REPORT OF DEPARTMENT OF METALLURGY. 273 



consideration a few representative works were selected for illustration, 

 and have been worked up as completely as possible. 



Beginning with the ore as mined, each step in its preparation for 

 smelting is shown, together with the by or waste products of such 

 treatment. To illustrate the smelting o])eration, the ores, the fuels, the 

 fluxes, and every other material entering into the operation are shown. 

 Following through the process, each product of each operation up to 

 the linal product of the works is represented. To these are added, where 

 practicable, illustrations of materials of construction, such as fire-clays, 

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

 descrii)tions. 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 bo giv'eu 

 in regard to them. 



In order to be satisfactory the series must be complete, 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 AVorks, 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 1851, and have been twice enlarged. 



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

 spelter furnaces were added, and in 1881 the spiegel furnace. The 

 works have been in constant oi)eration from the very beginning. 



There arc 48 furnaces, 6 bj^ 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 sauic 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, Ogdensburg, Sasses? County, New Jersey. 

 S. Mis. 33, pt. 2 18 



