188 Sir Benjamin Baker [June 6, 



another twenty years before the structure was sufficiently strengthened 

 by British engineers to fulfil the duties for which it was originally 

 designed. All the difficulties arose from the nature of the foundations, 

 as the timber sheet piling wholly failed to prevent the substructure 

 from being undermined by the head of water carrying away the fine 

 sand and silt upon which the barrage was built. At Asyut, cast-iron 

 sheet piling was used, as will hereafter be described. It is impossible 

 to say what the cost of the old barrage has been from first to last, 

 but probably nearly ten times that of the recently-completed Asyut 

 Barrage. Forced labour was largely employed in its construction, 

 and at one time 12,000 soldiers, 3000 marines, 2000 labourers, and 

 1000 masons were at work at the old barrage. 



In connection with the Nile Reservoir, subsidiary weirs have been 

 constructed below the old barrage to reduce the stress on that 

 structure. The system adopted was a novel one, reflecting great 

 credit on Major Brown, Inspector-General of Irrigation in Lower 

 Egypt. His aim v^as to dispense almost entirely with plant and 

 skilled labour; and so, without attempting to dry the bed of the 

 river, he made solid masonry blocks under water, by grouting 

 rubble dropped by natives into a movable timber caisson. Both 

 branches of the Nile were thus dammed in three seasons, at a cost, 

 including navigation locks, of about half a million sterling. Many 

 other subsidiary works have been and will be constructed, including 

 regulators, such as that on the Bahr Yusuf Canal. 



Asyut Barrage. 



By far the most important of the works constructed to enable the 

 water stored up in the great reservoir to be utilised to the greatest 

 advantage is the Barrage across the Nile at Asyut, about 250 miles 

 above Cairo, which was commenced by Sir John Aird and Co. in the 

 winter of 1898, and completed this spring. As already stated, 

 in general principle this work resembles the old barrage at the 

 apex 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 one 

 of stone. 



The total length of the structure is 2750 ft., or rather more than 

 half 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. The 

 object of the work is to improve the present perennial irrigation of 

 lands in Middle Egypt and the Fayoum, and to bring an additional area 

 of about 800,000 acres under such irrigation, by throwing more water 

 at a higher level into the great Ibrahimiyah Canal, whose intake is 

 immediately above the Barrage (Fig. 2). 



The piers and arches are founded upon a platform of masonry 

 87 ft. wide and 10 ft. thick, protected up and down by a continuous 

 and impermeable line of cast-iron grooved and tongued sheet piling, 



