Object Details
- Description
- 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.
- The brass instrument was made in England, perhaps before 1500, although the sundial scale drawn on the back is of a later date.
- Reference:
- 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.
- John Davis, "Two Medieval English Astrolabes in the Smithsonian Museum," Bulletin of the Scientific Instrument Society, 2023, #157, pp. 2-17. Davis dates this instrument to the second half of the fourteenth century.
- Location
- Currently not on view
- Credit Line
- Gift of Lessing J. Rosenwald
- 1350-1450
- 1400-1600
- ID Number
- MA.318198
- catalog number
- 318198
- accession number
- 232129
- Object Name
- astrolabe
- Physical Description
- brass (overall material)
- Measurements
- 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
- See more items in
- Medicine and Science: Mathematics
- National Museum of American History
- Record ID
- nmah_997134
- GUID (Link to Original Record)
- https://n2t.net/ark:/65665/ng49ca746a5-1c95-704b-e053-15f76fa0b4fa
