We just learned about the Connecting Rod.
Another part of a steam locomotive is the Piston Rod.
This is the big straight metal rod that is connected to the piston that goes up and down with the steam and vaccuum.
The piston rod is connected to other metal rods that help turn wheels and make the engine go, but the piston just goes straight back and forth and does not turn around at all.
(from: wikipedia - piston rod)
Kid Facts - Blast from the past: Linear Actuator
