322 
THE GEOLOGIST. 
In his resnme of the nature and Talue of the eridence, Mr. Prestwich says : — 
" It is essential, as a preliminary step, to recollect that the arc^ument" does 
not rest npon the evidence of skill, but upon the evidence of design. The 
skill being rude (for the flints are only chipped into form and in no degree 
ground down) is not always evident at first sight, and hence the existence of 
design has been sometimes denied. Tlints from the chalk hills of tbe district 
itself readily supplied the material of which the flint implements are formed. 
The exterior of all chalk-flints invariably presents a white earthy crust, from 
which small fossils frequently project, while the interior of the flint is black or 
dusky, but clear or semi-transparent. The fracture is conchoidal or splintery, 
and there is no tendency to break in one direction rather than in another. It 
may happen that a shattered flint (byAvhatever natural cause produced) should 
give flakes or splinters closely resembling simple forms produced by one or two 
blows applied artificially. But here the coincidence must cease ; for it is ob- 
vious that blows applied by hazard and resulting from natural causes, as in a 
melee of gravel, would necessarily multiply their direction of strike in propor- 
tion as the blows themselves were multiplied, and consequently the shape of 
the flint would tend, up to a certain point, to become more and more irregular ; 
whereas, on the contrary, blows applied by design, and with a given object in 
view, would tend to give to the flint more and more finish, form, and evident 
art. So with respect to the flints in the gravel the more broken the more 
irregular, whereas, on the contrary, with the flint implements the more they 
are chipped and broken the clearer is the design. 
"With regard to the possibility of the flint-implements resulting from 
natural wear, I have abeady mentioned that in many of the specimens the 
outer coat of the flint is frequently adapted and left, when possible or con- 
venient, in the finished instrument, and such original surfaces show so little 
trace of wear that small delicate fossils, so often found projecting on them, 
still remain untouched. If the flint had been so extensively fashioned by wear, 
how could one portion, and always a prominent part, have remained unworn, 
while other portions have been so largely abraded ? Besides, the tendency of 
wear, if sufiiciently long continued, is ultimately to reduce the flints to the 
rounded form of pebbles, a condition of things incompatible with the retention 
of the sharp points and cutting edges of these implements. 
" Finally, we have to consider whether it is possible for the flint implements 
to have been introduced into their present position within some comparatively 
recent period, or whether they are contemporaneous with the accumulation of 
the gravel ; and further, whether the remains of the large extinct mammals 
could have been derived from some older beds, and therefore be of anterior 
date to the flint implements. 
"These implements might have got embedded in the gravel — 1st, by artifi- 
cial excavations ; 2ndly, by rents in the ground. To anybody accustomed to 
the examination of drift deposits, there is little difficulty in distinguishing 
between the fresh and uniform appearance of undisturbed beds, and the mixed 
and confused make of made ground, independently of the occurrence of any 
charred materials, pottery, &c., and of bones in a comparatively fresh condition. 
The lines of original stratification once broken cannot be so restored as not to 
show the break of continuity. In the St. Acheul pits, the several divisions of 
the gravelly clay, b (figs. 5, 6, 7, 10, II), and the two of the underlying sands 
and gravel, c d, each present distinct divisional lines and differences in colour. 
Kow these lines and this bedding continue uninterruptedly over the portion of 
the lower gravel where the flint implements are found. There is no break, no 
disturbance, and the smaU delicate fossils in the sand c remain uninjured, except 
at such places where the ground has been dug for brick-earth or otherwise 
excavated, and then the disturbance is sufficiently apparent. At St. Acheul 
