"[Volvelle]", Galluci, Giovanni Paolo
Subject: Cartographic Miscellany
Period: 1657 (published)
Publication: Theatro del Mundo ye del tiempo Granada
Color: Black & White
7 x 10 inches
17.8 x 25.4 cm
A fascinating and fully functional volvelle. This was used for finding the position of the moon in the zodiac, given the position of the sun and the age of the moon. There is an engraved circle with 31 divisions, into which a separate piece of paper is attached with a red satin ribbon. This inner piece is marked with the twelve signs of the Zodiac, and rotates around the circle.
The ribbon is original, and it is still fully functional after 350 years!