1873.] CAMPBELL GLACIATION OF IRELAND. 213 



glacial period. But if one half of the world was so covered, the other 

 half cannot have escaped. The change in climate which produced 

 this period of intense cold is theoretically accounted for by astrono- 

 mical facts. 



The whole theory was based upon many sets of observed facts 

 which combine severally and in groups, and lead gradually from 

 smaller to greater conclusions as the number of facts observed 

 grows. 



My observations made this year in Ireland, combined with the 

 rest of my facts, have led me from small mountain-glaciers to a sheet 

 more than 2000 feet thick, covering the northern half of Ireland. 

 I have got a long way towards the most advanced glacial theory 

 since I printed ' Frost and lire,' in 1865 ; but I cannot yet see my 

 way to a universal ice-crust. Wbat would become of vegetation 

 and animal life if the uppermost geological formation were every- 

 where frozen water ? That being the advanced theory, and one dif- 

 ficulty, let me add more facts to my budget, and look at the other 

 half of Ireland, with the most advanced glacial theory borne in 

 mind. 



8. S. W. Ireland. — Any map of Ireland shows the general shape 

 of the south-western end of the island. The coast-line is that of a 

 series of long sea-loughs. The country is a series of long ridges of 

 high land, with deep grooves between, which trend generally south- 

 westward on the strike. It will be argued that the strike accounts 

 for the shape of the land. I do not think that it does. 



The sea ebbs and flows in these grooves, and rivers come down 

 through drift at the ends of the sea- loughs. Knowing something 

 of Irish glaciation, one of these long ridges explains the rest. 



The first place examined in 1872 was Bere Haven. There glacial 

 action is conspicuous. Bocks at the sea-level are polished and 

 striated, and Boulder-clay with scratched stones in it rests upon 

 grooved rock in Bere Island. A hot day's wank there showed that 

 ice which did this work came off the ridge from the flanks of the 

 highest hill in sight, " Hungry Hill." It crossed Bere Haven, and 

 went over Bere Island at a height of about 800 feet. It was very 

 heavy ice according to the record. If the ice was at least a thousand 

 feet thick, and moved down from the ridge on one side, as in case 5, 

 it must have done the same on the other. In fact on the other side 

 at Killmakillogue Harbour, and at Derreen House, two large local 

 glaciers met and left their story inscribed in plain lines upon the 

 rock. In the middle of this harbour is " Spanish Island." It is a 

 pile of large glaciated rolled stones arranged in a crescent-form, 

 with a small patch of scarped Boulder-clay ten feet high and a few 

 yards wide left standing by the sea. 



On this patch grass grows ; and all the stones in the clay are finely 

 glaciated. The north-eastern horn of this harbour is the scarped end 

 of a long hill of Boulder-clay of the same kind, on which is a good 

 farm, running parallel to the long arm of the sea which is called 

 Kenmare river ; and ridges like it are features in the landscape on 

 both sides of the lough for many miles. To an eye used to look for 



