- Early scenic devices of the Greek and Roman theater, probablyconsisting of painted prisms that were rotated to indicate a changeof scene. Each of the surfaces bore a traditional image to suggesta location, such as waves, trees, or the column of a building. Theyalso helped to project sound from the stage.
When details of the periaktoi were discovered in thewritings of the Roman Marcus Vitruvius Pollio (70 - 15 BC),architects of the Renaissance theater adopted and improved the devicesunder the name of telari. Removable canvas panels were introducedfor the prism faces.