Torquetum
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The torquetum or turquet is a medieval astronomical instrument designed to take and convert measurements made in three sets of coordinates: Horizon, equatorial, and ecliptic. In a sense, the Torquetum is an analog computer.
The first torqueta is thought to have been built by Khajeh Nasir-o-Din Tousi[1] in the 12th century or 13th century,[2] though the only surviving examples date from the 16th century.
A torquetum can be seen in the famous portrait The Ambassadors (1533) by Hans Holbein the Younger. It is placed on the right side of the table, next to and above the elbow of the ambassador clad in a long brown coat or robe. The painting shows much of the details of the inscriptions on the disk and half disk, which make up the top of this particular kind of Torquetum.
[edit] Notes and references
- ^ Lorch, R. P. (1976), “The Astronomical Instruments of Jabir ibn Aflah and the Torquetum”, Centaurus 20 (1): 11-34
- ^ Thorndike, Lynn (1945-10). "Franco de Polonia and the Turquet". Isis 36 (1): 6-7. ISSN 00211753.
[edit] See also
- Astronomical clock
- Antikythera mechanism
- Armillary sphere
- Astrolabe
- Orrery, a free-standing solar system model
- Planetarium
- Prague Orloj
- Celestial sphere
