60 
tains of Chuniban^ in the province of Los Pastos ; 
the bridge of Madre de Dios, called Danto, near 
Totonilco, in Mexico ; the pierced rock near 
Grandola, in the province of Alentejo, in Por- 
tugal; are geological phenomena, which bear 
some resemblance to the bridge of Icononzo: 
])ut I doubt whether in any part of the Globe a 
phenomenon has been discovered so extraordi- 
nary as that of the three masses of rocks, which 
support each other by forming a natural arch. 
I sketched the natural bridges of Icononzo 
from the northern part of the valley, with a side 
view of the arch. The first proofs of this plate 
indicate erroneously Mr. Gmelin of Rome as the 
engraver, instead of M. Bouquet of Paris. 
