The discussion of the advantages of the different methods of forming Nile reservoirs does not belong to this paper, but there is a probability that a reservoir in some form will be made, and that the Fayûm will receive its share of the resulting increase of the summer water supply. Its present summer supply would probably be doubled, which would enable the province to increase the area under cotton from about 50,000 to 100,000 feddans, but would otherwise have no great effect on the province. The expansion of the present area under cultivation in the Fayûm to the lands along the north-east and south borders of the province does not depend so much on an increase to the present supply as on the construction of canals designed to carry sufficient water at a high enough level to command the lands above the present limits of cultivation. There is no want of water during Nile flood time outside the intake of the Fayûm, but its present canals will not carry more than a total discharge of 7,000,000 cubic metres a day, and therefore that is the maximum allowed to pass through the Lahûn bridges. If, however, the Wadi Raiân were to be made a reservoir, the reclamation of the lands along the south and south-west borders of the Fayûm would be made comparatively easy. What this area amounts to is rather uncertain. In Chapter III. the conclusion was arrived at, that the Wadi Raiân depression had never hitherto acted as a regulator to control the Nile floods and supplement the Low Nile, and that its past history shows no record of useful work, so far as the irrigation of Egypt is concerned. But this fact does not affect the question of its possible uses in the future, for which its physical features and geographical position may fit it. It is a depression, separated by a short width of hill from the Nile Valley, and if filled with water up to R.L. 24·00, would become a lake, having a surface area of about 600 million square metres, and a greatest depth of 64 metres. There is no doubt that the communication could be made; the only question is, would it be worth the expense, and could not better results be obtained for the same expenditure by the adoption of other rival projects. This question is now being considered by the Ministry of Public Works. There are four uses which the Wadi Raiân depression might be made to serve, if a communication with the Nile Valley were established. It might be used, (1) As a reservoir of control for the Nile floods. (2) As a reservoir of storage to supplement the Low Nile. (3) As an area to be brought under cultivation. (4) As a receptacle for the drainage of the Nile Valley during the flood season.