237 
petature, which reigns under this zone, is the 
cause why the limit of perpetual ice is not sub- 
ject to those irregularities, which we observe in 
the Alps and the Pyrenees. On the northern 
declivity of Chimborazo, between that mountain 
and Carguairazo, the road leads from Quito to 
Guayaquil, and toward the coasts of the Pacific 
Ocean. The paps covered with snow, which 
rise on this side, remind us, by their form, of that 
of the dome of Goute, seen from the valley of 
Chamonix. On a narrow ridge, which rises 
amidst the snows on the southern declivity, M. 
M. Bonpland, Montufar, and myself, attempted 
to reach, not without danger, the summit of 
Chimborazo. We carried instruments to a con- 
siderable height, though we were surrounded by 
a thick fog, and very much incommoded by the 
great tenuity of the air. The point where we 
stopped to observe the inclination of the mag- 
netic needle was more elevated than any yet 
attained by man on the ridge of mountains ; it 
was more than eleven hundred metres higher 
than the top of Mount Blanc, which the most 
enlightened and most intrepid of travellers, Mr. 
de Saussure, had the satisfaction of reaching, 
after struggling against difficulties still greater 
than those we had to conquer near the summit of 
Chimborazo. These laborious excursions, the 
narratives of which generally excite the atten- 
tion of the public, offer but a very small number 
