220 BERTHA'S VISIT TO HER 



Another very remarkable instance of mirage, 

 my uncle says, has been more than once seen at 

 Reggio, in the straits of Messina, where it is 

 called the Fata Morgana. When the rays of the 

 sun form an angle of about 45 with the sea, and 

 that the bright surface of the water in the bay is 

 not disturbed by wind or current, if the spectator 

 be placed with his back to the sun, there sud- 

 denly appears on the water the most incom- 

 prehensible variety of objects pilasters, arches, 

 and castles, lofty towers and extensive palaces, 

 with all their balconies and windows or per- 

 haps trees, vallies, and plains, with their herds 

 and flocks armies of men, on foot and on 

 horseback, and many other strange objects ; all 

 in their natural colours, and all in action, passing 

 rapidly in succession along the surface of the sea. 

 But if, besides the circumstances before de- 

 scribed, the atmosphere happens to be loaded 

 with a dense vapour, which the sun had not 

 previously dispersed, the observer will behold a 

 representation of the same objects in the air, as 

 if traced there on a curtain ; though not so dis- 

 tinct or well defined as those on the sea. These 

 curious appearances were fancifully called by the 

 Italians, the castles of the Fairy Morgana. 



My uncle says that the celebrated Dr. Wol- 

 laston has proved, by some very ingenious ex- 

 periments, that they arise from the irregular 

 refraction of the rays of light, in passing through 



