The incredulity and even contempt with which the application of a system of archæological periods to the antiquities of Britain was received, in recent years, by a certain class of critics, was inevitable, from the exclusive attention previously devoted to Roman and medieval remains. But the attention of the antiquary, as well as the geologist, is now being directed to conclusions forced on both by the traces of man in the stratified gravel of post-pleiocene formations. The circumstances attending their repeated discovery place their remote antiquity beyond question. The difficulty indeed is to bring the phenomena illustrated by palæolithic relics of the quaternary period into any conceivable harmony with the limits of chronology as hitherto applied to man. The pre-Celtic architects of the British long-barrow, and the allophyliæ of the European stone age, are but men of yesterday in comparison with the =Flint-Folk of the Drift=. They belong to a lost Atlantis,—another continent, now in part at least buried beneath the ocean; and compared with which the Old World of history is as new as that found for it by Columbus. The disclosures of geology have familiarised us with the conviction that the “stable land,” the “perpetual hills,” and the “everlasting mountains” are but figures of speech. But the idea forces itself on reluctant minds that man himself has witnessed the disappearance of Alpine chains and the submergence of continents. The Pacific archipelagos are but the mountain-crests of a southern continent, which in earlier ages may have facilitated the wanderings of the nations. The startling discoveries in the French and English drift are results of oscillations of the northern hemisphere, which, in times nearer to historic centuries, depressed the bed of the Baltic in the era of the Danish kjökkenmöddingr, and made dry land of the upper estuaries of the Forth and Clyde. It is doubtful, indeed, if the shallowing of Danish and Scottish seas by the rise of their ocean-beds is altogether a work of prehistoric times. The rise still going on in parts of the Swedish coast is a phenomenon long familiar to geologists; and the upheaval of the Scottish region, embracing the valleys of the Forth and Clyde, it now appears probable, has been protracted into historic times, and has even affected the relative levels of sea and land since the building of the Roman wall.