CHAP. III.] 



VOLCANOES IN BRITISH ISLANDS. 



45 



lifted up their heads in Wales, Cumbria, and Scotland 

 not less than about 10,000 feet above the sea. 



Volcanoes in British Islands. 



The fossil vegetation under the sheets of basalt and of 

 volcanic tufa in the Hebrides and in the north of Ireland, 

 proves that in the north and west of the British Isles there 

 were active volcanoes in the Meiocene age. Some of these 

 were of enormous size. " The base of the volcano of 

 Mull "* (Fig. 7), writes Professor Judd, " must have had a 

 circumference of at least forty miles ; Etna, which has a 

 greatly truncated cone, nevertheless rises to over the 

 height of 10,900 feet from a base of only thirty miles in 

 circumference. A similar relation between the base and 



CLASHVCN 



1516 



CRUACHAN 

 DEARQ 



BEIKN MORE 



31 



CRCACH 



> BE'NN 



~--l62l 



SmmdofMuH. 



Granite Volcanic Agglomerate. 



FIG. 7. Section through Beinn More. The dotted line = Meiocene Surface. 



the altitude of the great volcanoes of Sicily and Mull 

 would lead us to infer that the elevation of the latter 

 was at least 14,500 feet." From another calculation, 

 founded on the inclination of the beds of lava, he infers 

 that the volcano of Mull could not have been less than 

 10,000 feet high. The volcano of Skye was not smaller 

 than that of Mull, and those of Eum, Ardnamurchan, 

 and St. Kilda, though smaller, were mountains of great 



1 Fig. 7 is taken from Professor Judd's Section, Quart. Jour. Geol. 

 Soc. Lond. xxx. p. 259, PI. xxiii. 



