DU' NOYEK — ON THE SOUTH OF IRELAND. 
243 
tions will be wrought by the sea at the surface, and by the earthquake 
power beneath the crust of the globe, far beyond the most visionary 
flights of imagination ever indulged in by the most accomplished 
philosopher of nature. 
The last great geological event of which we can detect the traces 
over the British Islands, was their gradual upheaval from beneath 
the sea ; before that period, which comparatively speaking is a very 
recent one, we know not how often our islands and Western Europe 
had been submerged and elevated, or what were the outlines of the 
land at these ditferent post-Tertiary periods ; neither can we fix the 
particular time when the Chalk of the South of England and the 
North-west of France was cut through to form the Straits of Dover, 
or the Basalt of the county of Antrim and the west coast of Scotland 
divided by the Irish Channel. We have however every reason to 
believe that what are now the British Islands formed a portion 
of the European Continent before the creation and distribution of 
the existing Elora ; and doubtless during the lifetime of the 
elephant, rhinoceros, hippopotamus, hyena, bear, etc., whose bones are 
found in our caves as well as in those of the Continent. While from 
recent discoveries it is possible that Man even may have been co- 
existent with these now extinct animals. 
The traces left by the sea during the period of the last upheaval, 
of the land, are generally understood by the term "Drift," and 
they are such as to lead to the belief that ice floating over the 
sea and glaciers forming in the mountain gorges were the chief 
agencies of destruction, while the former, aided by tides and currents, 
caused the transportation of rock masses over wide-spread areas. 
The presence of icebergs being once admitted, we must infer that 
the temperature of the sea was much lower in these latitudes then 
than now, and at the cessation of this period of upheaval the climatal 
conditions must have closely approached to those of the Arctic zone ; 
our mountain glens were occupied by glaciers for a very long period 
indeed, as is proved by the extensive moraines now to be seen at their 
mouths, and the grooving and polishing of the rocks along their sides. 
The last great current of the glacial sea certainly flowed from N. 
and N.W. to S. and S.E. ; this is chiefly demonstrated by the occur- 
rence of large boulders of peculiar rocks scattered on the surface to 
the southwards of where they are recognized in situ. 
By studying the contour of the loftiest mountains in the South 
of Ireland, such as Carrantuohill — the highest, 3414 feet above the 
