I was listening to Ajahn @sujato teaching the Samannaphala Sutta while I was at work. This teaching was broken up into several separate recordings, as the group he was teaching was given an account of each version that exists at the moment. During one talk, the subject of King Ajatasatu’s military innovations, specifically a mechanized chariot with spinning blades on its axles, was briefly mentioned by the venerable after he consulted Wikipedia. The claim of this invention did not cite a reference, however.
So, today, I came across this article, which mentions this very same innovation, as well as something quite amazing for the time period: robots and androids!