306 THE ADVENTURES OF 



shown as much emotion as the Indian on seeing two butter- 

 flies which he fancied belonged to a Swiss species; and I 

 brought forward these feelings to oppose the intention he so 

 often expressed of taking up his abode in the midst of the 

 wilderness, so as to live and die in solitude. 



On the great plateau the sun shines rather later than in 

 the lower regions. As the luminary approached the earth, 

 the sky was lighted up with a purple color, and I saw stand- 

 ing out on our left in bold belief the jagged outline of the 

 Cordilleras of 1'Encuerado's country. The whitish ground 

 gradually assumed a transparent appearance ; our eyes de- 

 ceived us to such an extent that we fancied AVC saw an im- 

 mense tract of water, above which the trees, appearing as if 

 they were submerged, raised their green heads. 



The moon rose, and, far from destroying the mirage, it 

 rendered the illusion still more striking. I resolved to de- 

 scend from the hill in order to convince Lucien how much 

 our vision was deceived. 



" There is no mistake about the plain being dry," said he, 

 as we returned to the bivouac, " and yet one might fancy 

 that, as we were mounting the hill, the water was rising be- 

 hind us." 



" The layers of the air," I replied, " are unequally warm- 

 ed, and their refraction, which causes the rays of light to 

 deviate in their course, reverses the objects which cover the 

 plain, and, on the other hand, causes them to appear more 

 elevated than they really are." 



"So we see water in a place where in reality there is 

 none." 



" You don't take the sky into account, which is reflected 

 on the ground beneath us as in a mirror. But the air is 

 becoming cooler, and you will soon see the phenomenon 

 slowly disappear, as if*some invisible hand was pushing the 

 mist back towards the horizon." 



