From what we have learned of the development of primitive society, it will not surprise us to learn that the first division of the age of stone comprises a vastly greater portion of time, and is far more ancient, than the second. We will give an outline showing the order of use of different materials; but it is here necessary to remark that Bronze was the first metal that man learned to use, and Iron the second. ORDER IN WHICH DIFFERENT MATERIALS WERE USED FOR WEAPONS AND IMPLEMENTS BY PRIMITIVE MAN. Age of Stone. Rough, or Old Stone Age Paleolithic Polished, or New Stone Age Neolithic Age of Metals. Bronze Age. Iron Age. In this outline the words Paleolithic and Neolithic are the scientific terms for the two divisions of the Stone Age, and will be so used in these pages. The only races of men that we could expect to find in Europe during the Glacial Age would be Paleolithic tribes, and it is equally manifest that we must find traces of them in beds of this age, or in association with animals that are characteristic of this age, or else we can not assert the existence of man at this time. The valley of the river Somme, in Northern France, has become classical ground to the student of Archæology, since it was there that such investigations as we have just mentioned were first and most abundantly made. It is now well known that the surface features of a country—that is, its hills and dales, its uplands and lowlands—are mainly due to the erosive power of running water. Our rivers have dug for themselves broad valleys, undermined and carried away hills, and in general carved the surface of a country, until the present appearance is the result. It must be confessed that when we perceive the slow apparent change from year to year, and from that attempt to estimate the time required to produce the effects we see before us, we are apt to shrink from the lapse of time demanded for its accomplishment. Let us not forget that “Time is long,” and that causes, however trifling, work stupendous results in the course of ages. Paleolithic Flints.