Description

Astrolabe made of brass pertaining to the Mamluk era. It consists of a round body which ends at the top in a pointed shape with a ring (armilla) to hang the instrument, called the "throne" (al Kursi).

The edge of the disk (limb) is marked in degrees and the frame includes numbers pertaining to astronomy. Astrolabe is originally a Greek word, which literally meant "to take the star" or star mirror. 

The astrolabe is a precise astronomical instrument to measure the location of the sun, planets and some stars in the hemisphere. It measures angles, shape, size and height as well as the course of celestial objects around the celestial pole.

The top part of the astrolabe shows round and flat discs made of brass with a metal pointer. These discs are embossed with the names of the houses in the zodiac and stars.

Origin of the Astrolabe

It is difficult to trace the invention of the astrolabe to a particular person, although the first time it is mentioned is in relation to Aristarchus of Samos of the Alexandrian School, who is known to have used an instrument to measure the sky. He is followed by Hipparchus who is considered, by some, the greatest astronomical observer in antiquity.

Astrolabe Uses

The astrolabe is used to solve many astronomical issues. It played a big role in the navigation of military and commercial ships. It was also used to calculate time night and day, while Muslim astronomers used it to determine prayer time, the direction of the Qibla and the eclipses of the sun and the moon.

The Role of Muslim Astronomers in Developing the Astrolabe

The sciences were vigorously pursued in the Islamic world, particularly astronomy and astrology. Muslim scientists developed astrolabes and Mohamed ibn Ibrahim El Farazi was the first to compile a book describing the making and uses of the astrolabe. He is considered the first to have constructed an astrolabe in the Muslim world in the eighth century A.D. (second century Hejira).

Abu Ishaq Ibrahim al-Zarqali (Arzachel) in the eleventh century A.D. developed a 'universal' astrolabe which could be used from anywhere on earth, i.e. it did not depend on the latitude of the user.  He called it "Sahifet Al-Zarqali" and wrote a thesis giving important information on the making and the use of this universal astrolabe. This instrument became known as the "Saphaea" in the European world and was used by both Muslim and Europeans alike. Europeans took the knowledge developed by Muslim astronomers via Andalusia during the twelfth century A.D..

In the fourteenth century, Ahmed ibn al-Sarrag developed an astrolabe which combined all the advantages of previous inventions. There is only one example of this particular astrolabe dating to 1328 A.D. at the Benaki Museum in Athens, Greece.

Sharaf al-Din ibn Mohammed al-Tusi invented the linear astrolabe, which is also called the "staff of al-Tusi", a three-dimensional instead of a two-dimensional observation instrument.

During the fourteenth century A.D., Abu Hassan Alaa ed-Din, also known as Ibn al-Shatir, invented the first astrolabic clock to determine prayer time. It was called "Al-Basseet". He put it in the minaret of the Umayyad Mosque in Damascus, where he worked as the religious time-keeper or 'muwaqqit'.

The legacy of Ibn al-Shatir lies in mathematics and astronomy. His most important works are a book entitled "The Final Quest Concerning the Rectification of Principles" and his "Ta'liq al-Arsad" (Discourse on Observations) which has not survived and "Zij".

The astrolabe was manufactured in Europe at the beginning of the sixteenth century A.D. and its use became prevalent in the Ottoman empire in the early twentieth century only.

• Zahi Hawass, ed., Bibliotheca Alexandrina: The Archaeology Museum (Cairo: The Supreme Council of Antiquities, 2002): 133-134.
• David A King, A Catalogue of Medieval Astronomical Instruments: Parts 1.1-2.3: Islamic Astrolabes 9 to ca . 1550 With Additional 'Old-Style' Astrolabes to ca .1800 (Frankfurt: Johann Wolfgang Goethe University. Institute for the History of Science, 1996): 501-504, online e-book, https://www.researchgate.net/publication/331327474_MEDIEVAL_ASTRONOMICAL_INSTRUMENT_CATALOGUE_ISLAMIC
• Mona Serry, ed., Bibliotheca Alexandrina: Antiquities Museum, introduction by Ismail Serageldin (Alexandria: Bibliotheca Alexandrina. Antiquities Museum, 2015): 227, 329.
• حسن الباشا، موسوعة العمارة والآثار والفنون الإسلامية، مج. 2 (بيروت: أوراق شرقية، 1999): 222.