About the Plateau eoliths, Prestwich (1892, p. 256) stated: “The trimming slight though it may be, is to be recognised by its being at angles or in places incompatible with river drift agencies, and such as could not have been produced by natural causes.” Prestwich admitted that some specimens resembling the more advanced valley paleoliths were found along with the Plateau eoliths, and stated (1892, p. 257): “It is not easy to account for the presence of these abnormal specimens. If contemporaneous with the others, we might assume that there were then some workmen more skilled than their neighbors in the fabrication of flint implements.” Working against this hypothesis, according to Prestwich, was the fact that the rude Eolithic specimens were heavily patinated and were very worn, whereas the finished Paleolithic specimens were unpatinated and had perfectly sharp edges. Prestwich surmised the latter might have been left on the Plateau by Paleolithic men in more recent times, long after the eoliths had been deposited. Prestwich (1892, p. 258) then made a very important observation: “Though the work on the plateau implements is often so slight as scarcely to be recognisable, even modern savage work, such as exhibited for example by the stone implements of the Australian natives, show, when divested of their mounting, an amount of work no greater or more distinct, than do these early palaeolithic specimens.” This implies that it is not necessary to attribute the Plateau eoliths to a primitive race of ape-men. Since the eoliths are practically identical to stone tools made by
In the discussion that followed Prestwich’s presentation of his report, Sir John Evans repeated his point that the presence in the Plateau drift gravels of paleoliths made it possible that eoliths were contemporary with them and thus more recent than Prestwich and Harrison believed (Prestwich 1892, p. 271). Years later Harrison wrote in a letter, dated June 3, 1908, to W. M. Newton: “At the meeting of the Anthropological Institute in 1891, Dr. Evans closed his observations with the following sentence, ‘Before we accept these’ [the Eolithic implements] — l ooking at Prestwich —‘we must think twice,’—looking at me— ‘we must think thrice, and’—looking round the whole meeting— ‘we must think again’” (E. Harrison 1928, p. 165).
Other members of the Anthropological Institute also commented. General Pitt-Rivers maintained that stones resembling the eoliths were to be found in all gravels, insinuating that eoliths were simply a product of purely natural forces (Prestwich 1892, p. 272). In support of Prestwich, J. Allen Brown reported that some flints from the upper terraces of the Thames River resembled the Ightham ones, and might be of the same age and origin (Prestwich 1892, p. 275). The journal of the Anthropological Institute recorded a summary of Prestwich’s concluding remarks: “In reply, Professor Prestwich said that he had looked forward to the possibility of there being some substantial objections to his views which might have escaped him. He had, however, heard nothing but an amplified repetition of the very same difficulties which had occurred to him, and had been discussed and explained in the paper” (Prestwich 1892, p. 275).
Careful study of the report bears out Prestwich’s statement. With regard to the doubts of General Pitt-Rivers, Prestwich had already demonstrated that the chipping on the eoliths was quite different from that produced by purely natural forces on river gravels. He had also offered explanations for the presence of both paleoliths and eoliths in the Plateau gravels, explaining that some of the paleoliths, which were sharp and unworn, had probably been introduced into the Plateau gravels at a much later period than the deeply stained and much worn eoliths.