194 



the bottle which contained the air of the crater 

 escaped unhurt. 



We at length enjoyed the refreshing breeze in 

 the beautiful region of the arborescent erica and 

 fern; we were enveloped in a thick bed of 

 clouds stationary at six hundred toises above the 

 plain. In crossing this, we remarked a pheno- 

 menon which was afterwards familiar to us on 

 the declivities of the Cordilleras. Small cur- 

 rents of air chased trains of clouds with unequal 

 velocity, and in opposite directions ; and bore 

 the appearance of streamlets of water in rapid 

 motion and in all directions, amidst a great 

 mass of stagnant waters. The causes of this 

 partial motion of the clouds are probably very 

 various ; we may suppose it to arise from some 

 impulsion at a great distance ; from the slight 

 inequalities of the soil, which reflects in a great- 

 er or less degree the radiant heat ; from a dif- 

 ference of temperature kept up by some chemical 

 action ; or perhaps from a strong electric charge 

 of the vesicular vapors. 



As we approached the town of Orotava, we 

 met great flocks of canaries*. These birds, 

 well known in Europe, were in general uniform- 

 ly green ; some had a yellow tint on their backs : 



* Fringilla cariaria. La Caille relates, in the narrative of 

 his voyage to the Cape, that on Salvage island these canaries 

 are so abundant, you cannot walk there in a certain season 

 without breaking their eggs. 



