Locomotive "Onward" of the Portland and Rochester Rly

The Hinkley Locomotive Works of Boston built this oddity as a demonstrator for the Swinerton Locomotive Driving Wheel company in 1887. The one set of drivers featured wheels that were actually 118 sided polygons instead of being round, the idea being that 118 times per revolution there was a two inch long "flat" in contact with the rail for added traction.
As expected it offered no advantage and was soon converted to a regular 4-4-0. More info and a better picture here.
Also more info in an article in Scientific American.
The locomotive, even after being converted had a short life and was scrapped in 1905.