"[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
Volvelles were used to solve problems concerning the calendar, tide tables, the rising and setting of the sun, moon, stars, and the positions of planets. This example consists of two parts - an engraved circle with 31 divisions, into which a separate piece of paper is attached with a red satin ribbon. This inner piece, with a decoratively engraved center, is marked with twelve months, and rotates around the circle. An extremely interesting apparatus, more amazing for the fact that it is still fully functional.