In speaking of the length of time demanded for this change, Dr. Evans says: “Who can fully understand how immeasurably remote was the epoch when what is now that vast bay was high and dry land, and a long range of chalk downs, six hundred feet above the sea, bounded the horizon on the South? And yet that must have been the sight that met the eye of primitive man who frequented the banks of that ancient river, which buried their handiwork in gravels that now cap the cliffs—and of the course of which so strange and indubitable a memorial subsists in what has now become the Solent Sea?”37 The illustrations scattered through this essay are representations of the stone implements found in the drift of European rivers. During all the long course of time supposed to be covered by the Paleolithic Age, there are but very few evidences of any improvement, as far as we can judge from the implements themselves. This is in itself a melancholy proof of the low condition of man. He had made so little advance in the scale of wisdom, he possessed so little knowledge, he was so much a creature of instinct, that, during the thousands of years demanded for this age, he made no appreciable progress. The advance of the last century was many times greater than that of the entire Paleolithic Age. A blow struck on one end of a piece of flint will, owing to the peculiar cleavage of flint, split off pieces called flakes. This is the simplest form of implement used by man. It is impossible to say with certainty how they were used; but, from the evidence observed on them, they were probably used as scrapers. The men of that day doubtless knew some simple method of preparing clothing from the skins of the animals they had killed, and probably many of these sharp-rimmed flakes were used to assist in this primitive process of tanning. Flint Flakes. When the piece of flint itself was chipped into form, it was one whose shape would indicate a spear-head or hatchet. We present illustrations of each. Forms intermediate between these two are found. Some have such a thick heavy base that it is believed they were used in the hand, and had no handle or haft. Others, with a cutting edge all round, may have been provided with a handle. M. Mortillet, of France, who has had excellent opportunities of studying this question very thoroughly, thinks that the hatchet was the only type of implement they possessed, and that it was used for every conceivable purpose—but that their weapon was a club, all traces of which have, of course, long since vanished away.38 Spear Head Type and Hatchet Type.