French Planispheric Astrolabe

French Planispheric Astrolabe

<< >>
Usage conditions apply
Downloads
Description
The astrolabe is an astronomical calculating device used from ancient times into the eighteenth century. Measuring the height of a star using the back of the instrument, and knowing the latitude, one could find the time of night and the position of other stars. The openwork piece on the front, called the rete, is a star map of the northern sky. Pointers on the rete correspond to stars; the outermost circle is the Tropic of Capricorn, and the circle that is off-center represents the zodiac, the apparent annual motion of the sun. Engraved plates that fit below the rete have scales of altitude and azimuth (arc of the horizon) for specific latitudes. This astrolabe has a paper-covered wooden body with brass handle and ring, four paper plates, a paper rete, a brass alidade, a brass index arm, a brass rivet screw, and a brass wing nut. It is signed below the shadow squares on the back: PHILIPUS Danfrieus Siderographus Regius Generalis Lutetiae. The alidade is signed: Franc. Galandius. Finally, it is signed in the upper part of the back: A PARIS Chez Johan Moreau rue St. Jacques à la Croix blanche.
According to Gibbs and Saliba, the date 1584 is that when Philip Danfrie engraved the plates from which paper astrolabes of the style represented by this one were printed. The date 162? Is associated with when Johan Moreau assembled this particular example.
References:
For a detailed description of this object, see Sharon Gibbs with George Saliba, Planispheric Astrolabes from the National Museum of American History, Washington, D.C.: Smithsonian Institution Press, 1984, pp. 154-156. The object is referred to in the catalog as CCA No. 2007.
Location
Currently not on view
Object Name
astrolabe
date made
1584-162?
Physical Description
wood, covered with paper (body material)
brass (handle, body, alidade, index arm, rivet, wing nut material)
paper (plates, rete material)
Measurements
overall: 32 cm x 21.2 cm x 4 cm; 12 19/32 in x 8 11/32 in x 1 9/16 in
ID Number
MA.322083
catalog number
322083
accession number
247031
See more items in
Medicine and Science: Mathematics
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.

Note: Comment submission is temporarily unavailable while we make improvements to the site. We apologize for the interruption. If you have a question relating to the museum's collections, please first check our Collections FAQ. If you require a personal response, please use our Contact page.