The Little Engineer (1915)

While Hastings, the engineer of Freight No. 3205 is at lunch- in the Lone Point station, Bobby Heywood, the son of an engineer, climbs into the cab of the engine. Having frequently observed his father start his locomotive, Bobby jerks the throttle open. Helen sees the freight speeding down the track. Remembering that Bobby has been playing about the station, the girl surmises what has occurred.