492 A JOURNEY IN BRAZIL. 
ing on the hill to the east of Thcresopolis, the whole range 
presents itself in a perfect profile ; the axis, on either side 
of which dip the almost vertical beds of metamorphic rocks 
composing the chain, occupies about the centre of the range. 
To the north, though very steeply inclined, the beds are not 
so vertical as in the southern prolongation of the range. 
The consequence of this difference is the formation of more 
massive and less disconnected summits on the north side ; 
while on the south side, where the strata are nearly or 
quite vertical, the harder sets of beds alone have remained 
standing, the softer intervening beds having been gradually 
disintegrated. By this process have been formed those 
strange peaks which appear from a distance like a row 
of organ-pipes, and have suggested the name by which the 
chain is known. They consist of vertical beds isolated 
from the general mass in consequence of the disappearance 
of contiguous strata. The aspect of these mountains from 
Rio is much the same as from Theresopolis, only that from 
the two points of view one being to the northeast, the 
other to the southwest of the range their summits pre- 
sent themselves in the reverse order. When seen in com- 
plete profile their slender appearance is most striking. 
Viewed from the side, the broad surfaces of the strata, 
though equally steep, exhibit a triangular form rather than 
that of vertical columns. It is strange that the height of 
the Organ Mountain peaks, so conspicuous a feature in 
the landscape of Rio de Janeiro, should, not have been ac- 
curately measured. The only precise indication I have 
been able to find is recorded by Liais, who gives 7,000 feet 
as the maximum height observed by him. 
" These abrupt peaks frequently surround closed basins, 
very symmetrical in shape, but without any outlet. On 
