English Planispheric Astrolabe
date: label: date made
content: 1350-1450
label: date made
content: 1400-1600
notes: label: Description
content: The astrolabe is an astronomical calculating device used from ancient times into the eighteenth century. The openwork piece on the front, called the rete, is a star map of the northern sky. Pointers on the rete correspond to stars – on this “zoomorphic” instrument they are in the shape of animal tongues. The outermost circle is the Tropic of Capricorn, and the circle that is off-center represents the zodiac, that is to say the apparent annual motion of the sun. On the brass instrument, the scales below the rete are for a latitude of 52 degrees (there are no separate plates). Measuring the height of a star using the sighting device on the front, one could set the map to find the time of night and the position of other stars.
label: Description
content: The brass instrument was made in England, perhaps before 1500, although the sundial scale drawn on the back is of a later date.
label: Description
content: Reference:
label: Description
content: 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.15, 23, 45-47, 153-154. The object is referred to in the catalog as CCA No. 2006.
label: Description
content: John Davis, "Two Medieval English Astrolabes in the Smithsonian Museum," <I>Bulletin of the Scientific Instrument Society</I>, 2023, #157, pp. 2-17. Davis dates this instrument to the second half of the fourteenth century.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Mathematics
creditLine: label: Credit Line
content: Gift of Lessing J. Rosenwald
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.318198
label: catalog number
content: 318198
label: accession number
content: 232129
objectType: label: Object Name
content: astrolabe
physicalDescription: label: Physical Description
content: brass (overall material)
label: Measurements
content: overall: 17.9 cm x 12.9 cm x 1.1 cm; 7 1/16 in x 5 3/32 in x 7/16 in