270 CARTHAGENA. 



his companions, who were concealed among the 

 trees, excited their suspicions, and induced them to 

 return on board. These blacks were probably Ma- 

 roon negroes, who had escaped from prison. The 

 appearance of a naked man, wandering on an unin- 

 habited shore, and unable to rid himself of the chains 

 fastened round his neck and arm, left a painful im- 

 pression on the travellers ; but the sailors felt so 

 little sympathy with these miserable creatures, that 

 they wished to return and seize the fugitives, in 

 order to sell them at Carthagena. 



Next morning they doubled the Punta Gigantes, 

 and made sail towards the Boca Chica, the entrance 

 to the port of Carthagena, which is eight or ten 

 miles farther up. On landing, Humboldt learned 

 that the expedition appointed to make a survey of 

 the coast under the command of M. Fidalgo had 

 not yet put to sea, and this circumstance enabled 

 him to ascertain the astronomical position of several 

 places which it was of importance to determine. 



During the six days of their stay at Carthagena, 

 they made excursions in the neighbourhood, more 

 especially in the direction of the Boca Grande, and 

 the hill of Popa, which commands the town. The 

 port or bay is nearly eleven miles and a half long. 

 The small island of Tierra Bomba, at its two ex- 

 tremities, which approach, the one to a neck of land 

 from the continent, the other to a cape of the isle 

 of Bani, forms the only entrance to the harbour. 

 One of these, named Boca Grande, has been artifi- 

 cially closed, for the defence of the town, in conse- 

 quence of an attack attended with partial success 

 made by Admiral Vernon in 1741. The extent of 

 the work was 2640 varas, or 2446 yards, and as the 

 water was from 16 to 20 feet deep, a wall or dike of 

 stone, from 16 to 21 feet high, was raised on piles. 

 The other opening, the Boca Chica, is from 36 to 38 

 yards broad, but is daily becoming narrower, while 

 the currents acting upon the Boca Grande have 



