224 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 22, 



valleys and anticlinals was obviously the work of the great formative 

 forces by which the whole island had been forced up above the sea, 

 by lateral pressure, squeezing the harder deposits into folds, and 

 these carrying up upon their backs the deep covering of loose ma- 

 terial which had lain upon them as sea-bottom. As the land 

 emerged, this loose material was affected by tidal and wave-action, 

 caused to slip and slide down all declivities, even very small ones, 

 and, in doing so, scratched and furrowed the supporting surfaces of 

 rock in a way that he believed it impossible to distinguish from 

 the traces left by similar movements of masses of ice. And if 

 this were so, as like phenomena must be as universal as the emer- 

 gence of land was everywhere from beneath the sea, so it seemed to 

 him that, so far as the evidences of scratching and polishing or 

 denuding of rocks went, the glacial hypothesis was unnecessary. 

 He admitted the scratching and transporting power of ice as a vera 

 causa of some geological phenomena ; but he believed that its effects 

 had been enormously overrated, and that much had been attributed 

 to its action which, when submitted to the test of " measure, 

 number, and weight," in place of, as was the habit, perpetually 

 dealing with " quahty " only, would prove to be physical impossi- 

 bilities. Thus the work capable of being done upon the ocean- 

 bottom by the grounding of even the largest iceberg, could, when 

 all the dynamic conditions were held in view, be proved to be ex- 

 tremely small. The general facts, as respects the direction of the 

 striation or scratching of the rocks, as well as the direction of trans- 

 port of boulders in the detritus above, were, for the whole surface of 

 Ireland, that the scratches tended to lines down the great declivi- 

 ties, both laterally and longitudinally, but influenced by a great 

 general trend from the west, and north, and south-west. The lines 

 of boulder-travel had, on the whole, followed the same direction as 

 the scratches. He could not, therefore, admit the views of the author 

 as to the direction of these scratches being on the whole from north- 

 east to south-west as representing the facts. Mr. Mallet referred 

 to a case of a large subangular boulder found in deep clay by him- 

 self and Dr. Oldham, stopped in the very act of making an uncom- 

 pleted groove, and under conditions that forbade any supposition of 

 ice-action or any other source of movement but that of the quasi- 

 fluid movement of the whole mass of clay carrying the boulder with 

 it. He also pointed out that moraines, or masses dropped by ice, 

 could not be distinguished generally from torrentially moved masses 

 of clay, gravel, and rock, or from escars or eddy-bars formed by 

 tidal-stream action, pointing out two cases, one in Wicklow, the 

 other not far from Dublin, both pronounced by Agassiz to be indu- 

 bitably moraines, but the former being manifestly a torrential bank, 

 the other the effect of a tide-stream eddy when the plain of Dublin 

 was still from 500 to 700 feet beneath the sea-surface. 



Mr. Evans disputed Mr. Mallet's conclusions as to the propagation 

 of motion through ice and the effects of grounding icebergs. 



Mr. Tiddeman had examined a large portion of the western side 

 of the north of England opposite to Ireland, but did not attribute 



