Everywhere, but not always within the same thousand years or so, we see as we go still farther back, the use of metal giving place to the use of stone. In Europe we see a highly-developed material civilisation from three to seven thousand years ago. The people till the land, sow crops, keep herds, build houses (of wood), make pottery, combs for the hair, necklaces of amber and of shells, and other ornaments, but they have no metal weapons or implements. They sometimes use native gold to make decorative ornaments; but their knives, daggers, swords, saws, and hammers are all of stone, either flint or dense greenstone. We reach this purely Stone Age in Europe at 2000 B.C.; in Egypt we do not get back to it so soon, but, about 5000 B.C., we there come upon a pre-Pharaonic population which made use of beautifully-finished stone knives in place of metal. The first people we come upon in Europe as we pass from the Bronze to the Stone Age had a great deal of skill and an elaborate social organisation. Their stone weapons were beautifully chipped and often highly polished (Figs. 66 and 67). We find the slabs of grit upon which they rubbed the chipped flint adzes in order to make them smooth. But soon we find, as we go back, that polishing is unknown, and that the chipped flint adzes are used in a rough state. On entering the Stone Age we find that we are only on the fringe of an immense period of “stone-weaponed humanity,” extending back for tens of thousands of generations of men, when stone (and in Europe especially, that stone which we call “flint”) was the one great stand-by of the human race—the one hard cutting material which man learnt to shape and apply to his own purposes—so as to make holes with it, saw with it, scrape with it, cut with it, kill with it. On account of its prodigious range in time it is found necessary to divide the Stone Age into two periods—a later, called the “Neolithic” (the new stone period), and an older, stretching back until the traces of it are lost in geologic changes of the earth, which is called the “Palæolithic” (the old stone period). Thus if we start on a time-journey to explore the earliest traces of man in Europe, we pass along the centuries back, through the Iron and the Bronze Ages of humanity, and arrive at the vast Stone Age, which stretches away into the obscurity of more than a hundred thousand, probably of many hundred thousand, years. The later or newer fringe of the Stone Age is called the “Neolithic,” or newer Stone Age, or Age of Polished Stone, because the men of that period polished their stone implements after chipping them into shape. That which we dimly see beyond is the “Palæolithic,” or older period of “stone-weaponed” humanity, when polishing was unknown.