538 



Mirage and Meteors. 



tance. The contrary to this happens in the Alps, where the traveller, 

 though at ten leagues from a mountain, will think that he is going to 

 touch it with his hand. 



« These optical illusions remind me of a phenomenon which is 

 frequently seen in India, and which naturalists designate by the name 

 of mirage. I have seen some singular effects from it : clouds, raised 

 many degrees above the horizon, and perfectly resembling mountains 

 of sand ; 10% palm trees, of which I perceived only the tops, as if 

 suspended in the air ; and sometimes a fine lake, suddenly placed in 

 the dry plains which I had just been crossing, and which, as an ad- 

 ditional wonder, appeared to communicate with the sea. When the 

 mirage appears at the horizon, it presents the aspect of the firmament, 

 of which it seems to be but the continuation — as if the sky made 

 a breach in the earth, crossing, to a certain extent, the foot of the 

 trees and mountains, and allowing only their tops to be seen. When 

 it appears in the middle of a plain, you think you see water ; but it is 

 really the aspect of the sky, produced by refraction. This water, 

 which you suppose you see, has the property of reflecting the sur- 

 rounding objects. You see their image, but not very distinctly, on 

 account of the very great distance ; for the mirage appears always a 

 great way off. 



" I have also had the opportunity of observing another phenomenon, 

 which they call a flying-star. On sea one of them appeared which 

 seemed to fall into the waves, lighting the entire vessel, and leaving 

 after it a long train of light, which dazzled the sailors who were hid 

 behind the sails. One evening, near Calleditidel, I saw, at a few 

 paces from me, a similar meteor, which was flying and scattering on 

 its way a quantity of brilliant sparks, exactly like a rocket, but with- 

 out the hissing noise. I was in doubt for an instant whether it was 

 a rocket. ' What fire is that ?' said I to an Indian. 1 It is a star/ he 

 replied. I have seen another which, in the moment of being extin- 

 guished, resumed its brightness four or five times, advancing in 

 bounds, but much more slowly than the ordinary flying stars. 



" They are almost always followed by a train of sparks, by which 

 their substance is wasted, and, like the rockets, they cease to be visi- 

 ble when it is exhausted. Such facts — would they not prove that 

 these pretended stars are only meteors, formed by the lower regions 



