File:Notices of the proceedings at the meetings of the members of the Royal Institution of Great Britain with abstracts of the discourses (1902) (14783276632).jpg

Identifier: noticesofproceed1719roya (find matches)
Title: Notices of the proceedings at the meetings of the members of the Royal Institution of Great Britain with abstracts of the discourses
Year: 1851 (1850s)
Authors: Royal Institution of Great Britain
Subjects:
Publisher: London : William Clowes and Sons
Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

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hn Aird and Co. in thewinter of 1898, and completed this spring. As already stated,in general principle this work resembles the old barrage at theapex of the Delta; but in details of construction there is no simi-larity, nor in material, as the old work is of brick and the new oneof stone. The total length of the structure is 2750 ft., or rather more thanhalf a mile, and it includes 111 arched openings of 16 ft. 4 in. span,capable of being closed by steel sluice gates 16 ft. in height. Theobject of the work is to improve the present perennial irrigation oflands in Middle Egypt and the Fayoum, and to bring an additional areaof about 300,000 acres under such irrigation, by throwing more waterat a higher level into the great Ibrahimiyah Canal, whose intake isimmediately above the Barrage (Fig. 2). The piers and arches are founded upon a platform of masonry87 ft. wide and 10 ft. thick, protected up and down by a continuousand impermeable line of cast-iron grooved and tongued sheet piling,
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1902.) on the Nile Dams and Reservoir. 189 with cemented joints. This piling extends into the sand bed of theriver to a depth of 23 ft. below the upper surface of the floor, andthus cuts off the water and prevents the undermining action whichcaused so much trouble and expense in the case of the old barrage.The height of the roadway above the floor is 41 ft., and the lengthof the piers up and down stream 61 ft. The river bed is protectedagainst erosion for a width of 67 ft. up stream by stone pitching,with clay puddle underneath to check infiltration, and down streamfor a similar width by stone pitching, with an inverted filter-bediunderneath, so that any springs which may arise from the head ofwater above the sluices shall not carry sand with them from under-neath the pitching. It is easy enough to construct dams and barrages on paper, butwherever water is concerned the real difficulty and interest is in thepractical execution of the works, for water never sleeps, but day andnight is

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