GEOLOGY. 707 



at a distance when the idea came into my head to salute 

 this hospitable abode for the last time. But everything was 

 transformed. The picturesque village seemed enveloped 

 in a magnificent sheet of the most transparent waters, in 

 which the dwellings, palm-trees, and tombs were reflected 

 in a marvellous manner. The phenomenon was produced 

 with such exactness, and the sheet of water was so beau- 

 tiful and limpid, that if I had not a few minutes previously 

 traversed the spot which it occupied on the burning sand, 

 I should have thought it real. Such is the mirage, which 

 so often and so painfully deceived our worn-out soldiers 

 when they traversed these very regions. Exhausted with 

 fatigue and dying of thirst, they thought they saw in the 

 distance the water they longed for so much, while it was 

 only a bitter delusion ! 



Yet other phenomena engage the view of those who 

 traverse the desei^ts of Africa. Among these is the rising 

 of the sun, the splendour of which, as Byron says, is with- 

 out equal! 



After traversing the great cataract of the Nile, we re- 

 solved to rest for a few days in the island of Pliilse, situ- 

 ated at the entrance into Nubia. So soon as Ave had 

 anchored our boats on the east shore of the sacred island, 

 crowded as it is with religious monuments, we set to work 

 to erect our tent on the platform of one of the great gate- 

 towers or pylones of the temple of Isis. It so happened 

 that there was at this place a complete gathering of 

 scientific men : M. Grimaitx, my friend and travelling com- 

 panion, whom Itouen numbers among her chosen men of 

 eminence; Captain Tuifort, who commanded the advanced 

 guard in the expedition to the sources of the Nile which 

 we had just rejoined, and my sons Georges and James 

 Pouchet, the one naturahst to the expedition, the other an 



