"Wait till we get to the Ahaggars, if you want shade," smiled Mr. Lewis. "Some of that region resembles the mountainous part of Arizona. There are deep ravines, narrow valleys, high peaks, unknown caves, and many other remarkable phenomena of nature." "That is where our journey comes to an end, isn't it?" asked Bob. "Yes. In the southern part of the Ahaggar range. Thus far, Fekmah hasn't had much need of the map, because he has directed us more by compass. But when we see the mountains, it will be necessary for him to consult it frequently. Whether or not it will prove accurate, made from memory as it was, we have yet to see." The way now led through a dry river valley, which wound through the many black rocks. Some of the rugged hills near by towered to two and three thousand feet, their perpendicular sides gray or deep black. There was sparse vegetation, but a few gum trees were scattered about over the hard soil. Tishmak had informed them that they would come to a well some time that afternoon. The water, he said, would be very cool, for it came from far underground. "I'd like to see that Land of Thirst you were talking about," remarked Joe to Fekmah, as the Arab mentioned the well of cool water that lay ahead of them. "It must be an interesting region." Fekmah shook his head. "Caravans avoid it much as can," he said grimly. "Too much danger of falling dead. Then, too, it is supposed to be inhabited by evil spirits." "Evil spirits?" "Yes. Superstitious natives near there never see parts of it. I much glad we not have to go through it, because we sure to get very much thirsty." Shortly after the explorers had passed around a large hill they heard camel steps from behind a sharp corner in the river bed. "Quick!" directed Dr. Kirshner. "Let's hide in back of these rocks. It may be more bandits." The adventurers drove their dromedaries out of sight and then followed, looking about cautiously. The sound of footsteps grew louder, and soon a small caravan of natives came into view, looking very strange indeed with their faces tightly covered with black veils. "Tuaregs!" exclaimed Dr. Kirshner, who had made a study of the peoples in the Sahara. "Tuaregs at last!" He rode out from behind the place of hiding and shouted a friendly greeting in their own language. The people at once called back and moved on up to the archæologist. "Guess we might as well go out," smiled Mr. Holton, urging his camel to move forward. Soon the others joined Dr. Kirshner, who seemed to be having no trouble in understanding the people. "They live in the Ahaggars," explained the archæologist, after a few minutes of conversing with them. "They're on their way north to In Salah. That's a town of considerable importance." The natives did not stop long, and the American expedition was also anxious to be going.