Assertion: steam engine's piston | /r/HasProperty | operated by the second
Facets:
value: by the lower-pressure steam
type: OTHER
Source sentences:
text: In a simple steam engine, expansion of the steam takes place in only one cylinder, whereas in the compound engine there are two or more cylinders of increasing size for greater expansion of the steam and higher efficiency; the first and smallest piston is operated by the initial high-pressure steam and the second by the lower-pressure steam exhausted from the first.