820 SoLLAS — A Map to show the Distribution of Eskers in Ireland. 



time it was abrading the bare rocks of the country, and (ii.) a system of drumlins, 

 which indicate its direction, after or during the deposition of the boulder clay. 

 But these two systems, that of the strise and that of the drumlins, corresjDond, 

 giving concordant indications, and thus prove that the movement of the ice 

 was that of a steady and persistent flow, throughout a great part of the 

 Glacial Period. 



Mr. Close has laid down these two systems on a majj (given also in the Geol. Mag. 

 for May, 1867), showing the general glaciation of Ireland, on which he also repre- 

 sents a third system of indications, those furnished by the transport of rocky 

 material, and the evidence of this is in strict agreement with that of the two pre- 

 ceding systems. We have transferred to our maps of eskers some of Mr. Close's 

 results, indicating a line of flow by a straight line, or, when its direction is known, 

 by an arrow ; the nature of tiie evidence is shown by a (A) for drumlin, a (2) for 

 rock striae, and a (T) for transport of material, placed by the side of the line or 

 arrow. 



It follows from Mr. Close's observations that, during the period with which his 

 map is concerned, the area of Ireland was glaciated by ice formed upon its own 

 surface, except the eastern side of Ulster, which was swept by an ice-flow from a 

 little west of north to a little east of south, which flow doubtless came from the 

 western side of Scotland. A great flow proceeded to move southward from the 

 north-east neighbourhood of Carrick-on- Shannon ; but evidently, in consequence 

 of the resistance of the ice to the southward, it divided near where that town now 

 stands, part going south-eastwards towards Dublin, and part turning sharply west- 

 ward from the plain country and then north-westward, when it was joined by the 

 northward flow from the head of Lough Corrib, to move off the present area of 

 Ireland in the neighbourhood of Killala bay. The south-eastern part of Ireland 

 has been glaciated by ice, first flowing eastwards, then south-eastwards, and 

 then southwards ; the county Clare and its neighbourhood was swept by ice 

 moving south-westwards, the place of parting of these two great flows being about 

 18 miles inland of the head of Galway bay. The hill-country centres of ice- 

 dispersion were all on the west of Ireland ; there were none elsewhere ; though 

 there were many corry-glaciers on the east and south-east of Ireland. 



The movement of the ice in the districts occupied by the esker systems is less 

 completely known than in the regions surrounding them. Irish geologists are 

 credited with a discovery they have not made, and are not likely to make, of 

 a coincidence between the direction of eskers and ice-flow (Woodworth, loo. cit., 

 p. 205). Mr. Woodworth does not cite authorities ; but the asserted coincidence, 

 when it exists, is only accidental. 



lu this connection it may be pointed out tliat, in addition to striations, drumlins, 

 and transport of material, we have a fourth criterion supplementing these, by 



