Cod.: paper, I+138+II^a ff. (foliated with Arabic-European numerals in pencil mostly in the upper left corner of rectos, repeating ‘94’ and with an unnumbered folio after ‘116’; catchwords, often invisible due to damage or restorations). First lines of the first page in a different naskh hand than the scribe’s, probably due to the later restoration of that page. A single naskh hand with minor nastaʿlīq influence; rarely dotted ductus; some vowel marks, hamzas and shaddas, frequent mukhaffafa marshūqa lām-alif-ligatures). Book headings mostly in bold and black letters and mostly introduced by a basmala; chapter beginnings in red and introduced by bold and black abjad numerals in the main text; propositions numbered with overlined red abjad numbers in the margins; qāla/aqūlu mostly in red. Abjad numerals often in red and overlined in red or simply overlined; Hindu-Arabic numerals (Persian variants) in the main text often in red or in red with red overlines. Mostly carefully drawn diagrams with red lines and black letters or vice versa; diagrams sometimes in the margins (e.g., 53r, 55v, 61v). Numerous tables with lines in red, sometimes sloppily drawn; some tables upside down (78v), incomplete (128v), or empty (128v, 129r). One-and-a-half pages (with blank spaces for diagrams) crossed out due to the erroneous repetition of parts of chapters V.14–15 (67v–68v). Codex in acceptable condition; some folios missing, some in disorder in the last part of the codex; damage by insects, mostly in the fold; minor water or moisture damage in the margins throughout the codex; few pages loosening; some margins and parts of the fold restored. Dimensions: 19×12.5 cm; 24 lines per page. Vinaceous leather covers with frame and central, goldish-coloured mandorla; marbled doublures. Type II binding.

Cont.: astronomy. — Index: unidentified notes with diagrams (1r); Ptolemaica (2v–138r). Blank: Iv, 79r, I^ar, II^av.

Bibl.: Mohamed Souissi, La lange des mathématiques en arabe, Tunis: Imprimerie officielle, 1968, p. 23 (listing the manuscript as ‘Tunis, 14555’); Julio Samsó, ‘A propos de quelques manuscrits astronomiques des bibliothèques de Tunis’, in Actas del II Coloquio Hispano-Tunecino de Estudios Históricos, Madrid: Instituto hispano-árabe de cultura, 1973, pp. 171–190, here p. 173 and n. 10; ParraMª José Parra, ‘A List of Arabic Manuscripts of Naṣīr al-Dīn al-Ṭūsī’s Taḥrīr al-Majisṭī’, Suhayl 16–17 (2018–2019), pp. 251–322, p. 308 (no. 124, referred to as ‘Ṣādiqiyya, 1455’).