GEOLOG-ICAL CONSIDEEATIONS. 
303 
The gravels of Moulin Quignon and St. Acheul are placed respectively 88 and 89 feet 
above the valley of the Somme, are not commanded by any higher ground immediately 
adjacent, and are out of reach of all running water, or of any possible interference from 
agents in present action. At Menchecourt and St. Roch, on the contrary, the beds are 
placed against the side of the chalk hills, and slope from a height of about 60 feet down 
to the valley. Still these lower-level deposits are, although not to the same degree, quite 
beyond the agency of present river action, and are independent of recent changes. 
It is probable that the various beds, although on these ditferent levels, belong to the 
same general period, and may be nearly synchronous. Had I, however, been asked to 
decide upon physical evidence alone, I might have been disposed to consider the gravels 
on the low hills of Moulin Quignon and St. Acheul as a stage anterior to those of Menche- 
court and St. Roch ; but although I throw out the suggestion for the purpose of directing 
attention to the point, as one not to be overlooked, it is one which could not be decided 
without further evidence, and which I should hesitate at present to adopt. It is suffi- 
cient, for the object we have under immediate consideration, to substantiate the views 
expressed by M. Bouchee de Peethes relative to the existence of the works of man 
associated with the remains of extinct animals in ground which has never been artifi- 
cially disturbed, and belonging to strata of the Pleistocene period, irrespective of slight 
differences of age amongst the beds themselves, if any such really exist. 
It may be instructive to inquire on what grounds this discovery and other analogous 
cases have been so long considered inadmissible as scientific facts. I have already 
noticed some criticisms called forth by M. Bouchee de Peethes’ work. One great cause 
of its neglect must have arisen, I conceive, from the injustice which the plates do to the 
objects described. The sketches of the implements are mere outlines of greatly reduced 
size, so that it is really often difficult to detect any definite shape or form even in those 
which belong to his group of hatchets. This, without a knowledge of the objects and 
of the localities, must have led, both in France and this country, to their being con- 
sidered by many as merely chance forms of flints. It was probably this circumstance 
which caused Dr. Mantell *, from his not having seen the original specimens, to rank 
these discoveries as amongst the many cases of mistaken observation and determination. 
While admitting the value of his antiquarian labours. Dr. Mantell considered that 
M. DE Peethes had not made himself sufficiently acquainted with geological phenomena, 
and observed “ that the so-called works of art, figured and described by M. Bouchee de 
Peethes, are nothing more than accidental forms of pebbles and stones, similar to those 
that occur in strata of immense antiquity, and which never can have been fashioned by 
the hand of man.” 
In the case of the occurrence of flint-implements in Kent’s Hole, as discovered by 
the Rev. Mr. M^^Eneet, attested by Mr. Godwin- Austen, and by Mr. Vivian f and the 
Torquay Natural History Society, I do not see the grounds on which the evidence was 
* Opus cit. p, 4. f Quart. Journ. Geol. Soc. vol. iii. p. 353. 
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