ART. 9. HISTORY OF INVENTIONS — HOUGH. 15 



took place no doubt when the shaping of wood became an important 

 feature in the savage economy. In the most primitive forms the 

 stone blade is flaked into shape (No. 1), and in the more highly de- 

 veloped (Nos. 4 and 5) it is pecked and ground, the distinguishing 

 characteristic of the implement being the single bevel of the edge. 

 The hafting is accomplished in a variety of ways. One of the highest 

 forms of the simple tool is the steel hand adz of the present period 

 (No. 12). This implement may be regarded as the prototype of the 

 modern planing machine, which is a compound adz, several blades 

 being mounted on a revolving shaft. A model of this device appears 

 in No. 13, which is the working part of the superb machines of to-day. 



No. 1. Blade of flint, reduced to a beveled edge by flaking. Simpler forms are 

 sharp stones identical witli the earliest axes. Virginia 1,073 



No. 2. Adz made of column of conch shell by grinding an edge, mainly from one 

 side. Simple style of hafting. Florida 3,687 



No. 3. Adz made of diorite flaked into shape and sharpened by grinding. 

 Primitive hafting. Samoa 19,342 



No. 4. Stone adz, pecked and ground into shape ; wooden handle attached with 

 twigs. British Columbia 88,720 



No. 5. Polished stone adz, neatly fixed to an effective wooden handle. New 

 Guinea 73,355 



No. 6. Stone adz, with hollowed blade, curved edge, and shell adz, showing 

 origin of this form. Rhode Island and West Indies 17,687, 747 



No. 7. Copper adz blade, shaped by hammering ; well specialized form ; curved 

 edge. New York 18,960 



No. 8. Copper adz blade, shaped by hammering; socket for handle, made by in- 

 curving margins. Wisconsin 32,615 



No. 9. Iron blade fixed on primitive handle by means of buckskin thong. Indians 

 of Washington 130,985 



No. 10. Iron blade of modern type, with highly specialized handhold attached by 

 leather strap. Indians of Washington 74,770 



No. 11. Small, rudely hafted adz ; blade and method of hafting advanced shape. 

 Ceylon 168,684 



No. 12. Common steel adz for use in one hand ; highly specialized shape. United 

 States. 



No. 13. Cutter head of modern planing machine. May be regarded as a com- 

 pound adz. 



SERIES 1. HAMMER. 



Plate 16. 



The hammer has been from the beginning an important factor in 

 human progress. The earliest known forms are round stones, which 

 were employed in various useful arts, for shaping implements, in war, 

 md in the chase. Identical forms are used by such living tribes as 

 still occupy the first few rounds of the ladder of culture. 



As the pioneers of civilization advanced step by step to higher levels 

 the hammer was modified and improved. The simple rounded stone 

 ^ave way to the specially shaped stone, and then the art of hafting 



