86 NORTH-WEST AFRICA. Western Sudan. Thanks to the gulf of the two Syrtes, which forms a bight in the contour of the continent of a mean depth of about 300 miles, the journey across the desert to the fertile regions of the interior is reduced by one-fourth. Moreover the route from Tripoli to Lake Tsad, which lies due south, is relatively easy, being relieved at tolerably short intervals by the Fczzan and other oases. Neither the hills nor the dunes present any serious diflBculties to modem engineers, while the scattered populations of the oases, long familiar with their European visitors, would certainly oppose no obstacle to the construction of highways of communication. " To the future master of Tripoli belongs the Sudan," exclaims the traveller G. Rohlfs, when urging Italy to take possession of Tripolitana. He proposes, either from the port of Tripoli or from that of Brdiga, at the head of the Great Syrtis, to construct a railway in the direction of Kuka, near the west coast of Lake Tsad. Even this line might perhaps be shortened by about 120 miles by creating a harbour in deep water on the west side of the Syrtis, somewhere near the Marsa-Zafran creek. Not only is this the shortest route for the line destined one day to connect the basin of the Mediterranean with that of the great inland lake, but it also seems to be the most convenient for the continental trunk line, terminating on the Atlantic coast at the head of the Gulf of Guinea, between the Niger and Congo basins. Hence there can be no doubt that the railway penetrating from Tripolitana south- wards must sooner or later become one of the great commercial highways of the world. But even this can scarcely exceed in importance the more westerly route, which is intended to connect the already developed network on the Algerian coast through the Wed-Messaura with the great bend described by the Niger below Timbuktu. In this direction both termini would offer an immense advantage in respect of population, abundance of natural resources, and commercial activity. Here also it would be a mere question of continuing lines either already opened, or for which concessions have been granted south of Algeria to a more southern latitude than Tripoli. Physical Features. The Tripolitana highlands take their rise eastwards in an unexplored region of the desert, where the Haruj-el-Aswad, or Black Haruj, so called from the colour of its lavas, forms a chain of volcanic origin with a mean direction from south-east to north-west. Hitherto Ilornemann is the only traveller who has crossed the eastern section of this range, although nearly a century has lapsed since his visit. More recent explorers have only seen these mountains from a distance, or heard of them from native report. The Black Haruj, which is also covered with much reddish scoria, lighter than the black lavas, consists of small low ridges and isolated peaks with abrupt sides furrowed by deep fissures and crevasses. These hills, which have a mean elevation of 650 feet above the plateau, itself about 2,000 feet above sea-level, are perhaps the volcanoes which formerly lit up the shores of the Mediterranean or of the lakes
