168 THE POPULAR SCIENCE MONTHLY. 



ing to Swedenborg) especially adapted to the working of bog-ores, 

 large quantities of which were actually smelted in New England, 

 it does not seem at all improbable that furnaces of similar form 

 may have been used there for smelting such ores ; and the fact 

 that this furnace produced wrought iron in masses of considerable 

 weight would make it of especial utility in connection with 

 forges, which were quite numerous in the New England colonies 

 at the beginning of the eighteenth century. 



The Stiickofen was an enlargement upward of the Osmund fur- 

 nace, and may be pretty accurately described, as one Osmund fur- 

 nace inverted upon another, its interior form being that of two 

 cones united at their bases, a hearth similar to that of an Osmund 

 furnace being formed at the lower part. We have no certain infor- 

 mation that the Stiickofen was ever used in this country ; but as 

 this furnace was well known in Europe, where it had been in use 

 for several centuries, those interested in the earlier smelting enter- 

 prises in the American colonies must have been acquainted with 

 its construction, and it is very probable that some of the earlier 

 blast-furnaces were Stuckofens under another name. The fact 

 that this furnace could be so worked as to produce either cast 

 or wrought iron, as desired, would make it especially valuable in 

 a new country, where there was not sufficient demand for either 

 metal to keep a furnace constantly employed. Besides those al- 

 ready enumerated, there was another method of producing a 

 '' bloom " of f orgeable iron ; viz., by the remelting of " sowe " or 

 " pig " iron in a " Catalan forge " or " blomary fire." In colonial 

 times this operation was largely used and was often described as 

 " refining," and the premises in which it was carried on were fre- 

 quently called a " refinery " ; but the reader must not conf ound 

 this term with that applied to a comparatively modern apparatus 

 of quite different construction and purpose, which we will de- 

 scribe later. 



This old refining process * consisted substantially of melting 

 the pig iron with charcoal, and then directing the blast upon the 

 melted iron which was stirred occasionally by proper iron tools 

 until its impurities in a great degree were expelled, and a spongy 

 mass of forgeable iron was formed (quite similar, in fact, to that 

 obtained when ore alone was used), which could be hammered 

 into a " bloom." 



Thus far we have confined ourselves mainly to a description of 

 methods and apparatus for the production of " sowe " or " pig " 

 iron and " blooms," which were either in actual use in America 



* This process is even now worked to a limited extent, but its use is steadily declining. 

 Mr. Swank reports that "the production of blooms and billets from pig and scrap iron in 

 1889 was 23,853 net tons, against 25,^87 tons in 1888, and 28,218 tons in 1S87." 



