These camels of the Touaregs are of the best breed. They can travel from three to seven days without water, and for two days without food; their speed excels that of horses, and they obey the commands of the "khatir," or leader of the caravan. They are known in the country by the name of "Mehari."
Such were the details furnished by the doctor, while his companions were studying this multitude of men, women, and children, traveling over the yielding sand with difficulty. The wind effaced their traces almost as soon as they had passed.
Joe asked how it was that the Arabs succeeded in guiding themselves in the desert, and reaching the wells so sparsely scattered throughout the immense solitudes.
"The Arabs," replied Ferguson, "have naturally a wonderful instinct for finding their way—where a European would be entirely puzzled an Arab would not hesitate; a small stone, a pebble, a tuft of grass, a shadow, the difference in the sand, will suffice for their safe direction. During the night they guide themselves by the polar star; they do not travel more than two miles an hour, and rest during the great heat of the day; so you can calculate what time they take to traverse the Sahara, a desert more than 900 miles long."
The "Victoria" had by this time disappeared from the wondering gaze of the Arabs, who envied her her rapid progress. In the evening the three travelers came to long. 2° 20′, and during the night they made more than another degree.
On Monday the weather changed completely. It rained tremendously. They were obliged to put up waterproof to resist this deluge, and the consequent increase of weight in the balloon and the car. This continual rain accounted for the marshes and swamps, which spread over the surface of the country. Here vegetation reappeared, with mimosas, baobabs, and tamarinds.
Such was Souray, with its villages roofed in the shape of Arminian caps. There were few mountains, but hills sufficient to make ravines and reservoirs, over which the guinea-fowl and snipe skimmed; here and there an impetuous torrent crossed the road. The natives crossed these by passing hand over hand from one branch to another of the over-
