12 



EASTERN ETHIOPIA 



is seen exactly over the spot where the sun is about to 

 appear. The extent and intensity of the luminuos 



In the silence of the library it was amusing to watch a gecko dart 

 across the ceiling catching flies. The inset shows the lamellae which 

 enable it to climb easily and quickly smooth vertical surfaces. 



area vary greatly, and the variations depend very 

 much on the condition of the atmosphere. In the 

 evening, about an hour after sunset, a similar luminous 

 cone appears in the sky at the place where the sun has 

 just quitted the horizon. 



