n 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
Archaeology, 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.

Picture of Paleolithic Flints.--------

But a river which is thus digging down its channel in one place,
deposits the materials so dug away at other and lower levels, as beds
of sand and gravel. In the course of time, as the river gradually lowers
its channel, it will leave behind, at varying heights along its banks,
scattered patches of such beds. Wherever we find them, no matter how far
removed, or how high above the present river, we are sure that at some
time the river flowed at that height; and standing there, we may try and
imagine how different the countr