CHAPTER I. 



THE SEA. 



At sunset on the third day they saw from the mast- 

 head an English convoy, sailing along the coast, and 

 steering towards the southeast. To avoid it they altered 

 their course. From that moment no light was allowed 

 in the great cabin, for fear of their being seen at a dis- 

 tance. Humboldt and Bonpland were obliged to make 

 use of dark lanterns to examine the temperature of the 

 water. 



From the time of their sailing until they reached the 

 86th degree of latitude they saw no organic beings, ex- 

 cept sea swallows and dolphins; they even looked in 

 vain for sea-weeds and mollusca. On the sixth day 

 however they entered a zone where the waves were co- 

 vered with a prodigious quantity of medusae. The sea 

 was nearly becalmed, but the medusae were bound 

 towards the south-east, with a rapidity four times greater 

 than that of the current. 



Between the island of Madeira and the coast of Africa, 

 they had slight breezes and dead calms, which were 

 favorable for the magnetic observations that occupied 

 Humboldt during the passage. The travellers were 

 never wearv of admiring the beauty of the nights; 



