(YouTube link)

In 2008, Czech master glassblower Michal Zahradník built a steam engine entirely out of glass! There are no seals here, just snug-fitting glass. This is a replica of an early locomotive steam engine designed by George and/or Robert Stephenson. If you're anything like me, you will watch this entire video waiting for something to blow up or break (which happened often, according to the video description). -via the Presurfer