A Pica for Irish Glaciology. 31 



ing influence of the New Geology ? Those who have listened 

 to Sir Robert Ball's eloquent description of the precession of 

 the equinoxes, and the periodic eccentricity of the earth's orbit, 

 the "breathing in and out" of that mighty ellipse, will realize 

 more clearly the astronomical side of the question, and more 

 readily believe that there may have been and may be other 

 glacial epochs. Some interesting facts in connection with 

 this view are given by Dr. James Geikie in a recent paper on 

 the evolution of climate 1 , where he mentions that erratics 

 have been found in Cambro-Silurian rocks as much as five 

 feet in diameter; and he quotes Sir William Dawson's account 

 of a large Carboniferous esker with erratics, and says that Sir 

 Andrew Ramsay believed he discerned ice- action in the Per- 

 mian breccias, and in erratics included in the Palaeozoic strata 

 of Scotland. Unfortunately, we are not likely to obtain much 

 information about those possible early glacial periods, but 

 surely we cannot rest content without investigating to the 

 utmost degree everything that speaks of what we must still 

 term par excellence The Great Ice Age ? 



Splendid work upon the glaciation of Ireland has been 

 already done by the Rev. Maxwell Close 2 , who has not only 

 given the fruits of years of careful study on his own part, in- 

 eluding a map showing the direction of the ice striations, but 

 has also brought together much work done by others, especially 

 by the officers of the Geological Survey of Ireland. Those 

 who wish to familiarize themselves with much that has been 

 already written upon the subject, should refer to Professor 

 Hull's "Physical Geology and Geography of Ireland" 3 , which 

 contains a list of works on Irish geology in which papers on 

 glacial subjects by Mr. Kinahan 4 and other writers are quoted, 

 and which is also furnished with an interesting map showing 

 the general direction of ice striae in Ireland ; whilst for local 

 work, the maps and explanatory memoirs of the Geological 

 Survey afford valuable and convenient assistance. Readers of 

 the Irish Naturalist will not require to be reminded of Professor 



1 James Geikie—" Fragments of Earth Lore," 1893. 



2 M. H. Close — "On the General Glaciation of the Rocks near Dublin," 

 Jour. Roy. Geol. Soc. Ireland, vol. i., p. 3; " On the General Glaciation 



of Ireland," Ibid., p. 207; "The Elevated Shell-bearing Gravels near 

 Dublin," Ibid., iv., p. 36, and Geol. Mag., 1874, p. 193 ; &c. 



1 Hull— "Physical Geology and Geography of Ireland," London, 1878. 



4 See also Mr. Kinahan's " Geology of Ireland." 



