Word of Greek origin meaning "road measurement." The instrument is used to measure the distance traveled by a vehicle. Described by Vitruvius in De architectura (1st C. B.C.E.) and later by Hero of Alexandria (1st C. C.E.). In the Renaissance, different types of odometers were designed by Leon Battista Alberti (1404-1472) and Leonardo da Vinci (1452-1519), among others. Consists of a revolution counter attached to a wheel dragged by hand or fastened to a horse or vehicle. The distance traveled was obtained by multiplying the circumference of the wheel by the number of revolutions.
Word of Greek origin meaning "foot measurement." The podometer typically consists of a wheel with a pace-counting device. In other words, it measures the distance traveled on foot. The podometer wheel could be tied to a walker's ankle (model still in use), or dragged at the end of a stick. At every revolution of the wheel, whose circumference was equal to the length of a standard step, a gear mechanism shifted the pointer on the counting disk.