[5] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 621 



practicable, illustrations of materials of construction, sucli as fireclays, 

 sands, &c. The furnaces and tools are shown by specimens, views, and 

 descrii)tious. The interest and value of these collections does not lie so 

 much in the specimens themselves as in their being thoroughly con- 

 nected, and in the kind and amount of information that can be given 

 in regard to them. 



In order to be satisfactory the series must be complefe, and the in- 

 formation full and accurate. A great deal of time, care, and attention 

 is necessary in making such a collection. 



To illustrate the nature and scope of these collections, a single one, 

 that from the Passaic Zinc Works, will be described in detail. These 

 works are located at Jersey City, K. J., and use the zinc, iron, and 

 manganese ores from Franklin, Sussex County, New Jersey ; they were 

 started in 1854, and have been twice enlarged. 



From 1854 to 1875 only oxide of zinc was manufactured ; in 1875 the 

 spelter furnaces were added, and in 1884 the spiegel furnace. The 

 works have been in constant operation from the very beginning. 



There are 48 furnaces, 6 by 4 feet, making oxide of zinc, arranged in 

 double rows of 8 and 10. There are 12 spelter furnaces arranged in 

 blocks of 4 each. The spiegel plant consists of one 9 feet 8 inches by 

 37^ feet blast furnace. 



The Franklinite ores are treated first in the oxide furnaces for the 

 production of oxide of zinc and the residues containing iron and man- 

 ganese are smelted in the blast furnace for the production of spiegel. 



The silicate and carbonate ores are smelted in the spelter furnaces 

 for the production of metallic zinc. 



The collection from the zinc furnaces shows — 



The Franklinite ore, consisting of a mixture of Franklinite or proto- 

 sesquioxide of iron with zinc and manganese replacing the iron, Zincite 

 or oxide of zinc, Willemite or silicate of zinc, Calcite or carbonate of 

 lime, in lumps as mined, from the Buckwheatfield mine, Franklin, Sus- 

 sex County, New Jersey. 



The same ore crushed ready for the furnace. 



The Franklinite ore, consisting of a mixture of Franklinite or proto 

 sesquioxide of iron with zinc and manganese replacing the iron, Zincite 

 or oxide of zinc, Willemite or silicate of zinc, Rhodonite or silicate of 

 manganese, and Calcite or carbonate of lime, in lumps, as mined from 

 the Sterling Hill mine, Ogdeiisburg, Sussex County, New Jersey. 



The same ore crushed ready for the furnace. 



The silicate and carbonate ore, consisting principally of calimine or 

 hydrated silicate of zinc with a little carbonate of zinc resulting from 

 decomposition, in lumps, as mined from the Sterling Hill mine, Ogdens- 

 burg, Sussex County, New Jersey. 



The same ore after roasting to expel water and carbonic acid. 



The roasted ore crushed ready for the furnace. 



Anthracite coal used for heating purposes. 



