Astrolabe

Invented in antiquity and refined in various regions of the Islamic world during the medieval period, the astrolabe was used to locate the qibla direction, establish correct prayer times, predict positions of heavenly bodies, and determine horoscopes, among other purposes.[2] The present piece is an extraordinarily well-documented example. Its inscription attributes it to a Rasulid prince of Yemen, ‘Umar ibn Yusuf, and dates it a few years before ‘Umar ascended to the throne under the regnal name al-Ashraf (1295–96). ‘Umar is known to have compiled a number of treatises on subjects related to the sciences, including a text on the construction of astrolabes, sundials, and magnetic compasses.[3] One of the extant manuscripts of this treatise (possibly an autograph version) contains not only illustrations and tables that correspond to this astrolabe but also a certification by ‘Umar’s teachers attesting to his competence as a maker of such devices and describing several of his works, one of which can be identified with this very piece.[4] On the basis of that description and the particular wording at the end of the inscription, it has been proposed that the astrolabe was created by the prince in collaboration with an unnamed metalworker.[5]

In most respects, ‘Umar’s instrument follows the form typical of other astrolabes from the medieval Islamic world. Made of brass, it consists of a rotating rule; an openwork rete, or "star-net," with an ecliptic ring and star pointers; a case, or mater, housing four plates; a rotating sighting bar, or alidade, on the back of the case; and a pin (modern). The back of the case bears the previously mentioned inscription along with several registers of astrological symbols and notations. From the top there protrudes a decoratively pierced suspension bracket of arabesque design attached to two rings. Inscribed around the outer edge of the rete are the names of the twenty-eight lunar mansions. One of the four plates is not original and appears to have been reused from another astrolabe. The others, all original, bear the latitudes for four specific locations in Yemen as well as for Mecca and Medina.[6]

Ellen Kenney in [Ekhtiar, Soucek, Canby, and Haidar 2011]

Footnotes:

2. An explanation of astrolabes and their uses is found in Maddison, Francis, and Emilie Savage-Smith. Science, Tools and Magic. Pt. 1, Body and Spirit, Mapping the Universe. The Nasser D. Khalili Collection of Islamic Art, edited by Julian Raby, vol. 12. [London], 1997, pp. 168–282.

3. Copies of this text survive in Cairo, Tehran, and Berlin (nos. TR 105, MUI 150, and Ahlwardt 5811 [Sprenger 1870], respectively). On the particular interest in astronomy demonstrated in Yemen, see King, David A. Mathematical Astronomy in Medieval Yemen: A Biobibliographical Survey. Catalogs (American Research Center in Egypt), 4. Malibu, 1983.

4. Cairo TR 105. These evaluations are based on ‘Umar’s completion of six astrolabes and two magnetic compasses, as well as other instruments (King, David A. "The Medieval Yemeni Astrolabe in the Metropolitan Museum of Art in New York City." Zeitschrift für Geschichte der arabisch-islamischen Wissenschaften 2 (1985), p. 101; 4 (1987–88), pp. 268–69 [errata].

5. The Museum’s astrolabe is the only instrument that has been securely attributed to this ruler.

6. Aden, Ta‘izz, Sana‘a, and North Yemen (King 1985 [see footnote 4], p. 104).


Astrolabe

This astrolabe was constructed by a Yemeni prince, 'Umar ibn Yusuf, who later became the Rasulid sultan known as al-Ashraf. He was an enthusiastic astronomer and the author of two major works, one on astronomical instruments and the other on astrology. The instrument is the standard planispheric astrolabe type and contains four plates, only three of which are original, and their six sides serve different latitudes in the Yemen and the Hijaz. The fourth plate is from an older Islamic astrolabe and shows markings that reveal that it was used by a Byzantine astronomer. The rete is unusual in that it contains around its outer edge a list of names of the twenty-eight lunar mansions. The sighting device is also unusual because it has a conical tube to facilitate measuring the altitude of stars. The back of the instrument is engraved with astrological information and the planets are referred to by symbols. This instrument is of interest in that it is the only surviving astrolabe that is specifically mentioned in a medieval text: a manuscript in the Egyptian National Library in Cairo of a treatise on the construction and use of the astrolabe written by Sultan al-Ashraf concludes with notes of recommendation by the sultan's teachers describing and recording their approval of no fewer than six astrolabes made by the sultan, one of which is this instrument.

David A. King in [Berlin 1981]


Astrolabe

Astronomy was an important science in Medieval Islam. Muslim scholars translated astronomical treaties into Arabic from most of the languages spoken in the lands conquered by them (Sanskrit, Syriac, Pahlavi, and Greek). In addition to theoretical studies they also developed and built various instruments such as celestial globes and astrolabes, and wrote many treatises about the construction of these instruments. Astrolabes were used to measure the altitude of celestial bodies with the help of a rotating alidade (sighting bar, 'adada in Arabic). From the measurements the user would be able to determine the time of day and night. This astrolabe is similar in general to the astrolabes that were built throughout the Islamic world. It is constructed of several pieces of brass which include the case, the alidade, the net, the plates, and the pin.

This astrolabe was made by al-Ashraf ‘Umar (the son of al-Malik al-Muzaffar Shams al-Din Yusuf, the Rasulid Sultan of Yemen, who was the dedicatee of the brazier MET no. 91.1.540, cat. no. 80 in this volume) who reigned for a very brief time (A.D. 1295–96). The inscription on the back of the object indicates his name and the date: "This astrolabe is the work of ‘Umar ibn Yusuf ibn 'Umar ibn ‘Ali ibn Rasul al-Muzaffari by his own hand and [also] under his supervision in the year 690 (A.D. 1291)." It is known that al-Ashraf ‘Umar also wrote a treatise on the construction of the astrolabe known through a copy which is now preserved in the Egyptian National Library.

Abdallah Kahil in [Walker et al. 1994]

Signature: Made and signed by the Rasulid prince al-Ashraf `Umar ibn Yusuf, later Sultan of Yemen (r. 1295–96)

Inscription: Inscription in Arabic in naskhi script on back of case:

هذا الاصطرلاب عمل عمر بن یوسف بن عمر بن علي بن رسول المظفري مُباشرةً وإملاً سنة ح ٦٩

This astrolabe is the work of ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari directly [by himself] and by his instruction in the year A.H. 690 [1291 A.D.]

Edward C. Moore (American), New York (until d. 1891; bequeathed to MMA)

Berlin. Museum für Islamische Kunst, Pergamonmuseum, Staatliche Museen zu Berlin. "The Arts of Islam. Masterpieces from the M.M.A.," June 15, 1981–August 8, 1981, no. 56.

New York. The Metropolitan Museum of Art. "Renaissance of Islam: Art of the Mamluks," November 21, 1981–January 10, 1982, suppl. #12.

Museum Fünf Kontinente. "3000 Jahre Kunst und Kultur des Gluecklichen Arabien," April 29, 1987–April 5, 1988.

Mexico City. Colegio de San Ildefonso. "Arte Islámico del Museo Metropolitano de Arte de Nueva York," September 30, 1994–January 8, 1995, no. 81.

New York. The Hagop Kevorkian Special Exhibitions Gallery, The Metropolitan Museum of Art. "The Five-Petaled Rosette: Mamluk Art for the Sultans of Yemen," June 22–December 31, 1995, no catalogue.

Paris. Institut du Monde Arabe. "The Golden Age of Islamic Sciences," October 25, 2005–March 19, 2006, no. 26.

"Specimens of Mohammedan Art in the Metropolitan Museum of Art." Metropolitan Museum Studies vol. 1, no. 1 (November 1928). p. 107, ill. fig. 8 (b/w).

"Masterpieces from The Metropolitan Museum of Art New York." In The Arts of Islam. Berlin, 1981. no. 56, pp. 146–47, ill. p. 147 (color).

Metropolitan Museum of Art, Daniel S. Walker, Arturo Ponce Guadián, Sussan Babaie, Stefano Carboni, Aimee Froom, Marie Lukens Swietochowski, Tomoko Masuya, Annie Christine Daskalakis-Matthews, Abdallah Kahil, and Rochelle Kessler. "Colegio de San Ildefonso, Septiembre de 1994–Enero de 1995." In Arte Islámico del Museo Metropolitano de Arte de Nueva York. Mexico City: Consejo Nacional para la Cultura y las Artes, 1994. no. 81, pp. 206–7, ill. (b/w).

L'Age d'Or des Sciences Arabes. Paris: Institut du Monde Arabe, 2005. no. 26, pp. 98–99, ill. (color).

Ekhtiar, Maryam, Priscilla P. Soucek, Sheila R. Canby, and Navina Haidar, ed. Masterpieces from the Department of Islamic Art in The Metropolitan Museum of Art. 1st ed. New York: The Metropolitan Museum of Art, 2011. no. 107, pp. 158–59, ill. p. 158 (color).

King, David A. Islamic Astronomy and Geography. Farnham, England: Ashgate, 2012. p. 156, ill. fig. 9.6.