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 



