XXVIII. THE STONE-SHAPING AETS 



Synopsis of Pkocesses 

 i, fracture rrocesses 



(a) Percussion fracture 



(b) Pressure fracture 



Direct, freehand 

 Direct, rest 

 Indirect, freehand 

 Indirect, rest 

 Freehand 

 ^ Rest 

 (c) Heat fracture 

 (fl) Water ex])ansion fracture 



II. CRUIMBLING PROCESSES 



Freehaud 



(a) Dii-ect percussion cruuihliuir ^ t^ , 



■ ' J vest 



ih) Indirect i:)ercussion cruniblinjii: I ,. ^ 



I Kest 



Fl -eel land 



III. ABRADING PROCESSES 



(a) Grindino"; Avhetting- 



(b) Sawing 



(c) Scraping 



/ 7x T^ -IT f 1. Dii'ect 

 {d) Drilling 



2. Rotary 

 (e) Engraving 

 (/) Polishing 



(a) Cutting 



(b) Shaving 



IV. IX CI SI NO PROCESSES 



V. PIERCING PROCESSES 



THE shaping processes, by means of ^Yhich stone is made to 

 assume artificial forms adajited to human needs, are varied 

 and ingenious, and their mastery has always been a matter of 

 the greatest importance to primitive peoples, as it is also in large 

 degree with civilized peoples. These processes are 

 cinssification of p„^.pjy niechanical, unless we regard fire, used some- 

 times in fracturing rock bodies, and perhaps to 

 some extent in minor operations, as a chemical agent. A wide range 

 of manual o])erations is represented, and these may be conveniently 



