Keywords: history of technology historyoftechnology mining smithsonian probably public domain probablypublicdomain blackandwhite monochrome black and white SI Neg. CCC-2619. Date: na....Arc Wall Mining Machine cutting coal.From the Consolidation Coal Company collection, National Museum of American History...Credit: unknown (Smithsonian Institution) SI Neg. CCC-2619. Date: na....Arc Wall Mining Machine cutting coal.From the Consolidation Coal Company collection, National Museum of American History...Credit: unknown (Smithsonian Institution) |