332 NATURAL SCIENCE [November 
the specimens with sharp concave edges would have served a 
better purpose as scrapers if left as nature had shaped them. The 
irregular chippings on the edges of the natural curves has spoilt 
them as tools. 
The vast number of the ‘flint implements’ from the plateau 
gravels is another difficulty in the supposition that they have been 
made by man. The’‘implements’ occur in an abundance described 
as ‘marvellous’ by their discoverers. We are told that two pits, 
dug in 1894 into a bed of gravel one foot in thickness, yielded 
thousands of artificial flakes and some hundreds of hollow-notched 
and horseshoe-shaped scrapers. The pits dug in 1896 in the same 
beds have yielded a similar profusion. Such results are indeed 
startling. Plateau man must have been a very prolific race, for his 
implements, almost all of one hollow-scraper type, far outnumber 
those of his palaeolithic successors, 
In ordinary palaeolithic gravels the proportion of implements to 
pebbles is extremely small, and there is no difficulty in drawing a 
line between. artificially and naturally shaped flints. But on the 
chalk plateau the stained flints are all more or less chipped. There 
are millions of flints on the plateaux, and it is therefore not sur- 
prising that a large number occur in which the shape resembles 
that of palaeolithic implements. But no distinctive line can be 
drawn between flints which are described as ‘good implements’ 
and others which are admittedly only naturally broken. 
But if the chipping be not the work of man, what agency, it 
will be asked, could have produced it. Careful examination of the 
chipped flints soon suggests suspicious features. In the first place 
the chipping is limited to the edges of the slabs; there are no 
known instances in which the flint has been artificially flaked into 
the form of the weapon; the asserted human workmanship is limited 
to chipping of the edges of naturally-shaped flints. 
Mr Harrison maintains that the chips were forced off by an 
agent which worked only from one face of the flint slab He 
regards this feature as an argument in favour of the artificial nature 
of the chipping. Why eolithic man should have worked only on 
one surface of the stone is not explained. But it is really rare to 
find an example that was chipped on one side only. Palaeolithic 
man certainly never allowed the utility of his tools to be limited by 
any such restriction. 
The chipping was evidently due to some pressure which acted 
more or less at right angles to the flat surface of the flint slab. 
The pressure and crushing that take place during movements of 
frozen gravel would, it seems to me, be quite sufficient to account 
for all the chipping. Pebbles in the gravel would be pressed 
1 Proc. Geol, Assoc., November 1893, vol. xiii. p. 162, 
