Planisphere Mobile. au moyen duquel on peut apprendre l’Astronomie seul et sans le secours des Mathemetiques
- Author: [DES-ROIS, Ginot], as “Mlle. Ginot DesRoy”
- Publication place: Paris
- Publisher: chez Bachelier
- Publication date: 1847.
- Physical description: Revolving planisphere, essentially a large volvelle, four moveable discs of engraved paper over pastboard, edges painted green, held together by a brass screw, paste-board pointer. A little toned.
- Dimensions: Diameter: 355mm (14 inches)
- Inventory reference: 15739
In addition to this educational planisphere, a ‘Tableau Uranographique’, ‘Planetaires Heliocentriques et Geocentrques’, Ginot Desroys, or Des- Rois, was the authoress of ‘Jeu des petits voyageurs aux cinq parties du monde, ou Enseignement mutuel de geographie descriptive et historique’, Paris, d’Auty et Desmaisons, Giroux, Bachelier, 1828.
The cartography is based on the planisphere made by the astronomer Alexis Jarrin, the Chief Geometer of the Department of Ain, France. The stars and constellations are given both their Latin and French name. The instrument is comprised of four pieces. At the top and centre is the smallest disc, the “Etoile Solaire”, or North Star; then an elliptical compass window and pointer; which moves across the third disc to reveal the constellations of the night sky at any given date; which in turn can be aligned with the last and largest disc which is marked by the hours of the day or night. Instructions, for this seventh edition of Des-Rois’ planisphere appear on the verso.
Rare: the BnF holds three examples of Des-Rois’ planispheres, dating from 1824.