230 On the Recent Discovery of Flint Implements 
and Manganese, assume in the process of crystalization; very many 
have also a slight incrustation of Carbonate of Lime on the lower 
or under surface. 
The implements or weapons of the drift period are without ex- 
ception formed by chipping alone; there is no indication of any 
attempt at polishing or rubbing down the sharp angles, a 
practice which was almost the rule during a subsequent stone 
period. Chipping was apparently the only idea of this primitive 
age. The result of this mode of manufacture in the immediate 
neighbourhood is shown, by the presence of unrolled imple- 
ments, and by a large number of the rough chippings or 
“‘waste flakes,’ such as of necessity must have been produced in 
the process of making the finished weapons. These rough flakings 
appeal but little to the uneducated eye, yet from the peculiar 
fracture of flint an expert can always tell the direction in which a 
blow was struck to remove a flake from a mass of flint. By 
carefully examining these flakes, a slight swelling or “ bulb of per- 
cussion” can generally be detected, indicating the point at which 
the blow was given to detach each piece from the core or nucleus 
of flint. 
Besides these ‘‘ waste flakes” others occur evidently made with 
a preconceived design ; they are more definite in their form, flat or 
slightly concave on one side, and present a greater or less number 
of facets on the other. This proves that one surface of the flint 
was trimmed into shape before the last blow which separated the 
flake from the parent block was given. A well marked “bulb of 
percussion” on the flat side, indicates the point at which this 
blow was struck. Some others are sharp pointed and triangular 
in form, and might have been used as heads for darts or arrows ; 
more likely the former, as the bow and arrow was probably a later 
invention. 
Intermediate between the simple flakes and the more finished 
implements, are a class of objects almost identical in form with 
certain “skin-scrapers” from the bone caves of France, especially 
from Le Moustier, Dordogne. They somewhat resemble large 
waste flakes, but have been carefully chipped on one side to a blunt 
