336 ARRIVAL AT LIMA. 
Returning to Peru, our travellers crossed the cor- 
dillera of the Andes the fifth time. In seven degrees 
of south latitude they determined the position of the 
magnetic equator, or the line in which the needle 
has no inclination. They also examined the mines 
of Hualgayoc, where large masses of native silver 
are found at an elevation of 12,790 feet above the 
sea, and which, together with those of Pasco and 
Huantajayo, are the richest in Peru. From Caxa- 
marca, celebrated for its hot-springs and the ruins 
of the palace of Atahualpa, they went down to 
Truxillo. In this neighbourhood are the remains 
of the ancient Peruvian city Mansiche adorned by 
pyramids, in one of which an immense quantity of 
gold was discovered in the eighteenth century. De- 
scending the western slope of the Andes they be- 
held for the first time the Pacific Ocean, and the 
long narrow valley bounded by its shores, in which 
rain ahd thunder are unknown. From Truxillo 
they followed the arid coast of the South Sea, and 
arrived at Lima, where they remained several months. 
At the port of Callao, Humboldt had the satisfaction 
of observing the transit of Mercury, although the 
thick fog which prevails there sometimes obscures the 
sun for many days in succession. 
In January 1803 the travellers embarked for 
Guayaquil, in the vicinity of which they found a 
splendid forest of palms, plumerize, taberne-mon- 
tane, and scitaminee. Here also they heard the 
incessant noises of the voleano of Cotopaxi, which 
had experienced a tremendous agitation on the 6th 
January. From Guayaquil they proceeded by sea 
to Acapulco in New Spain. At first, Humboldt’s 
intention was to remain only a few months in Mex- 
5 
