"[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
This unusual device was used to solve problems concerning the calendar, tide tables, the rising and setting of the sun, moon, or stars, and the positions of planets. It consists of a separate movable paper disc, engraved to represent the horizon and the movement of the earth and sun throughout the day and night. These were included in scientific books and atlases and because of their delicate nature most have not survived in tact.
This example has had its ribbon neatly replaced.