When he sighted the southern end of Lake Victoria on 3 August 1858, John Hanning Speke (1859b:397) realized that he had discovered the “source” of the White Nile, the most important tributary of the Nile proper, and so had “almost, if not entirely, solved a problem which it has been the first geographical desideratum of many thousand years to ascertain, and the ambition of the first monarchs of the world to unravel.” That Speke was an unknown explorer and that he had made his discovery on a solo “flying trip” during the East African Expedition of 1856-59, which, under the command of the renowned explorer Richard Francis Burton, had already also discovered Lake Tanganyika, made Speke's accomplishment all the more remarkable.As contemporaries soon asserted, Speke's discovery culminated a historical series of excursions, real and imagined, into the interior of Africa and placed Speke at the pinnacle of a line of explorers and geographers that ran from Herodotus, Julius Caesar, and Ptolemy to, in more recent times, James Bruce (the Scotsman who “discovered” the source of the Blue Nile, the second most important tributary of the Nile, in 1770), the German missionaries Ludwig Krapf and Johannes Rebmann (who “discovered,” respectively, the snow-capped mountains of Kilimanjaro in 1848 and Kenya in 1849), and noted “armchair geographers” like W.D. Cooley, Charles Beke, and James M'Queen.
