154 BEES—SUMMIT OF THE SILLA. 
western dome concealed the town of Caraccas ; but 
they distinguished the villages of Chacao and Pe- 
tare, the coffee-plantations, and the course of the 
Rio Guayra. While they were examining the part 
of the sea where the horizon was well defined, and 
the great chain of mountains in the distant south, 
a dense fog arose from the plains, and they were 
obliged to use all expedition in completing their 
observations. | 
When seated on the rock, employed in determin- 
ing the dip of the needle, Humboldt found his hands 
covered by a species of hairy bee, a little smaller 
than the honey-bee of Europe. These insects make 
their nest in the ground, seldom fly, move very 
slowly, and are apt to use their sting, the guides as- 
serting that they do so only when seized by the legs. 
The temperature varied from 52° to 57°, according 
as the weather was calm or otherwise. The dip of 
the needle was one centesimal degree less than at Ca- 
raceas. The breeze was from the east, which might 
indicate that the trade-winds extend in this latitude 
much higher than 9600 feet. The blue of the at- 
mosphere was deeper than on the coasts, Saussure’s 
cyanometer indicating 26:5°, while at Caraccas it 
generally gave only 18° in fine dry weather. The 
phenomenon that most struck the travellers was the 
apparent aridity of the air, which seemed to increase 
as the mist thickened, the hygrometer retrograding, 
and their clothes remaining dry. | 
As it would have been imprudent to remain long 
in a dense fog, on the brink of a precipice, the tra- 
vellers descended the eastern dome, and, on regain- 
ing the hollow between the two summits, were 
surprised to find round pebbles of quartz, a phe- 
