204 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 22, 



be seen ; but solid rocks and their surfaces are buried out of sight in 

 low lands. 



Accordingly the districts chiefly studied for glaciation were moun- 

 tain-tracts. 



1st. The coasts, loughs, and mountains about Dundalk, Newry, 

 the Mourne Mountains, hills in Down, Antrim, and Londonderry, as 

 far as Fairhead in the N.E. 



2nd. The mountains and sea-loughs in Cork and Kerry in the 

 S.W. 



3rd. Donegal, Sligo, Mayo, and Connemara, in the north and west. 



4th. The coast was seen from a yacht, and from a steamer which 

 visited the Lights, from Valentia, by Cape Clear and Dublin, round 

 to Malin Head and Instra Hull. 



5th. Points were also looked at in central districts about Dublin, 

 Kildare, and Gal way, Armagh, Omagh, Dungannon, Enniskillen, <kc. 



6th. Railway-cuttings and roadsides were watched from trains 

 and cars ; and every likely spot that could be reached was examined 

 for ice-marks everywhere. 



Where ice hardly exists it is necessary to consider the ways of 

 glaciers and icebergs, and their work of grinding rocks and carrying 

 the debris. I have tried to apply knowledge gained in rambling 

 about the world during many years to rocks in Ireland. 



In studying Irish " tool-marks and chips " I tried to assign them 

 to natural engines, like those which I have seen shaping the earth's 

 surface in the Alps, in Scandinavia, in Iceland, and in America, afloat 

 and ashore. 



XI. Slieve Liag. — I have said above that I attribute most of the 

 rock forms in Ireland to glacial and to marine action. In Donegal, to 

 the north of the bay near Carrick, is a peninsula of high ground jutting 

 out into the sea, and making the northern horn of the bay. The 

 end of it is a high mountain called Slieve Liag (stone or pebble hill) ; 

 it is nearly 2000 feet high. Seen from near Beinn Gulban in Sligo 

 on the other side of the bay, or from the Carrick Hotel at tbe foot 

 of the mountain, it looks like any other Irish mountain with steep 

 undulating sides. On the north the hill-side is covered with drift. 

 From the head of " Glen river" and from all the high grounds to 

 the east, down all the hollows which now contain rivers, at some 

 late time, a great sheet of glacier-ice slid and flowed towards this 

 tall hill, which split the flood, turned it aside, and shunted part of 

 it out to sea through Teelin Harbour, S.W. 



There can be no question about this part of the record. Glacial 

 striae are plain and perfect in quarries and gravel-pits, on rocks of 

 many kinds, on veins of glassy white quartz, on pudding-stone, 

 which is like a rude pavement of rolled stones ; on hill-tops and in 

 river-bottoms. I have rubbings of them. 



The sheet of ice certainly travelled some twelve or fourteen miles 

 downhill, some 1500 feet ; and then some of it was forced up a steep 

 incline. At the preventive station at the mouth of Teelin Har- 

 bour it went over the hill some three or four hundred feet high 



