Piston Engine is a sketch that appears in "Hamlet," the forty-third episode of Monty Python's Flying Circus.
Synopsis[]
Mrs Robinson and Mrs Non-Robinson have a conversation. Mrs Robinson has bought a piston engine. A woman sitting on a park bench (Eric Idle) listening to The Robinsons chucks the radio away saying it's rubbish, and the doctor in the hospital ward (Graham Chapman) says he wanted to listen to that.
Mrs Gorilla (Michael Palin) joins Mrs Non-Gorilla (Idle) at the park bench, and the two repeat the conversation heard on the radio. Mrs Non-Gorilla shows her the piston engine she bought and the camera pans away to Mrs Non-Smoker (Terry Jones) who is throwing her shopping at birds. Mrs Smoker (Graham Chapman) joins her, and they repeat the conversation on the radio. Mrs Smoker has bought a piston engine, and Mrs Non-Smoker buys it off her for £3. They begin to recite Hamlet lines.