INFLUENCE OF STRATA UPON SCENERY. 
269 
as for instance in the Mont Blanc district, at first 
sight resemble dolomite peaks. The transverse lines, 
however, are not continuous, and the summits are 
even more pointed, though in many cases, as, for in- 
stance, the Aiguille de Charmoz, what seems a 
pointed needle is really a long, narrow crest. The 
materials are among the very hardest in existence. 
Hornblende schist is sometimes quite pale, some- 
times very dark. It often becomes reddish by decay 
of the ferrosilicate, so that many mountains of this 
rock are known as the Rothhorn, Rothfluh, etc. It 
forms bold, sharp ridges, and torn, wild, pointed 
peaks. 
Porphyry, though rather rare, forms an extensive 
bed in the neighbourhood of Botzen, occupying 'an 
irregular strip, running from north to south, some 
40 miles long by 12 wide, through which the outlet 
of the Adige has been cut. The great rounded walls 
of dull purplish-red rock, clothed in many places 
with brushwood, and supporting large upland plateaux 
of the richest herbage, produce a scene of singular 
luxuriance and beauty, especially when their tints 
are heightened by the glow of the setting sun. 
Beautiful as they are at all times, there is then some- 
thing almost unearthly in their splendour; and no 
one who has not made an evening journey from 
