268 CARTIIAGENA. 



Chap.xxii. creatures, that they wislied to return and seize the 

 fuifitives, in order to sell them at Carthagcna. 



Pnnta Next morning they doubled the Punta Gigantes, and 



GlRantes. made sail towards the Boca Chica, the entrance to the 

 port of Curtliagena, 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 

 commami of M. Fidalgo, had not yet put to sea, and 

 this circumstance enabled him to ascertain the astrono- 

 mical position of several places which it was of impor- 

 tance to determine. 



Eaiirsion at During the six days of their stay at Carthagcna, they 



Cariiiagena. ^y^.^^^. excursions in the neighbourhood, more especially 

 in the direction of the Boca Grande, and the hill of 

 Popa, ^^■hich commands the town. The port or bay is 

 nearly eleven miles long. The small island of Tierra 

 Bomba, at its two extremities, 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 entrances to the 



BocsQvandc harbour. One of these, named Boca Grande, has been 

 artificially 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 2345 yards, and as the water was 

 from 14 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 about 550 yards broad, but is daily 

 becoming narrower, while the currents acting upon the 

 Boca Grande have opened a breach in it, which they 

 are continually extending. 



Climate. The insalul)rity of Carthagcna, which has been ex- 



aggerated, varies with the state of the great marshes 

 tluit surround it. The Cienega de Tesca, which is 

 upwards of eigliteen miles in length, communicates with 

 the ocean ; and, when in dry years the salt water does 

 not cover tlie wiiole plain, the exhalations that rise 

 from it during the heat of the day become extremely 

 pernicious. The iiillv ground in the neighbourhood of 



