The Nile has a length of course of some four thousand miles measured along the windings of the channel of its main stream,--the Kagera-Victoria-Mountain-White Nile. It is still doubtful as to whether the Missouri-Mississippi in North America is longer than the Nile, and thus the longest river in length of course in the world. In any case the Nile has the pre-eminence for actual length of basin, which, in a straight line measured from the furthest source of the Kagera to Rosetta on the Mediterranean, is about 2,490 miles. The area of the Nile basin is approximately 1,080,000 square miles.[132] This falls short of the area of the Congo basin by some 400,000 square miles. The volume of water which the Nile pours into the Mediterranean is trivial compared with the Congo’s contribution to the ocean; but then the waters of the equatorial zone in East Africa are evaporated from the surface of lakes, squandered in swamps, sucked up by the desert winds, and finally are employed to irrigate Egypt; so that no comparison with the output of the Congo would give a fair idea of the catchment in the Nile basin. This, perhaps (including the annual contribution to the Nile lakes), reaches to two-thirds of the volume of water poured into the Atlantic by the Congo’s single mouth. This geographical sketch is intended to place before the reader the main features in the geography of Nileland. It is the summing up of the results of exploration during four or five thousand years. The preceding chapters deal with the history of the way in which the Caucasian has laid bare the secrets of the Nile to the curiosity of the civilised. It is only the Caucasian race which has cared for geography in the past,--the Caucasian in all his types as Dravidian, Hamite, Semite, Iberian, and Aryan. The Mongol of Asia and America, the Negro of Papua and Africa has never cared to ascertain whence rivers flowed and whither, what lands lay beyond the ocean or the snow-peaks. Some early cross with a Caucasian race sent the Polynesian cruising about the Pacific and venturing over the Indian Ocean from Java to Madagascar; but the more purely Mongoloid brother in China and Japan did not care to trace the chain of Aleutian Islands to Alaska and America, or if he did so by accident, felt the question of no interest, sequence, or importance. Only the Caucasian, and mainly the White Caucasian, has worried about the Nile problem. He has attacked it first from the north (Hamite, Greek and Roman); then from the northeast and east (Hamite and Semite, Greek, Portuguese, and British); once more from the north (Arabs, Turks, French, British, Germans, Italians); resolutely from the southeast (British and Germans); latterly from the southwest (British, Belgians, and French); and, finally and completely, from the north and northeast. APPENDIX I THE ROLL OF FAME OF THOSE WHO STARTED ON THE NILE QUEST IN MODERN DAYS