Abstract: A device for measuring linear or curvilinear map distance and determining the rate or time of travel represented by such distance. The device includes an elongate, hollow body having a slot extending along a portion of its length, an indicator shiftable along the slot, and a traction element rotatably mounted at one end of the body. Rotation of the traction element, as the same is moved across a surface, such as a map surface, along a selected path, produces indicator shifting which is proportional to the distance represented by such path. The apparatus also includes a transparent, cylindrical sleeve mounted on the body for rotation relative thereto. This sleeve carries radial and axial calibrations which are alignable with the slot and the indicator, respectively, when the sleeve is rotated, to produce distance-related time and rate of travel determinations, respectively.