Astrolabe with Geared Calendar, by Muhammad b. Abi Bakr, Isfahan, 1221/2

Object is on display.

Inventory Number:

48213

Object Type:

Object

Persons:

Muhammad b. AbiBakr

Date Created:

Dated A.H. 618 (1221/2 CE)

Place Created:

Isfahan Iran/Persia Asia

Subject Classification(s):

Astrolabes

Accession Number:

1924-0/part

Brief Description:

This Persian astrolabe contains the world's oldest, mechanical device still in working order. It was made made in Isfahan in 1221-2 CE by Muhammad bin Abi Bakr. The front of this instrument is a regular astrolabe, with the only difference being the alidade that instead of being at the back, it is integrated to the rete on the front. The back of the instrument contains a mechanical calendar. The centre of the instrument is hollow and it ccomodates a gear train consisting of four double cogs that drive the three calendrical diagrams on the back of the instrument. The circular window at the top of the instrument represents the phases of the moon by showing a silvery disc increasing and decreasing. To the right, a rectangular windown shows a lunar calendar with the age of the moon. At the bottom of the instrument, there sit two concentric rings representing the relative positions of the sun (through a gold dot labelled جرم الشمس “the body of the sun”) and the moon (through a silver dot labelled جرم القمر “the body of the moon”) against the zodiac ring engraved around the edge of the window. The central cog features a square socket for a, now lost, pin that would have had a round top part, in order for the rete to rotate at the front, and a square bottom part, to set the entire mechanism into motion. The famous Persian scientist al-Biruni ,who lived in about CE 1,000s, describes a similar geared mechanism to the one made by Muhammad ibn Abi Bakr.

Primary Inscriptions:

صنعة محمد بن أبي بكر بن محمد الراشدي اﻹبري اﻹصفهاني. "Made by Muhammad b. Abi Bakr b. Muhammad al-Rashidi al-Ibari [or al-Abiri] al-Isfahani". Engraved in the middle of the back. فلك يُرِيْكَ به هلالا طالعا متزيدا ويعود في نقصان ويريك جرمَ النيرين كليهما يتقابلان به ويجتمعان ويريك مبلغ سير كل منهما في العام أو الشهر أو في الآنَ نَتَجَتْهُ همةُ عالِـمٍ بصنائع بنيت على التحقيق والبرهان انظر إلى فلك يريك عجائبا فيه تبيين حكمة الرحمن حركاته شتى بفرد محرك وله معاني فوق كل معاني في سنة خيح هجرية. "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." Engraved around the rim of the back. زيادة نور القمر ونقصانه. "Increase and decrease of the light of the moon." Engraved around the top circular window. عدد أيام الشهر. "Number of the days of the month." Engraved around the top square window. جرما النيرين يجتمعان يوم الاجتماع ويتقابلا يوم الاستقبال. "Sun and moon meet on the day of conjunction and they face each other on the day of opposition." Engraved in the middle of the concentric rings on the bottom. صاحب الفقير حسن شاه. "Its owner is the poor man Hasan Shah". Engraved on one of the internal cogs.

Provenance:

Presented by Lewis Evans in 1924. Recorded by Lewis Evans as 'Bought from Heilbronner Paris 1913'

Collection Group:

Lewis Evans Collection

Material(s):

Cu alloy
Silvered Cu alloy
Silver
wax

Dimensions: