Manchester Memoirs, Vol. liii. (1909), No. 8- 15 



small contiguous flakes. Tiiese flakes will replace the 

 series of minute flakes produced by the work. On re- 

 suming the work after re-sharpening, it will be found that 

 the splintering of the edge continues, and tends to reduce 

 the irregular outline due to the re-sharpening. These 

 effects are shown diagrammatically in Fig. 3. 



(54) A consideration of this figure will show that by 

 turning the implement and reversing the positions of the 

 faces A and B relatively to the operator and changing the 

 pulling motion into a pushing one, the effects of the work 

 on the flint edge would not be altered. 



(55) The " Racloirs" of Rutot are in his view used in 

 this way, but this method of working is open to criticism 

 on anatomical grounds, as the human arm is not capable 

 of exerting so much force in a push as in a pull, and it is 

 submitted that the most effective movement of the fore- 

 arm is towards the body. Its great strength and facility 

 in this direction has no doubt been induced from the 

 necessity of conveying food to the inouth. 



There are, however, certain classes of work, such as 

 the dressing of skins, in which the motion away from the 

 operator is advantageous. In the Blackmore Museum, 

 Salisbury, there is a stone scraper used by the S. American 

 Indians of the Amazon district in this way, the operator 

 squatting or kneeling with the skin to be scraped 

 stretched across the thigh of one leg. 



(56) There is, however, a further alternative ; if the 

 tool, instead of being posed with its cutting edge perpen- 

 dicular to the surface to be worked upon, be held with the 

 cutting edge towards the operator, and at angles up to 

 about 40"' from the horizontal, it will work quite well as a 

 pull tool, indeed in its initial state a great deal more 

 work can be done with a tool used in this way than in 

 either of the preceding fashions. The lower portion of 



