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Ptolemaeus Arabus et Latinus

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London, British Library, Harley 625

s. XIV1 (probably c. 1341 – cf. tables 1341-1344 now in MS Oxford, BL, Digby 178, f. 11r-12v – and, in any case, between 1326 and 1347, which correspond respectively to the year of composition of Richard of Wallingford’s Tractatus albionis (f. 140-147) and to the year of reported astronomical observations added by Simon Bredon in the lower margin of f. 3v – these notes are edited by K. Snedegar, ‘Simon Bredon, a Fourteenth-Century Astronomer and Physician’, in Between Demonstration and Imagination. Essays in the History of Science and Philosophy presented to John D. North, eds L. Nauta, A. Vanderjagt, Leiden, 1999, 285-309: 297 n. 37).


University of Oxford; MS annotated, perhaps partly copied and probably assembled by Simon Bredon.


Simon Bredon, who bequeathed the MS to Merton College in 1372; John Dee in 1569 (f. Ir); Sir Simonds d’Ewes, who sold the MS in 1705 to Robert Harley.

Parchment, I+175 f., several alternating hands, one of which copied at least f. 8r-123r, 140r-157r and 164v-173r, decorated initials. This was originally the beginning of a larger MS, which was dismantled in the 17th c. and whose other parts are now in MSS Oxford, BL, Digby 178 (see) and London, BL, Cott. Tib. B.IX (see Watson, ‘A Merton College Manuscript’ for full reconstruction).

Astronomy and mathematics: table of contents, medieval (Ir); another, earlier, table of contents ‘probably in Bredon’s hand’ acc. Watson, ‘A Merton College Manuscript’, 210 (Iv, see Note 1 below), among scattered and partly illegible notes (Iv-1r, see Note 2 below); Ptolemaica (1v-6v); Excerptum de astrologia Arati (6v); Hyginus, De astronomia, excerpts (7va-7vb); Ptolemaica (8r-123r); Pseudo-Jordanus, Liber de triangulis, incomplete (123r-130r); Ptolemaica (132r-136v); Johannes de Tinemue, De curvis superficiebus (137r-139v), with added note ‘Quia iste commentator Archimenidis non probat…’ (139v); Richard of Wallingford, Tractatus albionis (140r-157r); astronomical tables (157r-164r); Azarchel, Saphea, tr. Guillelmus Anglicus (164v-173r); Ptolemaica (173r-174v); Boethius, De musica, excerpt (175r-175v). Blank: 7r, 130v-131v.

Note 1

Simon Bredon’s table of contents f. Iv allows us to reconstruct the original volume. This table is reproduced in full below, together with the correspondences with MSS Oxford, BL, Digby 178 (=O) and London, BL, Cott. Tib. B.IX (=L): ‘Gebir 1°, Almagesti abbreviatum 77°. Jordanus de triangulis 115°. Plures conclusiones Almagesti abbreviati 124. De curvis superficiebus 129. Albeon 132. Caphea 157. Totationes capitulorum librorum Almagesti 165. Extracta de musica Boicii 167. Textus Euclidis 168 [O, 88r-107r]. Conclusiones Gebir 187 [O, 107r-108r]. Teodosius de speris 189 [O, 108v-111r], Mileus 192 [O, 111v-115v]. Tabule planetarum 196 [L, 1r-4v]. De divisionibus superficierum 206 [L, 225r-229v = Machomet Bagdadin, De superficierum divisionibus]. De 5 corporibus raribus 211 [not found]. De speculo combustivo 212 [L, 230r-235v = Roger Bacon, De speculis comburentibus]. Tabula equationis domorum in latitudo 51 gra<dibus> 225 [O, 4v]. Tabule latitudinum 226 [O, 5r-8v]. De motu Thebit 229 [O, 9r-10v]. De quadratura circuli 232 [O, 11v-13v, bottom]. 4 tabule Solis 232 [O, 11r-12v]. This table refers to an older foliation, still visible at the upper left corners of versos. This foliation is 7 folia below the current foliation because f. 1-7 were added last, yet before the more recent table f. Ir, which opens ‘Tractatus de figuris stellarum in oceana sacra fo. 1°’.

Note 2

The notes on f. Iv-1r include a longer text mixing astronomical and astrological elements said to be borrowed from a book by Ptolemy: ‘Item libellus qui intitulatur Tholomeus de dispositione orbis et temperiei dicit quod… (1r) et ex quodam libello qui intitulatur Ptholomeus de dispositione orbis et temperiei, et incipit: Dividitur orbis signorum. Item in eodem libello dicitur quod triplicitas Arietis, Leoni et Sagittarii dicitur septentrionalis… ’. This book corresponds to Geminus of Rhodes’s Elementa astronomie, also known as Liber introductorius Ptolomei ad artem spericam.


A Catalogue of the Harleian Manuscripts in the British Museum, London, 1808-1812, 4 vols, I, 391; M. Clagett, Archimedes in the Middles Ages, I, Madison, 1964, xxi; A. G. Watson, The Library of Sir Simonds d’Ewes, London, 1966, 208 (A911); C. E. Wright, Fontes Harleiani. A Study of the Sources of the Harleian Collection of Manuscripts in the British Museum, London, 1972, 384; A. G. Watson, ‘A Merton College Manuscript Reconstructed: Harley 625; Digby 178, fols. 1-14, 88-115; Cotton Tiberius B. IX, fols. 1-4, 225-35’, Bodleian Library Record 9 (1976), 207-217 (reprinted in A. G. Watson, Medieval Manuscripts in Post-Medieval England, Padstow, 2004, XIII); J. Roberts, A. G. Watson, John Dee’s Library Catalogue, London, 1990, 120-121 (M95); The Theory of Music, IV: C. Meyer, M. Huglo, N. C. Phillips, Manuscripts from the Carolingian Era up to c. 1500 in Great Britain and in the United States of America, München, 1992, 78; H. Zepeda, The First Latin Treatise on Ptolemy’s Astronomy: The Almagesti minor (c. 1200), Turnhout, 2018, 66.


‘[Title in red now illegible.] Illa que est super extremitatem Capricorni: (longitudo) 2s 0° 10’ – (latitudo) 66° 0’ – (magnitudo) 3. Illa que est post istam super caudam: 2s 0° 0’ – 70° 0’ – 4 — thaugebe dicuntur stelle comate.’

= Ptolemy, Almagesti (tr. Gerard of Cremona) (A.1.2), VII.5-VIII.1, star catalogue. A few marginal notes by Simon Bredon, including the reported observations of 1347 f. 3v.


‘Hic incipit liber primus Gebir [title added by a later hand in upper margin]. Scientia species habet quarum melior post scientiam si Dei est — sunt digniores et evanescant et destruantur. Et illud est propositum. Explicit Gebir.’

= Geber, Liber super Almagesti (C.1.2). Preface, 8r-9r; I, 9r-16v; II, 16v-23v; III, 23v-27r; IV, 27r-35r; V, 35r-48r; VI, 48r-60r; VII, 60r-73v; VIII, 73v-77v; IX, 77v-84v. Glosses by two or three contemporary hands. The text is followed by two paragraphs added by another hand: ‘A quocumque angulo equilateri trianguli inscripti… Infra quadratum propositum octogonum…’.

85r‑123r, 132r‑136v

‘Omnium recte philosophantium verisimilibus credibilibus (123r) tenebrarum sic se habent. Explicit. Explicit. (132r) Hec conclusiones sunt de libro quinto Almagesti abbreviata [title in upper margin, perhaps by the scribe]. 7a [in the margin]. Diametrum epicicli ipsius longitudo longioris equalem indicans — in numero quod potest deficere a vero…’

= Almagesti minor (C.1.3). The scribe omitted section V.7-19, which he supplied on f. 132r-136v (this was noted by a later scribe in the margin of f. 109v: ‘Hic deficiunt 13 conclusiones que ponuntur post triangulos Iordani’). Occasional short marginal notes by several contemporary hands, including that of the scribe. One more substantial gloss on f. 102v.


‘Liber Almagesti ex precepto Maymonis regis Arabum qui regavit (!) in Baldach — In dictione 13a Almagesti sunt 11 capitula… Capitulum undecimum in complemento libri.’

= Ptolemy, Almagesti (tr. Gerard of Cremona) (A.1.2), translator’s preface (second part) and full chapter index. No glosses.