99 



preceding days it had been at twenty-two de- 

 grees. I found in general the tint of the sky 

 deeper under the torrid zone, than in the high 

 latitudes ; but I have also proved, that, in the 

 same parallel, this tint is paler at sea than on 

 land. 



As the color of the firmament depends on the 

 accumulation and on the nature of the opake 

 vapors suspended in the air, we should not be 

 astonished, if during great droughts, in the 

 steppes of Venezuela and of Meta, we see the 

 sky of a deeper blue than in the basin of the 

 ocean. A very hot air, almost saturated with 

 humidity, rises perpetually from the seas toward 

 the high regions of the atmosphere, where a colder 

 temperature prevails. This ascending current 

 causes there a precipitation, or rather a conden- 

 sation of vapor. Part assembles in clouds, under 

 the form of vesicular vapor, at times when we see 

 no clouds appear in the dryer air that reposes on 

 the land ; another part remains scattered, and 

 suspended in the atmosphere, the tint of which 

 it renders paler. When, from the summit of the 

 Andes, we turn our eye toward the great South 

 Sea, we often perceive a haziness uniformly 

 spread to fifteen or eighteen hundred toises in 

 height, and covering, as with a thin veil, the 

 surface of the ocean. This appearance takes 

 place in a season when the atmosphere, beheld 

 from the coast and at sea, appears pure and 



