I followed the verbal explanation, but I'd have liked a diagram. At one point he was waving around a length of drain-pipe with a tube at one end, but he didn't show how it fitted in with the piston.
I did like the bit about the difference between turbines and windmills, though.
I noticed this, for all the explanation that was given, this item given such reverence he was wearing gloves as he handled it, might just as well have been a bit of the exhaust muffler from his car.
Maybe it was and it was still hot?