When that day comes—and I repeat that it is not far distant—the merchants of Nigeria and the Sudan will run up to Algiers, or even to Paris, to do their buying, just as Mid-West merchants go to New York; the sons of the great Mohammedan chieftains of Darfur and Wadai will be sent to the Moslem universities of Fez and Tunis as the sons of Western ranch-owners are sent to Yale and Harvard; the products of French Equatorial Africa—the greatest untapped reservoir of raw materials on the continent—will go rolling northward to the factories of Europe in a steady stream, while the manufactured goods of Europe and North Africa will find their way in ever-increasing quantities to the rich markets of the South. Caravans of motor-buses, doing their twenty miles an hour, will bear merchants, drummers, students, soldiers, scientists, officials, tourists, across the great divide. The road is perhaps the most effective agency of civilization. As Mr. Hilaire Belloc has so admirably put it: “More than rivers and more than mountain chains, roads have moulded the political groupings of men. The Alps with a mule-track across them are less of a barrier than fifteen miles of forest or rough land separating one from that track.” * * * * * The sun was but a slender crimson arc above the horizon when we set out from Tozeur in the twelve-wheeler to push southward into what some one has aptly termed “the last home of mystery.” The early morning is always cold in the Sahara, and even our Arab guide shivered beneath the folds of his camel’s-hair burnous. For the first few miles our route led us across a rocky, stone-strewn plain, the big car rumbling and shaking like a motor-truck. Then, topping a rise in the _hammada_, we beheld the sand-dunes. Silent, mysterious, forbidding, they reared themselves across our path, their flanks as trackless, as destitute of vegetation, as the polar snows. I don’t know how high they were, for everything is enormously magnified in the clear air of the desert, but they seemed appalling as they rose abruptly from that bleak, monotonous expanse. As for climbing them in a motor-car, I should as soon have thought of driving up the side of the Great Pyramid. But I leaned back in my snug, leather-cushioned seat unconcernedly, confident that the chauffeur, a veteran at the business, knew a way to circumvent them.