Even as late as December, steaming up the 550 miles of river, often half a mile or more across, between Cairo and Assouan, against the strong current, watching the majestic sweep of those wide waters pouring irresistibly towards the sea, it is hard to realize the anxiety of later months. But May or June has a very different tale to tell. To take and store the precious water, which now during the flood and winter rushes down in untold volume, to be lost and squandered in the sea, and use it to feed the lean summer months, is almost absurdly obvious. No wonder that since Mehemet Ali gave so great a stimulus to the cultivation of cotton and sugar the idea of the Reservoir has been constantly in the minds of the rulers of Egypt. The strange thing is that so many hundreds, even thousands, of years should have elapsed without any attempt of the kind being made. Perhaps it was due partly to the reverence felt for the mighty and inscrutable power of the great river, partly to the passive fatalism innate in the Oriental mind. A few years ago Sir Benjamin Baker asked a prominent and representative land-owner in Egypt, a Pasha, and a descendant of the Prophet, what he thought of the prospects of a Nile Reservoir. With a shrug of his shoulders, he replied that ‘if it had been possible it would have been done 4,000 years ago.’ He reasoned wiser than he knew. At the second cataract above Wadi Halfa there are marks upon the rocks and other indications which go to show that a Dam once existed at that point, used to regulate the flow of the Nile. Swept away by some unrecorded disaster, no other direct knowledge of it remains. But it is far from unlikely that Herodotus, in his account of Lake Mœris in the Fayoum, has mixed up some tradition of this ancient work in Nubia. At any rate, whatever be the truth about Lake Mœris, his account proves beyond all question that the idea of a Reservoir was familiar to the ancient Egyptians. The tradition of a Reservoir somewhere on the upper waters of the Nile lingered long in Egypt. There is a curious reference to it in a book of travel by F. Vansleb, a Dutchman who visited Egypt about the year 1670. The fertility of the Nile flood is caused, he says, by a fall of dew, which usually takes place on June 17, just after the appearance of the ‘green’ water. This dew purifies the foul water, and makes it swell by fermentation. ‘Some of the country,’ however, he proceeds, ‘that are ignorant of the true causes of this increase, imagine that it proceeds from a large pond in Ethiopia _in the river itself_, which the Abyssins begin to open about June 12, and let the water out by degrees, more and more till September 14, by which time they begin to shut it again. But this is a foolish fancy of the Copties.’