396 COLUMBIAN HISTORICAL EXPOSITION AT MADRID. 



If thin copper or stone chisels were used for some parts or corners 

 of the pattern, certain ancient workshops should be littered with 



Tig. 26. 

 CHIPPED SCRAPERS, MOUNTED IN ORIGINAL BONE AND WOOD HANDLES, FOUND IN USE AMONG THE 



ESKIMO OF ALASKA. 

 Collection of the U. S. National Museum. 



battered and broken tools of this nature, yet Senor Troucoso has found 

 no partly finished specimen with used tools lying near; nor did Senor 

 AlfarOj curator of the Costa Eican exhibit, meet with these missing 



Fig. 27. 



STONE COLLAR, PORTO RICO; HAMMER STONES AND ADZES, UNITED STATES AND PORTO RICO AND 

 COPPER ADZ, MEXICO. 



A marvel of aboriginal work. One of the &quot;collars&quot; from Porto Rico carved from very hard stone by the ancient inhabitants of the 

 island. The process of manufacture has not been proved. Theories of round hammer stones, hafted hammers, stone and metal celts 

 (see cut), and fragments of stone have been advanced to explain the work, but no specimens have heen found in positions to demon 

 strate what kind of carving tools were used. 



links of evidence at the partly quarried metates discovered by him 

 recently in Costa Eica. 



