PRELIMINARY HANDBOOK OF THE DEPARTMENT OF GEOLOGY. 45 



including a fall suite of the ores, fuels, and flaxes used, the bullion 

 and slag produced, and a variety of by products, matte, speiss, flue- 

 dust, accretions, etc. The value of the specimens in this case has 

 been greatly enhanced by the large amount of information kindly fur- 

 nished. The course of the operation has been fully described and plat- 

 ted. Nearly every specimen is accompanied by a careful and complete 

 analysis. Numerous photographs show the disposition of the works. 



The refining of base bullion is illustrated by a collection of 18 speci- 

 mens from the Cheltenham Works. The smelting of a charge contain- 

 ing a large proportion of oxidized ores, using iron to reduce the sul- 

 phide, and the subsequent refining of the base bullion, are illustrated 

 by 13 specimens from the Kansas City Works. 



The southeastern Missouri lead region is well represented by two col- 

 lections, one containing 30 specimens from the St. Joe Works, and the 

 other 29 specimens from the Desloge Works. These are particularly 

 interesting as illustrating two distinct methods of separating the galena 

 from the limestone, through which it occurs disseminated. At the St. 

 Joe Works the crushed material is delivered directly to the jigs with- 

 out any sizing, while at the Desloge Works sizing is very carefully done. 



A series of 28 specimens illustrates the smelting of galena with the 

 recovery of the fume as a white paint at the Lone Elm Works, Jopliu, 

 Missouri. 



The application of lead is illustrated by 11 specimens showing the 

 Dutch process of making white lead. 



The mineralogy of copper is illustrated by 22 specimens. All the 

 ordinary copper minerals are shown. The ores of copper are divided 

 into metallic, oxidized, and sulphuret ores. The metallic copper ores 

 are very well represented by collections from three characteristic Lake 

 Superior copper mines, " mass," u amygdaloid," and "conglomerate." 

 The mass mines, in which copper is found in large masses, are illus- 

 trated by a collection of 31 specimens from the Central mine. The 

 amygdaloid mines, in which the copper occurs disseminated through a 

 soft amygdaloidal melaphyr, are illustrated by a collection of 6L speci- 

 mens from the Osceola mine and 21 specimens from the Osceola mill- 

 The conglomerate mines, in which the copper occurs disseminated 

 through a tough felsitic conglomerate, are illustrated by 01 specimens 

 from the Delaware mine and 17 specimens from the Delaware mill. 

 These Lake Superior collections were made with great care for the 

 Museum by special collectors. 



The location of nearly every specimen within the mine was carefully 

 noted, and the collections include many complete sections. The smelt- 

 ing of the separated copper is illustrated by a collection of 17 speci- 

 mens from the C. G. Uussey Works, Pittsburgh, Pennsylvania, and 11 

 specimens from the Lake Superior Native Copper Works. Taken alto- 

 gether, these seven collections, with L'l!) specimens, form a complete 

 illustration of the Lake Superior copper industry, 

 H. Mis. 224, pt. 2 59 



