chariot-and-pole method

The chariot-and-pole method was a stage machinery technique used in theater to shift scenery. Developed by Giacomo Torelli in the 17th century, it mechanized the groove system, allowing a single operator to change all the stage wings simultaneously. Flat scenery pieces were connected by poles running through slots in the stage floor to "chariots" on rails. A reverse movement of these chariots would pull the scenery offstage. This system remained a standard in Western theater until the late 19th century.1

The term "deus ex machina" originates from ancient Greek and Roman theater, referring to a crane used to lower a god onto the stage to resolve the plot. This device was employed by playwrights like Euripides. In modern usage, it describes an improbable event or character that suddenly resolves a seemingly unsolvable problem in a story.2