Firestone rubber plant. Akron, Ohio. February 1942. "Conversion. Beverage containers to aviation oxygen cylinders. After the circumferential straps are welded to the cylindrical portion in the metal division of a large Eastern rubber factory, rough edges and accumulated weld scale are removed by a skilled workman. The twin rotary brushes do their work on the inside and outside of the cylinder in the same operation. This process is required in the manufacture of shatterproof oxygen cylinders for high altitude flying." 4x5 nitrate negative by Alfred Palmer for the Office of War Information. View full size.