802 



diterranean ; and if I here note some observa- 

 tions drawn from my nautical journal, it is that 

 I may not lose the thread of my narrative, and 

 to recall some facts that are connected with 

 meteorology and physical geography in general. 

 In order to know well the modifications of the 

 atmosphere, they must be studied on the decli- 

 vity of mountains, and in the immensity of 

 seas ; there is no passage however short, no 

 voyage even to the Canaries, or the Madeira 

 islands, which may not give rise to new views 

 in the minds of naturalists long accustomed to 

 interrogate nature in the retirement of their 

 study. 



We sailed from the road of Nueva Barcelo- 

 na on the 24th of November, at nine in the 

 evening ; and doubled the small rocky island 

 of Borachita ; there is a very deep passage be- 

 tween this island and the Gran Boracha. The 

 night had that coolness which characterizes 

 the nights of the tropics, and of which the 

 agreeable effect can only be conceived by com- 

 paring the nocturnal temperature from 23° to 

 24° cent., with the mean temperature of the 

 day, which in those latitudes is generally, even 

 on the coast, from 28° to 29°. The next day, 

 soon after the observation of noon, we reached 

 the meridian of the island of Tortuga: desti- 

 tute of vegetation, similar to the small isles of 

 Cooke and Cabagua, it is remarkable for its 



