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Ptolemaeus Arabus et Latinus

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Escorial, Real Biblioteca del Monasterio de San Lorenzo, d.II.5

s. XV2 (before c. 1474 for f. 44-63) and XV or XVI (f. 64-71); the rest of the MS seems to date mainly from the 16th c. (Antolín mistakenly dates the whole MS to the 14th c.).


f. 44-63 are Regiomontanus’s autograph; the first part (f. 1-112), except the Ptolemaic sections, might be Spanish (cf. table of geographical coordinates of regions, opening with ‘Hispania Betica, Lusitania, Tarraconensis…’, f. 87v; and added notes in Spanish, e.g. f. 8r, 11v, 26r, 94r, 95r).

Paper, 363 f. Collection of MSS and documents of various origins, of which f. 1-112 form one unit, into which the two Ptolemaic sections have been inserted. These Ptolemaic sections consist of two distinct MSS, each copied by a single neat hand (Regiomontanus’s for f. 44-63).

The first part of the MS (f. 1-112) consists of texts, notes, tables, diagrams and drawings mainly of geometry, astronomy and physics in great disorder. This part opens with the abbreviated title ‘Pet. Goth. Cord. math. spec. lib. I’ (1r), followed by the text in question, or rather its draft, seeing the numerous corrections and confused organisation: ‘Perpendicularem supra aliquam…’ (1r-43v); Ptolemaica (44r-63v and 64r-71v); ‘1. Dimensio est partium sibi invicem coherentium…’ (72r); ‘De celi et terre figura. Celum spheram esse et motus indicat…’ (72v-81v); calculations, tables, diagrams and notes (82r-112v). The rest of the MS (f. 113-363) is made of documents and letters of various kinds, mostly of a non-scientific nature.


G. Antolín, Catálogo de los códices latinos de la Real Biblioteca del Escorial, I, Madrid, 1910, 414-421.


‘… ostendit per compositionem quod corde dupli arcus gh ga proportio ad cordam dupli arcus ae componitur etc. Intentio huius nugatoris est quod Ptolemaeus per eandem figuracionem demonstrare voluerit habitudinem figurae sectoris quam coniunctam vocant — angulus enim map non est in centro circuli cuius est arcus mp, sed in centro alterius circuli, scilicet ecentrici; sic accumulate inscitiam tuam prostituisti…’

= Regiomontanus, Defensio Theonis contra Trapezuntium (C.1.23), c. 1-3, beginning gone due to missing folia and abrupt end a few lines from the bottom of f. 63v. Chapter 1, 44r-48r; 2, 48r-57r; 3, 57v-63r (=MS St Petersburg, BAN, IV-1-935, f. 13r-36r). Carefully drawn diagrams. A few corrections by the scribe (including crossed-out sections, as above).


‘<C>um sit possibile, o Syre, et plurimum necessarium ut in plano representur circuli in spheram corpoream incidentes — et cum circulis meridianis signa distinguentibus. Finis.’

= Ptolemy, Planispherium (tr. Hermann of Carinthia) (A.6.1), Class I, without the translator’s preface. A few glosses by another (?) hand, including Maslama’s note 1 f. 64r.