Suhayl. Journal for the History of the Exact and Natural Sciences in Islamic Civilisation

al-Ashraf ̔Umar’s Tabṣira, Chapter xxiii: Timekeeping at Night by the Moon in 13th-Century Yemen and Beyond

Razieh S. Mousavi — 2023-12-05

This article explores methods for determining moonrise and moonset as evidenced within a range of pre- and early modern sources originating from Islamicate societies. The idea emerged during a workshop in July 2022 where a talk by the first author on Ibn Waḥshiyya’s moonrise-moonset text in his al-Filāḥa al-Nabaṭiyya («The book of Nabatean agriculture») and the second author’s project on the Kitāb al-Tabṣira fī ̔ilm al-nujūm («Book of enlightenment in the science of the stars») by al-Ashraf ̔Umar revealed overlaps. Given the resemblances observed in the two sources, chapter xxiii of Tabṣira has been selected as the initial reference point for tracing the technique across additional sources. It is important to note that this examination does not assert comprehensiveness, nor does it account for the reciprocal interdependencies among the examples presented. Nevertheless, the present article suggests a categorisation of the diverse methods predicated on various factors such as exactitude, complexity, state of completeness, literary formats, and audience.

The Tanbīh al-anām ̔alā mā yaḥduthu fī ayyām al- ̔ām (Warning to humanity about what happens during the days of the year) by ̔Abdu ̓ l-Raḥmān al-Jādirī (777/1375–818/1416)

Emilia Calvo — 2023-12-05

The article studies, translates, and edits a calendar entitled Tanbīh al-anām ̔ala mā yaḥduthu fī ayyām al- ̔ām (Warning to humanity about what happens during the days of the year), written by al-Jādirī (777/1375-ca. 818/1416). The author is a well-known muwaqqit who worked in Fes. The book was written at the request of an unknown scholar who asked al-Jādirī to adapt to the latitude of Fes a calendar written by the mathematician and astronomer Ibn al-Bannā ̓ (654/1256–721/1321) for the latitude of Marrakesh. Al-Jādirī calls this calendar Taqyīd fī l-shuhūr al- ̔ajamīya wa-mā yaḥduthu fī-hā. Even though there is no known reference to this Taqyīd in the bibliography about Ibn al- Bannā ̓, al-Jādirī’s Tanbīh most closely resembles his Risāla fī l-anwā ̓. This latter work was strongly in uenced by the well-known Kitāb al-anwā ̓ written by ̔Arīb b. Sa ̔īd (d. 370/980–981). Al-Jādirī knew ̔Arīb’s work and probably employed it in order to complete the calendar written by Ibn al-Bannā ̓, to which he added materials borrowed from other sources. This represents thus a revival of the Andalusi tradition of calendars and treatises about Arabic folk astronomy in the early 9th/15th century.

Sources of the Planetary Theories in Fahhād’s ̔Alā ̓ī zīj: Solving a Medieval Case of Intellectual Fraud

S. Mohammad Mozaffari — 2023-12-05

According to the anonymous 13th-century Shāmil zīj, Abu ̓l-wafā ̓ al- Būzjānī’s (10 June 940–after 25 May 997) planetary theories were adopted in Ibn al- Fahhād’s 12th-century ̔Alā ̓ī zīj without acknowledgement. This puzzling case of plagiarism, noted by the late Prof. E. S. Kennedy in 1956, is solved by means of a graphical approach, together with some astronomical analysis, in order to (A) visualize the perplexing network of the development of planetary theories in medieval Islam and (B) distinguish the types of relations existing between them. The paper describes the new strategies invented in the Islamic period to modify the available planetary theories in order to reconcile them with the observations, called istidrāk and i ̔tibār, which were different from the standard methods set forth in the Almagest. The accusations of fraud are shown to be unfounded. It is shown that Ibn al-Fahhād’s solar and lunar theories and his precessional rate of 1°/66y are taken from the Mumtaḥan tradition; his theories of Jupiter and Saturn were the results of his modifications of ̔Abd al-Raḥmān al-Khāzinī’s corresponding theories in the Mu ̔tabar zīj (1121 ce) on the basis of the results he achieved from his observations; his theory of Mars was constructed on the basis of his observations, independent of any other available theory; and his theory of Venus is taken directly and faithfully from Khāzinī.

Sonja Brentjes (ed.), Peter Barker (associate ed.) & Rana Brentjes (assistant ed.), Routledge Handbook on the Sciences in Islamicate Societies

Samsó Julio — 2023-12-05

Sonja Brentjes (ed.), Peter Barker (associate ed.) & Rana Brentjes (assistant ed.), Routledge Handbook on the Sciences in Islamicate Societies. Practices from the 2nd/8th to the 13th/19th Centuries, London & New York: Routledge, 2022 (XXXVII + 837 pp.)

Lola Ferre, Isaac Israeli’s The Definition of Fever and Its Essence in Its Hebrew Translations / Pauline Koetschet, Abū Bakr al-Rāzī, Doutes sur Galien / Sergi Grau Torras, Les transformacions d’Aristòtil. Filosofia natural i medicina a Montpeller

Miquel Forcada — 2023-12-05

Lola Ferre (with the collaboration of Esther Boucher and Basem Mahmud), Isaac Israeli’s The Definition of Fever and Its Essence in Its Hebrew Translations (Accompanied by Arabic, Latin and Old Spanish Editions and English translation), Philadelphia: American Philosophical Society Press, 2023, (256 pp.) (Transactions of the American Philosophical Society, volume 111, Part 5).

Pauline Koetschet, Abū Bakr al-Rāzī, Doutes sur Galien. Introduction, édition et traduction, Berlin, Boston: De Gruyter, 2019, (cxxxviii + 347 pp.) (Scientia Graeco-Arabica Band 27, herausgegeben von Marwan Rashed).

Sergi Grau Torras, Les transformacions d’Aristòtil. Filoso a natural i medicina a Montpeller: el cas d’Arnau de Vilanova (c. 1240-1311), Barcelona: Institut d’Estudis Catalans - Fundació Noguera, 2020, (267 pp.) (Treballs de la Secció de Filoso a i Ciències Socials 50).