18 Proceedings of the Royal Irish Academy. 



and minor lakes — lying north and south — seem to have been produced 

 at the same period, by earthquake action running in a direction almost 

 due north and south. 



Proceeding northwards, the record which relates to the eruption of 

 Lough Erne appears, also, corroborated by certain physical facts. 

 According to the chronicle, the breaking forth of the water drowned 

 some of the Ernai tribe, then upon its plain. The aspect of the locality 

 indicates ancient changes of level; thus, Dr. O'Donovan, when describ- 

 ing it whilst on the Ordnance Survey, wrote : "I passed over the great 

 cliffs that overhang the plain of Eweealt of Toorad. This Eweealt 

 is a level district running about five miles along the north-west bank 

 of the great Loiigh Erne. The name (Eaoi alt) signifies ' under the 

 height,' ' subrupian.' It is grand and beautiful, and seems to have 

 been formed when the awful commotion took place that formed Lough 

 Erne. It was by a depression of the earth, occasioned by some sub- 

 terranean commotion similar to the one that in later times destroyed 

 the city of Lisbon."*^ Distinct proof of a former upheaval is found in 

 the remarkable discovery, which Professor W. K. Sullivan has commu- 

 nicated, of a dolphin's skull, which lay twenty feet beneath the surface 

 of a bay, at Pettigo, near Lough Erne. It follows from this that the 

 locality was once submerged, that the sea ran in as far as the site of 

 the present town of Enniskillen, and that it was probably continuous 

 with the Eoyle, at Strabane and Derry. Thus, at that period, Donegal 

 would have been isolated. Afterwards, there was a great and extensive 

 upheaval, which raised this district so much that the surface of the 

 Lough is now about one-hundred and fifty feet above the level of the 

 sea at low water. 



As there are raised beaches along the northern coast, it appears 

 likely that they were elevated about the same period, and that the in- 

 fluence of earthquake action extended over the north of Ireland. It 

 is recorded that the late Mr. Du IS'oyer discovered some flint weapons 

 amongst the gravels of the raised beaches of Down and Antrim. If, 

 therefore, we hold, as seems most probable, that the various upheavals 

 in the province took place about the same period of time, we may come 

 to the curious conclusion that those who fashioned and used the flint 

 weapons, so discovered, may have been the contemporaries of the 

 Ernai. 



That there should be raised beaches at or near Lough Eoyle is 

 what we would anticipate from its seismical connexion (so to speak) 

 with Lough Erne. JN^or are they wanting. Instances of elevation may 

 be detected on the west or Innishowen shore, from Moville to Port-a- 

 dorus ; on the eastern, or Derry shore, the efi'ects of upheaval assume 

 larger dimensions. Evidence of subsidence is also present. Thus, on 

 the west strand, near Portrush, there has been found a large quantity 

 of hard flaky bog, which, lying below high-water mark, is laid bare by 



* Ordnance MSS., Fermanngh, Letters, p. 41. 



