propellers, used to make bars, dens, and livingrooms look better since WW1.

The metal variable pitch prop has a cool history:

This particular propeller was from a Lockheed Vega airplane owned by the Crosley Radio Corporation and flown by Ruth Nichols.
Flying in that airplane in 1931-32, Nichols became the only woman to hold simultaneously the women's international speed, altitude, and distance records for flight. She set the distance record in October 1931 when she flew 1,977 miles between Oakland, California and Louisville, Kentucky. Nichols' records proved the effectiveness of the new controllable-pitch propeller.

Just above that, the dark wooden very old prop;

This propeller is from a Curtiss Model D pusher biplane flown by Eugene B. Ely on January 18, 1911 for the first landing on a ship, the battleship USS Pennsylvania in San Francisco Bay, using the first ever tailhook system.

https://airandspace.si.edu/collections/propulsion?page=2
https://www.westlandlondon.com/antiques/decorativeitems/other/
https://riseofflight.com/forum/topic/31992-wooden-ww1-aircraft-propellers/
https://www.historicpropellers.com/woodenpropeller-ebora