PB00RES8 OF DI8C0'^BT. 411 1,000 miles north and south, from the foot of tho Atliu* to tbo Sudan. Yet, com- paratively short us is tho journey in this direction, how lulx>riuus and full of dangers for caravans slowly advancing under a fierce sun, in the midst of blinding sands, beguiknl by tho glittering mirage, tormented by the fear of finding dricd-up springs at the next watering station ! Excluding the oases of Burka and Kufra, Tripolitana and Fezzan, the smaller " Saharas " of TuniHia, Algeria, and Marocoo, together with the grassy zone skirting the fertile regions of the Sudan, the super- ficial area of the Great Desert may be roughly estimated at 2,480,000 squam miles. The whole population of the various oases, isolated uplands and humid depressions scattered over this vast extent is supposed not to exceed five hundred thousand souls. Progress of Discovery. As in the days of Herodotus and Strabo, the journey across the Sahara is always a laborious undertaking, probably even more so now than ut that epoch, tho ground having become more arid, rivers having dried-up, ond forests disappeared during the last two thousand years. The descriptions of the old writers are doubt- less exaggerated, as they needs must be at a time when explorers were unaided by scientific instruments, and when their reports, passing from mouth to mouth, at last merged in fable. Libya, south of the Mediterranean, was regarded as a land of fire, uninhabitable by men, beasts, or plants, whore the very soil was calcined. Nevertheless, journeys of exploration and military exixKlitions made itevident that these " torrid " regions were not inaccessible. Herodotus relates the adventures of the five young Nasomous who had ventured into the desert in the direction of tho zephyr, and who after many days' journey reached a city in the country' of the Blacks, situated on a great river. But whether this was the Niger at its great bend in the Timbuktu district, or Lake Tsad, near the mouth of the Komadugu, or some other affluent, cannot now be determined. In any case, these Libyan pioneers had crossed the Sahara, judging at least by the direction followe<l by them, and the detailed account they give of the river peopled with crocodiles and flowing from west to east. Without getting so far, the Roman captains had also penetrated far to the south, for Cydamus and Garama still preserve the remains of their moimments, and Suetonius Paulinus had surveyed the valley of the Wod Guir, probably a tributary of the stream reached by the Nasomons. But how many other armies, how many caravans, were long ago lost in the wilderness, consmned by the burning sun, like the running waters gradually absorbed in their sandy beds ! Since the close of the last century, when the Society for the Exploration of Africa was founded in England, the routes of European travellers across the Sahara have been carefully traced on the map. Even those of Jewish and Arab tradere have been followed and attached to the network of scientific exploration. Tbo Sahara has already been traversed at several jwints from north to south ; but no traveller has yet made the complete journey in the direction of its length from the banks of the Nile to the shores of the Atlantic. The reader will remember the
