Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/1061

Rh mathematical considerations of their flotation, incapable of producing any great effect in grinding the shoals on which they may occasionally ground.

Many of the phenomena presented by our northern countries and attributed to ice-action are readily explained by the supposition of coast-ice acting on a rising area, but only with difficulty when either glaciers or ice-sheets are supposed to have been the grinding agents. In such cases, all that I ask is that coast-ice may have its due.

Cosmical changes, or even changes in the geography of land and sea, I think have been sufficient to bring coast-ice as far south as any of the low-lying regions which exhibit traces of ice-action. These changes may also on the higher ground have given rise to glaciers which ground out lake-basins and moulded valleys; but that these changes produced large ice-caps, filling oceans and covering countries, I do not see that we are justified in supposing until there is a greater convergence of such evidence as can be brought to bear upon the subject.

If we take a map of Northern Europe on which are indicated the general direction of ice-markings, any inference which can be drawn from such directions, which all point more or less at right angles to the sea-coast, is as favourable to the view that they were produced by coast-ice acting on a rising area as it is to the fact that they point out the direction in which the great ice-sheets travelled.

In conclusion, I will say that one thing appears to me certain—namely, that, even if we accept the most favourable views of large ice-caps, the appearances presented by many countries, which have hitherto been ascribed to their action, ought rather, for reasons already stated, to have been accredited to the action of coast-ice on a rising area.