"I guess you're right," agreed Joe, thoughtfully. "There's no use wasting time trying to do a thing that can't be done. Have you made inquiries as to about when we can expect the train to be ready?" "Yes," answered Dr. Kirshner. "The station agent said inside of two days, but it probably won't be that soon." "Let's hope it will," said Bob. "I'm anxious to get started into the desert. How long will it probably be before we reach our destination, once we get started on camelback?" "That all depends," replied the archæologist. "If we see fit to use dromedaries, or the one-hump camel, we will make much better time. They can travel from ninety to a hundred miles a day with ease, and if forced, can do much better than that." "But the jolting is most uncomfortable," Mr. Lewis reminded him, and Fekmah nodded. "Soon get used to it, though, don't you?" asked Joe. Fekmah laughed. "No, never," he said. "But not feel it so bad after many days of riding." "But getting back to your question," resumed the archæologist, speaking to Joe, "if we have good luck we should cover the thousand miles to the Ahaggar Mountains inside of two weeks, considering, of course, stops at oases, small towns, and the like. Then how soon we can find the hidden riches would be a mere guess, because without the map Fekmah will probably have much more difficulty in recognizing various landmarks." "But you must remember that our main object was to work for the good of science," Bob's father said. "Mr. Lewis and I were to get specimens of any animal life that exists in the far reaches of the desert, and you were to look up the remains of ancient civilizations. Incidentally, though, we'll search for the hidden riches." "And Joe and I were to take motion pictures when we get started on camelback," said Bob proudly. "Speaking of animal life," began Mr. Lewis, "suppose in the morning we get out in the open country and see if we can collect any specimens. From what I've read and heard, I guess it is necessary to go at least as far as Arba before we would find a region that is worth hunting in." "I'm with you," said Mr. Holton. "We'll engage an automobile to take us the fourteen miles or so to Arba, and then foot it from there. It will be funny if we can't bag a few worth-while specimens, at least." "Of course Joe and I can go, can't we?" grinned Bob. "You bet. And Dr. Kirshner and Fekmah, if they care to." But those persons announced that they would remain in Algiers and further discuss the coming expedition. "Then too," the archæologist remarked, "I'd like to keep posted on the progress made in getting the train ready for the journey to Wargla." It was well past noon, and the explorers now realized for the first time that they were extremely hungry. The strain of the eventful morning had stimulated their appetites to a high degree, and they felt they could devour almost anything in the way of food.