The whole east of the African continent from the cape in the south up to Abyssinia in the north, and, I believe, farther, is marked by one persistent feature, the existence of several more or less parallel mountain-ranges rising in tiers from the coast. At the top of the last and highest mountain-range lies the great elevated inland plateau, stretching like a broad back along the continent. The first line of hills or low mountains runs at a distance of from ten to fifty miles from the coast of the Indian Ocean, and all the country between it and the sea forms a low coastal belt, which seldom rises more than a few hundred feet above sea-level, with a distinct coastal climate and vegetation. Between these coastal hills and the next range lies the second belt, called in South Africa the low veldt, again with a climate and rainfall and vegetation of its own. Next and last, at a distance of from a hundred to one hundred and fifty miles from the Indian Ocean, runs a mountain system, often rising to great altitudes, on which rests the great elevated inland plateau from four thousand to six thousand feet above the level of the sea. This plateau continues for hundreds of miles westward, and then begins to slope toward the Atlantic Ocean in the far distance. Sometimes, as in Central Africa, the slope to the west is very sudden, and another range of mountains forms the western buttress of the great central plateau. All the great rivers of Africa, with the exception of the Niger, rise on this plateau or on its mountain-flanks, which have a very high rainfall. The bush, or great forest, which is almost impenetrable in the coastal belt, becomes somewhat more open in patches in the middle belt, while on the plateau open, park-like country alternates with treeless, grassy plains, and the forest is confined to the deep valleys or the mountain-slopes. The rainfall, which is fair on the coast, becomes very light in the middle belt, which in consequence tends to have an arid character; on the plateau it is high or very high. Because of these marked differences the economic character of the three regions varies considerably. Semi-tropical products, such as maize, coffee, cotton, and millet, can be raised on an almost unlimited scale on the plateau; while rice, rubber, sisal, and copra are raised in the two lower belts. [Sidenote: The chain of large lakes.] [Sidenote: Extinct and active volcanoes.]