Abstract
When British engineer George Stephenson laid a railway between Stockton and Darlington in 1825, he adopted 4 feet and 8.5 inches (1,435mm) as the inner distance between the two rails of the track. It is clear that the value became a world's standard gauge of a railway afterwards. However, few people have interests of its origin. Authors thought that the origin of the standard gauge of the railway might result from an interval of wheel ruts of prehistoric ancient carriages. The authors did fieldwork for a long time to prove this supposition at the ruin of Eurasia, Mediterranean zone and African Continent, also in some museums. In those areas, intervals between wheel ruts which were carved on a street of ancient city were measured, and tread of carriages of traditionally practical use were measured. Moreover, authors investigated some literatures on chariots or wagons excavated from tumulus. As a result, it was proved that a hypothesis of authors' was approximately right.
