“Suddenly I heard the Professor’s voice just as if he were right out there on the desert.”

THE RADIO BOYS
SEEK THE LOST ATLANTIS

By GERALD BRECKENRIDGE

Author of
“The Radio Boys on the Mexican Border,” “The Radio Boys with the Revenue Guards,” “The Radio Boys on Secret Service Duty,” “The Radio Boys Search for the Inca’s Treasure,” “The Radio Boys Rescue the Lost Alaska Expedition,” “The Radio Boys in Darkest Africa.”

Frontispiece

A. L. BURT COMPANY
Publishers New York

THE
RADIO BOYS SERIES

A SERIES OF STORIES FOR BOYS OF ALL AGES
By GERALD BRECKENRIDGE

The Radio Boys on the Mexican Border The Radio Boys on Secret Service Duty The Radio Boys with the Revenue Guards The Radio Boys Search for the Inca’s Treasure The Radio Boys Rescue the Lost Alaska Expedition The Radio Boys Seek the Lost Atlantis The Radio Boys In Darkest Africa

Copyright, 1923
By A. L. BURT COMPANY
Made in “U. S. A.”

PREFACE

Dear Boys:

One of the greatest, if not the greatest story of all the ages, is the legend of Atlantis. According to this legend, there existed at one time a great continent in the Atlantic Ocean not far west of the Pillars of Hercules, those two great rocks of Gibraltar in Spain and Jibel Kebir in Morocco which guard the entrance to the Mediterranean.

The legend says that this continent was the first region in which man rose from barbarism to civilization, and that in the course of ages it became a populous and mighty nation from whose shores immigrants went out to settle the shores of the Gulf of Mexico, the valley of the Mississippi, the valley of the Amazon, the Pacific coast of South America, the shores of the Mediterranean, of the Baltic, the Black Sea and the Caspian and the western coast of Europe and Africa.

From this continent, continues the legend, the first colonists penetrated western Africa clear to Egypt where they took root in the Nile valley and developed what is today conceded to be the earliest known civilization.

Many other startling statements are made in this legend. For instance, it is said that the civilizations of the Incas in Peru and the Mayas in Central America, like the civilization of Egypt, were derived from Atlantis through immigration; that the Atlanteans were the first manufacturers of iron, and that the implements of the “Bronze Age” in Europe were derived from them; that the Phoenician alphabet, parents of all European alphabets, was derived from Atlantis, bearing a startling resemblance to the alphabet of the vanished race of the Mayas in Central America, whose ancient cities are just this very day, as you can read in your papers, being unearthed; that the gods and goddesses of the ancient Greeks, the Phoenicians, the Hindus and the Scandinavians were merely the kings and queens and heroes of Atlantis, about whose real historic actions the migrating Atlanteans remembered stories which eventually went to create the mythology of their descendants.

There is much else of this sort, all culminating in the great outstanding feature of the legend which is that Atlantis was destroyed in a terrible convulsion of nature, and sank beneath the ocean with almost all its inhabitants, leaving only a few of the loftiest peaks sticking above the water, which today comprise the islands of Madeira, the Azores and the Bermudas.

From this cataclysm a few Atlanteans, it is related, escaped to neighboring shores in rafts and ships, bearing their tale of horror. And from these tales arose the legend of a great Flood or Deluge, which has survived to our own time in the Book of Genesis in the Bible and in the mythologies of all peoples of both the Old and the New Worlds.

This is the legend, then, and that for thousands of years it was regarded as a fable proves nothing.

People used to believe the legends of the buried cities of Pompeii and Herculaneum were myths. They believed so for a thousand years, before archaeologists exposed the ruins. The historian Herodotus was called “the father of liars” for a thousand years, because he wrote of the wonders of the ancient civilizations of the Nile valley and of Chaldea. But now it is known he spoke the truth.

It is so with this legend of Atlantis, of which the great Greek, Plato, has left us the most detailed account. All these thousands of years since Plato wrote his account of Atlantis, 400 years before the Birth of Christ, he has been regarded as a poetizer. But in the light of recent researches, which really are just beginning, it appears as if what he wrote was not legend but history, and as if, indeed, his story is one of the most valuable documents which have come down to us from antiquity.

Some day you must hunt up and read for yourselves a book entitled “Atlantis or the Antediluvian World.” Written by Ignatius Donnelly, it was published by Harper & Brothers in 1882. In it are collected Plato’s story of Atlantis and a wealth of evidences which go to prove, in the author’s opinion, that Atlantis did actually exist, that it was the home of the white race, the Semitic race and, perhaps, the Turanian, and that it was destroyed by a convulsion of Nature.

Since Donnelly’s book, investigation has gone further. Savants uncovered near the southern edge of the Sahara Desert about the time of the outbreak of the Great War the ruins of two great cities of an unknown civilization, believed to have been seats of a migration from Atlantis. The war, however, halted their research, and up to a recent period the investigation had not been resumed. In one of these cities, people of an unknown white strain resided in a semi-savage state. I, therefore, have made them the background for this story, and that you will like it is the hope of

THE AUTHOR.

Emerson Hill, Staten Island, N. Y. 1923.

CONTENTS

I. [Introduction.] 3 II. [A Cry for Help.] 11 III. [The Mystery at the Oasis.] 17 IV. [The Mystery Deepens.] 23 V. [Allola’s Story.] 32 VI. [The Tale of the Slave Trader.] 41 VII. [Chasing Ostriches.] 50 VIII. [Bob’s Fight Against Odds.] 58 IX. [A Puzzling Prophecy.] 67 X. [Squelched by an Ostrich.] 76 XI. [The Stranger Revives.] 85 XII. [Amrath Speaks.] 94 XIII. [Korakum Reached.] 101 XIV. [A New Radio Station.] 110 XV. [Meeting the Revolutionists.] 119 XVI. [Revolt of the Exiles.] 129 XVII. [The Fight for the Pass.] 136 XVIII. [A Dark Hour.] 147 XIX. [At Low Ebb.] 153 XX. [An Old Friend Appears.] 159 XXI. [Reunion.] 166 XXII. [Frank to the Rescue.] 176 XXIII. [The Fliers Warn Korakum.] 182 XXIV. [Into the Coliseum.] 190 XXV. [A Surprise for the Janissaries.] 199 XXVI. [The Revolutionists Succeed.] 207 XXVII. [Athensi Falls.] 213 XXVIII. [Conclusion.] 219

THE RADIO BOYS SEEK THE LOST ATLANTIS

CHAPTER I.
INTRODUCTION.

Jack Hampton wearily passed a hand across his eyes. Would they never sight the oasis at which Ali had promised they would arrive at the end of the day’s march? Even after many days of travel on camel-back, Jack had not become sufficiently accustomed to the soft-footed swaying brute to make a long day’s ride a pleasure.

And this was a long day’s ride indeed. Except for a brief halt at noon the caravan had been on the march across the lifeless sand dunes of the desert, unbroken by trees, rocks, animals or human beings, unbroken by anything, in fact, except occasional stunted bushes, since dawn. In another half hour the sun would descend, and if the promised oasis were not sighted by then, they would be forced to spend another night on the desert.

Looking back from his position at the head of the column, Jack could see Bob Temple and Frank Merrick, both mounted as was he, behind them a half dozen shuffling camels with astride each among the bundles a swarthy Arab enfolded in the inevitable jillab, from the folds of which stuck out a long-barrelled rifle, and bringing up the rear Jack’s father and Ali, his head man, both engaged in conversation.

The loop aerial rigged up on Frank’s camel caught Jack’s gaze, and his eyes brightened. He decided he would break the monotony of this desert travel by kidding his friend. And with that purpose in view, he halted his camel, to await Frank’s approach.

To himself Jack chuckled as he thought of the bewilderment and wonder which Frank had aroused amongst the camel drivers by his aerial. Attached to a light frame strapped to the camel’s hump, ground wire trailing between the animal’s feet, Frank had rigged up the set the day before upon Ali’s declaration that another day would see them at the Oasis Aiz-Or. He wanted to be in a position to receive any message which Professor Souchard, a Swiss savant, who awaited their coming, might send out. For with him Professor Souchard had a duplex radio apparatus for both sending and receiving, which the boys jointly had devised.

Many months before Professor Souchard had entered the Sahara to prepare for their coming. Not that it was his first visit to the Great Desert, however. On the contrary, twenty years of his life had been spent in poking about its endless reaches in search of the ruins of an incredibly ancient city which he had reason to believe had been founded in prehistoric times by colonists from the lost continent of Atlantis, that fabled land in the Atlantic ocean which had been the seat of all civilization and had been swallowed up in a tremendous cataclysm of Nature giving rise to the universal legends of The Flood.

Toward the end of his period of explorations, Professor Souchard had come to an oasis lying far from the few known routes, the Oasis of Aiz-Or, inhabited by a small desert tribe. From it he had glimpsed far to the southward the peaks of a mountain range. When he asked the Arabs what mountains lay there, they had replied it was the Land of Shaitun, which in English means Satan. The mountains were accursed said the Arabs, and all who ventured near were never heard of again.

At least five days’ travel intervened, said Professor Souchard’s hosts, with no water holes in the direct route, although three small springs bubbling from beneath great rocks lay somewhere between the oasis and the mountain wall. But without guides, a traveller would be unable to find them.

Nothing daunted, Professor Souchard accompanied by his faithful companion, Ben Hassim, had set out. For the mountains of Shaitun, he believed, were unknown to geographers. And the ancient Egyptian inscriptions which spoke of the great city of the past for which he had been searching through the years referred to the mountains surrounding it. Perhaps, therefore, the city he sought was within that mountain wall.

The scientist and Ben Hassim finally did manage to attain to the foot of the mountain wall, which rose unbroken from the plain, on the fifth day. But their supply of water was exhausted, they were semi-delirious. For two days they travelled along the base of the wall, seeking some pass or valley which pierced the barrier.

At length on the seventh day they came upon a stone-paved road and, scarcely able to believe the evidence of their senses, they began to follow along it into the mountains. Before proceeding far, however, they were overcome by fever and thirst and fell insensible. In this condition, they were found and rescued.

Upon recovery they found themselves amidst great stone ruins of ponderous architecture, in the midst of a luxuriant valley watered by a broad stream encircling one side, which emerged from a tunnel in the mountains and disappeared again into the mountains, not to reach the surface more.

Their rescuers were kindly men, several of whom possessed a good command of English, and they were white. But as Professor Souchard’s knowledge of English was strictly limited, they could not understand each other well.

However, while being nursed back to strength, the scientist managed to make out that his rescuers were political refugees from another city in the heart of the mountains known as Athensi, and that in this city and the plateaus surrounding it dwelt a white race of semi-civilized people ruled over by a religious Oligarchy. His rescuers were men of superior intelligence and a high state of culture and that they had travelled about the world was apparent. With his slight knowledge of English and a smattering of their tongue which he picked up, he was able to come to that conclusion.

To him it became apparent that the ruined city of Korakum, overgrown by rank jungle growth and in the midst of which the Athensian exiles cultivated little patches of garden, was the city he had been seeking. But the little he could learn of Athensi fired his imagination. Apparently, at some dim age in the past the settlers of this ruined city which had been called Korakum had withdrawn into the mountain country and built Athensi, where were palaces, temples, a vast Coliseum, above all, a great Library housing thousands of papyrus rolls.

If he could only gain access to Athensi, thought Professor Souchard, what wonders and mysteries of the ancient world, perhaps of a civilization existing in Atlantis before the Flood, would be revealed.

However, on his recovery, the exiles told him it was best for him to depart before the Athensian authorities discovered his presence, as they wished to preserve isolation from the outside world and did not want their secret discovered. Therefore, after supplying him with water and food, they started him and Ben Hassim on the return journey.

Well did Jack recall the arrival of Professor Souchard at his father’s home on Long Island with this tale. Mr. Hampton, himself an explorer and engineer of wide reputation, had been enthusiastic. He had promised the scientist, whose funds had become exhausted and who was unable to obtain backing for further explorations in war-exhausted Europe, to finance an expedition to Athensi.

With this promise, Professor Souchard had returned to Africa, and as soon as he could put his affairs in shape for prolonged absence, Mr. Hampton had followed. With him he had taken Jack and the latter’s close chums, Bob Temple and Frank Merrick.

Those of our readers familiar with the three Radio Boys by reason of following their adventures chronicled in “The Radio Boys on the Mexican Border,” “With the Revenue Guards,” “On Secret Service Duty,” “In Search of the Inca Treasure” and “Rescuing the Lost Expedition,” will realize that three more reliable young fellows in just such a situation could not be found.

Jack and Bob were both six feet tall, and Bob in addition was possessed of extraordinary strength. As for Frank, an orphan, who made his home with Bob on the Temple estate, adjoining that of the Hamptons’ near Southampton, Long Island, what he lacked in inches and girth, was made up in quickness of intellect. All three were students at Yale.

This was the way matters stood, with the party at length after its trip across the Sahara from Khartum drawing near the Oasis Aiz-Or, when Jack paused to await the approach of his comrades.

As Frank drew nearer, Jack smiled. He was thinking of the other’s comical appearance. Wrapped in the voluminous jillab which all wore as it provided greater protection against sand and heat than European clothing, Frank was crowned by a sun helmet, startling by contrast, and beneath it wore headphones clamped over his ears.

Jack was on the point of calling out some laughing remark about the latter’s vain wait for a message from Professor Souchard, when Frank’s face suddenly betrayed alarm. And with a shout he tore the headset from his ears, sending the sun helmet spinning out on the floor of the desert. Turning about, he beckoned wildly for Mr. Hampton and Ali to approach.

“What is it?” shouted Jack. “What did you hear?”

For, that Frank had received some message filling him with alarm was apparent.

Frank did not reply. His face grew pale beneath the heavy tan.

CHAPTER II.
A CRY FOR HELP.

The long rays of the setting sun, which almost touched the horizon, were flung across the desert, turning it into dazzling gold, as Mr. Hampton and Ali pushed their camels close to where the three boys had come together. The camels stood with feet spread apart, seemingly asleep. Jack and Bob, who also had drawn close, were bombarding Frank with questions and, almost inarticulate at first, he had just begun to answer when Mr. Hampton and Ali arrived.

In the background crowded the half dozen Arab guards, sensing something amiss.

“A cry for help,” Mr. Hampton heard Frank say. “The Professor was sending out an appeal to us.” Frank looked wildly around at the group. “Great Scott, can’t we do something?” he appealed.

“Calm down, Frank,” said Mr. Hampton. “Tell us about it, and then we can decide what to do.”

Frank nodded as he got a grip on his emotions.

“Well, maybe, I was a little inarticulate,” he said, with a rueful smile. “But, just think. Here I was, bumping along on my camel, and half asleep. I had the headpiece on, the phones to my ears. But I hadn’t any real idea I’d hear anything. What’s there to hear, way out here, away from all the world? The only chance was that Professor Souchard would take a notion to broadcast something for our benefit.

“Then it happened.”

He paused and looked at the others, before swallowing and resuming, with his face still pale.

“Suddenly I heard the Professor’s voice, just as if he were right out there on the desert.”

Frank pointed off into the sunset, and involuntarily, so strong was the impression created by his words, the others stared, too. All, however, in a moment restored their gaze to Frank’s face—that is, all except Ali. He continued to stare through the sun wrinkles about his sharp, dark eyes. He even raised a strong brown hand to shield his eyes from the sun. The others, however, paid him no attention. They had eyes only for Frank.

“Yes, sir,” re-iterated Frank, “it sounded as if the Professor were right out there on the desert. His voice was agonized, he was stammering as if in a frenzy of terror.

“‘If you hear me, my friends, come. This is Souchard. I have run fast to get to this little instrument. It is a raid. I think they are white. I think they are Athensians, and——’”

Dramatically, sensing the breathless interest of his auditors, Frank paused.

“And,” he said slowly, “that was all. No, not really all, for there was a sudden sharp crash that almost broke my ear drums. Then silence.”

He stopped. They continued to gaze at him. Nobody spoke for a long minute. Every face was pale. Every one of Frank’s three white auditors breathed faster. Even the Arab guards, bunched in the background, unable to understand Frank’s rapid narrative in English, still understood something was amiss. Only Ali paid no attention.

“This is terrible, Frank,” said Mr. Hampton, breaking the weighty silence. “You’re sure you could not have been mistaken?”

Frank shrugged his shoulders under the flowing burnoose such as they all wore, finding it more effectual to keep out the heat and wind-whipped sand than any European costume.

“Just as I told you, Mr. Hampton,” he said. “The Professor’s voice might have been coming from no farther than you.”

“Ah, I thought so.”

The interruption came from Ali, whose command of English was fluent. Ali was a cosmopolitan from the teeming streets of Cairo, a man of many languages.

Now he turned to Mr. Hampton, pointing off to the west, straight into the eye of the sinking sun, which now was half below the horizon.

“See,” he said.

Faintly limned against the shining disk of the sun, yet as clear as an etching, could be seen a tracery of lines that might, by active stretch of the imagination, be considered palm trees.

“The Oasis of Aiz-Or,” said Ali.

“What. That close,” cried Mr. Hampton. “Come, perhaps, we can still be in time to help. That cannot be far.”

“Five miles at least,” said Ali. “But we shall hurry.”

Turning, he addressed the Arabs in their own tongue. On each face came a gleam of determination. These were men who could be depended upon, men, moreover, not only ready but eager, in all likelihood, for a fight.

Those whose only knowledge of camels has been gleaned from circus or zoo cannot appreciate the speed of which these desert travellers are capable under urging. A clatter of grunts, punches and camel cries succeeded Ali’s command to his men, and then the caravan was under way.

Lurching this way and that, clinging for dear life, the boys and Mr. Hampton managed not only to retain their seats, but also to keep up with the others. On galloped the camels, every moment exhorted to further efforts. For a few minutes, while the sun still held, the trees of the oasis outlined against it seemed literally to hurl themselves forward, so rapid was the pace of the approaching party. Then the sun dropped out of sight, literally fell away, and was succeeded at once by darkness.

Still the party kept on without abating its pace, the long legs of the camels eating up the miles at an unbelievably rapid rate. Jack, Bob and Frank had no time for thought. They were wracked in every limb. They felt as if they were being torn apart on a torture machine. Still they clung, while their camels surged forward with the rest.

Then Ali’s voice was raised in a sharp command, and at once the other Arabs repeated certain cries to their camels which slowed them down. The boys had the good sense to realize what was wanted, and they, too, emitted the necessary grunts which seemed to constitute the language of camels.

What was the explanation of this maneuvre? Simply that Ali saw looming ahead the shadowy outlines of the tall feathered palm trees constituting the little oasis, and had no desire to charge blindly without preparation or plan.

Mr. Hampton urged his camel alongside that of Ali, and the boys also approached. Although twenty-five years older than his son, Mr. Hampton had an iron frame inured to fatigue through years of roughing it in the out-of-the-way places of the world. He was less blown as a result of the wild ride than the young fellows.

Long since he had given up any idea of keeping the boys out of danger. All were strong and cool-headed in emergencies, and he had received plenty of evidence during recent years that they could take care of themselves.

Rapidly he outlined what was to be done. Let all dismount, hobble the camels and leave them in charge of two of Ali’s men, and the balance of the party, consisting of Ali, four Arabs, the three boys and himself, nine in all, would advance afoot. In this way, the noise of their approach could be minimized. Besides, so far as four of their number were concerned, they would be better able to render a good account of themselves than if on camel back.

Ali acquiesced, the necessary commands were given, and all caused their camels to kneel while they dismounted. Then two of the number were left adjusting hobbles and guarding the animals, while the others spread out a yard apart, and began to steal forward.

CHAPTER III.
THE MYSTERY AT THE OASIS.

There is something wonderfully exhilarating in night on the open desert. The boys felt it, so did Mr. Hampton. Who knows? Perhaps Ali and the Arabs were subject to this mysterious influence, too. Shortly, a little after seven as they knew from experience, the moon would be up, silvering the plain. All now, however, was in darkness except for the dim light of the stars. Yet it was a darkness filled with caressing breezes and the feeling of beauty.

Despite the adventurous quest upon which they were embarked, despite the possibility, nay, the probability, that in a moment the night would be shattered with strife and death, each found himself yielding insensibly to this softening influence.

Suddenly the howling of a dog broke the stillness. It was a long wailing cry that made the nerves quiver and caused each member of the party to grow tense. When does a dog howl like that? Ali and the Arabs knew. The rest, with their sensitive intelligences, guessed at the meaning. That howl meant mourning over a fallen master.

As if it were a signal, other dogs joined in. A whole chorus of wailing notes effectively shattered the stillness of night.

“Forward.”

Mr. Hampton’s whisper ran along the ragged line.

Again they advanced. Still not a sound from the oasis except the howls of dogs.

The trees were closer now. Their leafy tops stood out stark against the sky. Abruptly as the seashore meets the land and ends, sand, the desert sand, met the thick grass of the oasis and ended. They were under the trees, in the grass, pushing forward.

Suddenly the moon rose, and a new weird light fell over everything, bringing out the outlines of the trees, shedding a silver radiance between their tall trunks. Jack, who was in the middle of the advancing line, paused, startled. Some huge objects, black and indefinite in shape, seemed to rise out of the ground in front of him.

What were they? He glanced hastily at the shadowy forms of his companions, whom he could discern among the trees right and left of him. Evidently, they, too, had seen, for they also had paused.

The line moved forward, Ali and the Arabs taking the initiative. Jack advanced, too. If Ali felt no alarm, certainly he was not going to exhibit any. Bob and Frank experienced similar feelings.

Then, in a moment, the nature of those strange objects became apparent. They were tents—great rambling horsehair tents of the Bedouins or desert Arabs.

The howling of the dogs continued, at no great distance now, seeming to come from the other side of the tents which were a half dozen in number. Not a light was apparent. Not a human sound fell on their ears. A low command from Ali to his Arabs, from Mr. Hampton to the boys, drew in the scattered members of the line to a central group. They were at the rear of one of the Bedouin tents, the largest of all, probably that of the tribal sheik. So close were they that they could have put out their hands and touched it.

“Strangest thing I ever saw,” muttered Mr. Hampton. “Not a soul around apparently. Out with your flashlights now, fellows, and we’ll make a search. Keep your rifles ready to deal with emergencies.”

Around to the front of the tent they stole. The trees were thinned out. In the weird glow of the moon which penetrated to this open space, everything was plain to be seen. The five tents stood a little apart from each other, clustered to one side. On the other side could be seen a well, its water gleaming in the moonlight.

Not a soul advanced to meet them. Not a light showed in any tent.

The howling of the dogs continued, Ali with a muttered word of command to his Arabs strode forward, passing the well on his left. Two of his followers went at his heels. In a moment he was among the dogs, kicking them aside, as their sharper yelping testified.

Before Mr. Hampton or any of those left behind could begin an investigation of the tents, Ali came flying back, leaving his two Arabs behind him.

“Three men dead,” he declared tersely. “One the Professor, another Ben Hassim, the third a strange white man in strange clothes.”

“I’ll have a look,” said Mr. Hampton. “In the meantime, do you investigate the tents to see if there is anybody here.”

Ali nodded and Mr. Hampton strode away, calling the boys to follow. Jack turned as he passed the well. Already Ali, flashlight in hand, was diving into the biggest of the tents, with an Arab at his heels, while another was stationed in the open space on guard. The cautious Ali was taking no chance of being surprised in the rear.

A little beyond the well, they came upon the two Arabs left in charge of the dead by Ali, while the dogs, reduced to low whines, crouched or circled at a distance. The bodies of the fallen men had been straightened. They lay on their backs, their faces upturned to the moonlight.

Mr. Hampton knelt beside the body of the Professor, placing one hand on his forehead and the other on his wrist. He shook his head sorrowfully and raised a heavy glance toward the boys.

“Dead,” he said.

No sign of life could be discovered, either, in the body of Ben Hassim.

Then that of the third man was approached. As Ali had said, he was a white man, of medium height, with a sharp, hawk-like cast of features. Even in the weird moonlight, the strangeness of the white toga-like garment, belted in at the waist with a dark heavy cord, falling to a little below the knees and leaving the legs bare, could be seen. Unlike the others, whose eyes were opened in death, this man lay with his eyes closed. Mr. Hampton bent forward with a sharp exclamation.

After making a quick examination, during which the boys whispered to each other in comment on the man’s unusual dress and appearance, Mr. Hampton got quickly to his feet.

“This man shows signs of life,” he said. “Two of you carry him back to the tents.”

He turned to the Arabs and directed them to take up Ben Hassim’s body. Then he and Jack lifted that of the Professor. Bob and Frank, bearing the body of the third man, led the way, and the little procession moved back to the clearing.

They were met by Ali, who in the short time of their absence had managed to search all the tents, and had succeeded in finding neither living nor dead except for one old woman who could hardly be said to be either. Although alive, she was half dead from fright.

CHAPTER IV.
THE MYSTERY DEEPENS.

The old woman was given in charge of the Arabs to be questioned later. She was so old that she went without a veil when in the presence of men. Reduced to a state of abject fear by events yet to be learned, she was left in charge of two Arabs placed on guard by a fire lighted in the middle of the open enclosure.

The first thing to be done was to look after the wounded man. Mr. Hampton ordered him carried into the large tent, which had been that of the Sheik Abraham, leader of this little tribe of Arabs which inhabited the Oasis Aiz-Or. Grass mats were scattered about the roomy interior, and there was a divan covered with faded rugs. On a little tabouret burned a lamp of palmolive oil which gave off a not unpleasant odor.

The boys who followed close at the heels of the Arab bearers looked around with curiosity, while the body of the wounded man was laid on the divan and Mr. Hampton began making a critical examination to determine the extent of his injuries.

Casting their flashlights into the shadows not penetrated by the feeble rays of the lamp which Ali had found and lighted, the boys discerned a heavy curtain cutting off one part of the tent. Ali came up to them.

“That is the women’s quarters,” he said. “Sheik Abraham kept his three wives there. I have never been here before. The oasis is far from all travel routes and Sheik Abraham rarely, if ever, got to the bigger desert towns and villages. But I believe he must have had three wives, for there are that many divans. Ordinarily it would be death for an unbeliever to penetrate into the women’s quarters. Sheik Abraham is a Mohammedan, of course.” He shrugged. Ali was a cosmopolite and to the boys spoke cynically of all religion. Yet they had seen him spread his prayer mat and perform his devotions night and morning with the other Arabs.

“Now,” said Ali, lifting the curtain, “you can see an Arab sheik’s selemlik without fear. Behold.”

After all, the boys were disappointed. Desultory reading about Arab sheiks had led them to expect they knew not what. Certainly, handsome tents, softly carpeted, filled with silks and perfumes, with shining lances and silver-mounted rifles. As for the selemlik, or women’s quarters, they believed such a place would be a nest of beauty.

Instead, there were three or four divans covered with rugs of faded patterns and colors, a cheap cracked mirror hanging askew on one wall of the tent, a veil thrown awry over one divan, and that was all.

Ali explained.

“The women left in haste,” he said. “Perhaps, they were carried off by the attackers. Yet they had time to bundle their clothes and take them along.”

Questions burned on the boys’ lips, and they flung them at Ali. Who had attacked? Had the whole tribe been carried off into captivity? Why had the Professor and his faithful servant, Ben Hassim, alone been killed?

Ali shook his head. They must wait until the old woman was in a state to be questioned. Perhaps, too, some information could be wrung from the lips of the wounded captive, although it was possible from his appearance that he did not speak Arabic. Never had Ali seen a man dressed as he, and a white man, too. It was all a nightmare, non-understandable. Let the boys wait until Allah sent an interpretation.

With this they had to be content. Dropping the curtain, they emerged into the main portion of the tent, finding Mr. Hampton absorbed in his attempt to revive the wounded prisoner. He looked up only long enough to explain he had been unable to find any wound from bullet, sword or spear. The man had been felled by a blow on the head. Mr. Hampton was not certain whether concussion of the brain had followed.

One of the Arabs he had despatched to bring up the two guards and the camels, left in the desert. When the caravan arrived, he would be able to get his medical and surgical supplies. Then he would see what further could be done. Possessed of a knowledge of rude surgery acquired in his out-of-the-way expeditions, Mr. Hampton was able to set broken limbs and perform minor operations, but trepanning was beyond him. Should that prove necessary, he would be helpless to aid the fallen man.

“We’re going to have a look at the Professor’s tent, Dad,” explained Jack, following his father’s remarks. “We’ll be back soon. Want to see what happened to his radio outfit, for one thing.”

Mr. Hampton nodded, and the boys trooped out at Ali’s heels. Three Arabs hunkered over the fire, for the night had turned chill, as it invariably does on the great desert. Beside them was the figure of the old woman. They were not speaking, but sat motionless, staring into the flames. The fourth man had gone for his two comrades left in charge of the camels.

Ali led the way into another tent. While the boys played their flashlights about the interior, he found and lighted an oil lamp, a shallow copper vessel with a spout that held a wick. When this was lighted, they examined the place more closely.

Smaller than Sheik Abraham’s tent, there was no dividing curtain, as here was no need for a selemlik. On two divans had slept the Professor and Ben Hassim. Everything was in wildest confusion. Three long narrow trunks were broken open and their contents of clothing, books, maps and scientific instruments were scattered about. These things the boys put aside for later inspection.

“Where was his radio?” asked Jack.

A cry from Bob answered.

“Look here, fellows,” called the big husky. “Smashed as if with an ax. A perfect ruin if ever I saw one.”

They hastened to his side. The broadcasting set which the boys had made themselves and which had been their gift to Professor Souchard, had been made to fit into one—the smallest—of the three shallow trunks. It had included a folding table on which it was to be mounted.

The table had been set up in one corner of the tent. Instead of dry cells, the current was supplied by a motor. Everything had been properly set up in the method into which the boys had drilled the Professor. The key had been screwed to the middle of the table and near the front edge. Back of it had been placed the high tension condenser, with the oscillation transformer still farther in the rear. To the left of the oscillation transformer had been placed the alternating current transformer and in front of it was the quenched gap.

Even though the table and its contents had been smashed, as if with an ax, this much could be seen. Doubtless, too, the wiring had been done according to directions. Otherwise, the Professor would not have been able, of course, to communicate with Frank. But the wrecking of the station had been so thoroughly carried out that it was impossible to tell.

Where the wires from the motor had been connected with a single-throw, double-pole switch, which in turn was connected with the primary coil of the alternating power transformer and with one post of the key, the other post of which was connected with the switch, there was now only a mass of tangled and chopped wires. As for the connections between the motor of the rotary spark gap to the power circuit, and between the secondary coil, the quenched spark gap, the condenser and the primary coil of the oscillation transformer, thus completing the closed oscillation circuit, they too, were a tangled mess.

The telephone instrument wired as an alternative to the key, thus permitting the sending either of telegraph or conversation, had been ripped away and ground into the hard-packed earth of the floor. At first it could not be found, but Frank stubbed a foot against it finally.

The three boys looked at each other, while Ali stood to one side.

“If you can make anything out of that, you fellows,” said Bob, “you’ll be going some. That’s all I can say.”

Jack shook his head dubiously.

“Oh, come,” expostulated Frank, who never liked to take a dare, and this looked like a dare to him, “give me time and I’ll have that fixed up. We’ve got all sorts of radio supplies in our luggage, you know, and as long as the motor hasn’t been wrecked we can fix this up. I’ll bet on it.”

The motor had not been subject to the general attack, as a matter of fact. Standing below the table, perhaps it had been overlooked. At Frank’s words, therefore, the others nodded.

“That’s right, old thing,” said Jack, slapping him on the back. “We’ll pitch in on this tomorrow, and we’ll have it fixed up in no time. That is,” he added, pausing, “if something else doesn’t come up for us to do, like——”

“Like what?” demanded Bob.

“Well, either defending ourselves or pursuing the raiders.”

“Pursuing them?” asked Frank.

Jack nodded.

“When that old woman is able to talk, we’ll find out what happened here tonight,” he said. “If Sheik Abraham and his few tribesmen and women were carried off captive, and there is a chance we can help them, I know father will want to do it.”

“And I’ll want to do it, too,” said big Bob, gruffly. “Darned shame these people getting into trouble, and perhaps on our account, too.”

“Our account?” It was Jack’s turn to look surprised.

“Sure thing,” said Bob, slangily. “Why not? How else can you figure it? Who was killed? Nobody but the Professor and Ben Hassim, the two men who had penetrated the Shaitun Mountains and found this old city and learned about a way to get to Athensi. Who killed ’em? Well, by the looks of that wounded fellow your father is doctoring, it was a raiding party of Athensians.”

Everybody looked thoughtful. As for Jack, he felt increased respect for his big friend’s powers of reasoning.

“But, great Scott, Bob, what would bring them six or seven days across the desert?” he demanded. “As far as the Professor ever could discover, they never left their hidden strongholds. Oh, of course, once a year a party went to Gao. But I understood that lay in an opposite direction from this oasis across the desert.”

Ali, who had been an interested listener to this discussion, interrupted.

“Perhaps, these strange people learned the Professor meant to disturb their privacy and bring the world to their doors,” he said. “And they resented, and took this method of putting a stop to it.”

“But how could they have learned about him or his plans?” demurred Frank. “Oh, this is a mess. Well, when that wounded chap finds his tongue, maybe we’ll learn something. Or when the old woman becomes able to answer questions. Anyway, let’s look around here for any letters or papers or other things the Professor might have left, and then go back to your father, Jack.”

CHAPTER V.
ALLOLA’S STORY.

Several days passed, however, during which the wounded Athensian, for such they all considered him to be, lay in a stupor resembling death. Little enough had the party to go on toward solving the mystery of the raid on the Oasis Aiz-Or.

The old woman whose name was Allola, and who proved to be the Sheik Abraham’s mother, recovered the use of her wits and her tongue, but what information she was able to supply was only scanty.

She knew the Professor and Ben Hassim, not alone from their most recent stay with her tribe, but from their former visit. “The Crazy One,” she described the Professor, bowing her head and hushing her voice in reverence as she did so, for among all primitive peoples those afflicted with insanity are regarded as under the special protection of Providence. And, although the Professor in reality was far from insane, yet these desert Bedouins so considered him because of his eccentricities and his search for a lost city and his invasion of the dread Shaitun Mountains.

When the Professor with Ben Hassim had arrived a second time at their isolated and almost forgotten oasis, Allola said the Sheik Abraham, her son, together with the dozen men of the tribe and twice as many boys greeted him with joy, while she and the women with their faces veiled watched curiously from the tents.

A welcome visitor was the Professor to this little tribe living apart from the world which rarely saw or entertained anybody from the outside. For the men he brought cigarettes, for the women many cakes of sweet chocolate. They were very grateful, and a tent had been set aside for him, and women assigned to look after his needs.

Days had slipped into weeks and weeks into months, while the Professor and Ben Hassim stayed on. Frequently they would depart on long expeditions, leading two fine camels which they had brought with them, carrying food and water, and bestriding their own fine animals. Allola’s sharp eyes regarded Mr. Hampton. She did not know why they made these expeditions. Perhaps, he——

Mr. Hampton smiled a little at her curiosity. Then he turned to Ali and the boys who were attentive listeners like himself.

“The Professor and Ben Hassim were scouting around the base of the Shaitun Mountains,” he said. “When he left me to come on in advance, Souchard said he intended to put in his time prospecting the mountain wall in both directions from the old stone road up which he had stumbled into Korakum in the first place.

“You will remember that the men of Korakum told him the only way to gain entrance to Athensi was along the course of the subterranean river passing around the walls of Korakum. This river had its rise in the heart of the mountains behind Athensi, passed through the valley in which that city was situated, then disappeared again into the mountains and after passing through a series of natural caves or tunnels interspersed by open stretches of canyon, emerged into the plains of Korakum. Then it dived into the outer ring of mountains, never to reappear above ground. Probably, eventually, it reaches the Niger far to the west of us.

“Well, it was my friend’s belief, based on hints dropped by one member of the exiled Athensians living in Korakum, that the heights above the hidden city could be gained by another method. Very long ago, he gathered, there had been another great road leading out from these heights to the desert, but the Athensians had destroyed it in order to preserve their isolation. It had been a great engineering feat to build it, but they had ruthlessly destroyed bridges across chasms and stone viaducts along the faces of steep cliffs, thus ensuring the impregnability of their city. However, Souchard understood, although his informant never would make a positive statement, that some of the exiles had been busy patching up the gaps in this road, flinging rude rope bridges across the chasms, and so on, to the end that men might pass single file. Doubtless, this was for purposes of accomplishing a coup of their own.”

“And he was seeking that old road?” asked Jack.

“Yes,” said Mr. Hampton. “And my guess is that, perhaps, he was discovered at it, and was tracked here and disposed of, in order that the secret might not escape.”

“Wow,” cried big Bob, letting a long breath escape. “Pretty mess we’re planning to go into. I thought this was going to be a gentlemanly expedition, with overtures made to the Athensian rulers to let us come in and study their habits and history.”

“And here we are stepping into a hornet’s nest,” supplemented Frank.

Mr. Hampton smiled slightly.

“Professor Souchard gave me to believe that it would be possible to approach the Athensians peaceably,” he said. “Otherwise I would not have undertaken this expedition, and brought you boys into danger, of course. But I’m beginning to believe now that he exaggerated the ease of approach, and minimized if he did not entirely ignore the dangers. Remember, he knew nothing much of the real Athensians. The exiles living in Korakum were his sole source of information. And, although he learned their language enough to converse with them haltingly, so short was his stay that there were many vital facts which he was unable to learn.

“I pointed this out to him,” he added, “but he said that when we arrived, we would stay at Korakum examining the ruins, which in themselves are worth any scientists’ time and study, and in the meantime learn the Athensian language from the exiles and gain a good working knowledge of the manners and customs of the people of the hidden city and the interior plateaus.

“That, as you know, was to be our first step. Afterwards, we were to proceed as our increased knowledge dictated. If it seemed the proper thing to do, we planned to send an embassy to the Athensians, asking permission to visit their city.”

“Could it have been the exiles of Korakum, Dad, who were responsible for this raid?” asked Jack.

Mr. Hampton shook his head.

“I do not believe so,” he said. “Souchard described them as friendly to him, and as you know they aided him to return to civilization. But enough of that,” he added. “Let us hear the rest of Allola’s story.” And turning to Ali, who acted as interpreter, he asked him to bid the old woman continue.

Nothing loth, for she relished being the center of attention and had resented this conversation in a tongue she could not understand, Allola described events on the day of the raid. “The Crazy One” and Ben Hassim had been absent more than two weeks from the oasis, but as they had stayed away equally long if not longer in the past, nobody worried. On leaving they had taken food and water on their led camels sufficient for a protracted stay, and it would not be necessary to feel anxiety about them for at least another week.

In the morning, however, on looking at a calendar which “The Crazy One” had given him and which was a source of much satisfaction, as he had never before been able to keep track of the passage of days, Sheik Abraham had noticed a black mark drawn around the date. Then he had recalled that long before his friend had told him that on this day, the thirtieth of the month, friends would arrive from the east.

“That’s right,” said Mr. Hampton, while the boys nodded. “We had arranged with Professor Souchard to time ourselves so as to arrive on this day. Leaving Khartum on such and such a day, if all went well, we would spend so many days in desert travel and reach the oasis on the thirtieth.”

Allola proceeded. Noting the date and recalling “The Crazy One’s” words, the Sheik Abraham had told the tribesmen to keep a sharp look out across the southern desert, for the return of him and Ben Hassim. All day the men and women, working about the oasis, in their little farm patches or grinding oil, had paused now and again to glance to the south.

Not until late in the afternoon, however, had they descried the looked-for figures approaching. They had gone out a little way into the desert to welcome them, and it had been a triumphal procession homeward. Everybody had crowded around to hear the tale of “The Crazy One’s” latest wanderings, as explained by the merry Ben Hassim, and it had not been dreamed necessary to keep watch. No watch ever was kept, anyway, as the tribe had no enemies and few, indeed, were the travellers who came this way.

Suddenly, a body of white men, strangely-clad (like that other, said Allola, nodding toward the tent within which lay the wounded Athensian) and mounted on swift camels, dashed into the midst of the encampment. They bore short heavy swords and lances, but made no effort to harm anyone.

In number they were, perhaps, two score. Dividing, they encircled the enclosure where the whole tribe was gathered. The dozen men and the score of half grown boys of the tribe, caught without arms, were helpless to resist. All were made prisoner, the Sheik Abraham was dragged from his tent where he was conversing with “The Crazy One.” The women were brought forth. Only “The Crazy One,” rolling quickly beneath the wall of the Sheik Abraham’s tent, managed for the moment to escape. Allola saw him from her retreat beneath the Sheik Abraham’s divan, where she had thrown herself. She was overlooked.

“Then I heard his voice screaming into the devil machine,” said Allola. “And I knew he had fled to his tent and was calling upon his gods for protection. The strangers heard, too, and pursued and caught him. There was a fight. I heard, but I could not see. I lay hidden then until you came.”

Mr. Hampton looked thoughtful. “That explains some things,” he said. “Professor Souchard hurrying to get back to meet us was tracked by Athensians. Probably he had aroused some watcher’s suspicions on an earlier scouting expedition along their mountain wall, and when he appeared this time a war party was summoned. Before it could arrive, unconscious of his impending fate, he had departed. But his trail across the desert was followed, the war party pushed its animals and, although he may have had a whole day’s start, they caught up with him an hour after his arrival at the oasis. He was cut down as he called for help.”

Jack groaned. “Poor old Professor. If only we had been here. Our party, with guns, could have put the Athensians to flight in a twinkling.”

“Well, boys, that’s all for the time being,” said Mr. Hampton, at length, after some further discussion. “When we buried Professor Souchard and Ben Hassim, as you will recall, there was no mark of bullet. They had been garroted, their necks broken, in the fashion of the Hindu Thugs. Now Allola says she saw no guns among the Athensians. These two circumstances would seem to indicate they are without firearms. Nevertheless, I cannot believe that a people, keeping up an annual contact with the outside world, would be without knowledge of firearms. Besides, those of the tribesmen were taken, for there isn’t one in the oasis. Would they have taken guns without knowing their use? No, they might have suspected they were weapons and have smashed them, but they wouldn’t have carried them away. Then, too, there is this matter of carrying off the whole tribe of Sheik Abraham. What was the reason for that?”

“Probably the raiders planned to use them as slaves,” said Ali, to whom the dark secrets of the slave-raiders who still practice their trade in many places in the heart of the Dark Continent from the Abyssinian borders on the east to the Niger and Kongo territory, were not unknown.

“Perhaps,” said Mr. Hampton, slowly. “If the tribesmen were to be used as slaves, that would indicate why their lives were spared. But it is also possibly the Athensians suspected Professor Souchard might have imparted information regarding their country, and they were taking no chances on leaving any witness against them behind.”

CHAPTER VI.
THE TALE OF THE SLAVE TRADER.

Days succeeded during which the party marked time. Mr. Hampton was resolved to take no further steps until first having a talk with the wounded Athensian. He was showing signs of recovery, and was being fed broth at intervals, but was delirious. Should he return to his senses, Mr. Hampton planned to question him in his own tongue. From Professor Souchard he had acquired an elementary vocabulary in that language as taught the latter by the Athensian exiles in Korakum.

In the meantime, after exhausting the possibilities of the oasis and its small vegetable farms and flocks of sheep and goats, which had been left behind by the raiders, the boys found time hanging pretty heavy on their hands.

Frank had more to occupy him than his comrades, as he was intent on making good on his boast that the radio station could be repaired. Almost every waking hour he spent in this occupation.

Ali’s stories of African life helped somewhat to while away the time for all. This swarthy-cheeked, hawk-nosed Arab had poked his nose into every corner of northern Africa. And, when one considers that the Sahara Desert alone is more than 3,250,000 square miles in extent, or the size of all of the continent of Europe, that meant Ali had done a lot of poking. He was intimately acquainted with the life of every Mediterranean city from Tangiers and Morocco to Port Said. He had crossed the desert by every camel route. He knew the great mountain of Asben in the middle of the Sahara. He had travelled to Timbuktu. He had penetrated to Lake Schad and the sources of the Nile, and had voyaged on the Niger. In a word, Ali was a mine of information on northern Africa.

Putting two and two together, he was able even to say he had heard of the Athensians before the Professor brought their existence to his attention. Not that he heard of them by that name, however. He told about it at the camp fire one night, while Jack threw on the blaze several handsful of dried coarse grass and the light leaped high, bringing out the curious faces of the boys and Mr. Hampton and the impassive features of the Arabs.

It was from another Arab, a slave trader who had been to Gao, that Ali had the tale. This man Ali encountered at a desert oasis one night. It had been years before.

“We were the first travellers who had visited that oasis in a long time,” said Ali. “Some of these isolated oasis are the homes of robbers who raid caravans. But like Sheik Abraham, this sheik was a harmless and pleasant old fellow. He made us feel welcome. We sat on little grass mats on each side of him in front of his tent. Before us was a blazing fire on which his favorite wife now and then, would throw a stick of wood or some grass. She was young, veiled, and her hands were elaborately tattooed. Silver bracelets and ankle-rings jingled at every step. Yes, evidently she was the old patriarch’s favorite wife.

“It was very pleasant sitting there, and the woman brought us bowls of kous-kous-soo and tiny brass cups of sweet Moorish coffee on a tray. After eating, we lighted cigarettes and began to talk. We felt it was our duty to tell strange stories of our adventures in order to repay our host’s courtesies. He was a man who did not travel, and it was our duty to entertain.”

All paused a long time, staring impassively into the fire. At length he resumed:

“Well, the talk passed from this to that, and presently this slave trader began to tell of a strange people from whom every year came to the slave marts of Gao a delegation seeking strong men.

“‘With them,’ he said, ‘comes a man who can speak to Frenchman, Arab, Berber, Tuareg, all the peoples of the desert, in his own tongue, a man who speaks many Negro dialects, too. He is the leader. There are two minor chieftains and a guard of two score men armed with short swords, lances and Arab rifles. The rifles have very long barrels and much silver work on the stocks. They are worth a great deal of money.

“‘On the outskirts of Gao this party encamps, while a picked force of ten warriors accompanies the three leaders into the slave bazaars. As you know, we dealers traffic in all sorts of human cattle. We have Negroes from many different tribes, captured in battle and sold us by the victors. Arabs, Tuaregs, Berbers, also come to us from those who have captured them in the fight. Even white men, Frenchmen and Spaniards, captured in Morocco and Algiers and Tripoli by fierce tribesmen, like the Riff tribes who are forever fighting the Spaniards in the Atlas mountains, reach us for sale into slavery—’”

“Oh, come, now, Ali,” interrupted Mr. Hampton, good-naturedly, “that’s a bit too thick.”

Ali shrugged. “Many things go on in Africa which the whites cannot stop,” he said, simply. “It is true, this I tell you.”

“But white men,” protested Mr. Hampton.

“What think you, then, becomes of the men taken prisoner from the French and Spanish and Italian foreign legions when detachments are trapped in the desert?” asked Ali. “They are not butchered. No, they are too valuable. Some desert sheik or the kaid of some desert city buys them for slaves.”

“All right,” said Mr. Hampton. “Go on.”

He was quite convinced, yet he knew enough of the mystery of this vast land to many parts of which white men never even had penetrated to this day, to realize what Ali described was not impossible.

“‘Then,’ said this slave trader,” continued Ali, “‘these strangers select the very strongest and youngest of the men, be they white, black or brown. Unless a man is of exceptional strength he is not chosen. Sometimes they select only two or three, sometimes a dozen.

“‘Only once have I been at Gao when these strangers appeared. Much had I heard about them. My curiosity was excited. That time I had among my slaves a very strong man, a man of the Kongs. He was a full six feet tall, beautifully proportioned, with a fine intelligent head and a brown body like mahogany. He was only twenty-one.

“‘The leader of the strangers came to me and pointed out this man. He spoke in Arabic. He wanted to know the Kong’s antecedents, and I said he had been taken in battle only after he had slain five Bakus, being finally entrapped in a net thrown over his head and arms.

“‘He took the Kong without even asking my price, which was high. As he turned to go, I said on the impulse, “Whence come you?” He stared at me haughtily. For a moment I thought either he would not answer or else would order his guards to cut me down. Then he laughed, a wild, reckless laugh. My blood chilled. “I come from the country of the past and of the future,” said he. Then he was gone.

“‘I made inquiries. But from none could I learn more than I have told. Slave traders come and go. Within the memory of the oldest of us, reaching back fifteen or twenty years, this stranger had come once each year to the slave marts. For how long before that he had come, I do not know. None ever had pursued him into the east, to see whence he came. That is all.’

“So,” concluded Ali, “I have since been thinking. That man was a big chief among the Athensians, if not the greatest leader himself. Who he is, how he has acquired a knowledge of many languages, I do not know. That he and his people are white, of course, is not so marvellous, as the Berbers and Arabs are white races, and so are the Kabyles who inhabit the mountains of Morocco.”

Mr. Hampton nodded. “An offshoot of the white race which has maintained a splendid isolation in those mountains south of us, undoubtedly. Yet how this leader acquired his knowledge of civilization puzzles me. And why, Ali, are these annual expeditions to Gao made? And only the strongest slaves selected?”

Ali shrugged. “It is for Allah to say,” he replied, and lapsed into silence. Evidently, for that night, the loquacious Ali had said all he intended to say.

His story, however, furnished Mr. Hampton with food for reflection and on several occasions he discussed the matter with the boys. Especially, did he note that the slave trader’s account, as repeated by Ali, betrayed that the Athensians possessed rifles. This made them more dangerous enemies.

“In fact, boys,” he concluded, one day, after a lengthy discussion, “I have become pretty firmly convinced that these Athensians cannot be peacefully approached as had been our original intention. Therefore, we shall have to abandon the expedition. I shall wait a few days more to see whether this man recovers sufficiently to be moved, and then, if we can gain nothing from him in response to questioning, we shall set out to return.”

“What,” cried Jack in dismay, “leave without attempting to learn what we came all this way to discover?”

His father nodded gravely. “Professor Souchard and Ben Hassim have been slain,” he said. “Sheik Abraham and all his tribe have been carried into slavery. Quite evidently, the Athensians want no intruders and we would only imperil our lives by pursuing our investigations further.”

“But what’ll you do, Dad?”

“I shall lay the matter before the French and British governments. Now that the Great War is over, it may receive attention. They can send embassies, supported with sufficient power to compel recognition. Then, it is possible, the Athensians will yield on being shown no menace to their freedom threatens, and may admit scientists to their mountains to study the ruins of Korakum and the library of Athensi, if such really exists.”

“Dad,” asked Jack, after a pause, “I know I’ve spoken of this before, but I can’t get it out of my mind. Isn’t it possible the Professor may have been deluded, that all he told you was a creation of fancy?”

“No, there was this raid on the oasis, the description of the raiders, this wounded captive, and Ali’s story of the annual visit of the Athensians to the slave marts of Gao.”

“Granted all that,” Jack stubbornly objected, “yet it does seem nothing short of miraculous that a city such as Athensi should exist unknown to the rest of the world.”

“Well, but, Jack,” interrupted Bob, while Mr. Hampton approvingly nodded, “look at Llassa, the Secret City of Thibet. Only one white man has ever penetrated it and lived to tell the tale. And that is in the heart of Asia, the oldest continent known to civilization, while here is Athensi in the heart of a continent which is still in many parts unexplored.”

Jack threw up his hands in token of surrender. “All right, old thing,” he said. “I’m just as keen as you to carry this through, and I was just arguing. I do wish father would continue with it, but I suppose his plan is the best.”

CHAPTER VII.
CHASING OSTRICHES.

“Ali, come here. Take a look through these glasses and tell me what you see,” called big Bob early one morning.

As he spoke he was approaching the encampment, where the Arabs were preparing breakfast, at a run.

Ali looked up inquiringly, and Bob grasped him by an arm and urged him forward, past the well, through the patches of garden stuff, down among a grove of fig trees, to the edge of the oasis. They were facing eastward, and the sun which had not been up long cast a dazzling radiance over the sand dunes. These latter lay scattered indiscriminately, like the waves in a choppy sea—great bare swellings of sand, with here and there low stunted clumps of bush.

At first, gazing into the path of the sun, Ali could descry nothing, but under Bob’s direction he finally located what had attracted the other’s attention. This was a number of dark black objects seeming like bushes in motion. But Ali’s better-trained desert eye solved what had merely been a puzzle to Bob, and without taking the glasses from his eyes he exclaimed

“Ostriches.”

“Ostriches?” Big Bob could hardly believe he had heard aright. “Why, you don’t find ostriches here, do you? I thought the only ones left in Africa were the domesticated ones on South African farms.”

Ali smiled.

“They run wild in the waste places and on the desert,” he said.

“Great Scott,” cried Bob, in high excitement, a sudden thought striking him. “Can’t we break the monotony by having an ostrich hunt? Even if we don’t catch any, it’ll be fun.”

“To hunt those birds we should have horses,” said Ali, dubiously. “They run very swift. With horses, the hunters pursue them in a great circle, relays of horsemen relieving the tired ones.”

“But won’t camels do?” Bob was eager to put his scheme into effect and an appealing note crept into his voice which caused the kind-hearted Ali to smile.

“We can try,” he said. “Only you must not be too disappointed, if you see them run away from you.”

“All right,” promised Bob. “I won’t. Come on, let’s tell everybody,”

They hurried back to the encampment and Bob’s bellow quickly caused the others to assemble. Then the news was told. It aroused less enthusiasm than Bob had looked for. None of the Arabs was keen, to go, believing that with camels it would be next to impossible to run any ostrich to ground. Besides, what would they stand to profit? Ostrich meat is tough, stringy and practically inedible. The great bird’s sole good to man is to provide feathers for women’s adornment. As for Frank, he planned to put the finishing touches to the restored radio set and could not be turned aside from his project. Mr. Hampton intended to stick by his patient who was beginning to mutter in his delirium. Most of his mutterings were in Athensian, which Mr. Hampton could recognize as such but which was meaningless to him. But in the midst of Athensian words, he believed he could distinguish an occasional French word, and this puzzled and interested him.

“Well,” said Bob, disappointed, “if nobody else goes, Ali and I will go it alone.”

Jack grinned. “Count me in, old thing,” he said. “I’m as keen as you for a little excitement. Only thing is, I hate to ride those dratted camels. But what must be, must be. Let’s go.”

Three camels were brought up, accordingly, and saddled, and then Ali, Bob and Jack mounted and ambled away. Mr. Hampton accompanied them to the edge of the desert, warning them to look out that they did not come to close quarters with an infuriated ostrich, especially if by any chance they were unarmed.

“These African ostriches stand seven or eight feet tall, boys,” he warned, “and they have tricky tempers. If by any chance you become dismounted and an ostrich charges, throw yourself flat on the sand and stay there. Then the ostrich can’t kick you. He’ll probably sit on you, but hold your position until one of your comrades can come up and shoot him. Remember, the ostrich kicks forward or sidewise, and a blow from his powerful leg can cave in a man’s head or break a horse’s leg.”

“All right, Dad, we’ll be careful,” promised Jack, “but it’s hardly likely we’ll ever get to close quarters. I imagine when the ostriches see us coming, they’ll give a flirt of their tails and sail away.”

During the time taken for saddling up and getting started, the ostrich herd had moved eastward and now was out of sight, even through the glasses. Ali led for the place where they had been seen, and as they rode gave the boys a little homily on the great birds they hoped soon to stalk.

Ostriches are found throughout Africa, except in the central and coastal regions of great forests. Especially do they haunt the waste places and deserts, where stunted bushes furnish sufficient food for their needs. Their hardihood and fleetness makes life possible where other animals could not exist. Even sand and pebbles apparently can be digested by them, and it is a fact that the domesticated ostriches of farms and zoos have been known to swallow glass, barbed wire, bright-colored bits of metal, bed springs, and other similar objects.

Unfit for food, these great birds are valued because of their beautiful feathers, which can be plucked at certain seasons of the year without harm to them. For this reason, the Arabs of northern Africa and the colonists of South Africa for long have domesticated ostriches. In South Africa alone, latest estimates were that the number of domestic ostriches was between 800,000 and 900,000. Ostrich-raising also has been introduced into California and Arizona with varying success. One of the chief worries of the ostrich raiser is proper incubation of the eggs, which take at least forty days to hatch and more frequently a full seven weeks.

In their wild state, the ostriches lay their nests of great eggs—ivory white in color among the birds of the Sahara, mottled among those of Basutoland and South Africa—on the top of a sand dune, whence they can see in all directions and guard against surprise. The male takes his turn with the female in sitting on the nest. Jackals, drawn by the chance of obtaining some of these eggs, almost invariably haunt the ostriches. When an unguarded nest is found, the jackal pushes a big egg up the sand slope with his nose and then lets it roll down into the nest. Coming into contact with another egg, usually both become cracked. Then the jackal sucks the contents. There is so little on the desert to feed the jackal that the dangers he runs from the attack of an infuriated ostrich are braved in order to obtain such a succulent feast. Observers have reported seeing a jackal pursued by an ostrich and running in zigzag fashion for his burrow. If he fails to reach it in time, one swipe of the ostrich’s leg tosses him yards away and disembowels him.

When the desert people conduct an ostrich hunt, it is for the purpose of capturing birds to be incorporated into their herds. They go out in numbers on fleet horses, circle widely to fixed stations, and the chase begins. The fleeing ostrich for a time can outrun the swiftest horse. Therefore, the pursuer keeps going until his horse lags, whereupon he gives way to another horseman. A desert creature, strangely enough the ostrich is not inured to great heat, and sometimes when being pursued under a hot sun will suddenly keel over, dead of apoplexy.

Some of the above Ali explained to the boys as they lurched forward on camel-back. It was not their intention to kill an ostrich, but, if possible, to capture one. For this purpose, Ali had provided lengths of rope, weighted at each end, which if well cast would wrap around the legs of an ostrich and bring it down. Bags to be clapped over the head also had been provided. Ali smiled discreetly to himself, however, realizing that on camel-back and without practise, it was next to impossible that either Jack or Bob would succeed in bagging an ostrich.

The latter pair, however, while resolved to do their best, given the opportunity, were under no illusion, either. They did not count on capturing an ostrich. What they sought was a closer view of them, a chase and the attendant excitement. That would repay them for the trip, would provide a welcome break in the dullness of their days.

Before leaving, each had taken with him a small radio receiving set, fastened in the crown of the solar topee or sun hat. It differed materially from the set Frank had borne on camel back as they approached the oasis, and over which they had received Professor Souchard’s last message. This set was built on a small panel fastened on the inside of the sun helmet. To use it, it would be necessary to halt and set up an aerial and bury a ground. The ground, a small mass of zinc, was carried slung to Bob’s saddle, and the aerial—seventy-five feet of thin wire, hung coiled in the same place. A pair of jointed steel rods, of special construction, both light and durable, was strapped to his rifle scabbard. Before returning, it was planned to set up the aerial, and test whether Frank had succeeded in repairing the Professor’s sending station.

Presently, surmounting a sand dune slightly in advance of the others, while Bob and Jack still struggled up its sliding slopes, Ali placing the glasses to his eyes saw the ostriches due east and about a mile and a half away. He dropped back at once, cautioning the boys to stay beside him rather than surmount the dune.

“Ostriches have very good sight, and almost as good hearing,” he explained. “I will stay here, and do you two work to right and left of me under shelter of these sand dunes until you judge we have the herd encircled. Then I’ll approach and start them. You keep your stations until I turn over the chase to one or other of you. The ostriches will run in a wide circle.”

“All right,” said Bob. “I’m off.” And he started away to the left.

With a wave of the hand, Jack set out to the right, little dreaming of the momentous events to occur before he saw Bob again.

CHAPTER VIII.
BOB’S FIGHT AGAINST ODDS.

As Bob rode along on camel-back in the lee of the sand dunes, there was never a thought of danger in his mind. The Sahara is not like the great grassy steppes of Siberia or the plains of western America, which are flat and level as a table top and across which one can see for miles in every direction. On the contrary, this great African desert is filled with shifting sand dunes, low hills of sand, which are whipped away when the strong winds blow and change their position, piling up in new drifts.

In appearance it was now to Bob’s eye like the sea when waves were kicking up. In the trough of these sandy waves he made his way forward, exercising care in advancing from the shelter of one dune to another to keep below the crests.

It was lonesome riding, under the baking sun, in that land of stillness, without sign nor sound of any human being. He had an eerie feeling, as if something were about to happen. But he shook this off, and laughed at himself. Merely a touch of nerves, he thought, due to the loneliness of the surroundings.

Before setting out, it had been decided he and Jack would have to ride a good half hour away from their starting point, from the place where Ali was posted, before they would be in the proper position. Therefore, looking at his watch now and again, he kept on without exposing himself to gain sight of the ostrich herd, until the full half hour had elapsed. It seemed to him a much longer time, and if it had not been for his watch he would have been tempted several times to clamber up a sand dune and look around.

When at length, the allotted time having elapsed, he did urge his camel up the top of the nearest sand dune, there was no sign either of ostriches or of his companions. Far in the distance could be seen the tops of the palm trees of the oasis, dwarfed and beautiful as a painting against the blue sky. All else was hidden from his sight.

“Shucks,” thought Bob, “in dodging to keep below the tops of the sand hills, I must have gotten off my course.”

That, in reality, was what had occurred. Instead of the small circle he had planned to make, which would have put him on the point of an arc a third of the way around the herd from Ali’s station, he had borne off the course gradually but surely in his attempts to remain hidden. Moreover, he had gotten into a region of larger sand dunes, so big they amounted to low hills.

“Who knows,” he grumbled aloud, wanting to hear his own voice for the sense of oppression had grown stronger, “who knows, the ostriches may be over the next dune or so, and I just can’t see them from here. Well, there’s the oasis, and I can make for it if worse comes to worse. But I’d feel like a jackass to go back and say I went and got myself lost.”

As he spoke he was swinging the glasses slowly over the surrounding country.

“Confound the luck,” he grumbled again, when unrewarded, “believe I’ll fire a shot or two. If Ali or Jack hears, he’ll answer.”

Unlimbering his repeating rifle, he threw it to his shoulder, aiming for the crest of a nearby sand dune, and pressed the trigger. The report followed, and a spurt of sand showed the accuracy of his aim. Again he pressed the trigger. But this time the gun failed to be discharged.

In surprise, Bob bent down to examine it. What could be the matter? Evidently, the mechanism had become jammed. Must have forgotten to clean it, and, perhaps, the all-pervasive desert sand had clogged it. A pretty note, he thought, and experienced a momentary feeling of panic. What if it had happened at a time when he needed it to protect his life? The thought made him shudder, and glance around quickly.

Then a sight met his eyes at which words failed him. For a moment, he sat as if paralyzed, unable to move or even to think.

Ten horsemen had filed silently, soundlessly, from behind the shoulder of the sand dunes in his rear. They were already almost upon him. From momentary paralysis, Bob’s mind leaped into lightning-like activity. He saw his escape toward Ali and Jack was cut off on one side, and on the other his retreat toward the oasis.

It would be useless to attempt to flee, for his camel soon would be overtaken by the swifter horses, if he were not shot down in the meantime. For that first swift appraising glance assured him these men were armed with long Arab rifles.

In the same glance, he noted something else which made his heart skip a beat. These men, tanned though they were, were recognizable as white men. And they were dressed exactly as was the wounded Athensian, lying delirious at the oasis, in fact they were Athensians, in short toga-like garments, bare legs and soft leather moccasins.

All these observations and thoughts passed through Bob’s mind in a moment. He had a wild idea of throwing himself from his camel, causing the latter to kneel, and from behind it, as from behind a bulwark, fighting off the attackers. For, that they intended harm to him, Bob felt assured. But even in the moment of leaping from the saddle, he realized the futility of such procedure. His rifle was out of commission.

What should he do? The party was closing in. Bob gave one wild searching glance to the south, where he had left Ali and Jack. They were nowhere in sight. Neither, for that matter, were the ostriches.

Under other circumstances, Bob would have made a fight for his liberty with his bare hands. Those of our readers who have followed his career under other skies know well what a superb wrestler is Bob. And with the additional weight and strength of an added year or two, Bob was now a wrestler and boxer second to none. But even as the thought of grappling with the leader entered his head, he saw by the loosening of rifles in the hands of others that his first movement would bring a swarm of bullets his way.

Or would they shoot? A new idea came to Bob. In this still desert air, the sound of shots would carry far. If his one lone shot of a minute before were to be succeeded by a volley, Ali and Jack would take alarm, and perhaps even back at the oasis the alarm would be given. This party consisted only of ten men. Perhaps, they preferred moving soundlessly rather than run the risk of bringing a party of equal strength upon them. Perhaps, they would not use their rifles at first, should he attack their leader, expecting to see him overcome. Well, if they only withheld their fire until he could grasp the rascal and seize his rifle, Bob wouldn’t care. With a weapon in his hand, he could go down fighting. What a fool he was, anyway, to have left the oasis without his automatic.

One phase of the situation which Bob did not take into account was that, even if Ali and Jack managed to discover his predicament and either came to his rescue themselves or set out to rouse the oasis, the attacking party could escape because of the greater swiftness of their horses as compared to camels.

Instead, as the leader of the attackers approached—a strikingly handsome young man, with a round firm face, hawklike nose and crisping brown hair, Bob set himself for a flying leap from the camel. The leader rode slightly in advance of the others, who mounted the sliding sand hill in a semicircle behind him, toward Bob sitting his camel on the top of the hill. Then an astonishing thing happened.