Explanation of six propositions on sines and chords by Georg Peurbach (1423-1461), largely based on John of Gmunden’s De sinubus, chordis et arcubus (1437). Ptolemy is named in the title of both early printed editions, as well as (apparently) in the title of MS ZZ – Unknown location, olim Maihingen, A.B. VII.3.2º 7, but not in the earliest witness, MS Vienna, ÖNB, 5203, copied by Regiomontanus.

Text ‘(Vienna, ÖNB, 5203) ‘Tractatus sinuum et chordarum Georgii Peurbachii. Sinuum, cordarum et arcuum noticia ad celestium motuum cognitionem pervalde necessaria existit, ideo de eorum doctrina restat in presenti perquirendum — Et similiter sciemus quantitates reliquarum chordarum, facilis ergo est secundum premissorum tenorem cordarum ad suos arcus cognitio. Finis.’

Bibl. J.-B.-J. Delambre, Histoire de l’astronomie du Moyen Age, Paris, 1819, 282-283; H. H. L. Busard, Der Traktat de sinubus, chordis et arcubus von Johannes von Gmunden, Wien, 1971, 75; H. Grössing, Humanistische Naturwissenschaft. Zur Geschichte der Wiener mathematischen Schulen des 15. und 16. Jahrhunderts, Baden-Baden, 1983, 106 and 115-116; 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: 422 (reprinted in R. Lorch, Arabic Mathematical Sciences. Instruments, Texts, Transmission, Farnham-Burlington, 1995, V); H. Zepeda, The First Latin Treatise on Ptolemy’s Astronomy: The Almagesti minor (c. 1200), Turnhout, 2018, 108; M. Malpangotto, Theoricae novae planetarum Georgii Peurbacii dans l’histoire de l’astronomie, Paris, 2021, 39.

Modern ed. ---