50 EARLY COLLECTION OF GOLD CHAP. XVII. 



stage of society, simple, rude, and with little re- 

 gard to extracting the whole of the precious metals 

 from the ores. The mines had been wrought 

 for the Incas, and the use of mercury had not 

 been adopted till more than forty years after the 

 conquest. The smelting was performed in small 

 portable furnaces or cylindrical tubes of clay, 

 very broad and pierced with a great number of 

 holes. In these the Indians placed layers of 

 silver ore, galena, and charcoal, and the current 

 of air which entered the holes quickened the fire 

 and gave it a great degree of intensity. These 

 furnaces were moved from one elevation to an- 

 other according to the degree of high or low wind. 

 When it was found that the wind blew too strong 

 and consumed too much of the fuel, they were re- 

 moved to a lower situation. By these means the 

 natives obtained argentiferous masses, which were 

 smelted again in their own cottages. This was 

 performed by a number of persons, ten or twelve 

 at a time blowing a fire through copper tubes, 

 from one to two yards in length, pierced with a 

 small hole at the extremity towards the fire, which 

 thus acted in the same manner as the modern 

 blowpipe. By such processes as these, though a 

 very large portion of the silver must have re- 

 mained in the scoriae without combining with the 

 galena, yet such a quantity could be obtained as would 

 satisfy the demands of the fiscal officers of the Inca, 



