In the 1920s German manufacturer Eugene Dietzgen Co. designed and produced this brilliant drawing tool, the 932S Excello, for draftsmen.
Check out the video in the post for an explanation and example of how it works. Really cool. (via David Nunez)
Old School Drafting Tool: Watch This Incredible 1920s Gadget That Lets You Draw Perfect Dotted Lines By Hand – Core77
