“In your issue of the 16th September Sir Hanbury Brown has reviewed the scheme suggested by Mr. J. S. Beresford, C.I.E., and conditionally approved by Sir William Garstin, for diverting the waters of the Albert Nile (known as the Bahr-el-Gebel) from Bor to the mouth of the Sobat river, on a length 340 kilometres, and sending them down a canal capable of carrying 600 cubic metres per second, at an estimated cost of £5,500,000. In his review Sir Hanbury puts his finger on the weak point in the project, viz., the difficulty and loss of water entailed at the crossing of the Albert Nile just upstream of the Sobat mouth. The difficulty will be got over, as Sir Hanbury himself suggests, by an earthen embankment provided with a regulator. The loss of water cannot be got over. “I have taken the following figures from Sir William’s report and from the gauge records of the Public Works Ministry:-- DISCHARGE IN CUBIC METRES PER SECOND DURING FEBRUARY, MARCH, AND APRIL OF THE ALBERT NILE. 1901. 1902. 1903. 1904. At Gondokoro above Bor 600 600 700 1,000 Upstream of the mouth of the Sobat river 300 300 350 435 “Now, in a year like 1901 or 1902, with 600 cubic metres per second passing Gondokoro, the diversion canal might be allowed to take in 500 cubic metres per second, leaving 100 cubic metres per second for the Albert Nile, Atem river, and all the Nuer, Dinka, and Shillook country between Gondokoro and the Sobat mouth. An allowance of 100 cubic metres per second would not be liberal, and would probably result in the water becoming stagnant and very impure; but we shall leave that alone. Starting with 500 cubic metres per second of clear water the high level diversion canal would never lose less than 50 cubic metres per second through percolation and evaporation before it reached the Sobat mouth. Many authorities would put the loss at 40 per cent., but we shall say 10 per cent. “We should then have 450 cubic metres per second entering the White Nile at its head, just at the end of the Albert Nile and at the mouth of the Sobat river. At this point, however, under normal conditions the Albert Nile would have been discharging 300 cubic metres per second. This supply, after the opening of the diversion canal, would have failed utterly, as the waters of the Albert Nile would have been diverted down the diversion canal. Whatever water there was in the Albert Nile would, moreover, have been at so low a level that it could not have flowed down the White Nile together with the high level water of the diversion canal. We should therefore have had in a year like 1901 and 1902 a net gain of 450 less 300 cubic metres per second, or 150 cubic metres per second at the head of the White Nile. By the time this extra water reached Assuân it would have become 100 cubic metres per second.