iving several tributaries, such as the
River Sobat and the Bahr-el-Ghazal, whose waters, combining with the
Bahr-el-Abiad, or White Nile, as it is called, maintain the steady
constant flow of the river.

Eventually it is joined by the Bahr-el-Azrak, or Blue Nile, which
rises among the mountains of Abyssinia and enters the White Nile at
Khartum.

During a great part of the year this branch is dry, but filled by the
melting snow and torrential rains of early spring, the Blue Nile
becomes a surging torrent, and pours its muddy water, laden with
alluvial soil and forest debris, into the main river, causing it to
rise far above its ordinary level, and so bringing about that annual
overflow which in Egypt takes the place of rain.

It is certain that the ancient Egyptians knew nothing as to the source
of their great water-supply,[4] their knowledge being limited to the
combined river which begins at Khartum, and for 1,750 miles flows
uninterruptedly, and, with the exception of the River Atbara, without
further tributaries until it reaches the sea; and it is curious to
think that for every one of these 1,750 miles the Nile is a _slowly
diminishing_ stream, water-wheels, steam-pumps, and huge arterial
canals distributing its water in all directions over the land. The
large number of dams and regulators constructed within recent years
still further aid this distribution of the Nile water, and it is a
remarkable and almost incredible fact that with the closing of the
latest barrage at Damietta, the Nile will be so completely controlled
that of all the flow of water which pours so magnificently through the
cataracts not a drop will reach the sea!

[Footnote 4: Many of the ancients believed the First Cataract to be
its source.]

One can easily understand the reverence with which the ancients
regarded their mysterious river, which, rising no one knew where, year
by year continued its majestic flow, and by its regular inundations
brought wealth to the country, and it is no wonder that the rising of
its waters should have been the signal for a series of religious and
festal ceremonies, and led the earlier inhabitants of Egypt to worship
the river as a god. Some of these festivals still continue, and it is
only a very few years since the annual sacrifice of a young girl to
the Nile in flood was prohibited by the Khedive.

Though regular in its period of inundation, which begins in June, its
height varies from year to year; 40 to