When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Museum worthy piece: A Movable Planisphere of the Heavens at Every Minute by Henry Whitall, Philadelphia: 1869
Hand-colored circular planisphere
Printed paper on cardboard, each with a central turning disk, some varnished
15 inches diameter
Round planisphere inside the paper shows the constellations as mythological figures in full color. A planisphere is a portable device designed to aid in the study of stars and constellations visible in the night sky at any given date and time, generally for a particular locale. It consists of an outer rotating card with cutouts set against an inner hemispheric celestial map. The disk is rotated to match up the hour and minute of the day and compass points to printed data of day and month on the edge of the inner map, revealing the visible constellations within the cutout area. The disk is sometimes referred to by the antiquated word volvelle, used to describe rotating disks on various calculating devices.
