatchet, and Ned the money belt containing over five hundred dollars in gold.

The sealed glass tubes of matches were divided between the two boys and then, as it was noon, the sextant that Ned had been so careful to bring with them was used for the first and last time. The observation made and noted, and the record of it divided as planned, Ned and Alan were ready to begin their attempt to make their way out of the rock-bound wilderness. With provisions, water, blanket and arms each lad was carrying about thirty-five pounds.

"Would you still like a few pounds of Aztec treasure?" laughed Ned as they stood with packs adjusted.

"I should say not," retorted Alan; "I'm satisfied."

The method of lowering themselves from the hole in the face of the cliff to the ground, one hundred feet beneath, had been worked out in detail and the apparatus made in the evenings by the light of their camp fire. And early that morning Alan had carried the long rope ladder down the chasm and to the mouth of the tunnel. Now, in addition to their packs, the two boys carried between them a section of one of the pine trees, about six feet long.

As they stood, ready to leave, Ned raised his cap.

"Good bye, old Cibola," he said with moisture in his eyes, "until we meet again, if ever."

"If ever?" added Alan quickly with as much gaiety as he could summon. "You don't think we'll ever let anyone else lift that little pile?" and he pointed to the well filled entrance room of the temple.

"No," answered Ned, soberly, "if we have as good luck on the land as we had in the air."

Ned and Alan meant to reach the earth by means of a rope ladder. This they had constructed from the stout Italian hemp suspension cords of the Cibola. These ropes, each thirty feet in length, were knotted and then doubled to insure strength. For the last twenty-five feet at the bottom the landing ladder of the balloon was used. The rungs, two feet apart, were of pine from a felled tree, and were thirty-eight in number.

For anchorage, the six-foot length of tree was dragged to the mouth of the tunnel and, five feet from the opening, wedged between the floor and roof of the tunnel, slightly inclined forward. The strain on the bottom would thus only fix the supporting section more firmly in place. From the bottom of the pine shaft a loop of four of the suspension cords reached just out of the tunnel opening. To this loop the top rang of the ladder was tied, with a separate hundred-foot length of cord. After the ladder had been made firm with a running slip knot the hundred-foot length of cord was dropped to the ground.

This arrangement had been provided in order that the rope ladder might be removed after the descent. By a jerk of the cord the slip knot would be loosened and the ladder, released, would fall of its own weight. Another length of rope had been prepared, this one somewhat over a hundred feet long and also doubled for strength. This was for the lowering of the packs and other articles by one of the boys after the other had descended. To insure its free running and to prevent its wearing through on the edge of the cliff, a six inch section of the pine tree had been prepared, flattened on one side and having a wide smooth groove in the top. This, attached to a short length of rope, which was made fast with the ladder loop to the upright shaft in the tunnel, was fixed on the verge of the opening.

Finally everything had been arranged and made fast. Each of the two boys insisted that he should go down first. To solve the dispute, they cast lots and the risk of testing the rope fell to Ned. Slipping off his shoes and socks, which he hung about his neck, he sprang to the ladder. Alan hung over the edge and watched him with apprehension, but Ned, feeling his way carefully, was soon on the ground.

His shout was the signal to begin the work of lowering the packs. And down they came, one after another; provisions, revolvers, blankets, water bottles, and even the money belt, for Ned had made himself as light as possible for his descent.

At last it was Alan's turn. The last load had descended, the lowering line had been released, drawn up and stowed away. The slip knot was examined anew and then Alan followed Ned down the slender, fragile swaying rope ladder. When he had reached the ground by Ned's side and the strain was over, the boys shook hands jubilantly.

"—And now," shouted Ned with a laugh, "last chance! If you want to go back for a new load say so before it is too late."

Alan, exhausted with the climb, shook his head.

"Then stand from under," cried Ned.

As he jerked the slip knot cord the boys sprang aside and the long ladder, wriggling, crashed at their feet.

The only means of reaching the towering elevation had been removed and the only visible sign of their brief occupancy of the secret mesa had been destroyed.

CHAPTER XXXI - AN ADVENTURE WITH THE NAVAJOS
Three days later, Ned Napier and Alan Hope, worn and almost exhausted with the steady climb and descent of countless rocky heights, made their camp for the night at the foot of a rugged slope. Their shoes were torn so that a protection of rags was necessary. The hot and pitiless sun had seemingly dried up their boyish spirits. Silent with fatigue, having plodded steadily forward since sunrise, they threw themselves on the sand.

The young adventurers were headed straight for the east. And still the last range of mountains was beyond them. Led by the compass, they held to their course, sometimes passing miles out of their path to avoid some inaccessible mesa, but more often scaling ragged and tiresome heights.

Eating had now become a matter of form and necessity. There was no longer the keen joy in making camp. During the three days the boys had seen no living object except birds, rabbits, many deer and two bears, all of which they had left unmolested in their eagerness to press forward. But at noon on this day Alan, having occasion to glance backwards, was positive that he saw a human head. Whether white man or Indian he could not determine. The incident gave the lads no little, concern, but as no further sign of a human being was seen that day they finally forgot the matter.

That night, after making tea and taking a little more pains than usual with their supper in an effort to revive their spirits as well as their tired bodies, Ned and Alan spread their blankets at the edge of a pine grove. Almost before it was dark they were both sound asleep.

Some hours later Alan awoke with the instant consciousness of an unusual sound. Motionless and straining his ears, he heard deep breathing just behind him. A new moon was just sinking below the buttes on the far side of the little valley in which they had stopped for rest, but under the pines the shadows were deep. He knew that danger was near and he did not move. In another moment he felt a soft hand on his waist, as swift and as silent as a snake, and he knew that the hand was extracting his revolver.

Then, from his half-opened eyes, he saw a figure crouching over his chum just opposite. Some one no doubt was also removing Ned's weapon. Then there was the pressure of stealthy footsteps on the pine needles and Alan moved his head until he could see two indistinct forms moving from the shadows of the timber across the open space to the dying embers of their little fire. There he could easily discern five or six figures. He was about to put his hand on Ned's face to awaken him gently when he saw the entire group coming directly toward their sleeping place. Their movements now revealed plainly that they were Indians.

With cold beads of perspiration covering his body Alan again pretended sleep. It was now apparent that they had been followed, and, no doubt, by Navajos. Perhaps this was the end of their toilsome retreat. With visions of death presenting themselves, he wondered again whether he ought to arouse Ned. Then he realized the futility of such action. As the moccasined feet drew near Alan could read death in each approaching sound. But at the edge of the trees there was another pause, and then he knew that the Indians had scattered.

Straining every muscle in an effort to breathe naturally, like one asleep, the boy counted the seconds while he waited for the clutch of a savage hand. And as the moment passed and the attack did not come he tried to speculate on what the strangers were doing. A guttural half exclamation soon allowed him a quick breath of temporary relief. The Indians were only after their supplies.

The savages had found the half-concealed packs of the two boys. Alan knew this by the location of the sounds that now came to him, and then, as the prowlers withdrew again into the open and the faint moonlight, it could be seen that they were bearing all the belongings of the two lads. For perhaps ten minutes Alan lay without moving and watched the Indians. He could make out that they were hastily looking over the packs and dividing what yet remained among themselves. Then ponies were led to the place of the camp fire and the members of the band quickly threw themselves on their animals and disappeared into the night.

Almost paralyzed with the knowledge of what this meant Alan now softly put his hand on Ned's face:

"Are you awake?" came instantly from Ned.

"Are you?" retorted Alan in surprise.

"Yes," whispered Ned, "I saw it all. But I didn't move, because I was afraid of arousing you."

"Here, too," exclaimed Alan. "Did you feel them take your revolver?"

Ned's band flew to his belt.

"Is yours gone too? I saw them when they came up from the fire. But you did right to keep still. If we had moved I expect we'd have had our throats cut."

"That was one of them I saw to-day," added Alan, "and I guess we're lucky to be alive."

"Yes," added Ned rising to his feet, "we are. They are satisfied, I suppose, to let us starve."

The prospect was a trying one. If the range behind them was the one they hoped it was, there was only one more valley between its summit and the outer ridge of the Tunit Chas. If they could reach this ridge they believed they might see Mount Wilson's peak. But even that meant another thirty miles to the scene of the attack on Buck's camp on the banks of the Chusco. And from that place it was eighty-five miles to a railroad and help!

The boys sat in the edge of the pines as the new moon disappeared, leaving them in utter darkness, and tried desperately to encourage each other. Both had the grit to set themselves stoutly to the apparently hopeless task. Without food or firearms and possibly without water, they knew they would find the task gigantic. But nothing was to be gained by waiting for starvation and death in the wilderness, and their decision was to do what they could, to try the almost impossible, and if they failed to fail with their faces toward the east.

"Why not start now?" urged Alan. "Let's use what strength we have."

But Ned showed him the folly of this.

"A night's rest will enable us to make better time to-morrow. And besides, we can't make headway when we can't follow the compass."

Retiring a little further into the woods the boys composed themselves again and before long were once more fast asleep.

CHAPTER XXXII - ALAN SUCCUMBS TO EXHAUSTION
The boys were up at dawn. Not an article had the marauders left but the two water canteens which had fortunately been left hanging from the low branches of a pine. It was useless to look for more—there was nothing more to be found.

"Anyway," laughed Ned, "it leaves us in light marching order and we can make better time. I'm glad we had a good supper."

As no breakfast was in sight the two boys filled the water bottles at the creek in the valley, and at five o'clock, taking their bearings due east, Ned and Alan struck upwards through the pine woods. It was a not unpleasant climb while the boys were fresh, but as the slope grew more precipitous the work began to tell. At one o'clock the crest was reached.

"How would you like a piece of broiled bacon, some pancakes and a cup of coffee, Ned?" asked Alan as they paused to rest.

"In the middle of the day and on the top of a mountain I always prefer plain water," laughed Ned in reply. "Here's to you!"

With a big drink from the lukewarm canteens the boys did not pause long.

"To-night," continued Ned, "we ought to sleep high up in the foothills over there."

With that inspiration the sore-footed and jaded lads made good time going down the slope. Then another rivulet was encountered, in which they bathed and by which they rested a spell. Alan would have been glad to pass the night here, but Ned urged him on, and as night fell again the hungry, exhausted boys found themselves far up on the new slope. Then they slept again, restlessly and on the rocky ground, for they had abandoned their blankets.

The boys did not wait for daylight. In the half dawn they were afoot.

"Take another hitch in your belt, chum, and don't think of the Placida." laughed Ned. "We'll make it all right, somehow."

Stiff in limb, their feet twitching with the pain of blisters, Ned and Alan toiled slowly through the last of the pines and out into the rocky higher slopes of the range. It was like climbing an upright wall, Alan said, but the pain of going on was less than the despair of giving up. A little after six o'clock Ned, ahead, pulled himself breathless to the highest point.

Alan stopped a little below and waited in anxiety. Before he could ask whether it was the last ridge, Ned's voice broke out into a shout.

"Come on, old man, we're all right. There's old Wilson, the grandest mountain peak in the world. Hurrah for Mount Wilson!"

But there was no echo to his exclamation. Poor Alan, succumbing to pain and exhaustion, had sunk insensible to the ground. In another moment Ned was at his chum's side. Forcing some water between Alan's lips and bathing his face with some more of the precious liquid, Ned soon brought him back to consciousness. Alan sprang up in chagrin, and with tears in his eyes insisted that he had only stumbled and fallen. But Ned knew the truth. His friend's bright eyes and feverish skin told that his condition was grave. The unseen tears came to Ned's eyes, for it was at least thirty miles to more water and the plains. And should they even reach the Chusco, he could see only death in the desert.

"You'll feel better in the cool of the woods down there," said Ned gently, "and maybe we can kill a rabbit. Hurrah, come on, Alan! Brace up. It's all down hill, now. Here's for the woods and broiled rabbit!"

In a new spurt of life another start was made and the two chums set out down the slope. In one of Ned's hands was a rock. It was to be the death warrant of any small animal, and his eyes were busy examining each sheltered rocky nook and bush. Suddenly a feverish hand caught his.

"Look," whispered Alan.

Ned's eyes followed his chum's gaze.

It was a spiral of thin smoke in the trees below.

With a shout, Ned sprang forward. Then he turned. Alan was standing still. Ned's heart grew cold:

"See the smoke," Alan was repeating, "see the nice smoke. Maybe it's a house on fire."

His friend was delirious. Ned flew to his side once more and again his touch revived the exhausted boy. Almost five days of wandering and the exhausting toil on the mesa had proved too much for the more delicate Alan, and Ned realized with sickening horror that the situation was critical.

"I'm all right, Ned," answered Alan when his chum was once more with him; "just a little lightheaded. But that's all."

What was to be done? The smoke might be that of a forest fire. And it might mean Indians. But even an enemy is welcome when starvation and death confronts one. Almost at the end of his own resources, the determined Ned forced himself into a last effort. He used no words of persuasion, for Alan allowed Ned to take his hand, and thus, silently and slowly, the two moved forward again. Perhaps another half mile was made between rocks and down gullies and then Alan exclaimed pitifully:

"It's no use, Ned, I can't, I can't. My feet." Burying his fevered face in his hands, the boy wept, partly in pain and partly because he knew that he was holding back his chum.

At such periods Ned Napier was at his best. With kind words he sought to encourage his friend. He used the little water left to bathe Alan's face, and the last of his shirt in binding anew his friend's bleeding feet. He tried to joke and speculated on the possibilities of the smoke beyond them, but it was without avail. Poor Alan could not rise again. The fever of exhaustion was on him and with a last appeal to Ned to leave him the boy threw himself on the ground and fainted away.

There was no doubt now as to what was to be done. Unless he could bring help to his friend in a short time Ned knew it would mean death. And that meant death for both, for young Napier would never abandon his friend. Like a drunken man Ned turned and stumbled forward.

CHAPTER XXXIII - A FORLORN DASH FOR HELP
An hour later Alan Hope, carried by the faithful Elmer Grissom and the jovial Bob Russell, was laid gently on a blanket by the fire whose smoke had attracted the attention of the ragged, worn wanderers. Not until the sun had set did the exhausted lad open his eyes again. But water and food had been forced through his lips and when reason came back strength was not far behind.

Ned sat by his chum's side all day, bathing his face and making him as comfortable as possible; from Elmer's medicine packet. A few mouthfuls of food had sufficed Ned. But that night, when Alan came again to his senses, the four boys held a thanksgiving about a cheerful fire and ate together. But it was no banquet.

What had happened was soon repeated to the weak but happy Alan. Elmer and Bob had waited and watched for ten days, using their stores sparingly and ready always for the return of Ned and Alan. Two days they had seen the Cibola a speck in the sky far to the west, and had watched it from the little waterfall on the edge of the plateau. Then it disappeared and they never saw it again. This was three days after the boys departed from Camp Eagle.

Husbanding their provisions as well as they could, they at last decided to start on their return to the outside world.

This was two days before. The tent and the heavier articles were hidden in a cache. Their food had been reduced to a meager quantity. They had two pounds of bacon, six pounds of flour, two ounces of tea and a little over a pound of beans. In addition they had a half dozen bouillon tablets, a little salt, pepper and sugar, and a complete and unopened medicine packet in which were quinine, adhesive plaster, cotton, bandages, morphine, and other needed and compact drugs. With this light pack each boy had a rifle and a revolver, a few cooking utensils and a blanket.

Elmer had his own water bottle, and Bob improvised two out of the empty baking powder can and a lard pail.

Thus equipped, Camp Eagle was abandoned, and led by their compass Elmer and Bob had set out bravely for Mount Wilson and the Chusco. But it was with no small regret that they made their way up the long slope behind them and then across the valley beyond. But, fresh and strong of limb, they pushed forward and with Mount Wilson as a landmark made camp on the second night in the timber on the slope of the outer range.

Never wholly despairing of meeting Ned and Alan again, the two boys were frugal both of their strength and their stores. The food they carried would have been sufficient for a healthy man for perhaps a week. They could not count on reaching civilization again within that time, even with good luck. That meant half rations at the best. But if accidents came and delay even half rations would be cut down. So, that night, in camp, there was no feasting. A little tea, and a cake of dough apiece made their supper; and then they slept.

In the morning as they were about to breakfast and be off again Bob caught sight of a deer. A little jerked venison would not come amiss, he thought, and as the ammunition was plentiful he darted through the woods in pursuit. The fact that Bob was a poor hunter probably saved Alan's life. He was gone an hour and a half and when he returned it was after seven o'clock.

The two boys had just extinguished their fire and were about to shoulder their packs when a well-known but strained call arrested them.

"Camp ahoy?"

It was their leader, Ned Napier, his cheeks sunken, and his body swaying from weakness, but cheery as of old, advancing slowly through the trees.

Food and a night's rest restored Ned's strength. "And now, my friends," said he in the morning, "these bandages and a little food and good companionship have worked wonders. We are all ourselves again. But we can't stay here, pleasant—as it is. Alan ought not to travel for another day and then he ought to have some husky attendant. Bob, you are nominated for that job. Elmer and I will take a few pinches of tea, the soup tablets, one revolver and a rifle and—"

"And what?" exclaimed Alan, suspicious of Ned's suggestion.

"And," continued Ned, "We'll just dash on ahead and bring you some help."

"No, siree," shouted Alan. "Do you think get back to Clarkeville, one hundred and fifteen miles or more, on six soup tablets? And for me? If you think you ought to go, all right. But you'll take half of the food."

"Or more," interrupted Bob, "give us a little flour and salt and some matches. I reckon I can get a deer before night."

But Ned convinced them in the end that he was right. He argued that each mile he and Elmer made in advance was nearer help. Alan must advance slowly.

"All you've got to do," he explained to Bob and Alan, "is to reach the Chusco, where Elmer camped, and take care of yourselves for seven or eight days. And we'll be there to help you, unless something happens. You won't have much to eat but you'll have water and you have ammunition."

And at seven o'clock that morning they parted. Just before the farewells Alan called Ned to one side and said:

"Hadn't you better take my bag?" indicating the jewel case under his arm.

"Why?" answered Ned.

"Well, you know we may never see each other again."

Ned took his chum's hand.

"Alan," he said, "we were not born to lose ourselves in the woods, much less to die there. We'll meet again all right. Don't you have any fears on that point. But if we shouldn't, I won't care for amethysts or pearls. If I don't see you again it'll be because I'm beyond the need of those things."

There were handshakes and cheering, good wishes, and the relief section was off.

"Elmer," said Alan, after the two had been trailing through the trees Indian fashion some time, "it is daylight at four o'clock and dark at seven—that's fifteen hours. Can you walk two miles an hour?"

"Sho'ly," smiled Elmer, showing his white teeth.

"Well, that's thirty miles a day. If we could do that for four days we'd be in Clarkeville!"

"Claikeville in fo' days it am den," echoed Elmer, "or bust."

"We've got six soup tablets. If we dine on one at ten o'clock in the morning and one at seven o'clock in the evening we'll have regular meals for three days."

"And de las' day we won't need none, we'll be in such a hurry," added the colored boy, happy again in Ned's company.

That was the spirit in which the expedition started. Late that afternoon they emerged from the timber and were on the sandy foothills where progress was faster. Ned's feet bothered him and he was in constant pain, but the adhesive plaster and cotton had been of the greatest help. There was no pause. The first day's schedule he was determined to make and at about eight o'clock the relief expedition gave a shout. The Chusco lay before them.

A little fire, some tea and bouillon—made in the pan after the tea was consumed—and the two boys found a bed on the soft sand with no covering but the deep Mexican sky. At dawn they were up and away after a bath in the muddy river. Elmer was now the guide and he readily picked up Buck's old wagon trail. Sharp at ten o'clock a halt was made for breakfast, bouillon now without tea. Ned, his face a little more sunken and his legs a little more unsteady than the day before, was sitting on the ground resting his burning feet, when Elmer suddenly touched him on the shoulder, set the soup pan quickly on the sand and drew his revolver.

Far down the trail a horseman was approaching. Behind him in the distance followed a wagon. What did this mean?

"Well, whoever it is, we'll have the soup," said Ned.

This consumed, Ned and his friend started forward.

"If it's good luck we'll meet it sooner this way," said Ned, "if it's bad we'll know the worst quicker."

But it was good luck. The rider soon galloped up and swung his wide hat in the air. It was Curt Bradley, the mayor of Clarkeville.

CHAPTER XXXIV - THE RESCUE
They told Ned afterwards that he keeled over in the sand and fainted dead away, but he always insisted that he didn't faint, that he knew everything that was going on. Yet he did not hear a word of the long story told by Elmer. When he roused himself he was lying in the shade of the big freight wagon and a couple of cowboys were getting breakfast ready.

Then Mayor Bradley explained his presence in that mysterious way in which bad news always travels. Friendly Indians had sent him word of the attack on Buck's outfit and of the death of the veteran plainsman. This news had just reached Clarkeville and Mayor Bradley had at once set out to find the body if possible, and assist those who escaped.

Of course all speed was made toward the foothills and that evening Alan and Bob, the former only a shadow of the lively youngster who had left Clarkeville but two weeks before, were found and rescued. That night there was a new camp on the Chusco and meat and hot bread. The only shadow to dim the happiness of the rescued boys was the recollection of the murdered Buck.

The return to Clarkeville was made by easy stages in four days, and even Alan was nearly his old self when that town was reached. One night's rest in real beds, with fresh linen from the baggage they had left behind them, and baths, removed the traces of privation and suffering. There was little more to detain Ned and Alan.

A telegram was dispatched to Major Honeywell at Kansas City, where the boys and their patrons had agreed to meet. Then Ned's tool chest was forwarded by freight to Chicago. In company with Mayor Bradley Ned and Alan visited Mrs. Bourke, Buck's widow. Retaining enough to cover the costs of transportation to Kansas City he gave the widow what remained of his funds, nearly five hundred dollars, and all the heavy stores remaining in the corral.

At midnight of that day four wide-awake and alert boys, neatly clad in summer suits, boarded the local train bound east for Albuquerque. The last hand they shook was that of Mayor Bradley.

"Mr. Mayor," said Ned as he parted from his friend, "I'm sorry I can't tell you why we were here, or what we were doing. But you were our friend and we'll never forget you. Some day I'm going to show you how highly we regard you. And some day I hope I'll be able to tell you what our mission was."

Three days later the quartette of boys sprang from the Limited in the Union depot at Kansas City. The parting had come. None of the boys knew what that meant until the last moment.

"'Ned," said Bob Russell, once again in the field of his profession, "I've had many a strange assignment in my work and I expect to have many another, but I'll never have one like this. I've got the story of my life, but I haven't got yours. If the time ever comes when I can write it, when you are free to tell it, just remember your best friend, Bob Russell, reporter, Kansas City Comet."

"Bob," answered Ned wringing his hand, "you have missed a good story. I'm sorry. It wasn't because you were not a good reporter. It was just our good luck. But if things work out the way I hope, I'm going to give you something better than a good story."

"And," broke in Alan, "just want to say this: if chance ever throws adventures my way again I hope that the companions I share it with will always include Bob Russell."

The details of how Ned and Alan, just one day late, kept their engagement with major Honeywell and Senor' Oje in the Coates House, and of the almost unbelievable report they made and the rich evidence of its genuineness that they submitted do not really belong in an account of the flight of the Cibola. Two things were done at once, however. A handsome gold watch was purchased and sent to Mayor Bradley with the compliments of Ned and Alan, and Senor Oje forwarded an additional check for a thousand dollars to Buck's widow.

The report on the value of the stones carried from the treasure temple by the two boys was such that Senor Oje gave them his check for $25,000. Out of this each boy contributed part of his share toward a sum sufficient to give Elmer a business education. Finally the two boys bought a draft for a thousand dollars, payable to Robert Russell. With it went this note: "Please accept this as some slight compensation for the story you did not get."

But in good time Bob Russell did get his story. For, otherwise, this narrative would never have been written.

How it came about that Bob got his story; how the treasure left in the Turquoise Temple was finally lifted; how the young aeronauts in doing it battled successfully with a maelstrom in the clouds, were driven far out over the Pacific, cast away on a derelict and finally made an escape with their "sneering idol" by aeroplane into the wilds of Mexico, is a later and more remarkable chapter in the adventures of Ned Napier and Alan Hope, to be told in "The Air-Ship Boys Adrift, or Saved by an Aeroplane."

THE END