Picryl description: Public domain image of a power dam, cascade, free to use, no copyright restrictions.
Picryl description: Public domain image of an industrial building, factory, workshop, workers, 20th century, free to use, no copyright restrictions.
Public domain photograph of laboratory, scientist, free to use, no copyright restrictions image - Picryl description
Public domain photograph of 1930s-1940s US industrial development, Second World War, US war production, indusry, no copyright restrictions image - Picryl description
Picryl description: Public domain image of people, meeting, eating, drinking, food, beverage, 1930s, free to use, no copyright restrictions.
Public domain photograph - working class people, the 1930s United States, work, labor, worker, free to use, no copyright restrictions image - Picryl description