Volvelle
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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
A 15th century volvella of the moon
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.
A volvelle from the sixteenth century edition of the De sphaera mundi by Johannes de Sacrobosco.
Astronomicum Caesareum
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Astronomicum Caesareum is a book by Petrus Apianus first published in 1540.
Volvelle
…A 15th century volvella of the moon 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…
Cover page of the 1540 edition