1894-95.] J 93 



Britain and America, he professes to trace all along its southern 

 boundary the remains of a great terminal moraine. It was the 

 advance of this icecap which, filling the bed of the Irish Sea, 

 forced up in several places portions of shells, in a broken 

 condition, to the elevations already referred to. Amongst 

 other proofs of this he holds to be the general direction taken 

 by the boulders and erratics whose parent rocks are known, 

 and the comparative scarcity of stratified and shelly beds, the 

 absence of which seems hardly compatible with a long or 

 general period of submergence. We are bound to remember 

 that all those who have advocated the putting of extensive land 

 ice into the forefront of their theory, and the regulation of 

 submergence and floating ice to a secondary place, have been 

 impelled by what appeared to them to be the exigency of facts. 

 Every geologist is familiar with the perpetual variations in the 

 level of land and water : it is part of his stock-in-trade, without 

 which geology as a science could not exist ; but we are not 

 familiar with such comparatively rapid and extensive variations 

 as we are asked to believe in by the advocates of glacial sub- 

 mergence. We cannot rationally blame geologists of the 

 school of Carvill Lewis and others if they say that to admit 

 such rapid oscillations in recent times is at least as great a tax 

 upon our powers of belief in the probable as to admit the 

 extension of ice for which they contend. Nearly all the 

 observers, again, who have made a study of glacial striae, and 

 have mapped their results, have agreed that the striae indicate 

 a condition of land ice approaching the nature of such an icecap 

 as I have described. The soundings in and at the mouth of 

 the sea loughs or fiords of the West of Scotland, and several in 

 Ireland — Carlingford Lough for instance, and probably Lough 

 Swilly, as well as the estuary of the Clyde right out into the 

 North Channel — are also attributed by Sir A. Geikie and 

 others to the action of glaciers of such extent that they could 

 only have radiated from an icecap as already described when 

 the land was somewhat higher than at present. There are 

 other evidences, however, of no little importance which seem 



