Prestwich (1892, p. 252) then gave an extensive answer to an objection raised by Sir John Evans: “Then again, is it not possible that similar rude specimens occur in the valley drifts, and have been overlooked owing to the prevalence of the better finished implements to which attention had been exclusively given.” If eoliths were found in connection with the paleoliths or neoliths in the valleys, that might weaken Prestwich’s argument for their great age, which was based on the fact that they tended to be found only in the very ancient Plateau drifts. Prestwich (1892, p. 252) answered as follows: “A large number of rude and badly finished specimens have been collected in the valley drifts, but they all belong to one set of types, and though I have seen and handled many hundreds of these, I question whether, with the exception of the
After giving testimony about not finding specimens like the Plateau eoliths in Boucher des Perthes’s collection, Prestwich (1892, pp. 252–253) stated: “Nor had Mr. Harrison, during his rigorous examination of the Shode Valley, discovered any specimens in the valley drifts of the Ightham district to correspond with the group of plateau implements. At my request, he has re-examined several of these localities, as well as the large pit at Aylesford in the Medway Valley, and the pits at Milton Street (Swanscombe) in the Thames Valley, with this special object in view. He reports to me that he finds no contemporary specimens of the plateau type, and very few derived specimens of that type.”
Prestwich (1892, p. 268) then cited evidence from De Barri Crawshay, who stated: “I find that on examination of my collection of over 200 specimens of implements and scrapers from the 100 foot level around Swanscombe, Kent, I have but one . . . which is a plateau specimen undoubtedly derived. . . . I have always made specially careful search for all these ochreous flints in the low level gravels, and have rarely found one at all.”
Derived specimens are those washed down from the Plateau and left in the lower level gravels. Prestwich (1892, p. 253) stated: “The derived plateau specimens are easily distinguished, by their greater wear, distinct colour, and peculiar shapes, from the implements contemporary with these valley drifts.”
The valley Paleolithic specimens were very extensively worked, with fine, regular chipping, and generally took the form of points meant, perhaps, to be used as spear heads. There were some crude, unfinished specimens among them, but they were obviously of the same type as the finished paleoliths, and not of the Plateau type (Prestwich 1892, p. 255).