VALLEY OF THE AMAZONS. 
161 
in every direction. A sheet of drift, consist¬ 
ing of the same homogeneous, unstratified 
paste, and containing loose materials of all 
sorts and sizes, covers the country. It is of 
very uneven thickness, — sometimes thrown 
into relief, as it were, by the surrounding den¬ 
udations, and rising into hills, — sometimes 
reduced to a thin layer, — sometimes, as, for 
instance, on steep slopes, washed entirely away, 
leaving the bare face of the rock exposed. It 
has, however, remained comparatively undis¬ 
turbed on some very abrupt ascents; as, for 
instance, on the Corcovado, along the path 
leading up the mountain, where there are very 
fine banks of drift, — the more striking from 
the contrast of their deep red color with the 
surrounding vegetation. I have myself fol¬ 
lowed this sheet of drift from Rio de Janeiro 
to the top of the Serra do Mar, where, just 
outside the pretty town of Petropolis, the river 
Piabanha may be seen flowing between banks 
of drift, in which it has excavated its bed; 
thence I have traced it along the beautiful 
macadamized road leading to Juiz de Fora in 
the province of Minas Geraes, and beyond this 
to the farther side of the Serra da Babylonia. 
