Geared astrolabe inscription
The circular inscription around the back of the astrolabe not only describes what the face does technically but also provides a theological resonance:
"This is an astrolabic disc, which can show you: a crescent moon, which progressively waxes and then returns to its waning phase; the celestial bodies of the sun and moon, when they are in opposition or in conjunction; and the points on their paths in a given year or month or at this moment. This disc is the product of the endeavour of someone learned in the technical arts, which are based on precision and scientific proof. Behold the disc! It will show you many of the wonders that prove the wisdom of the Merciful; its different motions are by virtue of a single mover, and it has meanings going beyond all meanings. Made in 618 AH (1221/2 AD)."
Inside the sun and moon rings the text says "The celestial bodies of the sun and the moon lie next to each other on the day of conjunction, and they lie opposite to each other on the day of opposition."
The two rings themselves are marked:
(1) The body of the moon (Jirm al-Qamar)
(2) The body of the sun (Jirm al-Shams)
On the moon ring is an additional dot which may have been for a handle. Beside it is written 'body' (Jirm; without the dot), apparently engraved later and done either as an emphasis or simply to indicate that this ring holds the handle.
Translations and comments by Dr Afifi al-Akiti, Autumn 2010.
- Relationship between astrolabe and calendar
- Astronomical mechanisms
- Oldest in the world
- Special Exhibition Label: 'Al-Mizan: Sciences and Arts in the Islamic World' (26/10/2010 - 20/03/2011)
- Inventory no. 48213 - Former Display Label
- Exhibition Label - 'The Moon'; National Maritime Museum, 19 July 2019 - 5 January 2020