388 MIRAGE LANDSCAPES. 



these occasions, as if swimming in the water, beneath 

 which their bodies are completely hidden from view. 



The most beautiful effects are often produced, conjuring 

 up images of distant views of lovely scenery, such as 

 sheets of water bordered by groves of beautiful trees, 

 where nothing exists but a waste of burning sand ; or 

 again the mimic scenery may represent the stately outlines 

 of ancient castles, palaces, cathedrals, and other buildings 

 erected by human hands thus affording a practical 

 illustration of the poetic idea of " castles in the air. " 



All these things, however, are nevertheless in all 

 probability merely distorted images of natural objects, 

 having an actual existence in the landscape, reproduced 

 as already mentioned in an exaggerated form by the 

 vibrations of highly heated, rarefied atmosphere thus 

 a flat waste of sand sparkling in the intense light of 

 the solar rays, or a plain somewhat whitened by saline 

 efflorescence, is made to represent the glassy surface of 

 a lake ; while a thorny fringe of dwarf acacias, or other 

 shrubs, and even tufts of grass, become magnified and 

 made to do duty for belts of fertile woodlands growing 

 upon its banks; so also rocks and other irregularities 

 of surface may readily be conceived to form the 

 fabric out of which a city of palaces appears to rise, 

 as if by enchantment, from the stony wilderness. 



To the untutored minds of the desert nomads, of 

 course, such things can only be accounted for by sup- 

 posing them to be the work of evil spirits : and prob- 

 ably nothing has done more than the phenomena of 

 the mirage to invest the oriental mind with a super- 

 stitious belief in genii and other supernatural agencies. 

 The mirage in fact is often spoken of among the Arabs 

 as the " Bahr-es-Sheitdn? or "The Waters of Satan. * 



