Courtesy of the Ronald Reagan Presidential Library Museum, National Archives & Records Administration.
Portuguese Nautical Astrolabe
Artifact ID1985.00488.01a-b
Object Type
Astrolabe
Date
1985
Medium
Metal (brass), Wood
Dimensions7 in. (17.8 cm)
Physical DescriptionAn astrolabe (.01a) is attached to a wood plaque with a brass plate (.01b). The plate is engraved "PORTUGUESE NAUTICAL ASTROLABE DUNDEE Instrument recreated in Portugal in the 15th century, which allows the exploration of the seas by measuring the height of celestial bodies, thus allowing navigation out of sight of any coast. A reproduction of the original, dated 1550, is on display at the Dundee Museum, Scotland. Enatur Posadas de Portugal Lisbon 1985."Historical NoteThis plaque features a brass replica of a Portuguese mariner’s Astrolabe from 1555. Astrolabes allowed for ships to determine latitude by measuring the altitude of the sun at noon or a star at night, and was allowed for navigation in open waters, cloudy conditions, and heavy winds. (Zenith – Altitude) + Declination = Latitude. The astrolabe was an important tool in the golden age of exploration. The original astrolabe was made by Portuguese instrument maker Lopo Honem.
Additional Details
Custodial History NoteThe item was a gift from a member of the general public to President Ronald Reagan during the Reagan administration. It was received through the Executive Office of the President Office of Correspondence and maintained there until its transfer to the National Archives in January, 1989 for deposit with the Reagan Presidential Library.
National Archives Catalog CollectionRecords of the White House Gift Unit (Reagan Administration) (National Archives Identifier 6816362) and
National Archives Catalog SeriesGifts from the General Public (National Archives Identifier 6816363)
Use Restriction StatusUnrestricted
Use Restriction NoteReproduction or other use of these holdings or images thereof is unrestricted.
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