A periaktos (plural form periaktoi, from a

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word meaning ''revolving'') is a device used for displaying and rapidly changing

theatre Theatre or theater is a collaborative form of performing art that uses live performers, usually actors or actresses, to present the experience of a real or imagined event before a live audience in a specific place, often a stage. The perform ...

scene Scene (from Greek σκηνή ''skēnḗ'') may refer to: Arts, entertainment, and media Music * Scene (subculture), a youth subculture from the early 2000s characterized by a distinct music and style. Groups and performers * The Scene who reco ...

s. It was first mentioned in

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

's ''Republic'', in the story, "Allegory of a Cave" (c. 375 BCE), but its most intense use began in Renaissance theatre, as a result of the work of important theatrical designers, such as Nicola Sabbatini (1574–1654). It consists of a revolving solid

equilateral In geometry, an equilateral triangle is a triangle in which all three sides have the same length. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each oth ...

triangular

prism Prism usually refers to: * Prism (optics), a transparent optical component with flat surfaces that refract light * Prism (geometry), a kind of polyhedron Prism may also refer to: Science and mathematics * Prism (geology), a type of sedimentary ...

made of

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

. On each of its three faces, a different scene is painted, so that, by quickly revolving the periaktos, another face can appear to the audience. Other solid

polygon In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed ''polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two to ...

s can be used, such as cubes, but triangular prisms offer the best combination of simplicity, speed and number of scenes per device. Periaktos - Deus Ex Machina, 5th century BC (model)

Periaktos - Deus Ex Machina, 5th century BC (model)

A series of periaktoi positioned one after the other along the stage's depth can produce the illusion of a longer scene, composed by its faces as seen in perspective. These periaktoi must therefore be rotated simultaneously to a new position, thus achieving interesting

illusion An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people. Illusions may oc ...

s. This is made by coupling them by using

sprocket A sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a roller chain, chain, Caterpillar track, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial ...

gears at their bases and a

flat chain Flat chain is a form of chain used chiefly in agricultural machinery. Early machinery made extensive use of flat chain. It has been gradually replaced in most applications by roller chain, which is quieter, lasts longer, and requires less frequen ...

or conveyor belt mechanical transmission system. A similar concept is used in some modern

Trivision A Trivision, also called three-message sign, is a billboard/sign that consists of triangular prisms placed inside a frame. The prisms rotate 120°, each showing a new message of advertisement and/or information. As implied, three individual image ...

multi-message billboards, which are made up of a series of triangular prisms arranged so that they can be rotated to present three separate flat display surfaces in succession. Early motion picture mechanical devices, such as the praxinoscope, were also based on rapidly rotating solid polygons, which had the successive animation or photographic plates affixed or projected to each face, thus providing the optical illusion of movement.

External links

Geauga Lyric Theatre Guild's The Sound of Music
Scene by scene breakdown of design, in which the use of periaktoi is illustrated very well.

In: The Development of Scenic Spectacle. This excellent article shows periaktoi inventions by Sabbatini, Furttenbach and Danti, with QuickTime animations and descriptions.
The Praxinoscope

Building Periaktoi, Edward R. Murrow HS
Page showing the process of building Periaktoi for a high school production. History of theatre Scenic design {{theatre-hist-stub

See also

External links