BOOK V. X. 54-56 



and it belches out, by many mouths it is true, into 

 the Egyptian Sea." For a certain part of the year 

 however its volume greatly increases and it roams 

 abroad over the whole of Egypt and inundates the 

 land ^Wth a fertilising flood. 



Various explanations of this rising of the river have 

 been given ; but the most probable are either the 

 backwush caused by what are called in Greek the 

 Annual Winds,* which blow in the opposite direc- 

 tion to the current at that period of the year, the 

 sea outside being driven into the mouths of the 

 river, or the summer rains of Ethiopia which are 

 due to the same Annual Winds bringing clouds 

 from the rest of the world to Egypt. The mathe- 

 matician Timaeus produced a verv recondite theory 

 — that the source of the Nile is a spring called 

 Phiala, and that the river buries itself in burrows 

 underground and breathes forth vapour owing to the 

 steaming hot rocks among which it hides itself ; but 

 that as the sun at thc period in question comes 

 nearer the river water is drawn out by the force 

 of the heat and rises up and overflows, and with- 

 draws itself to avoid being swallowed up. This, 

 he says, begins to occur at the rising of the Dogstar, 

 when the sun is entering the sign of the Lion, the 

 sun standing in a vertical Hne above the spring, at 

 which season in that region shadows entirely dis- 

 appear — though the general opinion on the contrary 

 is that the flow of the Nile is more copious when 

 the sun is departing towards the north, which 

 happens when it is in the Crab and the Lion, and 

 that consequently the river is dried up less then ; 

 and again when the sun returns to Capricorn and 

 towards the south pole its waters are absorbed and 



261 



