A remarkable early-18th -Century Maghribi astrolabe made for a pilgrim to take to the Holy Cities of Mecca and Medina,
brass, with some silver -- 165mm. (6½in.) diameter; 6mm. (¼in.) thick
International Instrument Checklist no. 4300
See Back Cover and Illustrations
This previously undocumented astrolabe is at first sight a typical late Maghribi piece, with the rete or star-map in a standard Maghribi design, the star-names in the Maghribi-Andalusi tradition, a few plates for various latitudes, and a solar-calendrical scale in the Western Islamic tradition. However, closer inspection reveals a host of features that make this astrolabe unique amongst surviving Islamic instruments. The astrolabe is competently made.
First, the form of the star-pointers is unusual, as is the pair of elegant mauresque frames at the bottom of the rete. Second, the buttons on the star-pointers on the rete and the knobs on each side of its horizontal diameter are decorated with silver. Third, the piece is signed and dated, whereas most late Maghribi astrolabes are neither signed nor dated. Fourth, not only has one of the plates been constructed for the wrong latitude, but the maker has used a very unusual construction technique that is otherwise attested only in a text and on one other known astrolabe, both from medieval Christian Spain. Fifth, the most remarkable feature: the localities whose latitudes are served by the geographical plates represent a string of localities between Fez and the Holy Cities of Mecca and Medina. Whilst this is not in itself unusual, in this case, these localities are further identified in an inscription on the mater of the astrolabe under the plates, with their longitudes engraved.
The inscription on the back of the throne identifies the maker and date. It translates: "Praise be to God alone. (The) maker of (this astrolabe) is Ahmad [?? ??] al-Sharafi al-'Alami al-Maghribi in the year 1121 (Hijra). If the name of Ahmad's father is "'Ali" then the word "ibn" for "son of" is improperly engraved. An Ahmad ibn 'Ali al-Sharafi is known to us as the maker of an astrolabe dated 729 Hijra [= 1328/29] that is now in the Statens Sjvhistoriska Museum in Stockholm, but these three components are very common in Maghribi names. Otherwise the name could be read as "Ahmad ibn A'lam". The name A'lam would be most unusual but credible (there was an astronomer in 10th-century Baghdad named Ibn al-A'lam). The epithet al-'Alami is an attested Maghribi name, and there is a later Maghribi astronomer with the name 'Abd al-Salbm ibn Muhammad ibn Ahmad al-'Alamn (King, Survey of the Scientific Manuscripts in the Egyptian National Library, 1986, no. F62). The Egyptian polymath al-Suyûtî (ca. 1500) in his book on such names (al-Lubâb fî tahrîr al-ansâb, 1840 edn., p. 181) states that the epithet represents the name of an ancestor named 'Alam. In this case, perhaps "al-'Alamî" is derived from "al-A'lamî", which is linguistically feasible. On the other hand, the double epithet "al-Sharafn al-'Alamî" also relates to the descendants of the Moroccan saint and mystic 'Abd al-Salâm ibn Mashîsh (ca. 1200), who is buried in Mount al-'Alam near Tetuan (Encyclopedia of Islam, article "al-'Alamî").
The date, in Hindu-Arabic numerals, corresponds to 1709/10. All other numbers on the astrolabe, including the geographical data recorded below, are in standard Maghribi alphanumerical (abjad) notation.
The scale of the ecliptic is divided for each 6° of each of the named signs of the Zodiac. The star-pointers serve the following 25 (6+6+6+7) stars, here listed counterclockwise in the four quadrants starting at the vernal equinox on the left hand side:
batn qaytûs (ra's) al-ghûl al-dabarân qadam al-jawzâ 'ayyûq mankib al-jawzâ //al-'abûr al-ghumaysâ rijl al-dubb shujâ' qalb al-asad [al-ghurâb] (mislabelled al-a'zal) //al-a'zal râmih fakka al-hayya qalb al-'aqrab ra's al-hawwâ //wâqi' dhanab al-jady al-nasr al-tâ'ir al-dulfnn ridf mankib al-faras dhanab qaytûs
The selection of stars and their names are standard for a Maghribi astrolabe.
On seven out of the eight sides of the four plates there are standard astrolabic markings of the same kind, with altitude circles for each 6° and azimuth circles for each 10°. The altitude circles are numbered in typical Maghribi fashion. There are no curves for the prayers after midday and at midafternoon, such as are usually found on Andalusi and Maghribi astrolabes. The latitudes are stated 1a: 21° - Mecca 1b: 25° - Medina / 2a: 30° - Cairo / 3a: 31° - Alexandria 3b: 37° - Tunis / 4a: 33° 40' - Fez 4b: 36° - Tripoli. On one plate (2b) the markings are different. There are unlabelled altitude circles for each 6° and azimuth circles for each 5° rather than each 10° . However, these were not constructed using the standard procedure, but rather an approximate method outlined in a 13th-century Spanish Latin text on astrolabe construction. Only one other astrolabe with plates constructed using this procedure has come to our attention: the 14th-century Spanish astrolabe with inscriptions in Hebrew, Latin and Arabic that passed through these rooms on 15.04.1999. The latitude served by this plate is 41° , although it is written 41° 41', and it does not serve the locality for which it was intended, Constantine on the Algerian littoral, but rather Constantinople. The two localities have similar names in Arabic: Qusuntiniyya and Qustantiniyya, respectively, but this is a very curious error for a Maghribi craftsman to have made. See further below.
The back of the astrolabe bears markings typical of a Maghribi astrolabe: two altitude scales, a pair of solar and calendrical scales, a double universal horary quadrant and a double shadow square. The semi-circles crossing the curves of the horary quadrants are purely decorative. The equinox on the calendrical scale is at March 8, which is in order for the Julian calendar. The alidade and pin are original.
The inscription on the mater, unique of its kind, presents the names and longitudes of 10 localities, to which the latitudes represented on the plates have been added:
Locality Longitude Latitude
1) Constantine 37° 30' 41° 41' (!!)
2) Kairouan 40° -
3) Tunis 41° 45' 37°
4) Tripoli 42° 36°
5) Gabes 41° 30' -
6) Medina 76° 30' 25°
7) Mecca 77° 21°
8) Cairo 64° 30' 30°
9) Alexandria 61° 15' 31°
10) Fez 25° 33° 40'
This set of values does not correspond to any known collection of values in any medieval Islamic astronomical or geographical work, although resemblances are found here and there to other relevant tables of Maghribi inspiration. Preliminary investigations have relied on E. S. Kennedy and M.-H. Kennedy, Geographical Coordinates of Localities from Islamic Sources, Frankfurt, 1987, but these are not helped by the fact that the longitudes have been rounded to the nearest quarter degree and the latitudes, but for that of Fez, to the nearest whole degree. (The only other known astrolabe on which a longitude is noted is that made in Barcelona in 1375 by Petrus Raimundus, now in the Museum of Fine Arts in Boston.) The most secure coordinate here is the longitude of Fez, in the sense that it is attested in some medieval Maghribi geographical tables, and, not least since it is out of order in the list, perhaps Fez was the "starting point" of the engraver. The distinctive latitude of Fez appears for the first time on the astrolabes of the prolific Abû Bakr ibn Yûsuf of Marrakesh, dating from the beginning of the 13th century, and it is known that several determinations of latitudes (and the associated obliquity of the ecliptic) were made in the Maghrib in the 12th century. The object of the list is to present longitudes between Fez and the holy cities of Mecca and Medina, which would be of some use to a pilgrim. This list merits detailed investigation. The purpose of the list would have been to enable the calculation of the approximate distances between the localities or to provide the basic information to calculate the qibla or direction of Mecca in any of the intermediate stations, each operation being fully within the abilities of any medieval astronomer, but neither could not have been achieved using the astrolabe alone.