THE MIEAGE. 



227 



The phenomenon of reflection is almost always accompanied by 

 lateral movements which apparently alter the position of objects, in 

 the same way as plates of glass of unequal thickness do, we then see 

 large masses of different forms detaching themselves to the right and 

 left of the distant objects, and floating fantastically in the air. These 

 phenomena of mirage are most curious in the polar seas already strewn 

 with blocks and icebergs of every variety of contour. The surface of 

 the ocean bristles with points, needles, crests, and overhanging cor- 

 nices, which separate, rejoin each other, and then vanish, to reappear 

 again. Nowhere do we see more astonishing phantasmagoria. As 

 to the prodigious scenes that the mirage is said to present to the eyes 

 of the traveller, by showing him forests of palm trees, temples with 



B 





'fWM- 





Fig. 98.— Mirages of the " Vinceunes " and of the " Peacock," after Wilkes. 



colonnades, caravans, armies on the march, and people gathered for 

 fetes, they are probably in great part produced by fever under the 

 ardent sun, for in this fiery atmosphere which floats above the whiten- 

 ed plains and reflects the splendour and the heat, the head is burn- 

 ing, the imagination excited, and the eye sees no longer anything 

 but the forms of fanc3^ 



