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lower than the Peak of Teneriffe, the horizon, 

 though nearer, remained invisible toward the 

 north and north-north-east. Following* with 

 the eye the surface of the sea, which was smooth 

 as glass, we were struck with the progressive 

 diminution of the reflected light. Where the vi- 

 sual ray touched the last limit of that surface, the 

 water was lost among the superposed strata of 

 air. This appearance has something in it very 

 extraordinary. We expect to see the horizon 

 level with the eye ; but, instead of distinguish- 

 ing at this height a marked limit between the 

 two elements, the more distant strata of water 

 seem to be transformed into vapour, and min- 

 gled with the aerial ocean. I observed the 

 same appearance, not in one spot of the horizon 

 alone, but on an extent of more than a hun- 

 dred and sixty degrees, near the South Sea, 

 when I found myself for the first time on the 

 pointed rock, that commands the crater of 

 Pichincha ; a volcano, the elevation of which 

 exceeds that of Mont Blanc. The visibilitv of 

 a very distant horizon depends, when there is 

 no mirage, upon two distinct things ; the quan- 

 tity of light received on that part of the sea, 

 where the visual ray terminates ; and the ex- 

 tinction of the reflected light during it's passage 

 through the intermediate strata of air. It may 

 happen, notwithstanding the serenity of the 

 sky and the transparency of the atmosphere, 



