138 



SINGULAR DECEPTIONS CAUSED BY THE AT- 

 MOSPHERE. 



Mr. Salt thus describes the effects of the at- 

 mosphere on the vision, to which he was an eye- 

 witness " At day-break, we continued our route 

 to Aden. As we approached the .peninsula, we 

 were much struck with the appearances which 

 the sun put on as it rose. When it had risen 

 about half way above the horizon, its form some- 

 what resembled a castellated dome ; when three 

 parts above the horizon, its shape appeared 

 like that of a balloon ; and at length the lower 

 limb suddenly starting up from the horizon, it s 

 assumed the general form of a globe, flattened 

 at either axis. These singular changes may be 

 attributed to the refraction produced by dif- 

 ferent layers of atmosphere, through which the 

 sun was viewed in its progress. The same cause 

 made our ship in the bay look as if it had 

 been lifted out of the water, and her bare masts 

 appear to be crowded with sail : a low rock 

 also seemed to rise up like a vessel ; and a pro- 

 jecting point of land to rest on no other foun- 

 dation than the air: the space between these 

 objects and the horizon having a grey pellucid 



