334 ISLAND LIFE 



fathoms being from twenty to fifty miles, except where 

 there is a great outward curve to inckide the Porcupine 

 Banli 170 miles west of Gal way, and to the north-west of 

 Caithness where a narrow ridge less than 500 fathoms 

 below the surface joins the extensive bank under 300 

 fathoms, on which are situated the Faroe Islands and 

 Iceland, and which stretches across to Greenland. In the 

 North Channel between Ireland and Scotland, and in the 

 Minch between the outer Hebrides and Skye, are a series 

 of hollows in the sea-bottom from 100 to 150 fathoms 

 deep. These correspond exactly to the points between the 

 opposing highlands where the greatest accumulations of ice 

 would necessarily occur during the glacial epoch, and they 

 may well be termed submarine lakes, of exactly the same 

 nature as those which occur in similar positions on land. 



Proofs of Former Elcration — Suhmergcd Forests. — What 

 renders Britain particularly instructive as an example of a 

 recent continental island is the amount of direct evidence 

 that exists, of several distinct kinds, showing that the land 

 has been sufficiently elevated (or the sea depressed) to 

 unite it with the Continent, — and this at a very recent 

 period. The first class of evidence is the existence, all 

 round our coasts, of the remains of submarine forests often 

 extending far below the present low-water mark. Such 

 are the submerged forests near Torquay in Devonshire, and 

 near Falmouth in Cornwall, both containing stumjis of 

 trees in their natural position rooted in the soil, with 

 deposits of peat, branches, and nuts, and often with 

 remains of insects and other land animals. These occur 

 in very different conditions and situations, and some have 

 been explained by changes in the height of the tide, or by 

 pebble banks shutting out the tidal waters from estuaries ; 

 but there are numerous examj^les to which such hypotheses 

 cannot apply, and which can only be explained by an 

 actual subsidence of the land (or rise of the sea-level) since 

 the trees grew. 



We cannot give a better idea of these forests than by 

 quoting the following account by Mr. Pengelly of a visit to 

 one which had been exposed by a violent storm on the 

 coast of Devonshii>e, at Blackpool near Dartmouth : — 



