It's a $39.95 kit you can buy only on late night TV,
(Not available in stores.)
Good catch. I missed it and usually finding stupid statements is my specialty. These guys are archaeologists aka glorified ditch digger and don't know beans about engineering technology.
Very poor wording.
The steam isn't burned, he's refering to a regular steam engine that uses external combustion to heat water to steam, then uses the expansion to drive pistons on a crankshaft.
He should have used either steam engine or external combustion steam engine.