a safety-valve in the inundation, and, while they lengthen out the period of the flood in Lower Egypt, enormously decrease its volume at any given time; but when the same lands are receiving only an occasional watering, the volume that rushes to the sea is by so much the greater, and the pressure on the dykes is heavily increased. If Mehemet Ali had been content to preserve the old basin dykes, the vivifying effects of the flood-water might have been occasionally applied, and some of these dangers averted. But, as we have seen, everything had to give way to the immediate cultivation of cotton, and the dykes were levelled. Nor was this the only error committed. The new canals were faulty in slope and alignment. Too often their subsidiaries were constructed merely with the object of carrying water to the lands of powerful and favoured individuals, without regard to the general interest. It was found in consequence that an enormous silting up of the canals took place every year. But the Viceroy, with all the forced labour of Egypt at his free disposal, took little heed of this, and vast numbers of men were dragged from their homes every year to redig the canals. Even so it was impossible for the task to be completed before the next flood came round. The lower reaches of the canals remained choked with mud and weeds, and, worst of all, proper drainage was neglected. When Napoleon was in Egypt in 1798, his master mind, accustomed to go to the root of many matters in spite of all the alarms and distractions of war, perceived how much might be done by a regulation of the water at the point of the Delta. His idea was to close each branch of the river alternately during the flood, and so double its effect. Mehemet Ali proposed to apply the same principle to low-water, and began to close the head of the Rosetta or left-hand branch of the Nile with an enormous stone dam, so as to divert the whole supply into the Damietta branch. Linant Pasha, then chief of the French engineers, who had been brought over to advise upon the new works, persuaded him to abandon this design, and proposed instead to build a barrage upon each branch, constructing them in the dry, and then diverting the Nile into its new course by means of earthen dams. The Viceroy approved, and at once proposed, with characteristic energy, to dismantle the Pyramids and make use of their material, just as Sultan Hasan had once stripped the marble casing from the Great Pyramid to construct his famous mosque. Fortunately, the prosaic question of transport arrested this design, and new limestone quarries were opened near Cairo instead. But although workshops were built, material collected, and foundations dug, Mehemet seems to have lost all interest in the work, and in 1835 he abandoned it altogether, and for seven years nothing more was heard of it.