Circumferentor :: Circumferentor (n.) A surveying instrument, for taking horizontal angles and bearings; a surveyor's compass. It consists of a compass whose needle plays over a circle graduated to 360�, and of a horizontal brass bar at the ends of which are standards with narrow slits for sighting, supported on a tripod by a ball and socket joint..
Circumferentor :: Circumferentor (n.) A graduated wheel for measuring tires; a tire circle.