The received interpretation of the imperfect record which remains to us of the successive eras of geological change with the accompanying modifications of animal life, down to the appearance of man, and the deciphering of geological chroniclings as a coherent disclosure of the past history of the earth, are largely due to Sir Charles Lyell. In 1841 he visited America, and then estimated with cautious conservatism some of the evidences adduced for the assumed antiquity of American man. But subsequent observations led him to modify his views; and at length, in 1863, he “read his recantation” of earlier opinions; and—so far at least as Europe is concerned,—gave the full weight of his authority to the conclusions relative to the antiquity of man based on the discovery of flint implements associated with bones of extinct mammalia at Abbeville and in the valley of the Thames. The peculiar geological conditions accompanying the earliest evidence of the presence of palæolithic man in Europe proved, when rightly interpreted, to be no less convincing than the long-familiar sequence of more recent archæological indices by which antiquarian speculation has proceeded step by step back towards that prehistoric dawn in which geology and archæology meet on common ground. The chalk and the overlying river-drift, abounding with flint nodules, left no room for question as to the source of the raw material from which the primitive implements were manufactured. The flint is still abundant as ever, in nodules of a size amply sufficient for furnishing the largest palæoliths, in the localities both of France and England where such specimens of primitive art have been recovered by thousands. But there also other disclosures tell no less conclusively of many subsequent stages of progress, alike in prehistoric and historic times. Sir John Evans, in his _Ancient Stone Implements of Great Britain_, purposely begins with the more recent implements, including those of the Australian and other modern savage races, and traces his way backward, “ascending the stream of time,” and noting the diverse examples of ingeniously fashioned and polished tools of the Neolithic age which preceded that palæolithic class, of vast antiquity and rudest workmanship, which now constitute the earliest known works of man; if they are not, indeed, examples of the first infantile efforts of human skill. But alike in Britain, and on the neighbouring continent, a chronological sequence of implements in stone and metal, with pottery, personal ornaments, and other illustrations of progressive art, supplies the evidence by means of which we are led backward—not without some prolonged interruptions, as we approach the Palæolithic age,—from historic to the remotest prehistoric times.