Coal Burner, Steam reciprocating engine.

A steam engine is a heat engine that performs mechanical work using steam as its working fluid. In simple terms, the steam engine uses the expansion principle of chemistry, where heat applied to water transforms the water to steam. and then pushes a piston (cylinder). This pushing force is typically transformed, by way of a connecting rod and flywheel, into rotational force for work. The term "steam engine" is generally applied only to reciprocating engines as just described, not to the steam turbine.

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