THE explorers, particularly Tishmak, knew the danger of a sandstorm. It was not infrequent for large caravans to be completely engulfed by the heavy veil of sand, leaving only the dead bodies of the camels and their riders. The Americans remembered a tale that Fekmah had told them about a trading caravan of five hundred dromedaries coming to a tragic end in this region. Would their little caravan also perish?

“Get your goggles,” commanded Fekmah, his tone indicating that he was calm even in the face of danger.

“And be sure they fit tightly!” warned Dr. Kirshner. “Even then we’ll get some of the sand.”

The atmosphere was rapidly becoming extremely dry and hot, and at intervals a fierce wind brought minute particles of sand into the explorers’ faces.

“Now,” began Fekmah, after conversing briefly with the guide, “we must get dromedaries in group, so they not get fright and run away. Then we crouch down behind them.”

The camels were drawn up together and fastened in a circle with ropes.

“It might be wise to put up our tent, mightn’t it?” asked Mr. Lewis, but Fekmah shook his head vigorously.

“No, no,” he said. “Then we get in trap and not get out. If sand very heavy, we want to be in open.”

The dense mist was thickening and spreading, until it soon covered the whole horizon. The sky in the distance was not visible for the heavy cloud of fine particles.

The explorers got out blankets and wrapped themselves tightly. Even then, said Fekmah, the small bits of soil would get through to their skins.

They had scarcely finished preparations when the first breaker suddenly came with all force, striking the adventurers in the face and penetrating the blanket.

It was blinding, smothering, but they managed to get air and fought with a determination that was born of adventure. Crouching behind the sturdy dromedaries, they held their heads low to avoid as much of the fury of the storm as possible.

It was with great difficulty that the camels kept their positions together, but they succeeded admirably.

“Doesn’t seem right for them to have to stop the sand for us,” said Joe, shouting in order to make himself heard.

“It’s a shame,” Bob shouted back. “But they can probably stand it better than we can.”

Slowly they found themselves enveloped in a heavy opaque atmosphere, so dense as to seem almost as a wall. The thought of being completely covered up was constantly in their minds, bringing about almost a feeling of despair.

The burning wind was constantly lashing them in the face, until it seemed that they could stand it no longer. Indeed, if their heavy goggles had not been of unbreakable glass, the furious particles of sand would have smashed them in the explorers’ eyes. Even as it was, some of the sand found its way in.

“This is terrible!” moaned Joe. “Awful—simply——”

He stopped suddenly, as his mouth became filled with sand. Another gust of wind had come, bringing with it an enormous quantity of the burning sand.

The explorers’ eyes were smarting, their lips were cracked and bleeding. They felt that they would smother. Nothing could have been worse, it seemed.

They could hear the dromedaries snorting with fear and irritation. What if the brutes could not stand?

Conversation was now impossible, for they dared not open their mouths for fear of swallowing some of the stinging sand. Even when they breathed, the fine particles filtered through the net that hung over their faces.

The sky above was of a bright red color, and a weird light trickled through the fog of yellow. It was the most unusual happening that the Americans had ever witnessed.

“If it just wasn’t for this terrible wind!” muttered Mr. Holton, when there had come a slight lull.

“Yes,” agreed Fekmah. “Then it not be so hard to stand it.”

He had scarcely finished when another gust of hot sand struck them cruelly, making their faces sting anew.

Suddenly Tishmak noticed that they were nearly engulfed in a heavy pile of sand. With a quick motion he drew himself out and drove the dromedaries to another spot.

For a brief moment the explorers were exposed to the full violence of the storm. Then they again took places behind the newly located camels.

“Not taking any chances on being covered up, are you?” said Dr. Kirshner to Tishmak.

The latter did not understand the words, but he caught the meaning and smiled.

How long the terrific onslaught of sand lasted, no one knew. They had lost all sense of time, and the heavy atmosphere completely hid the sun.

It was only gradually that the terrible storm subsided, and then the air was exceedingly hot and dry, promising to remain that way for some time. Slowly the cloud of sand about them grew thin, until it finally cleared away completely. Now only an occasional hot wind annoyed them, but it was scarcely anything compared to the previous bombardment of sand.

“No more of anything like that for me!” muttered Bob, as he worked his feet loose from the high pile that strove to bury him alive.

The dromedaries, too, had their legs embedded in the sand so deeply that it required several minutes of constant digging to relieve them.

“Suppose we rest awhile before going on,” suggested Bob. “It has been a great strain for all of us, standing against that terrible rush of sand.”

The others readily agreed, and all thoughts of continuing the journey at once were dismissed from mind.

“At least,” Joe said, “we got out alive, and that’s more than you can say of many caravans.”

“Yes,” returned his father. “Perhaps under this very spot are the bones of men and camels that were not as lucky as we were.”

“That storm rather short lasting,” remarked Fekmah, glancing at his watch. “Many times storm last several hours.”

Joe sighed.

“I’d hate to have had to stand much more of it,” he said.

It was nearly noon, and the tent was pitched for the midday rest. All were very weary after the terrific strain.

“Let’s have our lunch,” suggested Mr. Lewis. “I’m very hungry, and I’m sure everyone else is.”

The noon meal and rest followed, the explorers not continuing until after three o’clock.

Late that afternoon they came to one of the largest uninhabited oases that they had yet seen. It was situated snugly on a narrow stretch between high dunes.

“It’s a wonder a small town hasn’t sprung up around here,” remarked Bob, drinking greedily of the refreshing water that gushed from the large spring.

Dr. Kirshner nodded.

“With all these palm trees and the abundance of water it is surprising,” he said. “But I suppose there are so few people, even among the natives, who would live here that it wouldn’t pay.”

The containers were hurriedly filled.

“It might be well to stay here for the night,” said Fekmah. “It is getting late, and we all need sleep very bad.”

He turned to Tishmak and put the question before him in the native language.

The guide at once gave his approval, more than glad of the chance to stop.

“He say he wanted to stay here for night, but thought we in big hurry,” Fekmah told the Americans.

“We are,” returned Mr. Holton. “But here is a very good place to camp, and I think we’d better take advantage of the opportunity.”

The tent and provisions were unpacked from the camels, which seemed more than glad of the chance to relax.

“Funny,” remarked Mr. Lewis, “that camels don’t care to lie in the shade when there is an opportunity. You would think the terrible sun would be avoided as much as possible, but that is not the case.”

“Either they like the heat or they are too lazy to move,” said Joe.

For some time the two youths sat with their elders. Then Bob got up and stretched.

“Suppose you and I get on our dromedaries and ride over to that distant hill,” he said to Joe, pointing away to the horizon. “I’d like to see what’s beyond there. This seems to be very high ground, and we might get a view of the distant mountains from the top of that dune.”

“Be sure and take your rifles, boys,” warned Mr. Lewis. “And don’t stay too long.”

The boys slung their guns over their shoulders and rode off, waving to their friends.

The hill that Bob referred to was at least a mile away, and the ground on the way was of loose sand. The boys urged their mounts to trot faster, however, and they would probably cover the distance in a very short time.

“I wonder if we could get a glimpse of the Ahaggar Mountains?” said Joe.

“Might. But you must remember that we are still a great distance away.”

As the boys had expected, they came to the hill in but a few minutes. It was very high and steep, but the soil was hard. The dromedaries had no difficulty in climbing steadily up.

At last they came to the top and gazed out into the distance.

“Look!” cried Joe. “The mountains! We can see them!”

Sure enough, the Ahaggar range was visible, stretching miles and miles to either side. A few sharp peaks protruded high above the others, but for the most part the line of mountains was rather regular.

“Suppose that high peak is Illiman?” asked Joe, pointing to a high crag that towered above the other mountains.

“You mean the one Fekmah was talking about? It might be. He would know if he saw it, I suppose. And of course Tishmak would.”

The youths spent nearly a half-hour peering out at the mountains, greatly impressed by the wonderful view.

“How far away do you suppose they are?” questioned Joe.

“Fifty miles, at least; maybe more. It will probably take us another half-day to get to them.”

Finally the youths turned and rode back down the hill to tell their elders of the magnificent view. Fekmah particularly would be pleased, Joe thought.

But the boys were not overly anxious to get back to the oasis at once. There were many other high sand dunes that they would like to ride over.

“We won’t stay much longer,” said Bob. “Just ride around a bit.”

To their right was another high hill that might afford a view in another direction. The youths rode over to it and climbed the gradual side.

Then, when they came to the top, they cried out in surprise and fear.

In the distance appeared to be a whole regiment of galloping horsemen coming toward them!