Page:Africa (Volume I).djvu/58

 should perhaps descend over five degrees to the south of the equator and two to the east of the emissary from the great lake. The winding of its bed lengthens its whole course by over three-fourths. In superficial area the Nile basin is inferior both to the Amazon and the Mississippi, and apparently about equal to the Congo. Except in its middle course, between the Makrara territory and Abyssinia, the lateral river valleys are of slight extent, and owing to the arid character of most of its basin, it cannot compare in volume to any of the other great rivers of the world. According to recent estimates, the Atrato, which falls into the Carribean Sea near the Isthmus of Panama, has a greater discharge, although its basin is nearly a hundred times smaller than that of the Nile.

The general tilt of the land from the central plateaux to the shores of the Mediterranean coincides with the Nile Valley. Nevertheless to its main fluvial arteries the whole of this region is exclusively indebted for its geographical unity. The lacustrine uplands of the interior, the marshy tracts where its chief affluents join the White Nile from the south-west, the isolated Abyssinian highlands, the Kordofan uplands encircled by solitudes, the Nubian deserts, the narrow winding valley of Upper Egypt, lastly the smiling plains through which the main stream ramifies as it approaches the Mediterranean, are all so many distinct geographical domains, which must have had a purely local development but for the unity imparted to them by the hydrographic system of the Nile. Thanks to the facilities for communication afforded by this great water highway, its lower reaches were peopled by Nubian colonies from remote times; the old Egyptian culture advanced up to Meroe, and even farther south; frequent wars were waged between the Ethiopians and the lowlanders for tilie command of the stream; and for centuries Egyptian viceroys have made incessant efforts to extend their possessions to the whole of the Upper Nile basin as far as the equatorial lakes and the "Great Divide." Along this main highway of North-East Africa the natural divisions between the riverain populations are marked by the obstructing cataracts and the confluences of the great affluents. Hence the study of the stream to which the surrounding lands owe their historic evolution claims our first attention.

The ancients asserted that the Nile had its source in the "Mountains of the Moon," and it is noteworthy that the southernmost affluents of the lacustrine system whence it escapes were met by Speke in the "Land of the Moon." But amongst these affluents is there one copious and large enough to be regarded as the main upper stream? This "head of the Nile" is still being sought, and as in the time of Lucan, no one can yet boast of having seen the farthest source of the Nile. According to the maps prepared from the itineraries of Stanley, Smith, Pearson, and the French missionaries, the Mwaru (Liwumba, Luwambé), which rises beyond the fifth degree of southern latitude, and flows north and north-west towards the