44 EARLY MAN IN BRITAIN. [CHAP. in. 



during both ages, and the rapid increase of depth in the 

 Atlantic to its west would allow of a considerable de- 

 pression taking place, without altering in any important 

 degree the position of the sea-margin. 



Professor Heer 1 places his Atlantis to the south-west 

 of the land represented in the map (Fig. 6) ; but the 

 enormous depth of the North Atlantic renders it very 

 improbable that there was dry land in that region at a 

 time, geologically speaking, so recent as the Meiocene age. 



The Mountains. 



The principal mountains in the British Isles were in 

 their present positions in the Meiocene age, but were con- 

 siderably higher. If we take the rate of denudation to be 

 the same as that which we know to have taken place in 

 the volcano of Mull in post-Meiocene times (Fig. 7), which, 

 exclusive of the cone, has been shown by Professor Judd 2 

 to have been 6000 feet high, while the present height of 

 Beinn More, the highest fragment now remaining, is 

 but 3172 feet, we arrive at the startling result that the 

 height of the Meiocene mountains in Britain was double 

 what it is now. It is therefore probable that in the- 

 western and northern parts of our island mountains 

 rose to a height of 6000 or 7000 feet, even if we do not 

 take into account the amount of elevation above the 

 sea necessary to allow of continuity between Britain and 

 Iceland. If the 500 fathoms of elevation of the Meio- 

 cene continent be added, the mountains must then have 



1 Climat et la Ve'ge'tation du Pays Tertiaire, transl. Gaudin ; 4to. See 

 also Lyell, Student's Elements, 1865, c. xvi. 



2 Quart. Jour. Geol. Soc. Lond. xxx. p. 259. 



