It has several great advantages. This lonely lake is situated some 6,000 feet above sea-level, in a wild and desolate country in Northern Abyssinia. It is 3,300 square kilometers in extent, and very deep. During six months in the year there are very heavy rains in the area which drains into the lake. Between Lake Tsana and Khartoum, a distance of 1,350 kilometres, the Blue Nile falls over 1,000 metres, and its rocky bed makes it very suitable as a channel for carrying the water. It is deep and narrow, with high, steep banks, and so the less liable to evaporation. For every metre by which the level of the lake was raised, 3,300,000,000 cubic metres would be stored, and it is obvious that, if the level were raised 4 or 5 metres, there would, after making a proper deduction for evaporation, be ample water to supply the greatest demand in Egypt, and also plenty besides available in the Soudan. There are also strong arguments for irrigation works on the Blue Nile. After the Cataracts of Rosaires, which are roughly speaking about halfway between Khartoum and Lake Tsana, the river passes through fertile plains consisting of rich alluvial soil, extending to a great distance on both sides. At present these lands yield only small returns, dependent as they are upon a somewhat capricious rainfall. With proper irrigation they would be most productive, and the water coming down from Tsana might be utilized, without any great difficulties, by a system of canals starting from this point, assisted by barrages and weirs. Further, the river would thus be rendered navigable at all seasons of the year, and would thus become an effective trade route in the most promising part of the Soudan. The great objection is that Lake Tsana lies wholly within Abyssinian territory. Nothing could be done without some very definite arrangement with the Emperor Menelik, and one that would be irrevocable by any successor of his who might be less friendlily disposed. Nothing, in fact, would be absolutely satisfactory unless complete sovereignty over the Reservoir district were assured to the Soudan Government. In view of the fact that the whole of this region is perfectly valueless to Abyssinia, or, indeed, to anybody else, except for purposes of water-storage, it does not seem impossible that by some cession of territory, or other compensation elsewhere, a satisfactory arrangement may be come to. But even so, the remoteness of the lake and the difficulties of transport would prevent the immediate realization of the scheme. Without a railway from some point in the Nile Valley it would be practicably impossible to collect the necessary materials and supplies, and such a railway will not be an affair of this year or next.