The post-glacial history of Scotland was a subject that early attracted James Geikie’s attention. He had devoted much study to it, and was in after years to present a masterly analysis of its stages and sequence. To trace the connection between the Ice Age and the present day, and to show the changes which had elapsed since the ice-sheets melted from the surface of Britain, was to him one of the most alluring departments of geology. A good deal of work had been done by Scottish geologists on the study of the raised beaches of Scotland, but no general account of their relation to one another and to the glacial boulder-clay and moraines had appeared before the publication of the first edition of _The Great Ice Age_. That the sea-level had undergone alterations around our shores was sufficiently demonstrated by the raised beaches, of which three were very well known, the 100-foot, 50-foot, and 25-foot beaches. But some authors, such as Chambers and Mackintosh, were ready to find raised beaches anywhere; gravel terraces at all elevations, many of which are now known to have been the deposits of glacial rivers and lakes, and rock escarpments and platforms of very varied origin, were appealed to as evidence of former submergence beneath the sea. Prof. Geikie at this stage was not altogether free from a belief in the great submergence, or at any rate he was not prepared to challenge its champions; but he knew how little value was to be attached to some of the evidence cited in its support, and his own studies had led him to a fuller understanding and a more satisfactory appreciation of the meaning of the raised beaches and the light they threw on the varied conditions that had prevailed in Scotland during and subsequent to the melting of the great ice-sheet. In particular, he maintained that the higher beaches were associated with the deposits of clay containing glacial shells that were so well known through the researches of Smith of Jordanhill, and belonged to a time when glacial conditions had not completely ceased in Scotland. The 50-foot beach was associated with the oldest relics of man in the midland valley of Scotland, while the 25-foot beach and lower beaches were laid down in climatic surroundings differing little from those of the present day. Between the epochs of depression which these sea-terraces recorded there had been intervals when the land stood at a higher level, so that the earth movements had been of an oscillating character, and not merely a succession of uplifts with intervening pauses during which the beach-platforms were produced. The buried forests and the peat-bogs furnished additional evidence of the elevation and depression of the land, and hinted, not obscurely, at the probability that changes of climate had also taken place during post-glacial time, the warm continental epochs encouraging the growth of trees, while the cold, damp, insular climates were favourable to the accumulation of peat.