if we so designate them, almost invariably go together; and if this be granted, we may, without much difficulty, rest assured that such rapid changes took place as are adequate to explain the facts by which so many are at present perplexed. Dr. Duns, after referring to Sir C. Lyell's description of the erosive action of running water, and his illustration of its force by the river Simeto making its passage, in the course of two centuries, through the lava of Etna (which had dammed up its bed in 1603), by opening through the solid mass a channel varying in width from fifty to several hundred feet, and in depth, in some parts, from forty to fifty feet, puts this apt question, “If the Simeto has, in two hundred years, cut a ravine through hard volcanic rock a hundred feet wide and fifty deep, how long would the Somme take to excavate its present valley in the soft chalk rocks over which it runs ? In the latter case, we have not hundreds of years, but thousands at our disposal."1 While there were at work other agencies than this erosion by water, its influence ought surely to be fairly estimated as producing geological changes. In an able paper on Valley Gravels, which Mr. Alfred Tylor read at the Geological Society, the not uncommon supposition was maintained, that the drift of the Somme valley was of marine origin, and that the flint implements had been introduced by floods, and were of recent date. While resisting both conclusions, Mr. Prestwich confessed that he regarded the gravels as having been deposited by forces far more powerful than any recognised at the present day, and that the time for producing the results now visible was therefore comparatively short. Sir Roderick Murchison has emphatically stated, in reference to a corresponding 1 "Science and Christian Thought," pp. 273, 274. subject, that "no analogy of tidal or fluviatile action can explain either the condition or position of the debris and unrolled flints and bones. On the contrary, by referring their distribution to those great oscillations and ruptures by which the earth's surface has been so powerfully affected in former times, we may well imagine how the large area under consideration was suddenly broken up and submerged. In short, the cliffs of Brighton afford distinct proofs that a period of perfect quiescence and ordinary shore action, very modern in geological parlance, but very ancient as respects history, was followed by oscillations and violent fractures of the crust, producing the tumultuous accumulations to which attention has been drawn." 1 In the view of these oscillations, and their occasionally violent movements, sometimes extended and sometimes limited in their area, we cannot reckon on long periods for producing effects which may have been rapidly accomplished, nor can we determine when these may or may not recur in the physical history of the earth's crust. 1 Sir R. Murchison "On the Distribution of the Flint Drifts of the South-East of England." CHAPTER XII. (SUBJECT CONTINUED.) Antiquity of Man-The Chronology of Archaeologists-Inferences as connected with Geology and History-The Danish Shell-Mounds, Swiss Lake Dwellings, and Egyptian Monuments. "The antiquities piece on in natural sequence to the geology; and it seems but rational to indulge in the same sort of reasonings regarding them. They are the fossils of an extinct order of things newer than the tertiary,-of an extinct race, of an extinct religion, of a state of society and a class of enterprises which the world saw once, but which it will never see again; and with but little assistance from the direct testimony of history, one has to grope one's way along this comparatively modern formation, guided chiefly, as in the more ancient deposits, by the clue of circumstantial evidence."-Hugh Miller. HERE is another class of facts which are more closely related to Archæology than to Geology, that are also claimed as evidence of man's antiquity. Although archæology, as a science, has to do exclusively with man and his works, it is difficult to determine where it begins in geology and where it ends in history, as it interweaves. with both and binds them together. While flint implements and human bones have been found in caves and mossdepths, or in other superficial formations, we have classed them under the section geology, because there has been nothing artificial in their resting-place to distinguish the remains of man from those of the lower animals; but where the remains have been connected with artificial structures of any kind, such as the Danish shell- mounds, the lake dwellings, or the American mounds, or Egyptian and other monuments, we should class them under archæology. This distinction, which we venture to suggest, will free the discussion from some of the embarrassment and confusion which arise from commingling the same facts under both the geological and archæological divisions. It is not absolutely accurate; because everything prehistoric which is related to man is archæological, whatever be the position or circumstances in which it is discovered; but the distinction is convenient, and it is sufficiently logical to give consistency to the discussion of the question before us. III. For these reasons, we have separated the facts which we have now to consider from those already examined, as more properly geological. 1. The first which we notice are the DANISH SHELLMOUNDS, or Kjökkenmödding—"kitchen refuse heaps." What are the facts here, and what the inference? "At certain points," says Sir Charles Lyell, "along the shores of nearly all the Danish islands, mounds may be seen, consisting chiefly of thousands of cast-away shells of the oyster, cockle, and other molluscs of the same species as those which are now eaten by man. These shells are plentifully mixed up with the bones of various quadrupeds, birds, and fish, which served as the food of the rude hunters and fishers by whom the mounds were accumulated." Similar mounds have been left near the shore by NorthAmerican Indians. "Scattered all through the Danish heaps are flint knives, hatchets, and other instruments of stone, horn, wood, and bone, with fragments of broken pottery, mixed with charcoal and cinders; but never any implements of bronze, still less of iron. mounds vary in height from three to ten feet, and, in area, are some of them 1000 feet long, and from 150 to 200 wide. The 2 They are rarely placed more than ten feet above the level of the sea, and are confined to its immediate neighbourhood." 1 Sir Charles also briefly repeats his argument based on the growth of a succession of different kinds of trees, and on the slow growth of peat-moss; but as his reasoning has already been fully considered, and its weakness exposed in the light of his own admissions, it is unnecessary here to make further allusion to it. All that is required is to notice such new reasoning as he has adduced, and for that purpose a few sentences will suffice. His arguments are (1), As there are parts of the coast where the western ocean is wearing down the cliff, it appears that, through a slow process, the land has been carried off on which shell-mounds were raised; and (2), As the cockle and mussel shells in the mounds are larger than those now existing in the neighbouring sea, a change in its littoral water has taken place. His other arguments regarding the smaller race of dogs then existing, and those birds, also, which are now all but extinct, carry little or no weight on his side of the question. That certain mounds are not found on the western shore, proves nothing as to their antiquity, nor does the fact of a moss intervening between the sea and any mound; for there is no evidence that moss was formed subsequently to such mounds, and besides, the early inhabitants may have preferred to rest on their landward side. The mere deterioration of the eatable shells can scarcely be accepted as evidence; for, as Professor C. H. Hitchcock has stated, while "similar heaps are scattered along the Atlantic coast, from Prince Edward's Island to Georgia," and while, in both Continents, "these heaps indicate that the oyster formerly flourished in abund 1 66 Chapter xi., pp. 213, 218. 2 |