458 
THE TERTIARY VOLCANOES 
BOOK VIII 
I have referred to the impressive evidence of denudation displayed 
on the west side of the island of Eigg. The vertical distance from the 
summit of the Eigg plateau to the bottom of the submarine valley between 
this island and Rum is about 1500 feet, but as that summit lies below the 
oiiginal suiface of the lava-field, the depth of rock which has been removed 
must exceed 1500 feet. We thus learn that since the close of the volcanic 
period the hollow between the islands of Eigg and Rum has been eroded to 
this great depth. 
Still more striking is the evidence of enormous waste presented by the 
Faroe Islands. Ihe cliffs there are loftier and barer, and the fjords have 
been cut more deeply and precipitously out of the basalt-plateau. I shall 
never forget the first impression made on my mind when the dense curtain 
of mist within which I had approached the southern end of the archipelago 
rapidly cleared away, and the sunlit slopes and precipices of Sudero, the 
two Dimons, Skuo and Sando, rose out of a deep blue sea. Each island 
showed its prolongation of the same long level lines of rock-terrace. The 
eye at once seized on these features as the dominant element in the geology 
and the topography, for they revealed at a glance the true structure of the 
islands, and gave a measure of the amount and irregularity of the erosion 
of the original basalt-plateau. And this first impression of stupendous 
degradation only deepened as one advanced further north into the more 
mountainous group of islands. Probably nowhere else in Europe is the 
potency of denudation as a factor in the evolution of topographical features 
so marvellously and instructively displayed as among the north-eastern 
members of the Faroe group. 
Availing ourselves of the datum-lines supplied by the nearly level bars 
of basalt, we easily perceive that in many parts of the Faroe Isles the 
amount of volcanic material left behind, stupendous though it be, is less 
than the amount which has been removed. Thus the island of Kalso is 
merely a long narrow ridge separating two broad valleys which are now 
occupied by fjords. The material carved out of these valleys would make 
several islands as large as Kalso. Again, the lofty precipice of Myling 
Head, 2 2 G 0 leet high, built up of bedded basalts from the summit to below 
sea-level, faces the north-western Atlantic, and the sea rapidly deepens in 
front of it to the surface of the submarine ridge 200 to 300 feet below. 
The truncated ends of the vast pile of basalt-sheets which form that loftiest 
sea-wall of Europe bears testimony to the colossal denudation which has 
swept away all ol the volcanic plateau that once extended further towards 
the west. 
Nevertheless, enormous as has been the waste of this plateau of the 
laroe Islands, we may still trace some of its terrestrial features that date 
back probably to the volcanic period. Even more distinctly, perhaps, than 
among the Western Isles of Scotland, we may recognize the position of the 
original valleys, and trace some of the main drainage lines of the area when 
it formed a wide and continuous tract of land. 
A line of watershed can be followed in a south-westerly direction from 
