THE RISE OF THE NILE WATERS. 515 



great tributary stream) towards the latter end of that 

 month. Some account of the sudden advent of this 

 flood will be found in our section on Climates and 

 Temperatures where together with other similar pheno- 

 mena, the story of the coming of the great Atbara 

 is sketched from the graphic account so admirably 

 given by Sir S. Baker. * The rains generally come 

 as far north as about Lat. 17, and thereabouts they 

 gradually cease; beyond that point the rainless zone 

 begins. At Cairo the effects of the rise in the south 

 is not generally felt until June, the important intelligence 

 of an approaching inundation being (at the present day) 

 immediately telegraphed from Wadi Haifa, the moment 

 the river begins to rise there. In Lower Egypt the 

 inundation occurs without rains and continues about 

 three months, but does not reach its highest point 

 until the end of September, but there is often a sud- 

 den and final rise in October, after which the flood 

 begins steadily to subside; and by the end of January 

 the lands it has covered begin to dry up again, and 

 the river is thenceforth confined to its natural channel, 

 gradually sinking lower and lower, until it rises again 

 the following year. 



A rise of about from 24 to 26 feet at Cairo is con- 

 sidered a good average one, and the highest rise of 

 modern date was 2 7 feet 3 inches, f The river at this time 

 is some 5 miles wide opposite Cairo, and extends right 

 across the valley to the foot of the Pyramid range at 

 Gizeh. For ages all these phenomena have been 



* The Nile Tributaries of Abyssinia, by Sir Samuel W. Baker, 1 86 1, 

 pp. 51 54. This event occurred on June 24th, when Sir S. Baker 

 \vas there in 1 86 1. 



t See Murray's Handbook for Egypt, 1892, p. 19. 



