I spent far more time than I should have done watching a steam-powered wood splitting device that was basically a large wheel with an axe head on it. Same principle as most of these, it relied on the person feeding it to have a good sense of rhythm. I saw it at a local show featuring agricultural machines at a small village in Finland, Sadly, I didn't take any pictures of it. It looked absolutely lethal, one false move and you'd lose half an arm.