Engine, Mt. Washington R.R. New Hampshire in 19th century. Stereoscope card.
Picryl description: Public domain image of an industrial equipment, workshop, assembly line, factory, power engine, 19th-20th century, free to use, no copyright restrictions.
1850 - 1930
New York Public Library
Creative Commons CC0 1.0 Universal Public Domain Dedication ("CCO 1.0 Dedication")