Their measurements of the distances traveled by Alexander's army show a high degree of accuracy to the point that it had been suggested that they must have used an odometer, although there is no direct mentioning of such a device: The overall accuracy of the bematists' measurements should be apparent.
The minor discrepancies of distance can be adequately explained by slight changes in the tracks of roads during the last 2,300 years.
[2]The table below lists distances of the routes as measured by two of Alexander's bematists, Diognetus and Baeton.
Eratosthenes calculated the circumference of the Earth based on work of Egyptian bematists.
[3][4] Notes: 1) 1 mille passus = 1,480 meters (1,620 yd) 2) 1 Attic stadion = 606 feet 10 inches (184.96 m) 3) The route is not recorded to have been followed by Alexander himself.