This is a typical late unsigned miniature brass Maghribi astrolabe, made with remarkable competence. The throne is large with three lobes on each side and is without engraving. The scale on the rim is divided and labelled for each 10°, subdivided for each 2°. The rete is in the simplest Maghribi tradition, with the horizontal bar counter-changed twice on each side, and the short equatorial bar supported by two dummy pointers attached to its ends. The one on the right could serve – as it does on other Andalusi and Maghribi astrolabes – qalb al-asad, Regulus, whose advanced position on the ecliptic confirms the late date of the piece. There are four knobs to rotate the rete over the appropriate plate for the user’s latitude.
There are 6+5+6+5 = 22 named pointers serving the following stars:
batn qaytus / ghul / dabaran / qadam jawza’ / ‘ayyuq / mankib // ‘abur / ghumaysa’ / dubb / shuja’ / ghurab // a’zal / ramih / fakka (broken at base) / al-hayya/ qalb al-‘aqrab / al-hawwa // w[a]qi’ / ta’ir / dulfin /mankib / dhanab qaytus
The three plates bear altitudes for each 6° and azimuths for each 10°, some with markings for midday, the zuhr prayer after midday, and the ‘asr prayer in the mid-afternoon (m, z and a) accentuated. They are arranged as follows:
25° Medina m
30° Cairo mza
32° Marrakesh mza
33° Salé m
34° Meknes mza
36° Tunis ma
It is curious that Mecca is not represented, not least because the markings for Cairo are superfluous. On the plate for Meknes, the curves for the twilight prayers – ‘isha’ and fajr – have been crudely scratched; this indicates that somebody used the astrolabe in that city.
The back bears two altitude scales divided and labelled for each 10°, subdivided for each 2°. The same divisions serve each 10° of the zodiacal signs, and inside these is a separate scale for the days of the solar months with their traditional Western Arabic names. The days are labelled 10 - 20 - n, where n is the number of days in the month. With these scales, which are common on Western Islamic astrolabes, one can find the solar longitude for any day of the solar year. The equinox is at March 9, which alas cannot be used to date the instrument. Inside these solar - calendrical scales and below the horizontal axis is a double shadow square with values 2-4-...-12 properly labelled mabsut for horizontal shadows and mankus for vertical ones. The alidade is missing.
In short, this a carefully made little astrolabe which well indicates the continued interest in astronomy and continued technical competence in the Maghrib around 1800.
For a history of astronomy in the Maghrib see D.A. King, 'On the History of Astronomy in the Medieval Maghrib', in Études d’Histoire des Sciences Arabes, Mohammed Abattouy, (ed.), Casablanca, 2007, pp.175-218.
For an ordered list of late Maghribi astrolabes see D.A. King, In Synchrony with the Heavens- Studies in Astronomical Timekeeping and Instrumentation in Medieval Islamic Civilization, vol. 1: The Call of the Muezzin (Studies II, pp. 1010-12 and 1014-15), Leiden, E..J. Brill, 2004-05.