the Nile Delta. While initially unsuccessful, the two barrages would ultimately permit conversion of over of the Nile Delta from seasonal basin irrigation to perennial irrigation; the increased availability of water lengthened the dry summer growing season, and dramatically increased agricultural output. But this massive work proved to be very costly and impinged upon engineering's state of the art. Construction took nearly 20 years and consumed untold wealth. The Rosetta section was 465 meters in length with 61 arches containing sluices, each of five meters in width. The Damietta section was 535 meters long with 71 arches containing similarly sized sluices. Navigation locks were provided on both branches, and the two barrages were joined by an elevated roadway 8.6 meters wide, with drawbridges over the locks. Elaborate fortifications with towers and turrets completed the imposing structure. By the time the barrages were finally completed in 1862, during the early reign of Viceroy Ismail Pasha (not yet khedive of Egypt), 3 million Egyptian pounds had been spent already. When it was time to operate the dam, the foundations had been so poorly laid that the whole purpose for which it had been built in the first place was abandoned. Poorly constructed, the barrages would have to be rebuilt during the British occupation. A more technical and specific description, some years later says: "When the work was subjected to a small head in 1863 and 1867, unmistakable signs of failure appeared in the form of cracks and displacements, and the barrage was forthwith put upon the sick list. The failure was due to "piping." Runs below the floor were developed under the influence of the head of water, and the sand of the foundation bed was carried away by the flowing water till the floor lost its support and settled down. The defects arose, not so much from faulty design, as from careless construction of the foundations. Worried by the impatience and impetuosity of the Viceroy, Mougel Bey's workmen laid the foundation concrete in running water, which carried away the mortar and left loose stone, without any binding material, through which the springs of the river bed had free passage. The design, if faithfully executed, was not much at fault. The floor was amply strong to resist the upward pressure due to the head, but its breadth was perhaps deficient; and the protection given both on the upper and lower sides of