Wheeled vertical-boiler stationary steam engine (Steam Fairground)
The piece is a fat-boilered stationary steam engine fitted to a base with four yellow spoked wheels. Although the axles are fixed, the vertical mounting of the cylindrical boiler allows the engine to have quite a short wheelbase, making swivelling axles less necessary. The engine's mechanism is not designed to be able to drive its own wheels, and is instead meant to be towed behind a traction engine.
The engine has a central chimney and a side-mounted piston driving a flywheel protruding form the end of the base, at right angles to its wheels.
The line of the cylindrical boiler extends to below the wheelframe, probably to suggest a large boiler that had to be mounted low to allow top-clearance and keep a low centre of gravity. However, on the model, the lower cylindrical part is hollow and holds the burner.