Volvelle

File:P.9 a volvella of the moon. A volvella is a moveable device for working out the position of the sun and moon in the zodiac.jpg

A volvella of the moon. A volvella is a moveable device for working out the position of the sun and moon in the zodiac, 15th century

File:Astronomicum Caesareum (1540).f18.jpg

A sixteenth-century wheel chart, a page of Astronomicum Caesareum by Petrus Apianus, 1540, apparently relating to the Moon. The red dragons mark out one odd-sized and 26 equal-sized central divisions; the orbital period of the moon is 27.3 days.

File:Sacrobosco Lunar eclipse.jpg

A volvelle from the sixteenth century edition of the De sphaera mundi by Johannes de Sacrobosco.

A volvelle or wheel chart is a type of slide chart, a paper construction with rotating parts. It is considered an early example of a paper analog computer. Volvelles have been produced to accommodate organization and calculation in many diverse subjects. Early examples of volvelles are found in the pages of astronomy books.

In the twentieth century, the volvelle had many diverse uses. In Reinventing the Wheel, author Jessica Helfand introduces twentieth-century volvelles with this:

The rock band Led Zeppelin employed a volvelle in the sleeve design for the album Led Zeppelin III (1970).

Two games from the game company Infocom included volvelles inside their package as "feelies": Sorcerer (1983) and A Mind Forever Voyaging (1985). Both volvelles served to impede copying of the games, because they contained information needed to play the game.

See also

• E6B
• Ramon Llull
• Planisphere
• Pop-up book
• Slide chart
• Zairja

Further reading

• Eye, No. 41, Vol. 11, edited by John L. Walters, Quantum Publishing, Autumn 2001.
• Lindberg, Sten G. "Mobiles in Books: Volvelles, Inserts, Pyramids, Divinations, and Children's Games". The Private Library, 3rd series 2.2 (1979): 49.
• An exhibition of volvelles at New York's Grolier Club.