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 A HISTORY OF CORNWALL standing the lapse of over sixty years since the publication of that report, during which the science of geology, then in its infancy, has advanced with rapid strides, the observations and deductions recorded in its pages have needed so little modification at the hands of subsequent observers, equipped with more modern methods, as to afford the most eloquent testimony to the accuracy of his facts and the soundness of his reasoning. The bibliography of Cornish geology is so extensive that it would be impossible within the compass of this treatise to do it jus- tice. 1 Those indeed who are at present engaged in these investigations suffer from an embarrassment of riches, so that it is no small task for the geologist of to-day to ascertain the facts that have been gleaned by former observers in the same field. The Geological Survey is at present engaged on a more detailed examination of the county, and in the official publications which will follow, the extent of their obligations to the labours of others will be adequately acknowledged. Before dealing with the successive processes of nature's operations which have evolved the present configuration of our county, it may be stated at the outset that the rocks which enter into its geology be- long to the earlier chapters of geological history, and form the natural foundations on which the strata of central and eastern England have been laid down. Moreover in the vast interval of time since their formation they have suffered profound alteration, and the pages of their history are not easily deciphered. Not only so, but the very changes which have altered the rocks to the condition in which we see them to-day were themselves brought about in a long distant geological epoch, the antiquity of which exceeds that of the most lofty mountain chains of Europe. Before inquiring therefore into the history of those ancient periods which gave rise to our rock formations, it will be convenient to take note of the changes that are going on at the present day within the ken of our own observation. For although the solid rocks of the county are of vast antiquity, its physical features and the present relation of land and sea, mark the final results of continuous agencies of change, the operations of which, though apparently slow, are yet taking place before our own eyes. Moreover it must not be understood that finality has been attained, for the changes in the past which have evolved the scenery of to-day are still going on, ever modifying to some extent the features inland and along the coast. While the surface of the county is covered by a mantle of vege- tation, save where our granite tors protrude their wild and fantastic eminences, and the rocky wastes break the continuity of the fertile pastures of the lower lands, the coast forms a line of cliffs steep and bare which almost girds the county. This dissected line affords us a series of sections of the great rocky platform which forms the mainland of Cornwall, and which otherwise is so much concealed by the materials of its own decay as to be largely beyond the limits of our observation. ' For List of Works on the Geology of Cornwall to 1873, see W. Whitaker, Journ. Roy. Inst. Cornwall, No. xvi. 1875. 2