French Planispheric Astrolabe
date: label: date made
content: 1584-162?
notes: label: Description
content: 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.
label: Description
content: 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.
label: Description
content: References:
label: Description
content: For a detailed description of this object, see Sharon Gibbs with George Saliba, <a href="https://repository.si.edu/handle/10088/2444"><I>Planispheric Astrolabes from the National Museum of American History</I></a>, Washington, D.C.: Smithsonian Institution Press, 1984, pp. 154-156. The object is referred to in the catalog as CCA No. 2007.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Mathematics
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.322083
label: catalog number
content: 322083
label: accession number
content: 247031
objectType: label: Object Name
content: astrolabe
physicalDescription: label: Physical Description
content: wood, covered with paper (body material)
label: Physical Description
content: brass (handle, body, alidade, index arm, rivet, wing nut material)
label: Physical Description
content: paper (plates, rete material)
label: Measurements
content: overall: 32 cm x 21.2 cm x 4 cm; 12 19/32 in x 8 11/32 in x 1 9/16 in