354 



BOOK IX. 



smelters by which of these methods they can obtain the most metal from 

 any one ore. Moreover, while sometimes there are many methods of 

 smelting the same ore, by which an equal weight of metal is melted out, yet 

 one is done at a greater cost and labour than the others. Ore is either melted 

 with a furnace or without one ; if smelted with a furnace the tap-hole is either 

 temporarily closed or always open, and if smelted without a furnace, it is done 

 either in pots or in trenches. But in order to make this matter clearer, I will 

 describe each in detail, beginning with the buildings and the furnaces. 



It may be of service to give a tabular summary indicating approximately the time 

 when evidence of particular operations appear on the historical horizon : 



Gold washed from alluvial 



Copper reduced from ores by smelting . . 



Bitumen mined and used. . 



Tin reduced from ores by smelting 



Bronze made 



Iron reduced from ores by smelting 



Soda mined and used 



Gold reduced from ores by concentration 



Silver reduced from ores by smelting 



Lead reduced from ores by smelting 



Prior to recorded civilization 



Prior to recorded civilization 



Prior to recorded civilization 



Prior to 3500 B.C. 



Prior to 3500 B.C. 



Prior to 3500 B.C. 



Prior to 3500 B.C. 



Prior to 2500 B.C. 



Prior to 2000 B.C. 



Prior to 2000 B.C. (perhaps prior 



to 3500 B.C.) 

 Prior to 2000 B.C. 

 Prior to 1500 B.C. 



1000 B.C. 



500 B.C. 



Prior to 500 B.C. 

 Prior to 500 B.C. 

 Prior to 400 B.C. 

 Prior to 300 B.C. 



Silver parted from lead by cupellation 



Bellows used in furnaces 



Steel produced . . . . . . . . . . . . Prior to 



Base metals separated from ores by water concentration Prior to 



Gold refined by cupellation 



Sulphide ores smelted for lead 



Mercury reduced from ores by . . (?) 



White-lead made with vinegar 



Touchstone known for determining gold and silver 

 fineness 



Quicksilver reduced from ore by distillation 



Silver parted from gold by cementation with salt 



Brass made by cementation of copper and calamine . . 



Zinc oxides obtained from furnace fumes by construc- 

 tion of dust chambers 



Antimony reduced from ores by smelting (accidental) 



Gold recovered by amalgamation 



Refining of copper by repeated fusion 



Sulphide ores smelted for copper 



Vitriol (blue and green) made 



Alum made 



Copper refined by oxidation and poling 



Gold parted from copper by cupelling with lead 



Gold parted from silver by fusion with sulphur 



Manufacture of nitric acid and aqua regia 



Gold parted from silver by nitric acid 



Gold parted from silver with antimony sulphide 



Gold parted from copper with sulphur 



Silver parted from iron with antimony sulphide 



First text book on assaying 



Silver recovered from ores by amalgamation 



Separation of silver from copper by liquation 



Cobalt and manganese used for pigments 



Roasting copper ores prior to smelting 



Stamp-mill used . . . . . . . . . . . . Prior to 1550 A.D. 



Bismuth reduced from ore . . . . . . . . Prior to 1550 A.D. 



Zinc reduced from ore (accidental) . . . . . . Prior to 1550 A.D. 



Further, we believe it desirable to sketch at the outset the development of metallurgical 

 appliances as a whole, leaving the details to special footnotes ; otherwise a comprehensive 

 view of the development of such devices is difficult to grasp. 



We can outline the character of metallurgical appliances at various periods in 

 few words. It is possible to set up a description of the imaginary beginning of 



Prior to 300 B.C. 

 Prior to Christian Era 

 Prior to 

 Prior to 



Prior to 

 Prior to 

 Prior to 

 Prior to 

 Prior to 

 Prior to 

 Prior to 



Prior to 1200 A.D. 

 Prior to 1200 A.D. 

 Prior to 1200 A.D. 

 Prior to 1400 A.D. 

 Prior to 1400 A.D. 

 Prior to 1500 A.D. 

 Prior to 1500 A.D. 

 Prior to 1500 A.D. 

 Prior to 1500 A.D. 

 Prior to 1500 A.D. 

 Prior to 1540 A.D. 

 Prior to 1540 A.D. 

 Prior to 1550 A.D. 



