T. BELT ON THE DRIFT OF DEVON AND CORNWALL. 89 



rapidly retired as f arjback as the extreme north of Scotland ; but the 

 sea had not yet returned to its former level, and the British Isles 

 were still joined to the continent. To it I assign the last great 

 foresi>period and the arrival of Neolithic man with the associated 

 fauna from the continent. 



Postscript. 



January 17, 1876. — Since this paper was read before the Society 

 I have again crossed Europe and examined the southern limits of 

 the northern drift as far as the cliffs of glacial clay around the 

 shores of the Sea of Azoff. I now attach much more importance to 

 the second advance of the Atlantic glacier, and believe it marks the 

 culmination of the Glacial Period. The restriction of the middle 

 glacial sands and gravels to heights not exceeding, if reaching, 500 

 feet above the sea, leads me to think that the first great European 

 lake drained around the hills of Brittany into the valley of the Loire, 

 and that the principal distribution of the Scandinavian drift and the 

 formation of most of the upland deposits belong to the period of the 

 second great lake, when the col to the east of Brittany was also 

 blocked up and the waters drained through the Black Sea to the 

 Mediterranean, cutting out gradually a passage through the Darda- 

 nelles that had not before existed. 



Discussion. 



Mr. Hicks stated that he had noticed that the glaciation at St. 

 David's is from the north-west. He had already stated before the 

 Society his opinion that there had been depressions proceeding from 

 a point in the Atlantic, probably not far from the coast of South 

 America, to the north-west and north-east ; and this might perhaps 

 have something to do with causing a flow of ice from Greenland to 

 the south-west in North America and to the south-east in Europe. 



Rev. 0. Fisher wished to know what would be the area of the 

 great freshwater lake supposed to be produced by the damming 

 action of the great Atlantic glacier. 



Mr. Belt stated that the area blocked up by the ice would be 

 about 400,000 square miles (2000 x 200), and would include all the 

 region drained by the present northern rivers. 



Prof. Hughes wished to know why the waters could not drain off 

 by way of the Black Sea, and why the advancing Atlantic glacier 

 should be supposed to stop just at the western poiut of Cornwall. 

 He could discover no evidence of there ever having been a lake 

 such as the author described. The drift gravels were the result of 

 all the agencies of denudation which had ever been at work ; and the 

 boulders at the bottom of the low-ground drifts were probably due 

 to the fall of debris from the summits. The boulders of the drift, 

 if the author's theory were true, ought to consist of Greenland rocks, 

 whereas they were really of local origin. With regard to the direc- 

 tion of glaciation in Britain and Northern Europe being from the 

 north-west, he could not agree with the author. In many places 



