From so lofty a watch-tower the prospect was necessarily extensive; but on surveying the plain below with anxious glance, Dr. Barth failed to detect any sign of the caravan. He was hungry and athirst; but his dates and biscuit were not eatable, and his supply of water was so limited that he durst not indulge himself with more than a mouthful. Feeble and spent as he was, to descend was imperative; he had no water left when he once more stood upon the plain. He dragged his weary limbs onward for some time, but at length was forced to own to himself that he did not know the direction he ought to take. He fired his pistol; but it elicited no reply. Wandering further and further from the route, he came upon a small grassy oasis, where some huts had been constructed of the branches of the tamarisk. With hopeful heart he hurried towards them; they were empty. Then in the distance he saw a long train of loaded camels ploughing their slow way through the sand; no, it was an illusion!—the illusion of fever. When night fell, he descried a fire gleaming redly against the darkened sky; it must be that of the caravan! Again he fired his pistol, and again there was no answer. Still the flame rose steadily towards heaven, and seemed to beckon him to a place where he should find rest and safety; but he was unable to profit by the signal. He fired again; no answering sound came forth from the silence of the mysterious night, and Dr. Barth, on his knees, entrusted his life to the Divine Mercy, and waited and watched for the dawn of day. The dawn came, as it comes to all God’s creatures, whether rich or poor, happy or wretched—comes with a blessing and a promise that are too often accepted without thought or emotion of gratitude; the dawn came, and still the calm of the desert remained unbroken. He loaded his pistol with a double charge, and the report, travelling from echo to echo, seemed loud enough to awaken the dead; it was heard by no human ear but his own. The sun, for whose beams he had prayed in the night-watches, rose in all its glory; the heat became intense; slowly the belated wayfarer crawled along the hot sand to seek the scanty shelter afforded by the leafless branches of the tamarisk. At noon there was scarcely shade enough to protect even his head, and in an agony of thirst, he opened a vein, drank a little of his own blood, and lost all consciousness. When he recovered his senses, the sun had set behind the mountain. He dragged himself a few paces from the tamarisk, and was examining the dreary level with sorrowful eyes, when he suddenly heard the voice of a camel. Never had he listened to music so delightful! For twenty-four hours had his sufferings been prolonged, and he was completely exhausted when rescued by one of the Towaregs of the caravan who had been sent in search of him.