although several left high and dry by the retreating waters have frequently had to shift their sites in order to maintain their communication with the river.
At the defile of Silsile, or the "Chain," where the valley, 4,000 feet across, appears to have formerly been barred by an iron chain, the landing-stages adjoin the old quarries which supplied blocks of stone and statues for the palaces of the Pharaohs. A sphinx's head is still to be seen here not yet detached from the rock. From this point the mountains begin to diverge on both sides, the river winding in a plain about 9 miles broad, the first below the cataract that affords sufficient space for the site of a large town. Tere formerly stood Thebes of the hundred gates. Farther on the valley becomes wider, the distance from mountain to mountain varying from
Scale 1: 650.000.
12 to 15 miles; but in this part of its course, as well as above Thebes, the river bears chiefly towards its right bank, eroding the base of the cliffs of the Arabian range. On the left side the hills are mere sandy dunes shifting and modifying their form with every gust of wind. The cultivated tracts are here invaded by the Libyan desert, an extensive view of whose dreary wastes may be obtained from the crests of the western range.
Near Keneh, 36 miles below Thebes, the Nile describes that great curve which brings it nearest to the Red Sea. At this point it is distant from the coast, in a straight line, not more than 60 miles. Precisely in this direction the eastern range is broken by one of the deepest transverse ravines occurring throughout its whole course, and it may be asked whether, in some remote geological epoch, the Nile
