No, it's not the title of a fanciful novel; it's a real thing, a sort of 3-D Wankel engine and if the site describing it didn't have a cutaway animation, I would still be puzzling over the drawings. How about 2.5 bhp at 500 RPM from a four-inch sphere? Inside, two quarter-spheres and a disc, assembled in a sort of universal joint and driven by steam -- we should not be surprised that the same man who conceived it was the first to puzzle out hydrodynamic lubrication (and not the hard way like most of us did, on bad tires in the rain).
Long ago, these little engines were used (per my sources, especially on British merchant ships) to spin dynamos, since they didn't need gearing. Turbines eventually took over that job, leaving Beauchamp Tower's fascinating engine an historical footnote. But what a footnote!
Another link, good in August, 2010: External view and description.