72 PROBABLE DATE OF THE SUBMERGENCE 



cumstance that, on the coasts of Devon and Cornwall, 

 the present coast line hugs the old line of Kaised 

 Beach and "Head" very closely, the two being 

 seemingly in no instance distant more than a quarter 

 of a mile apart. 1 In fact, the distance apart does 

 not usually exceed 50 to 500 feet, so that the time- 

 estimate would, no doubt, be well covered by the 

 term 1 have allowed for the wear of the south coast. 

 Although these findings cannot pretend to the 

 accuracy required, they confirm the other evidence ; 

 and the plan may serve as a basis for more exact 

 calculation. In any case, these tentative estimates 

 are in accordance with the conclusion I had arrived at 

 on other grounds, that the Glacial (including the post- 

 glacial) period, together with Palaeolithic Man, came 

 within 10,000 to 12,000 years of our own times. 



I cannot conclude without referring to the opinion 

 of some of the most eminent American geologists, 

 founded on independent data of a different character 

 from that which we have considered in these pages, 

 namely that the Glacial period came down to within 

 8,000 to 10,000 years of our times. 2 



1 On these coasts there is another scale which might be made 

 available. Some early British camps or enclosed earthworks, 

 situated near the edge of the cliffs, have, owing to the encroach- 

 ment of the sea, been in part destroyed. It would not be difficult, 

 where these are near a liaised Beach, to determine the extent of 

 loss ; and as the date of the earthworks could be approximately 

 ascertained, this, with a few years' observation of the present 

 rate of wear, would furnish further data for time-measurement. 



2 This was my original opinion, which subsequent observation 

 has confirmed (Proc. Royal Institution for Feb. 26, 1864). 



