the boatman who transported souls across the River Styx to the Underworld.

Speculation that a pair of oxen propelled a ship having a water wheel can be found in 4th century Roman literature "Anonymus De Rebus Bellicis". The concept was refined to use horses turning a capstan or a treadmill; this was a precursor to steam to drive paddlewheel boats. These were known as team boats. An example was the