the North-German climate promised only to aggravate, Nachtigal was compelled to seek a milder atmosphere in the south, and removed to Algiers, and afterward to Tunis, where he found a lucrative practice, and obtained a knowledge of the Arabic language, and of the manners and customs of the people, that proved useful to him in his future explorations. At Tunis he became physician to the Bey, whom he accompanied upon a campaign against some of his rebellious subjects.
Toward the end of 1868 Gerhard Rohlfs came to Tripoli, charged with a commission by the King of Prussia to dispatch an assortment of presents to Sultan Omar, of Bornoo, in acknowledgment of the hospitality he had given and the valuable services he had rendered to the German travelers Earth, Vogel, Overweg, Von Beurmann, and Rohlfs, who had at various times visited his capital, and in return for a silver-mounted harness which he had sent to his Majesty. King William was sending, in response to these favors, a fine collection of European manufactured goods, a throne-chair, and a portrait of himself. The occasion of this visit was the decisive point in Nachtigal's life. Rohlfs found in him just the man to carry the gifts to their destination, and he, the choice having been approved by Bismarck, left Tripoli, with his caravan of eight camels, on the 18th of February, 1869, on his long southern journey, traveling under the name of Edris Effendi. The first stopping-place was at Moorzook, the capital of Fezzan, where Nachtigal found that the country beyond was in so unsettled a condition, and the roads were so infested, that it would be futile to attempt to continue the journey at that time. Probably a year would have to pass before he could go on. He would not wait idly, and he resolved to use the occasion to make an excursion to the highland country of Tibesti, southeast of Fezzan, the ancient land of the Troglodytes, or cave-dwellers, which had long excited the interest of European travelers, but which no one had ever been able to reach. Its people, the Tibbu, had the worst reputation for robbery and treachery of all the Africans. Nachtigal attempted and made the journey from which all others had shrunk. He was smuggled secretly into the country by his guides. The party lost their way and wandered for many days through the desert without food or water, making a near approach to death by thirst. This, as a German biographer describes it, condensing from Nachtigal's own account, in the midst of summer in the burning wilderness, where two days without water meant death. Amid stones and sand, through barren ravines and over rocks, marched the travelers, their parched tongues cleaving to their mouths, and the half skin of water which they still had having to suffice for ten persons. The guide went upon a knoll to look around, while the rest of the party hung anxiously upon his eyes as he made his report, "None yet." The exhausted camels lay down, and Nachtigal by the side of one of them, to die, while the Mohammedan servants
