f 



136 The Palaeolithic implements and Gravels of Knoivle, Wilts. 



flint-gravels, would be sufficient to account for scratches in every 

 direction, quite definite, and well defined. Such a statement is 

 not easy to disprove, but we feel very doubtful whether a mere 

 land-slip would be likely to produce scratching on such a hard 

 substance as flint. Although unable to prove definitely that such 

 earth movements could not effect the scratching of flint, the im- 

 probability of this has been emphasised by certain rough experi- 

 ments recently undertaken, in which we have tried artificially to 

 scratch flint with flint, and have been impressed by the difficulty 

 of producing even obscure and indistinct scratchings. 



A further suggestion is that river action might produce scratches 

 of this nature upon flints. That is to say, that in the rubbing 

 together in a river bed such scratches might be produced. It is 

 difficult to conceive that the bouldering action of a river bed could 

 produce scratches, recognisable as such, and indeed, if this be the 

 case, we may ask why do not flints from all river gravels exhibit 

 similar markings ? 



Still another theory advanqed, is that the marks in question are 

 in reality cracks produced by blows, and not scratches at all. 

 Certainly the flints in a bed of gravel will have undergone a good 

 deal of knocking together, but while occasional cracks might be 

 produced, there does not seem to be sufficient reason for regarding 

 the marks as principally due to such a cause. The crucial test, 

 also, of examining a marked flint which has been broken in two, 

 points clearly in the same direction, for generally speaking no 

 trace of cracks extending from the surface is revealed. 



We come back, then, to the much- vexed question of the glacial 

 scratching of flint. It is by no means at variance with the 

 geological record, to suppose that certain constituents of these 

 gravels have been subjected to glacial action. The great ice sheet 

 of Northern Europe is generally considered to have reached down 

 to a point not very far noith of Knowle, and it is not unreasonable 

 to suppose that subsidiary smaller glaciers may have extended stiU 

 further south, under the influence of the extreme cold. Lord 

 Avebury 1 has pointed out the evidence of glacial action that the 

 1 " The Scenery of England." 



