- Torquetum
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
Jabir ibn Aflah (Geber) [citation|first=R. P.|last=Lorch|title=The Astronomical Instruments of Jabir ibn Aflah and the Torquetum|journal=Centaurus|volume=20|issue=1|year=1976|pages=11–34|doi=10.1111/j.1600-0498.1976.tb00214.x] in the 12th century or 13th century, [Cite journal
issn = 00211753
volume = 36
issue = 1
pages = 6–7
last = Thorndike
first = Lynn
title = Franco de Polonia and the Turquet
journal = Isis
accessdate = 2007-05-29
date = 1945-10
url = http://links.jstor.org/sici?sici=0021-1753%28194510%2936%3A1%3C6%3AFDPATT%3E2.0.CO%3B2-Y
month = Oct
year = 1945
doi = 10.1086/347897] 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.Notes and references
See also
*
Astronomical clock
*Antikythera mechanism
*Armillary sphere
*Astrolabe
*Orrery , a free-standingsolar system model
*Planetarium
*Prague Orloj
*Celestial sphere External links
* [http://www.humboldt.edu/~rap1/EarlySciInstSite/Instruments/Torquetum/Turq.html Instructions for the construction of a Torquetum]
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