Is not the midnight like Central Africa to most of us? Are we not tempted to explore it,--to penetrate to the shores of its Lake Tchad, and discover the source of its Nile, perchance the Mountains of the Moon? Who knows what fertility and beauty, moral and natural, are to be found? In the Mountains of the Moon, in the Central Africa of the night, there is where all Niles have their hidden heads. The expeditions up the Nile as yet extend but to the Cataracts, or perchance to the mouth of the White Nile; but it is the black Nile that concerns us. - Henry David Thoreau