XXX vi. ABSTRACT OF PROCEEDINGS — APPENDIX. 



remarkable as being the only solid dam which passes the 

 discbarge of a large river like the Nile through its body, 

 for which purpose it is provided with 140 low-level sluices, 

 each 23 feet deep by 6J feet wide, and 40 upper sluices 11^ 

 feet deep by 6^ feet wide. The lower sluices were designed 

 to be capable of passing the largest possible flood with a 

 relatively small head of water on the up-stream side of the 

 dam. The upper sluices were built for the purpose of dis- 

 charging under low heads the normal river when the 

 reservoir is full. 



The Government of Egypt, in consequence of antiquarian 

 agitation regarding the temples of Philae, agreed not to build 

 the dam higher than 85 feet (106*00 R.L.) which produced 

 a volume of 980,000,000 cubic metres, as this height, while 

 submerging some of the outer works and colonnades of 

 Philse, left the main temples high and dry. The require- 

 ments of Egypt, however, were not fully met by the 

 original dam and it became absolutely necessary to provide 

 additional storage-area. 



When the dam was originally under construction the 

 temples on the island of Philse were, where necessary, 

 carefully underpinned down to solid rock, and although the 

 depth of water about these temples is increased by seven 

 metres, there appears to be no reason to doubt their 

 stability. A few other temples of minor importance in 

 Nubia will be affected by the increased depth of water in 

 the reservoir. 



Before proceeding with the thickening and heightening 

 of the dam it became necessary to strengthen the aprons 

 on the down-stream side in order to resist the erosion of 

 the granite bed of the river immediately below the dam. 

 The effect of such an enormous volume of water flowing 

 through the sluices at a high velocity has rendered neces- 

 sary the construction of a heavy masonry floor set in 2 to 1 



