ABSTRACT OF PROCEEDINGS — APPENDIX. XXXV. 



depth. 5. On coarse saDd of very great depth. 6. On fine 

 sand of very great depth. 



The perennial system in Egypt has been rendered possible 

 by the construction of the Assiian Dam, which has been 

 thickened and heightened recently so as to provide a storage 

 of about 2,420,000 cubic metres of water. All the flood 

 waters of the Nile pass through the sluices of this great 

 dam, and during the months extending from November to 

 March the sluices are closed and the reservoir filled. Dur- 

 ing the months of April, May, June and part of July the 

 reservoir is drawn upon to supplement the deficient dis- 

 charge of the river. Extensive areas of the basin system 

 have been converted to the perennial system, producing 

 two crops a year, with considerable advantage to the 

 prosperity of Upper Egypt. Two important river regulators 

 have been built between Assiian and Cairo. The Assiiit 

 Barrage, which is constructed just below the head works of 

 the Ibrahimia Canal, and the Esna (or Isna) Barrage 

 between Luxor and Assiian. The Assiiit Barrage has been 

 built across the Nile to regulate the supply of the Ibrahimia 

 Canal, and it is designed to hold up a head of 2*55 metres. 

 The Ibrahimia Canal head is designed to withstand a head 

 of 3*25 metres. 



The Assuan Dam. 

 This great work is build across the Nile at the first 

 cataract. The dam is 6,400 feet long, or about \\ miles. 

 As stated in a report by the Director-General of Irrigation 

 Works in Egypt, Mr. Murdock MacDonald, c.m.g., 

 M.inst.c.E., there were three distinct phases in the construc- 

 tion of this dam, as it now stands. (1) The building of the 

 original dam; (2) the protection of the rock faces down 

 stream, and (3) the thickening and heightening of the dam. 



As originally built the height was only 85 feet, and the 

 area impounded 863,000 acre feet. This work is principally 



