“At least a hundred miles,” the Arab answered. “Perhaps many more. Dromedaries trot rather rapid.”

“Then, at that rate, it shouldn’t take us so very long to reach the Ahaggaras, should it?” asked Joe, who with Bob had not yet taken his place at the end of the caravan.

“No. But something could keep us back. Maybe storm, or could be bandits. Never know about that.”

As the explorers moved on, they occasionally saw small animals and birds. The naturalists were constantly on the lookout, shooting any creature that came within range of their guns. Among the victims of their marksmanship were desert larks, rats, hares, lizards, and a small animal called the ferrec.

Bob and Joe kept their time occupied in taking motion pictures of the country they were passing through. By the time that their caravan had stopped for the midday meal, the boys had “rolled off” a good many hundred feet of film.

“Here’s hoping our moving pictures here prove to be as successful as those that we took in Brazil,” said Joe, as he took out a bag of rations from a camel’s pack.

“If they do, the Neuman Film Corporation may give us a job on every future expedition we might make with our dads,” came from Bob.

Thus far the day’s traveling had not yet brought them to an oasis. Tishmak informed them that water would probably not be found until late the next night. The containers, however, held a large supply, making it unnecessary for the explorers to worry.

“It’s a good thing the dromedaries don’t need it often,” said Mr. Lewis, as he went about preparing the meal.

“Four or five days is often enough for them,” put in Mr. Holton. “They can go much longer than that, but it isn’t wise to risk it.”