Page:Popular Science Monthly Volume 7.djvu/234

222 about seventy feet high, mounds strewed with broken pottery, and a vast number of water-cisterns now choked with earth.

In Africa, Lieutenant Cameron, of the Livingstone Relief Expedition, has made an important discovery which fixes the source of the Nile within known limits, and which, there is every reason to think, will connect the net-work of lakes and rivers of the water-system that Livingstone was investigating, with the great rivers that flow to the western coast of Africa, and probably with the Congo. Livingstone and Stanley had settled the fact of Lake Tanganyika's being connected with Lake Albert N'yanza on the north by a river flowing into Tanganyika. The natives informed them that a river flowed out of Tanganyika at its southern extremity, which, if true, showed that Lake Tanganyika had no connection with the Nile. This outlet Lieutenant Cameron has found on the western side of the lake, about a third of the way up its length. He went into the river about five miles, when his boat was stopped by grass and rushes. The natives informed him that this river flowed into the Lualaba, the river that Livingstone had been following up when Stanley found him. From information got from the natives, Lieutenant Cameron believes that the Lualaba is connected with the Congo, and has started to ascertain the fact. If he should be successful, and return through the Congo to the western coast, it will be one of the most important geographical achievements ever accomplished in Africa. He ascertained the elevation of Lake Tanganyika to be 2,710 feet above the sea. Dr. Nachtigal has returned from an exploration of five years in Central and Eastern Soudan. He says the curse of the country he traversed is the internal slave-trade. It has depopulated large tracts, and the wretched fugitives are now driven to sell each other as a means of subsistence. He saw a caravan of 1,000 of these unhappy wretches chained, while they were driven to the distant market of Kuka on Lake Tchad, the drivers mercilessly cutting the throats of those who were, even under the lash, unable, from exhaustion, to continue their terrible march. The Libyan Desert has been explored and found to be the most sterile part of the Sahara, being a dried-up basin of a shallow sea below the level of the Mediterranean, the present surface of which was found to be a dry chalk plateau, like the Swabian Alps. A French expedition is making preliminary investigations as to the feasibility of M. Lesseps's project for creating an inland sea south of Tunis. The project is opposed by many familiar with this part of Africa, not only as useless, but it would have an injurious effect on the climate of the south of Europe, and also destroy the great source of wealth in this part of Africa, the cultivation of the date-tree. The existing commerce can be sufficiently carried on by caravans, so that the commercial results of the undertaking would never justify the enormous expenditure, which is estimated at £24,000,000. Along the western coast of Africa, explorations have been unusually active. Dr. Güssfeldt made a journey up