— 14 — 
From the Atbara junction to the sea, the Nile has a course of 
2,700 kilometres. In its first length of 1480 kilometres to Assuan it 
traverses the 5th and 4th cataracts between Berber and Dongola, the 
3rd and 2nd cataracts between Dongola and Wady Haifa, and the 
1st cataract at Assuan. All these cataracts are navigable in flood, but 
not so in summer. From Assuan to the Barrage at the head of the 
Delta north of Cairo, the Nile has a length of 970 kilometres and 
traverses Egypt without a cataract or interruption of any kind. At 
the Barrage, the Nile divides into the Rosetta and Damietta branches, 
and after a further course of about 240 kilometres in either branch, 
flows into the Mediterranean sea. Its greatest length from the sources 
of the Kagera river to the sea is 6350 kilometres, constituting it one 
of the longest rivers in the world. 
4. The Slopes and velocities of the Nile in its different 
reaches. — Table 2 of Appendix B and Plate II comprise all the 
information available under this head which 1 have been able to collect. 
For the slopes I have adopted the following data : 
R. L. of Lake Victoria 1129 metres above mean sea 
„ Fowera 1060 „ „ 
„ Lake Albert 680 „ „ 
„ Khartoum (flood) 389 „ „ 
From Khartoum to Wady Haifa I have adopted the generally accepted 
levels of the original Soudan railway survey. From Wady Haifa to 
the sea 1 have levelled myself. Upstream and downstream from the 
adopted levels I have carried the levels by the aid of slopes calculated 
from velocity and hydraulic mean depth data. It seems to me absurd to 
adopt a level for Lake Choga 50 metres above that for Fowera, and 
then to add, that in the 140 kilometres between the two places the 
Victoria Nile has a gentle slope, wide bed and gentle velocity. By a 
strange fatality, this very error has crept into the figures under Lake 
Choga on Plate II. The error is noted in the corrigenda attached to the 
Plate. The Section is drawn correctly but these wrong figures have 
been interpolated by an oversight. 
The Victoria Nile Falls 450 metres in 400 kilometres, but has four 
reaches ; the first 
1 2 0 0 ? 
the second 
i 
2 0 0 0 0 ? 
the third yw past the 
Murchison Falls, and the fourth YooTo- 
The Albert Nile falls 277 metres in 1290 kilometres. The first 
reach past Wadelai has a slope of yTooV? second over the Fola and 
following cataracts has a slope of y^o, the third y yo 'b b ? the fourth 
2 0 0 0 0 ’ 
the fifth 
and the last below lake No of 
in flood. 
2 5 0 0 0 ? 
7 5 0 0 0 
