100 BULLETIN 42, UNITED STATES NATIONAL MUSEUM. 



was then siibitiitted to a series of fusions in reverberatory furnaces for 

 the production of in^ot copper. The collection shows : 



Ore. 



(1) Chalcopyrite, pyrrhotite, blende and quartz, and a mixture of ferruginous sili- 

 cates, from the Ely Mine, Orange County, Vermont. (17298.) 



I utir mediate products. 



(1) Eoastedore. (29965.) 



(2) Sulphur, condensed from the roasting heaps. (29969.) 

 (:?) Sulphide of copper, fused in roasting. (473;").) 



(4) Matte, produced from smelting the roasted ores. (29964.) 

 (.^>) Slag, crystallized, from the fusion for matte. (29966.) 



(6) Roasted matte. (29962.) 



(7) Second matte, produced from (ir.st matte, by roasting fusion. (29963.) 



(8) Roasted second matte. (31013.) 



(9) Black copper, produced from roasted second matte, by roasting fusion. " Basin 

 cake." (29967.) 



(10) Pig copper, produced from roasted second matte. (31539.) 



FiuaJ product. 

 (1) Ingot, produced by refining pig or l)lack copper. (31540.) 

 THE DUCKTOWN COPPER, WORKS. 



These works were established in the mountains of Tennessee to util- 

 ize the ores of the Ducktown mines. Formerly a large amount of cop- 

 per was produced, but they have now been closed for several years, 

 with no probability of.starting up in the near future. 



Some oxidized ores were found in the upper portions of the mine, but 

 the large ore bodies were altered sulphides that yet contain a consid- 

 erable amount of sulphur. The sulphide ores were rudely roasted in 

 heaps, and then subjected to a series of fusions in shaft and reverbera- 

 tory furnaces. The collection shows : 



Ore. 



(1) Oxidized, carbonates of copper, oxides of iron, and quartz, (56370.) 



(2) Sulphide, partially altered pyrite, carbonate of copper, and quartz. (56369.) 



(3) Sulphide, chalcopyrite, pyi'ite, quartz, and calcite. (56368.) 



Intcrmediale products. 



(1) Roasted ore, roasted in piles of 1,000,000 pounds, two roastings being required, 

 and occupying 3 months. (6.5277.) 



(2) First matte, obtained in smelting ores in rectangular shaft furnaces 12 feet 

 high. Average composition, 20 per cent, copper, 45 per cent, iron, and 20 per cent- 

 sulphur. (31279.) 



(3) Slag, obtained in ore smelting, contains silica 33 per cent., oxide of iron 54 per 

 cent. (3127 S.) 



(4) Roasted first matte, the first matte is roasted several times in 60-ton i)iles, on 

 stone lloors, under sheds. (31274.) 



(5) Second matte, obtained by smelting roasted first matte in rectangular shaft 

 furnaces 12 feet high, contains 70 to 75 per cent, copper. (31275.) 



