Chaelesworth — Glacial Geology of North-West of Ireland. 179 



Eeferring to the earlier Scottish glaciation, lie remarks (p. 328) : — 



" A general trend and distribution or boulders from east to west is 

 noticeable in the north, and is doubtless connected with the epoch of 

 maximum glaciation, when ice crossed over from Scotland." 



Mr. W. B. Wright, in his book "The Quarternary Ice Age," published in 

 1914, clearly recognised the fact that the Donegal hills had been a centre of 

 ice radiation ; indeed, his observations and conclusions on the glaciation of 

 North Ireland are, in their larger features, singularly accurate. Yet the error 

 of the " Central Axis " would seem to persist in this excellent work. He 

 writes : — 



" The mountains of Donegal appear to have given rise to a minor 

 centre of dispersion, which formed a sort of offshoot of the great central 

 axis of dispersion of northern and western Ireland." (p. 60.) 



Thus summarily it may be stated that two basic theories of the glaciation 

 of North Ireland have in the past found general acceptance ; one, an extensive 

 Scottish invasion of the country from the Antrim coast to an uncertain line 

 which by Mr. T. Hallissy was drawn to the south of Lough Foyle, but by 

 J. E. Kilroe was regarded as coincident with the Atlantic coast; the second, 

 the overriding of this region by an ice-sheet moving northward from a central 

 axis stretching for a distance of upwards of 100 miles from Lough Corrib in 

 the W.S.W. to Lough Neagh, and possibly the Antrim coast, in the E.N.E. — 

 the " Central Snowfield " of E. Hull. 



It may perhaps at this place be stated that the area in this part of the 

 country which was covered by the ice proceeding from Scotland has, as a 

 result of these investigations, been restricted to within comparatively small 

 limits. The " Central Snowfield," over the 80 odd miles of country assigned 

 to it and examined by Dr. A. K. Dwerryhouse and the writer, has been shown 

 to have no basis in the field ; the character of the glaciation of the remaining, 

 western part of the " axis," which is situated in the Sligo hills, it is hoped to 

 investigate in the near future. 



It cannot, I think, be too strongly emphasized that the " Central Irish Ice " 

 of Mr. G. W. Lamplugh, f.r.s., which occupied the great Central Plain of the 

 country, was completely indebted to the ice-flows, of huge size and considerable 

 number, which streamed into the depression from the centres of radiation 

 situated in the larger mountain masses on its borders, and of which the 

 glaciers issuing from the Donegal Highlands were doubtless the most power- 

 ful. Escape from this pool of ice was only possible by gaps between the 

 mountain groups. There would appear to be no evidence whatever that the 

 ice in this pool ever assumed such thickness and dimensions as to raise its 



