In principle the Assiout Barrage is exactly the same as that at the point of the Delta, and the difficulties of construction were also exactly similar, for in both cases the foundations had to be laid on the same shifting sands, and as each section of the work was undertaken a portion of the river had to be diverted from its course by means of temporary earthen dams. The shifting nature of the river-bed, the almost personal malignity of the water, constantly bursting through in countless springs, each of which had to be separately dealt with and suppressed, called forth the highest exercise of engineering skill. But the experience gained in the long struggle with the imperfections of the earlier Barrage infallibly told its tale. Every difficulty was successfully encountered, and the Assiout Barrage was completed by the summer of 1902, and was able to hold up the 10 feet of water required of it, without any failure, at the first attempt. The visible part of this Barrage, which is just over half a mile in length, consists of a viaduct or bridge with 111 archways, each 16 feet 5 inches in width, closed by strong iron gates, working in grooves made in the supporting piers, and raised or lowered from above. In contrast to the Delta Barrage, it is built throughout of stone, and not of brick. At the western end is a lock, the largest in Egypt, through which the largest of the boats that ply upon the Nile can easily pass. Below the water lies the strength of the structure. The viaduct rests upon a solid platform of granite and cement, 10 feet deep and 87 feet wide, set at a suitable depth below the bed of the river. As a further precaution against the action of the water, there are also below the platform two continuous lines of iron sheet-piles, with hermetically sealed joints. With such a series of obstacles to encounter, the danger of the water forcing its way through underneath the Barrage is small indeed. The whole amount of masonry used in this Barrage is 220,000 cubic yards.