106 



THE OPAL SEA 



Sea 

 mirage. 



Fata 

 morgana. 



The ship in 

 the air. 



silver lying along the horizon, and quivers 

 slightly or shifts place not unlike the aurora. 

 The sailors explain it by saying the water is 

 "reflecting itself," and possibly that is true, 

 the water reflection being seen upon the air; 

 but a similar illusion is produced by the sky 

 being reflected from the denser air that lies 

 along the surface of the sea. 



The water mirage is a very beautiful illusion 

 but not one of frequent occurrence. Nor is 

 the fata morgana, where things are seen out of 

 their place and " upside down," an everyday 

 happening. The object is generally noticed 

 " looming " high above the horizon, and is 

 usually a ship, an island, or a coast city. Sea 

 captains frequently tell tales of seeing their 

 port of destiny in the sky long before the port 

 itself comes up over the ocean's edge; and the 

 sight of a ship in the air, hanging masts down- 

 ward, is something that almost every sailor can 

 spin a yarn about. The reversed ship does not, 

 however, appear every day or every year; and 

 many a tourist, boastful of the number of trips 

 to Europe he has made, has never seen it at 

 all. The cause for the distorted and misplaced 

 image is the thick strata of low-lying air which 

 bends the light ray so that we see not in a 

 straight line but in a curved line. From ex- 



