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. They can be traced back to "certain Arabic treatises on humoral medicine" and to the Persian astronomer, Abu Rayhan Biruni, who made important contributions to the development of the volvelle.

Led Zeppelin III is the third studio album by the English rock band Led Zeppelin, released on 5 October 1970. It was recorded in three locations. Much of the work was done at Headley Grange, a country house, using the Rolling Stones Mobile Studio. Additional sessions were held at Island Studios and Olympic Studios in London. As with the prior album, the band eschewed the use of guest musicians, with all music performed by band members Robert Plant (vocals), Jimmy Page (guitars), John Paul Jones, and John Bonham (drums). The range of instruments played by the band was greatly enhanced on this album, with Jones especially emerging as a talented multi-instrumentalist, playing a wide range of keyboard and stringed instruments, including various synthesizers, mandolin and double bass, in addition to his usual bass guitar. As with prior albums, Page served as producer on the album, with mixing done by Andy Johns and Terry Manning.