"Cumming observed in regard to one rock, the Foxdale granite, that whereas the highest point at which it occurs _in situ_ was 657 feet above sea-level, boulders of it occurred in profusion within 200 feet of the summit of South Barrule (1,585 feet), a hill two miles only, in a southwesterly direction, from the granite outcrop. "They also occur on the summit of Cronk-na-Irrey-Lhaa, 1,449 feet above sea-level. The vertical uplift has been 728 and 792 feet respectively. "In the low grounds of the north of the island a finely developed terminal moraine extends in a great sweep so as to obstruct the drainage and convert thousands of acres of land into lake and morass, which is only now yielding to artificial drainage. Many fine examples of drumlin and esker mounds occur at low levels in different parts of the island; and it was remarked nearly fifty years ago by Cumming, that their long axes were parallel to the direction of ice-movement indicated by the striated surfaces and the transport of boulders. "The foreign boulders are mainly from the granite mountains of Galloway, but there are many flints, presumably from Antrim, a very small number of Lake District rocks, and a remarkable rock containing the excessively rare variety of hornblende, Riebeckite. This has now been identified with a rock on Ailsa Crag, a tiny islet in the Frith of Clyde; and a Manx geologist, the Rev. S. N. Harrison, has discovered a single boulder of the highly characteristic pitchstone of Corriegills, in the Isle of Arran. "_The So-called Great Submergence._ "It may be convenient to adduce some additional facts which render the theory of a great submergence of the country south of the Cheviots untenable. "The sole evidence upon which it rests is the occurrence of shells, mostly in an extremely fragmentary condition, in deposits occurring at various levels up to about 1,400 feet above sea-level: A little space may profitably be devoted to a criticism of this evidence. "_Moel Tryfaen_ ('The Hill of the Three Rocks').--This celebrated locality is on the first rise of the ground between the Menai Straits and the congeries of hills constituting 'Snowdonia'; and when we look to the northward from the top of the hill (1,350 feet) we see the ground rising from the straits in a series of gentle undulations whose smooth contours would be found from a walk across the country to be due to the thick mask of glacial deposits which obliterates the harsher features of the solid rocks.