The only Cornish beam engine anywhere in the world that is still in steam at a tin and copper mine is housed in this small building and restored after 60 years by the 'Greasy Gang' (volunteers of the Trevithick Society). Not so cheerful is the fact that 31 miners died owing to negligence in 1919 when juddering of the man engine was ignored by the owners and it collapsed while bearing the miners up and down!