It will be noted that at the beginning of this paragraph I stated that “the perfection of the perennial irrigation of the Delta north of Cairo will in no way affect the Nile in flood.” This had reference only to the quantity of water taken from the Nile in high floods. There is however one very serious aspect of this question. The regulation on the Barrage in low floods, which has gone on steadily since 1899 when Sir Hanbury Brown used the Barrages in flood for the first time, has enormously increased the value of the works, but it has certainly caused the Main Nile to silt, and probably also the branches, owing to a reduced discharge and velocity of the silt-bearing water, whose capacity to carry on that quantity of silt depends on its velocity. It seems to me that unless steps are taken to insure the scouring out of this silt by the clear water of November, December and January the consequences will be very serious. High floods scour out their beds, but if a very high flood were to come early before the silt had been scoured out, it might overflow the banks near Cairo or in the middle reaches of the Nile branches in the Delta. Sir William Garstin has estimated the cost of converting the existing basins of Upper Egypt into perennially irrigated land at £7,000,000, thus made up:-- Conversion of Upper Egypt basins £ 5,000,000 Two barrages between Assyut and Kena „ 2,000,000 ----------- Total £ 7,000,000 =========== The resulting land tax from the improved irrigation in Upper or Lower Egypt he has estimated as follows:-- Upper Egypt. {Basin land converted 750,000 acres @ £ ·50 = £ 375,000 {Land irrigated by pumps 100,000 „ @ £ ·30 = „ 30,000 Lower Egypt. Reclaimed land 800,000 „ @ £1.00 = „ 800,000 --------- Total £ 1,205,000 =========