h the North Downs
and fall into the Thames, instead of flowing eastwards down the later
valleys. They started to carve their channels in the soft chalk in
the days gone by, when the watershed went north and south down the
slopes of the great dome. And the red gravels with the eoliths in them,
concludes Prestwich, must have come down the north slope whilst the
dome was still intact; for they contain fragments of stone that hail
from right across the present valleys. But, if the eoliths are man-made,
then man presumably killed game and cut it up on top of the Wealden
dome, how many years ago one trembles to think.

* * * * *

Let us next proceed to the subject of palaeoliths. There is, at any
rate, no doubt about them. Yet, rather more than half a century ago,
when the Abbe Boucher de Perthes found palaeoliths in the gravels of
the Somme at Abbeville, and was the first to recognize them for what
they are, there was no small scandal. Now-a-days, however, the world
takes it as a matter of course that those lumpish, discoloured, and
much-rolled stones, shaped something like a pear, which come from the
high terraces deposited by the Ancient Thames, were once upon a time
the weapons or tools of somebody who had plenty of muscle in his arm.
Plenty of skill he had in his fingers, too; for to chip a flint-pebble
along both faces, till it takes a more or less symmetrical and standard
shape, is not so easy as it sounds. Hammer away yourself at such a
pebble, and see what a mess you make of it. To go back for one moment
to the subject of eoliths, we may fairly argue that experimental forms
still ruder than the much-trimmed palaeoliths of the early river-drift
must exist somewhere, whether Mr. Harrison's eoliths are to be classed
amongst them or not. Indeed, the Tasmanians of modern days carved their
simple tools so roughly, that any one ignorant of their history might
easily mistake the greater number for common pieces of stone. On the
other hand, as we move on from the earlier to the later types of
river-drift implements, we note how by degrees practice makes perfect.
The forms grow ever more regular and refined, up to the point of time
which has been chosen as the limit for the first of the three main
stages into which the vast palaeolithic epoch has to be broken up.
The man of the late St. Acheul period, as it is termed, was truly a
great artist in his way. If you stare vacantly at his handiwork in