VOLVELLE
Feature
A slide chart of one or more graduated or printed concentric, rotating disks, sometimes pinned to a leaf, and rotated to make a calculation or display information. A modern volvelle, sometimes called a wheel chart, is typically made of paper card stock and may be bound into a book or be an independent, hand-held object. Collectors value both types and consider the latter to be collectable ephemera.
The first image is the recto of a volvelle and displays the route and mileage from Silver Springs, FL to major cities. The second image is the verso and displays the route and mileage from Weeki Wachee Springs, FL to major cities.
The Grolier Club, New York, NY USA, displayed and documented a great variety of volvelles in the exhibition Volvelles: the Magnificent Art of Circular Charting.