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fingal's cave. 
The entrance to this splendid cavern is 50 feet 
broad and 100 feet high, and its length 250 feet. 
On each side, as well as at the base, these columns 
are thickly studded ; the whole presenting a singu- 
larly rich and varied effect. The basalt of which 
the columns are composed is of a dark, greenish- 
black hue, highly coloured by iron. The columns 
consist generally of five or six sides, though they 
may range from 3 to 12 : and they are made up of 
numerous joints or separate pieces, united by a thin 
layer of silicious cement. The whole island of 
Staffa, which is two miles in circumference, is sur- 
rounded on every side by steep cliffs about 70 feet 
high, formed of clusters* of the same angular col- 
umns. Sometimes they are curved. 
* Mr. Gregory Watt, in 1 804, melted 700 weight of basalt, 
and kept it in the furnace several days after the fire was redu- 
ced. It fused into a dark-coloured vitreous mass with less heat 
than was necessary to melt pig-iron ; as the mass cooled, it 
changed into a hard, stony substance, and globules appeared ; 
these enlarged till they pressed laterally against each other, and 
became cemented into regular prisms. It is, therefore, clearly 
estabUsbed by this experiment, that the articulated structure 
