Abstract: A measuring instrument for rotatively measuring point to point distances in operative combination with a watch is provided. The measuring instrument comprises a wheel rotatably connected to the watch and having a discrete, continuous, rotative edge which is displaceable against a measuring surface. A driving gear is coaxial and operatively connected with the wheel for simultaneous rotation therewith. A driven gear mounted in the watch casing is cooperatively connected to the driving gear and the axis of said driven gear is perpendicular to the axis of said driving gear. Externally visible graduations are provided on the driven gear for indicating a point to point distance. The rotative displacement of the discrete, continuous edge of the wheel is translated into a distance measure according to rotative displacement of the graduations located on the driven gear.