FLINT FRACTURE AND FLINT IMPLEMENTS 49 



under pressure over the surface of the underlying stone very- 

 thin flakes or scalings are removed. This is due apparently to 

 the fact that the pressure is able only to attack a very narrow- 

 area of the edge of the moving stone, and in consequence only 

 very thin flakes are removed. 



In flaking produced by human blows, it is impossible to 

 strike so near to the edge of the flint as to remove flakes as thin 

 as those detached by pressure, and a hollow flaked by the 

 former means always appears, and is, more uneven and less 

 finished than one produced by pressure. 



The pressure hollows appear " smoother " than those of the 

 other kind, because, the flakes being thinner, the ridges inter- 

 vening between them are less prominent (fig. 10). 



WUfiVl SCOApFft 





Fig. io. 



Fig. ii. 



In the case of the human blows, which cut more deeply into 

 the flint, and remove thicker flakes, these ridges are corre- 

 spondingly more marked (fig. n). 1 



The foregoing experiments in fortuitous percussion and 

 pressure have been repeated many times and the results found 

 to be uniform in each case. 2 It is to be hoped that prehistorians 



1 The author has lately examined the Eocene flint-bed resting upon the chalk 

 at Bramford, near Ipswich, where many specimens have been fractured by natural 

 pressure in the bed in which they now lie. This examination has shown that the 

 fractured Eocene flints reproduce in a marked degree the characteristics of those 

 fractured by pressure in the experiments described. See Proc. Prehis. Soc. of E. 

 Anglia, vol. i. Part IV. pp. 397-404. 



* Further experiments are in progress, and if the results obtained throw any 

 further light upon the problems discussed in this paper, these will in due course be 

 published. 



4 



