at the NY Worlds Fair in 1939 a 30 minute presentation combined narration, diorama building and stage craft with model railroading to create "Railroads at Work".this model railroad show simulated day and night, with stage lighting effects for dawn, dusk, night and day; and lights on engines, homes lighthouses, etc. that increased luminosity for the "night" operations, O gauge in foreground and "OO" in background arranged so O gauge foreground trains disappered and reappeared in OO in the background. various operations were simulated mechanically, including ferrying loaded cars across real water, and loading coal into outbound freight ships. This must have been amazing to watch,  and it's a crime that it was not preserved to the present.