We just learned about the Smokebox at the front of the engine.
Another part of a steam locomotive is the Trailing Wheel.
Back behind all of the other big wheels that move the train is a smaller wheel.
This wheel has an axle bar going under the train that helps make the engine more stable especially where the fireman and engineer are standing.
Because it is not connected to any of the other gears that move the train along, this wheel is very strong and doesn't wiggle around so much.
(from: wikipedia - trailing wheel)
Kid Facts - Blast from the past: Windings