— 35 — 
From Lake No to the Sobat mouth, on a length of 134 kilometres 
is the tail reach of the Albert Nile. The Albert Nile flows into Lake 
No in its south-eastern corner and leaves it on its east side. On the 
west side the Gazelle river flows into the lake. Lake No has an area 
of some 20 square kilometres in times of low supply and 100 square 
kilometres in flood. In low supply the depth is between 1*50 and 
2*50 metres. In the reach between Lake No and the Sobat mouth, 
the river is very fairly straight; the summer channel is about 170 
metres wide and as a rule about 5 metres deep upstream of the 
mouth of the Lolle, though in one place about 8 kilometres from Lake 
No it becomes only 50 metres wide for a short distance. Between 
the tail of the Lolle river and the mouth of the Sobat river, the 
summer width widens out to about 400 metres with 3 metres depth of 
water. However extensive the marshes may be, the high land forming 
the limit of the inundation is everywhere in this reach visible from 
the main stream. The Gazelle river, which flows into Lake No, has a 
discharge varying from 0 to 40 cubic metres per second. The Lolle 
river which flows in on the left bank upstream of the Sobat mouth 
is probably an arm of the Albert Nile or an overflow of the Gazelle 
and has a discharge varying from 0 to 40 cubic metres per second. 
On the right bank, the Zeraf river flows into the Albert Nile, with a 
discharge varying from 30 to 160 cubic metres per second. The 
Megahid river flows in 30 kilometres below the tail of the Zeraf river 
and adds an undetermined quota of water. 
At its junction with the Sobat river, the Albert Nile discharges from 
300 to 450 cubic metres in summer; it does not discharge much more 
in flood as the waters of the Sobat river in flood hold up the Albert 
River and make it overflow the low lands up to Lake No and beyond for 
a depth of 3 metres in high floods. This reach of the Nile is a flood 
reservoir, which empties itself ordinarily by the end of winter. 
14. The Gazelle River.- — The Gazelle river, which flows into Lake 
No, has a catchment basin of 240,000 square kilometres, with an annual 
rainfall of 75 millimetres; and an additional catchment basin of 230 
square kilometres with an annual rainfall of 30 millimetres; and yet the 
river discharges nothing in summer and about 40 cubic metres per 
second in flood. It is the most extraordinary river in the world, often 
blocked by sudd and invisible. It has practicaly no banks in flood or in 
times of low supply, while the waterway varies in width from 6 metres 
to 90 and in depth from 2 metres to 6 metres. It makes its way between 
