ISLAND OF FOULA. 
2S9 
conforming in a general way with the tabulae of the sand- 
stone of which it is composed. An elevated platform, about 
600 feet high, projects to the north from the west end of 
the ridge, and terminates abruptly at the north-west point 
of the island ; and when viewed from the east, a few miles 
at sea, the last mentioned point, with the three peaks of the 
Snuke ridge, appear like separate hills rising behind each 
other, and then, with the Noup, may probably constitute 
the five hills of Foula with some, though, correctly speak- 
ing, it contains but two. 
This island is chiefly composed of sandstone, resting on 
primary rocks ; the upper 600 feet or 700 feet being of a 
loose texture, occasionally ferruginous, containing numer- 
ous small scales of mica dispersed through it. Pebbles 
of quartz, and fragments of other rocks, occur, but not 
frequently, and are arranged in layers and patches; the 
first conformable with the direction of the strata, which is 
also the line the patches assume in regard to each other. 
Green-earth also occurs in some places, in considerable 
quantities, in small compressed nodules, appearing, at first 
sight, like the fragments of a schistose rock dispersed in the 
sandstone. The sandstone, which occupies the upper part 
of the Snuke, has the direction of its strata nearly conform- 
able with the line of the ridge, having its outgoings on the 
steep north slope of the hill, while it dips to the south-west, 
at an angle of about 12°, constituting the cliffs on the south- 
west side of the island, from Ravenbrag to the south 
point. Along that portion of the coast, from the softer na- 
ture of the rock, and the inclination of its base towards the 
sea, full scope is given to the action of the waves, and a 
scene of ruin and impending danger arrest the attention of 
the spectator; enormous masses, quite detached, seem 
ready to fall on tlie shghtest application of force ; while 
