1S98] THE ESKERS OF IRELAND 175 



the arrangement of the materials is very curious. Irregular beds of 

 large blocks, or of small pebbles, or of the finest sand, are arranged 

 one over the other, generally with a rude attempt at conforming to 

 the external slopes of the ridges, but not preserving to any distance 

 either the thickness or the inclination." 



This description of the ' section,' although written with special 

 reference to a ridge quite at the eastern extremity of the great 

 central plain, would apply to the great esker at the College near 

 Athenry, particularly the remarks on the stratified arrangement of 

 the sand and gravel. 



The true esker, or ridge, when seen at a little distance bears a 

 striking resemblance to a railway embankment, and, as Kinahan 

 remarks, is sometimes so narrow at the top that people may almost 

 shake hands across the width. This is, however, rather exceptional. 

 I know well the Parsonstown esker described by Jukes. It crosses 

 the county road between Birr and Banagher — the road is, in fact, 

 cut through ' The Bidge ' ; and the latter runs across the country in 

 the direction of the Shannon, the top of it serving, for a consider- 

 able distance, as a bog-road or bore en. The Maryborough esker 

 — also locally known as The Bidge — is said by the country people 

 to extend " all across Ireland " : it can indeed be traced, more or less 

 continuously, for many miles. Adjoining the town of Maryborough 

 its slopes and top have until recently been used as a cemetery. 

 Geikie mentions certain kames in Scotland that had long been used 

 for the same purpose. 



So far we have been making approach to the interesting 

 but perplexing question — How came these eskers to be what they 

 are ? By what particular agency, or agencies, have sand, gravel, 

 clay, and shingle been ridged up, and at the same time sorted and 

 stratified as we find in the typical esker ? 



All who have attempted the solution begin by confessing the 

 very great difficulty of the question ; and the admitted difficulty 

 has given rise to a considerable amount of ' scientific ' romancing. 



" A small mound quite close to Dunfermline is locally famous 

 under the name Mont Dieu. According to an old story this drift 

 mound owes its origin to some unfortunate monks, who, by way of 

 penance, once carried the sand in baskets from the sea-shore at 

 Inverkeithing " (J. Geikie, "Great Ice Age," p. 212). And there is a 

 similar legend as to the origin of a mound in the valley of the Kali 

 Water, Boxburghshire. From the economical point of view these 

 cases are very good examples of ' unproductive ' labour. But, from 

 the inquirer's point of view, they are hardly more romantic than the 

 explanation put forth, in the cause of science, by Mr A. E. Torne- 

 bohm as to the origin of the Swedish asar or eskers. 



His belief is that the asar are ancient river courses, and he 



