"If it hadn't been for our proposed expedition, those two Arabs would have had no cause to wreck the train," Joe explained. "Oh. Indirectly, huh? Well, you're right." Very early the next morning the explorers were up making last-minute preparations. The train was to leave for Wargla at eight o'clock, giving them three hours or so to use to best advantage. "When do we reach our destination?" asked Bob, as he snapped the catch on his handbag. "At about noon day after tomorrow," answered Dr. Kirshner. "You see, it's a three-hundred-and-seventy-five-mile journey, and the train won't go any too fast through the mountains." "Mountains? Do we go through mountains?" queried Joe, a little surprised. "Yes, twice. Through these around here and then in the more lofty Aures. And the scenery is said to be wonderful." "What cities do we pass through?" Bob asked. "Setif, Batna, Biskra, and Tuggourt are the principal ones," the archæologist replied. "But there are a number of smaller towns. Get a map. There's one in the pocket of that bag over there." The boys took out the guide to Algeria and studied it closely. They found that the railroad did not make a straight run but curved considerably in order to pass through several important cities and towns. The map was not strictly up to date and consequently did not show the new stretch from Tuggourt to Wargla. "It's been constructed only recently," explained Mr. Lewis. "At present the French have proposed building a trans-Sahara route. When they will begin it, if ever, we don't know." "Perhaps not in our lifetimes," smiled Joe. "Large enterprises like that come very slowly." An hour before train time everything was in readiness, and it was Mr. Holton who suggested that they go down to the railroad station. The others were in favor of doing so, and as it was but a short distance away they were content to walk and carry their belongings. There was a good-sized load, but it was distributed evenly without anyone being overtaxed. At the station they checked the things securely and safely. Even then they had a leisure half-hour. "You may be surprised at sight of the train," said Fekmah. And they were. The Americans had expected to see rickety wood coaches attached to an incapable locomotive, but instead they saw a large, fine train of the French design. "All due to the influence of France, I suppose," remarked Dr. Kirshner, as he followed the others up in the coach. A few minutes later they felt a slight jerk and the train began moving slowly away from the station. Gradually it picked up speed, and before long Algiers disappeared on the horizon. "We're off!" said Joe enthusiastically. "Before long we'll see the great Sahara Desert!"