i8 The Irish Naturalist. February, 



of its latest chapter. It is to this last chapter that I ask 

 your attention this evening — nay, to a few of the concluding 

 paragraphs of this chapter. I have been endeavouring to 

 arrive at the interpretation of some of the phenomena of 

 the comparatively recent period intervening between the 

 close of the Glacial epoch, and the present time, and to 

 correlate those phenomena as displayed in our own district 

 with similar events in other parts of these islands. During 

 the Glacial period were displayed the last movements on a 

 grand scale of which we have any record : movements so 

 vast even in this region we occupy that I cannot help 

 thinking that the term cataclysmal is properly applicable 

 to them, despite the protest of a powerful and imperious 

 modern school of British geologists, who will not admit the 

 words cataclysm or catastrophe into the geological 

 vocabulary. At the close of the Glacial era, a period of 

 comparative repose'was ushered in. But this rest was only 

 comparative. The Quaternary gravels, esker-ridges, raised 

 beaches, and estuarine clays since formed have latterly 

 been provoking much discussion, various opinions have 

 been expressed as to the mode of their origin, but one thing 

 they unquestionably prove — that the geological forces are 

 still working, and have not ceased to work since the times 

 of the Boulder-clay. Movements of elevation can be shown 

 in some places, in others depression is seen to have occurred, 

 and some other regions exhibit evidence of alternate elevation 

 and depression. The last was undoubtedly the case here, 

 and, indeed, I think that it will be ultimately established 

 that these upward and downward movements of the land 

 have been not only general but simultaneous over the 

 country, or over large areas. Allow me at the outset to 

 state the conclusions at which \ have arrived, then to give the 

 grounds on which those conclusions are supported, and 

 lastly to try to show that these geological oscillations are 

 no isolated phenomena, but have extended more or less 

 over the British islands. 



Well then, I have arrived at the following conclusions : — 

 (i). At an era far back in post-Glacial times the land 



here stood at a higher elevation than it does at present. 



The elevation at that time I conclude to have been some 



