OCEAN PLAINS 



105 



through a great drift of these minute organ- 

 isms, and millions of them are overset and 

 frightened into fire, the effect upon the sea is 

 very marked. It glows like a metallic surface. 

 This is perhaps seen at its best from the taff- 

 rail looking down the wake; but the bow and 

 sides of the ship — wherever the water is dis- 

 turbed — will show lines of pale fire as well, 

 while outside of the disturbed area the sea re- 

 mains its normal darkness. A disturbance of 

 the surface is the usual cause of this phenom- 

 ena; though in southern seas oftentimes there 

 are great areas of animalculse that, of their 

 own volition, will glow at night and cast a 

 light upon spars, and sails, and human faces 

 almost as powerful as moonlight. 



Equatorial waters are the most favorable for 

 phosphorescent appearances though similar ap- 

 pearances are frequently seen at the colder 

 north. The tropical seas, with their heated sur- 

 faces and thick strata of atmosphere, are also 

 famous places for electric phenomena and for 

 illusions of the air. Here is seen the St. Elmo's 

 Light, the fata morgana or misplaced image, 

 and also the true sea mirage. The last named 

 appears when the sea is calm, the weather very 

 hot, and the air strata above the water are very 

 thick. It looks like a long, glittering band of 



Fields or 

 animalcuhf. 



Si. Elmc\ 

 Light. 



