136 Observations on Sculptured Marks on 



Sukkot, and Dar-el-Mahass, where the river flows over granite and 

 other plutonic rocks ; gneiss, mica-schist, and other hard rocks, which 

 Bussegger considers to be metamorphic. But between Semne and 

 the head of the second cataract at Wadi-Halfa, there is not a con- 

 tinuous rapid stream ; for Hoskins says, that about two miles above 

 that cataract, the river has a width of a third of a mile, and, when he 

 passed it the water was scarcely ruffled.* 



From the rapid of Hannek to Abu Hammed, the distance is 329 

 English miles, and the difference of altitude is 246 English feet. We 

 have thus an average fall in that distance of 9*00 inches in a mile. 



Thus, in the 776 miles between Abu Hammed and Philse, we 

 have an average fall of the Nile 



Of the Breadth, Depth, and Velocity of the Nile, in Nubia. 



Our information is very scanty respecting the breadth and depth 

 of the river, either at the time of lowest water or during the inun- 

 dations. About two miles above Philae, it is stated by Jomard^ to 

 be 3000 metres, or nearly two English miles wide. At the second 

 cataract, or rapid of Wadi-Halfa, it spreads over a rocky bed of 

 nearly two miles and a-quarter in width (2000 klafter),J but con- 

 tracts above the rapid to a third of a mile. Russegger also states, 

 that the Nile, near Boulak, in Lower Egypt, is 2000 toises, nearly 

 two-and-a-half English miles in breadth, and yet that it is consider- 

 ably wider in some parts of Southern Nubia ; but Burckhardt says, 

 that the bed of the Nile in Nubia is, in general, much narrower than 

 in any part of Egypt. Near Kalabsche, about 30 miles above 

 Philae, the river runs through a gorge not more than 300 paces wide, 

 and its bed is full of granite blocks. It shortly afterwards again 

 widens for some distance ; but near Sialla, 78 miles above Philse, it 

 is contracted by the sandstone hills on both sides coming so near 

 each other, that the river's bed is again not more than from 260 to 

 300 paces wide. It is about 600 yards broad about two miles above 

 the second cataract near Wadi-Halfa, but is again very much con- 

 tracted in the rocky region of Batn-el-Hadjar. At Aulike it is only 

 200 paces broad. § 



I have not met with any measurements of the depth of the river 



* Travels in Ethiopia, p. 272. 



t Description de I'E^ypte. — Separate Memoir entitled, " Description de 

 Syene et des Cataractes." 



X liussegger, Bd. ii., 3 Thl. 85. § Russegger, Bd. ii., 3 Thl. 76. 



