Keywords: history of technology historyoftechnology mining smithsonian probably public domain probablypublicdomain blackandwhite monochrome outdoor black and white SI Neg. CCC-3147. Date: 5/25/1936....29-B Straight-Bar Cutting Machine (Raised) Mine 206-6A.29-B Straight Bar Machine, 206-6A.From the Consolidation Coal Company collection, National Museum of American History...Credit: unknown (Smithsonian Institution) SI Neg. CCC-3147. Date: 5/25/1936....29-B Straight-Bar Cutting Machine (Raised) Mine 206-6A.29-B Straight Bar Machine, 206-6A.From the Consolidation Coal Company collection, National Museum of American History...Credit: unknown (Smithsonian Institution) |