362 BUREAU OF AMERICAN ETHNOLOGY [bhll. 60 



cannel coal, and fire clay are readily carved Avith stone tools while 

 fresh from the ground. 



Cutting tools of copper were doubtless in general use among the 

 more advanced peoples, but were not effective for the working of hard 

 stone. Bronze was in use in Middle and South America, and the 

 Incas especially understood the manufacture and use of this alloy; 

 yet to what extent cutting tools of this material took the place of 

 stone in the great work of hewing building stone and of sculpture 

 can not now be determined. 



It is observed that the processes employed in stone cutting and 

 sculpture generally, where hard stone is employed, are mainly the 

 fracture and crumbling processes. The chisel used in working 

 marble, granite, and the like, although a keen-edged tool, does not cut 

 the stone but fractures or crumbles it. 



