mountains on the west, during the whole of the Secondary period. The Pennine range, the backbone of England, was then very much as it is now, with its limestone cut into deep cañons or dales in the areas of Derbyshire and Yorkshire, and with the massive carboniferous sandstones rising into rugged heights, and traversed by deeply cut glens. The hills of Somerset, Devon, and Ireland also, were the same, and the surface contours of the lower ground must have been to a large extent what they are now, since they were carved by those agents by which the present hills and valleys have been formed. There are, however, differences to be remarked. The mountains were higher[1] and more precipitous, and the landscape could not, in those times, have offered the flowing lines and curves, which have been produced by ice, in the present surface. Nor must it be forgotten that in the long lapse of ages the whole of the Eocene land-surface has been removed by the action of those denuding agents, which we shall bring before our readers in treating of the Meiocene mountains.
From Professor Judd's observations on the western districts of Scotland, it is evident that the volcanic energy which raised a range of lofty volcanic mountains in the Western Isles in the Meiocene age, was felt in the same districts in the Eocene. We may therefore picture to ourselves groups of cones, similar to those of Auvergne, rising above the forests, then spreading from the rugged Alpine heights of the Western Highlands far away in one mass of green, broken only by the rivers, to Ireland and the remote coast-line of the western sea.
