Lombardini was no untrue prophet when he wrote that he was convinced that the more carefully the discharges were taken and the results known, the more would engineers be astonished at the extraordinary amount of the subsoil water which filtered into the Nile from the head of the White Nile to the sea, and which gave back to the Nile in the months of deflux of the river, the water which had percolated into the soil during the afflux. He predicted that heavy as the evaporation was in April, May and June in the Nile valley, the influx of subsoil water would be found to counterbalance it. When we calculate the extent of the water used in irrigation along the course of the Nile, and compare the discharges at Tewfikieh, Khartoum, Assuân, Cairo and at the tails of the Rosetta and Damietta branches during the time of low supply we can only admire the perspicacity of the greatest hydraulic engineer of the last century. 26. =Nile water.=--For the following information I am principally indebted to M. J. Barois’ “Les irrigations en Egypte” just published, and to an article by Mr G. P. Foaden in the Journal of the Khedivial Agricultural Society for January 1903. The colour of Nile water is generally a pale yellow, but in June, when the first indications of the coming flood are given by a continuous gentle rise of the river from its minimum gauge, the water changes to green and remains so for two or three weeks. This green water has a very disagreeable taste and odour, and is especially objectionable when the Nile has been very low and the rise is a slow one. In June 1900 it was extraordinarily bad, and the river water was so poor in oxygen that standing on Kasr-el-Nil bridge at Cairo one could see the surface of the water covered with fish which apparently could only live near the surface. In the deep reaches near Kalabsha in Nubia, the fish died in myriads. This green water is attributed by some to the immense amount of vegetable matter brought down by the White Nile from the Sudd region. Some say that it comes principally with the first rise of the Sobat river. But the generally accepted theory to-day is that the green water is the result of vegetable growths from germs is the water itself, and that wherever or whenever the current becomes exceedingly slack they multiply greatly. Upstream of the Assuân dam in June 1903 the water was extraordinarily green and exceedingly objectionable. As it was shot out of the upper sluices of the dam and broken up into spray on the downstream side of the dam it became so purified that I found it difficult to understand that the water flowing past Elephantine Island was what I had seen at Shellal. The green water is followed by the red water of the Nile flood, which has always thoroughly established itself at Cairo by the 1st of August. This red water comes from the scourings of the volcanic plateau of Abyssinia by the Blue Nile and the Atbara. Rich in mud and rich in manures, this red water is the creator of Egypt.