The Making of America, Volume 6

American anthracite asphaltum average bauxite Bessemer Bessemer process bituminous blast furnace borax brown hematite buckets California carbon Carnegie cars cent clay coal coke color Colorado Comstock lode Connellsville considerable copper cost crystals cyanide process deposits district drifts drill electric engineer exports extensive fire damp fuel gold grade graphite gypsum hematite hoisting important inches increase iron and steel iron industry iron oxide known Lake Superior lead less limestone locomotives machine magnetites manufacture material metal method miles million mills mineral mines motor natural gas Nevada North obtained Ohio open hearth operation output Pennsylvania petroleum pig iron pipe Pittsburg plants plates pounds production pump pyrite quantity quartz railroad rails railway red hematite region rich rock salt sand shaft short tons silver smelting solution steam Steel company stone supply surface talc tion tons trade United Utah veins Virginia wire zinc