422 
DAVIS: ANCIENT rLTXT-USEES OF YORKSHIRE. 
3 inches thick. The end of the shaft was bound with sinews or 
thongs of raw liide, to prevent its splitting. Across the upper end of 
the shaft was a transverse piece, against which the chest could be 
placed to give greater impulse to the pressure in using the implement. 
Obsidian, and the more easily flaked stones were placed between the 
feet, harder stones were partially imbedded in hard earth. A small 
indentation having been made on the block, the tool was placed in it 
and a sharp impulsive pressure given to it, and a flake was separated. 
Where large and massive flakes are required and the strength of a 
man was insufiicient to throw it off, an instrument similar to the one 
already described was used, except that in selecting the staff" care was 
taken to secure the trunk of a young tree with a branching stem at a 
few inches from the bottom. The latter was cut off" at a few inches from 
the main trunk, so as to form a notch, and whilst the pressure was 
applied b)^ the individual holding it, a second man gave a smart blow 
with a hammer in the notch. This combination of impulsive pressure 
and the percussion of the blow rarely failed to throw off* the flake, 
sometimes 10 or 12 inches in leng-th. "Where the best beds of chert 
occur intercalated with the limestone of the coal measures, the 
manufacture of stone implements found employment for many of the 
Indians. One set dug out and selected the chert in the quarry. 
Others prepared the blocks for the flaker, whose operations are 
described above, and succeeding workers took the flakes and manu- 
factured them into spear or arrow-heads, and such other tools or 
implements as were in request. As already mentioned with regard 
to the aborigines of Australia, the implements in America formed a 
staple article for barter and exchange. The flake was first attacked 
on the flat surface, that is, the one which had been separated last 
from the nucleus or core, and its edges reduced to something like the 
form of the object to be made, say the head of an arrow ; the opposite 
surface was next dealt with, a second series of pushes produced a line 
of fractures extending over the surface and leaving a serrated margin 
to the implement, repeated and more delicate operations gradually 
evolved the perfect arrow-head. A large variety of objects were thus 
made from the delicate drill or arrow-point to agricultural implements 
made from quartzite or chert, which are 12 to 16 inches in length, 
