Quote Originally Posted by drone
They did a show on the US History Channel about ancient inventions. They showed a cart that geared the cart's wheels to a rotating dial on the top. The dial would spin slowly, and at a known interval, drop a marble placed around the dial. By reloading the marbles, then counting the marbles at the destination, the distance was known. Basically an ancient odometer. Can't remember if this was greek or roman, but it could be used to measure roads quite accurately.
Interestingly it wasn't really used for official roaddistancing (if such a word exists), it was merely a taximeter.
But then again the first steamengine was only a spinning device (also invented around that time).