What is the Torelli system and how did it work?

In the seventeenth century, Giacomo Torelli perfected a system for instant set changes. A series of flats along the side of the stage are painted to create a receding perspective. The scenic flats are placed in tracks on the stage and are attached to pole supports that fit through slots on the stage floor. These supports are attached to chariots, a system of interconnected ropes and pulleys below the stage. When the mechanism for running the pulleys is turned, one set of flats slides out and another set with a different design rolls in simultaneously, creating rapid scenic changes.