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Ptolemaeus Arabus et Latinus

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Work C.1.9

‘Erfurt Commentary’ on the Almagest

A commentary on and a reworking of Almagest I.9-II.11 in Gerard of Cremona’s translation (A.1.2) arranged by propositions and proofs. Enunciations are close to those of the Almagesti minor (C.1.4), but the rest of the text differs. Zepeda, 91, suspects that the author ‘did not use the Almagesti minor itself, but a manuscript of the Almagest with some excerpts of it in the margins’. The ‘Erfurt Commentary’ was written no later than in the second half of the fourteenth century (date of all copies) and probably before 1367-1370 if the assumed dating of MS Vatican, BAV, Pal. lat. 1380 is correct. The origin and content of the four extant manuscripts point to France and probably Paris. MS Dijon, BM, 441 contains an expanded version, including a preface (‘Quelibet circumferentia circuli secundum astrologos…’) and a continuation for Almagest II.12-13, which is probably the work of Jean Fusoris (c. 1365-1436). In MS Erfurt, UFB, Amplon. F. 375, the text is followed (f. 127r-129v), by a supercommentary (C.1.10).


‘(Erfurt, UFB, Amplon. F. 375) Commentum super Almagesti Ptholemei. Data circuli dyametro latera decagoni, penthagoni, hexagoni, tetragoni et trianguli omni ab eodem circulo circumscriptorum invenire… Pro probacione istius proposicionis supponitur quod linea divisa — erit angulus DEA notus orientalis super orizontem, quod est propositum.’


R. Lorch, ‘Some Remarks on the Almagestum parvum’, in Amphora. Festschrift für Hans Wussing zu seinem 65. Geburtstag, eds S. S. Demidov, M. Folkerts et al., Basel-Boston-Berlin, 1992, 407-438: 421-422; H. Zepeda, The Medieval Latin Transmission of the Menelaus Theorem, PhD dissertation, University of Oklahoma at Norman, 2013, 184-221; H. Zepeda, The First Latin Treatise on Ptolemy’s Astronomy: The Almagesti minor (c. 1200), Turnhout, 2018, 89-91.


Partial critical edition in Zepeda, The Medieval Latin Transmission, 493-572 (from all four manuscripts).