Two things appear to have operated in his mind. It seemed simpler to keep on digging out the main canals by the help of the corvée, and cheaper, too, because nothing was wanted but the unpaid labour, though it was false economy. And, secondly, his ill-regulated but far-reaching imagination was already busy upon a new idea, nothing less than the construction of a great reservoir, which should store up the surplus water of the winter and let it out again in the summer, thereby, as he supposed, rendering unnecessary the construction of any minor work like a barrage. Surely there can be no more curious instance of the irony of fate than the history of these two great ideas—the Barrage and the Reservoir. Both in turn have been carried into successful execution by engineers and statesmen belonging to the very nation which shattered the ambitions of their first authors. Against the crumbling walls of Acre, held so stoutly for weeks by the English sea-captain, when even the notion of a day’s defence seemed a madness, Napoleon’s dreams of Eastern empire dashed themselves vainly to pieces. Forty years later the same walls could not withstand for half a day the guns of their former defenders, and Mehemet Ali in turn saw his own imperial dreams finally dissolve. Mehemet neglected the Barrage, because he thought the Reservoir would make it unnecessary; and yet in the end it was only the successful working of the Barrage which gave new life to the project of the Reservoir, and made its completion an absolute necessity. The Viceroy, perhaps, deserves little credit for his idea. In matters of irrigation it is often much easier to see what to do than how to do it; like other great men, he imagined better than he knew. Undoubtedly he was fascinated by the fame of King Amenemhat of the Twelfth Dynasty, and his construction of Lake Mœris in the Fayoum. He constructed a new regulator at the spot where the Bahr Yusuf enters that extraordinary province, and even built himself a house there. But whether because of the inherent difficulties of the subject, or because of foreign complications, nothing was done until in 1842 his mind reverted to the idea of the Barrage at the point of the Delta. The Frenchman Mougel had the address to couple his design with a scheme of military fortifications, and, attracted by this double advantage, Mehemet at once ordered the works to be begun, though, unfortunately, his energy was more devoted to making the point of the Delta the military capital of Egypt than towards the regulation of the water. By this time, however, Mehemet Ali’s career was drawing to a close, and in 1848 he died, leaving the work in which he never more than half believed still unfinished.