SoLLAS — A Map to shozv the Distribution of EsJcers in Ireland. 787 



had already, over twenty years previously, been suggested by Professor N. H. 

 "Wincliell in America, and by Dr. D. Hummel in Sweden in 1874. 



If by the foregoing personal account I admit myself to have been twenty 

 years behind the time, I willingly make the confession for the sake of what 

 appears to me a fact of some interest, viz. that independent observers, studying 

 eskers in three different countries, have been led independently, by personal 

 investigation, to a fundamentally similar interpretation of these puzzling geo- 

 graphical features. 



Literature of the Subject. 



Ridge-like hills, which owe their origin to glacial action, are of more than one 

 kind, and it is necessary to distinguish between them. The first and most 

 important step was taken by the Eev. Maxwell Close in 1865, who separated, under 

 the name of "Drumlins," those ridges which consist of unstratified boulder clay 

 from those formed of water-worn material. To these latter he restricted the 

 term " Esker."* 



A further distinction has been suggested by Professor T. C. Chamberlin,f who 

 proposes to divide eskers into two classes, the one containing those ridges that 

 run with the slope of the ground — these he calls asar — and the other, those that 

 run transversely to the direction of the glacial movement, and which are usually 

 associated with terminal moraines ; these alone are to be called kames. The 

 distinction may certainly be recognised in the case of Irish eskers, at least as 

 regards their relation to the form of the ground or the movement of the ice ; but 

 not, so far as I am aware, as regards their association, or otherwise, with terminal 

 moraines. In any case the term " esker" is too deeply rooted in the nomenclature 

 of Irish geology for us to abandon it without inconvenience ; possibly in Scotland 

 greater readiness vpill be displayed in restricting the meaning of " kame."J 



* Notes on the General Glaciation of Ireland, by the Eev. Maxwell H. Close (1865). — Joum. Eoy. Geol. 

 Soc. of Ireland, vol. i., p. 207, 1867. 



f The Terminal Moraine of the Second Glacial Epoch. — Third Annual Keport U.S. Geol. Survey, p. 300, 

 1883. 



J On referring to Dr. J. Geikie's Ice Age (3rd edition), I find, however, that while the term " kame " 

 is retained, it is proposed to abandon "esker" for "as." On page 746 we find the followiug : — ''As 

 between the alternate terms 'as' and 'esker,' the former has the sanction of priority, and is the local 

 term for the great Scandinavian type. Notwithstanding this, the term esker is growing into favour 

 among American Glacialists, doubtless for phonic reasons." I regret that I am unable to admit the 

 priority of the term "as" without further information. The series of esker-groups to be described later 

 on is part of what was formerly called by the general name of Esker Eiada. O'Donovan, in his transla- 

 tion of the Annals of the Four Masters at a.d. 123, where Esker Eiada is mentioned, says of it — " This is 

 a line of gravel hills extending from Dublin to Clarinbridge in the county of Galway. It is mentioned in 

 ancient Irish MSS. as reaching from Dublin to Clonard, thence to Clonmacnois and Clonburren, and 



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