THE AGE OF THE LAST UPRISE OF THE BRITISH ISLES. 181 



been described by the late Mr. Robert Chambers, is preserved 

 in the MiiseuiD of Scottish Antiquaries in Edinburgh. Enough 

 has probably now been stated to show that, at a period when 

 iron was in general use in North Britain amongst the lowland 

 inhabitants, the sea had occupied the land up to a level 

 of about 30 feet above the present surface of the ocean, 

 sufficiently deep to allow the ingress of whales ; in other words, 

 when the land was submerged to tliat extent : and when the 

 arms of the sea stretching into the interior of the country, both 

 from the eastern and western coasts were navigated by men far re- 

 moved in the arts from the savages wdio only used stone weapons 

 and implements. Consequently the whole region has been 

 elevated into land since that period, and these firths have been 

 converted into the river-valleys of the Clyde, the Firth and the 

 Tay, while the marginal tracts form the wide plains or " carses " 

 on either side of these rivers. We have now to consider the 

 question at what period did the rise of the land take place owing 

 to which this remarkable change in the physical geography of 

 the country was brought about. But before entering upon this 

 subject we must glance at the coast of Ireland in order to 

 determine whether, and if so to what extent, that country was 

 affected by the terrestrial movement here contemplated.* 



Effect of the suhmerge'tice on the land. — I have been able to 

 define, with a great approach to accuracy, the submerged areas 

 on the 1-incli ordnance map of Scotland by means of the contour 

 lines along the valleys of the Clyde, Forth and Tay, inasmuch 

 as tlie 50-feet contour closely coincides with the margin of the 

 30-feet terrace. This is owing to the fact that the 50-feet 

 contour represents the height above the mean level of the sea 

 at Liverpool — not above that of high-water — which is the 

 datum for the terrace itself. When tracing this contour on the 

 map, one could not but observe that it coincided with an abrupt 

 rise in ground above the nearly level plain formed by the 

 raised beach. As regards the change effected in the topography 

 of the country itself, the prolongation of the present estuary of 

 the Forth into the heart of the country above Kippen and 

 Thornhill in the valley of the Forth, had the result of almost 

 dividing Scotland into two parts. The distance of land from the 



The occurrence of several places in the valley of the Tay and 

 beginning with the word " Inch " (Celtic for Island) is very suggestive 

 of former conditions ; thus we find Inchture. Inchniartine, Megginch 

 Castle, Tnchyra and Inchcoonans. These are all remote from the present 

 sea-margin. 



