“Come back, Dick? Yes, if we have to abandon the balloon! if we should be forced to return to Lake Tchad on foot, and put ourselves in communication with the Sultan of Bornou! The Arabs cannot have retained a disagreeable remembrance of the first Europeans.” “I will follow you, doctor,” replied the hunter, with emphasis. “You may count upon me! We would rather give up the idea of prosecuting this journey than not return. Joe forgot himself for our sake; we will sacrifice ourselves for his!” This resolve revived some hope in the hearts of these two men; they felt strong in the same inspiration. Ferguson forthwith set every thing at work to get into a contrary current, that might bring him back again to Lake Tchad; but this was impracticable at that moment, and even to alight was out of the question on ground completely bare of trees, and with such a hurricane blowing. The _Victoria_ thus passed over the country of the Tibbous, crossed the Belad el Djerid, a desert of briers that forms the border of the Soudan, and advanced into the desert of sand streaked with the long tracks of the many caravans that pass and repass there. The last line of vegetation was speedily lost in the dim southern horizon, not far from the principal oasis in this part of Africa, whose fifty wells are shaded by magnificent trees; but it was impossible to stop. An Arab encampment, tents of striped stuff, some camels, stretching out their viper-like heads and necks along the sand, gave life to this solitude, but the _Victoria_ sped by like a shooting-star, and in this way traversed a distance of sixty miles in three hours, without Ferguson being able to check or guide her course. “We cannot halt, we cannot alight!” said the doctor; “not a tree, not an inequality of the ground! Are we then to be driven clear across Sahara? Surely, Heaven is indeed against us!” He was uttering these words with a sort of despairing rage, when suddenly he saw the desert sands rising aloft in the midst of a dense cloud of dust, and go whirling through the air, impelled by opposing currents. Amid this tornado, an entire caravan, disorganized, broken, and overthrown, was disappearing beneath an avalanche of sand. The camels, flung pell-mell together, were uttering dull and pitiful groans; cries and howls of despair were heard issuing from that dusty and stifling cloud, and, from time to time, a parti-colored garment cut the chaos of the scene with its vivid hues, and the moaning and shrieking sounded over all, a terrible accompaniment to this spectacle of destruction. Ere long the sand had accumulated in compact masses; and there, where so recently stretched a level plain as far as the eye could see, rose now a ridgy line of hillocks, still moving from beneath—the vast tomb of an entire caravan!