The Rope Trick
A young lady (top) poses on a swing in a photographer's studio. Except, she isn't really on a swing. Nineteenth-century photographers needed their subjects to remain stationary in order to get the proper focus and exposure. So swinging back and forth was out of the question. The swing was actually a prop available from a catalog (bottom). The ropes remained rigid and were not attached to anything above.
Links and References
Lothrop, E.S. (July-Sep 1984). The Rope Trick. History of Photography. 8(3): 236.