While the problems of Central Africa were thus being elucidated, the exploration of the nine great rivers which form the Bahr-el-Ghazal, the chief tributary of the Nile, was attracting much attention, the most valuable work being done by Georg Schweinfürth, who mapped the river with high accuracy. The Nile above Gondokoro was also surveyed by English officers; the Sahara and the Sudan were widely explored by G. Rohlfs and G. Nachtigal between 1860 and 1875, and the connection of the river Welle with the Congo system was established by W. Junker, who also travelled in the Sudan from 1875 to 1886. The British during this period were pushing their way northward from South Africa, and emigrants were flocking to the goldfields and diamond mines. The French have spread their explorations over the Sahara and their territories in the Sudan and West Africa. From the date of Stanley’s return African history underwent a rapid change. The period of driving the main lines of exploration through the continent was over, and a new era began in which branch lines could be laid down, and colonial expansion could take place along them. The continent is now partitioned among the European Powers, and has been more or less provisionally mapped; but it will take long years of survey and scientific investigation before its features, its resources, its peoples, and its possibilities are adequately known.
THE NINETEENTH CENTURY AND AFTER: ASIA AND AUSTRALIA