This is, quite astonishingly, a mechanical prime factorisation machine. See http://ed-thelen.org/comp-hist/Mike-Williams-Lehmer.html http://ed-thelen.org/comp-h

This is, quite astonishingly, a mechanical prime factorisation machine. See http://ed-thelen.org/comp-hist/Mike-Williams-Lehmer.html http://ed-thelen.org/comp-hist/Mike-Williams-Lehmer.html for more. Thanks to https://mathoverflow.net/a/385008/83468 https://mathoverflow.net/a/385008/83468 for pointing these out to me!