hodometer
hodometer (ho*dom"e*tẽr) , noun
[Greek "odo`metron, "odo`metros, an instrument for measuring distance; "odo`s way, path, road + me`tron measure: compare French odométre, hodométre. See also odometer.]
A device for measuring the length of a path, consisting of a wheel of known circumference attached to a rod held in the hand, and pushed along a surface, which is usually the ground or a floor. The number of times the wheel makes a complete circle multiplied by the circumference is a measure of the length of the path traversed. It may be used to measure distances on curved as well as straight paths. A variant which registers the miles and rods traversed is sometimes used by surveyors.