1902.] on the Nile Dams and Beservoir. 191 



Although the preliminary studies of Mr. Willcocks and the other 

 Government engineers occupied some four years, there was neither 

 time nor money to sink shafts in the bed of the river, to ascertain 

 the real character of wliat was called in the engineer's report " an 

 extensive outcrop of syenite and quartz diorite clean across the 

 valley of the Nile," giving " sound rock everywhere at a very con- 

 venient level." Unfortunately, the rock proved to be unsound in 

 many places to a considerable depth, with schistous micaceous masses 

 of a very friable nature, which necessitated carrying down the founda- 

 tions of the dam sometimes more than 40 ft. deeper than was originally 

 anticipated or provided for in the contract. As the thickness of the 

 dam is nearly 100 ft. at the base, this misapprehension as to the 

 character of the rock involved a very large increase in the contract 

 quantity and cost of the granite masonry of the Dam. The total 

 length of the Dam is about 1^ miles; the maximum height from 

 foundation, about 130 ft. ; the difference of level of water above and 

 below, 67 ft. ; and the total weight of masonry over one million tons. 

 Navigation is provided for by a "ladder" of four locks, each 260 ft. 

 long by 32 ft. wide. 



As remarked in the case of Asyut, the difficulties in dam construc- 

 tion are not in design, but in the carrying out of the works. It 

 would not be too much to say that any practical man standing on the 

 verge of one of the cataract channels, hearing and seeing the appa- 

 rently irresistible torrents of foaming water thundering down, would 

 regard the putting in of foundations to a deptli of 40 ft. below the 

 bed of the cataract in the short season available each year as an 

 appalling undertaking. When the rotten rock in the bed was first 

 discovered, I told Lord Cromer frankly that I could not say what the 

 extra cost or time involved by this and other unforeseen conditions 

 would be, and that all I could say was that, however bad the condi- 

 tions, the job could be done. He replied that he must be satisfied 

 with this assurance, and say that the Dam had to be completed what- 

 ever the time and cost. With a strong man at the head of affairs, 

 both engineers and contractors — who often are suffering more anxiety 

 than they care to show — are encouraged, and works, however difficult, 

 have a habit of getting completed, and sometimes, as in the present 

 case, in less than the original contract time. 



The contract was let to Sir John Aird and Co., with Messrs. 

 Ransomes and Rapier as sub-contractors for the steelwork, in 

 February 1898, and they at once commenced to take possession of the 

 site of the works, and of as much of the adjoining desert as they 

 desired in order to construct railways, build dwellings, offices, 

 machine shops, stores and hospitals, and provide sanitary arrange- 

 ments, water supply, and the multitudinous things incidental to the 

 transformation of a remote desert tract into a busy manufacturing 

 town. Two months after signing the contract the permanent works 

 were commenced, and before the end of the year thousands of native 

 labourers and hundreds of Italian granite masons were hard at work. 



