Flat, circular object with a small hole in the center. The top side is smoother and appears more glossy and polished than the bottom, which is rough in texture, lighter in color and scored by various marks.
Created by
James Walker
Date Created
01/31/2012
Source
Smithsonian National Air and Space Museum
Keywords
Aviation; Equipment; People; Research; Tools
Rights and Restrictions
Usage conditions apply For more information, visit the Smithsonian’s Terms of Use.