See Abu Jafar al-Muradi for the Egyptian grammarian.
Al-Muradí portrait.
Fragment of The Book of Secrets in the Results of Thoughts. 11th century

Alī Ibn Khalaf al-Murādī, (أبو جعفر علي ابن خلف المرادي; 11th century) was an Andalusian mathematician and astronomer who belonged to the scientific circle of Ṣāʿid al- Andalusī.[1]

He was the author of the technological manuscript entitled Kitāb al-asrār fī natā'ij al-afkār (Arabic: كتاب الأسرار في نتائج الأفكار, The Book of Secrets in the Results of Thoughts or The Book of Secrets in the Results of Ideas).[2] It was copied and used at the court of Alfonso VI of León and Castile in Christian Spain in the 11th century.[citation needed]

The manuscript provides information about a "Castle and Gazelle Clock" and many other forms of complicated clocks and ingenious devices. Al-Muradi was a contemporary of Abū Ishāq Ibrāhīm al-Zarqālī.[citation needed]

In 2008, the Book of Secrets of al-Muradi has been published in facsimile, translated in English/Italian/French/Arabic and in an electronic edition with all machines interpreted in 3D, by the Italian study center Leonardo3.

He also devised, with help from al-Zarqali, the universal astrolabe.[3] Both al-Muradi and al-Zarqali's design were included in the Libros del Saber (1227) of Alfonso X of Castile.[4]


  1. ^ Calvo, Emilia (22 September 2017). "Some Features of the Old Castilian Alfonsine Translation of ʿAlī Ibn Khalaf's Treatise on the Lámina Universal". Medieval Encounters. 23 (1–5): 106–123. doi:10.1163/15700674-12342244.
  2. ^ Ahmed Djebbar, "Technology in the service of progress: The examples of hydraulic technologies," in Civilization in the Mirror of Universal[permanent dead link], UNESCO, 2010, p. 292-304.
  3. ^ David A. King, World-maps for finding the direction and distance to Mecca, (Brill, 1999), 330.
  4. ^ Koenraad Van Cleempoel. "The Migration of Instrumental Knowledge from Flanders to Spain," in: Silent Messengers: The Circulation of Material Objects of Knowledge in the Early Modern Low Countries, Sven Dupré and Christoph Herbert Lüthy (eds.), (Transaction Publishers, 2011), p. 76.