Between the watershed of Rudolf and that of the White Nile are many mountains, but as one proceeds northward in the direction of the Sobat, the country is increasingly parched and sandy where it is not stagnant marsh. Nileland contains within its limits the highest point of the African continent,--the culminating peak (whichever it may be) of the Ruwenzori range, a ridge which presents some thirty miles of snow and glaciers, and perhaps attains twenty thousand feet in supreme altitude. South of Ruwenzori, and still partly within the Nile watershed, is the Mfumbiro group of volcanoes, two of which possibly exceed an altitude of thirteen thousand feet. Away to the northeast of the Victoria Nyanza is the great extinct volcano of Elgon, over fourteen thousand feet in height, while the mountains of Abyssinia, where the Sobat, the Blue Nile and its tributaries, and the Atbara take their rise, reach in places to altitudes of sixteen thousand feet, and are capped with patches of perpetual snow. Nileland, therefore, offers a wonderful range of climate, temperature, and vegetation. Its fauna comprises the most interesting, the biggest, and the handsomest of African beasts. And its human races include nearly every type of Negro and Negroid,--Congo Pygmies, Turkana giants, Masai like Greek athletes and Balega[118] like apes, long-shanked Dinka and Shiluk, short-limbed Lendu, burly Baganda, handsome Bahima, ugly Berta and Shangala, bearded Nyam-nyam and womanish Madi; the clothed, curly-haired Galas and the absolutely nude Nilotic Negroes. In Egypt are pure Caucasians; in Nubia and Abyssinia, in the lands between the Nyanzas, are people of this regal stock variously mixed with antecedent Negro. The Nile has been the main route by which in ancient times the Caucasian invaded Negro Africa, the once exclusive path by which the white man’s cultivated plants and domestic animals reached the torrid lands and dense forests where the Negro, before the Caucasian touched him, lived in the condition of the semi-beast. No Negro race cared whence the Nile came or whither it flowed. Interest in geographical problems, as it was remarked in the first chapter of this book, is almost the exclusive heritage of the Caucasian. This is the human race which for some three thousand years has felt first a flickering curiosity, latterly an intense desire, to wrest the secret of the Nile sources from the heart of Africa. Its aim is accomplished. The main features of the Nile system are placed on the maps of civilised men, are known to intelligent Egyptians, Arabs, Indians, and Abyssinians.