Alī Ibn Khalaf al-Murādī, (11th century) Al-Andalus, was a Mechanical engineer and author of the unique technological manuscript entitled Kitāb al-asrār fī natā'ij al-afkār (The Book of Secrets in the Results of Thoughts). It was copied and used at the court of Alfonso VI of León and Castile in Christian Spain in the 11th century.
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.
In 2008, the Book of Secrets of al-Muradi has been published in facsimile, translated in English/Italian/French/Arabic and in electronic edition with all machines interpreted in 3D, by the Italian study center Leonardo3.
- Technology in the service of progress: The examples of hydraulic technologies, Ahmed Djebbar, Arab-Muslim Civilization in the Mirror of Universal, (UNESCO, 2010), 292, 300.
- David A. King, World-maps for finding the direction and distance to Mecca, (Brill, 1999), 330.
- The Migration of Instrumental Knowledge from Flanders to Spain, Koenraad Van Cleempoel, Silent Messengers: The Circulation of Material Objects of Knowledge in the Early Modern Low Countries, Ed.Sven Dupré and Christoph Herbert Lüthy, (Transaction Publishers, 2011), 76.