It is a version of a Babbage Engine from the 19th century.
A simplified version of Charles Babbage's Difference Engine no. 2 has been constructed by Piers Plummer as part of a project with the Computer Science Department at Royal Holloway University of London, funded by The Leverhulme Foundation. In this video, it is performing calculations while being powered by steam!
I just love the looks of it, with all the pipes, valves, and a steam boiler! Even a hand crank!