An astrometeorological parapegma arranged according to the twelve months from September to August, but apparently unrelated to Book II of the Phaseis (A.4). The text was probably translated from the Greek, as suggested by the names of the stars, which are consistently given in Greek. In most manuscripts, as well as in ed. Venice 1509, it forms a chapter of Pseudo-Ptolemy’s Iudicia (B.3). The source of the Iudicia is in fact an anonymous text extant in at least two manuscripts: Burgo de Osma, Archivo de la Catedral, 7, s. XI-XII, f. 89r-89v (‘Prima die mensis Septembris, id est Carius, appareret cum Solis ortu — Vicesima die mensis eiusdem [Augusti] Protigitur apparet, scilicet VIIIa et Oistos ponet, est autem finis dekymos post dies XL’), and Paris, BnF, lat. 7443, f. 53v-54r. The author of the Iudicia copied the text without significant changes, except that he added the introductory sentence (‘Ut autem de temporum mutatione particulariter nosse verum desideraveris, regule que iam dicentur ab animo tuo non labantur’) and the Arabic word ‘Alferat’ (‘al-faras’, ‘the horse’) for ‘Equus’ under 25 September. The De temporum mutatione was later excerpted from the Iudicia and enjoyed considerable success in the fifteenth and sixteenth centuries under the name of Ptolemy (see Notes below).

Note 1 The chapter from Pseudo-Ptolemy’s Iudicia was borrowed by John of Eschenden in his influential Summa iudicialis de accidentibus mundi (c. 1347-48), Tractatus I, Distinctio 10, Capitulum 12: ‘Capitulum 12 de temperie aeris seu mutatione eius secundum ortus et occasus stellarum fixarum. Ptolemeus unus de regibus Egypti in quodam libro suo quem scripsit ad Aristotelem et incipit liber sic: “Signorum alia sunt masculine etc.” Et dicit Virgilius et Servius in Georgicis lib. prio. quod tam ortus quam occasus Arcturi tempestates gravissimas facit. Et Ptolemeus ibidem in fine libri sui fere dicit sic: “Aeris autem de mutatione temporum particularium nosce verum desideras regulae quae iam docentur ab animo tuo non labantur. Prima die mensis Septembris, si custos plaustri, apparuerit cum Solis ortu, et mutatur aer in septima hora, et hoc fit inter diem et noctem. Septima vero die eiusdem mensis, vespertinus apparet et mutatur aer — (20a die Augusti) et finis comunis, id est Canis, ante unum diem.” Istas regulas ponit Ptolemeus de mutatione temporis anni. Et nota quod iste non fuit idem Ptolemeus qui scripsit Albu. magis [i.e., Almagesti] et librum Quadripartiti sed fuit unus de regibus Egipti’ (ed. Venice, 1489, sig. 62va-62vb).

Note 2 John of Eschenden’s chapter (Note 1), in a slightly abridged version, became part of astrometeorological collections at the University of Cracow in the second half of the fifteenth century, as witnessed by three manuscripts, which, incidentally, also contain Ptolemaic material: Munich, BSB, Clm 51, f. 109ra-109rb (‘De ortu et occasu stellarum secundum autorem summe Anglicane distinctionem 10, capitulo duodecimo. September: Prima die Septembris oritur stella que dicitur Custos Plaustri et mutatur aer in 7 horis — Augustus: 15 Augusti Lira et mutatur aer, 19 die Delphines apparet, 28 die aer turbatur. Has considerationes posuit Ptolomeus, non qui librum Almagesti scripsit, sed unus rex Egipti, qui et Ptolomeus dicebatur. Hec autor summe Anglicane differentia 10, capitulo 12, laus altissimo Deo’); Dresden, SLUB, N. 100, f. 226r; and Paris, BnF, lat. 7350, f. 96v-97r. The copy of the Dresden MS was briefly noted by M. Markowski, Astronomica et astrologica Cracoviensia ante annum 1550, Firenze, 1990, 176 no. 74, who attributed the text to Petrus Gaszowiec for reasons that are not explained.

Note 3 Towards the end of the fifteenth century, the Cracow version (Note 2) was reused by Johannes de Glogovia, who inserted it, with minor changes, into two of his works, the Introductorium astronomie in ephemerides, Differentia 12 (‘Differentia duodecima de ortu et occasu stellarum secundum autoris summe Anglicane sententiam, dis. 10, cap. XII, in quarum ortu et occasu fit aeris variatio et mutatio. September: Prima die Septembris oritur stella que dicitur Custos Plaustri et mutatur aer in septem horis — Augustus: 15 die Augusti Lyra apparet et mutatur aer, 19 Delphinus apparent, 28 die aer turbatur. Has considerationes ortus et occasus stellarum inquit autor summe Anglicane loco preallegato. Posuit Ptholomeus, non ille qui librum Almagesti fecit, sed alius quidem rex Egipti, qui etiam Ptholomeus nominabatur’, ed. Cracow, Florianus et Wolfgangus, 1514, sig. [f_iiii]va-[f_iiii]vb) and the Tractatus preclarissimus in iudiciis astrorum de mutationibus aeris (1490), or Book II of his Summa astrologie, Differentia 42 (‘Differentia 42 de ortu et occasu stellarum secundum autoris summe Anglicane sententiam, dis. X, cap. XII, signantque et efficiunt aure mutationem et turbationem. September: Prima dies Septenbris oritur stella que dicitur Custos Plaustri et mutatur aer in 7 horis — Augustus: 15 die Augusti Lira apparet et mutatur aer, 19 due Delphines apparent, 28 die aer turbatur. Has considerationes inquit autor summe Angelicane (!) loco preallegato. Posuit Ptholomeus, non ille qui librum Almagesti composuit, sed quidam rex Egipti, qui et Ptholomeus dictus est’, ed. Cracow, Florianus et Wolfgangus, 1514, sig. g_ivrb-g_ivva).

Text ‘(ed. Burnett, ‘Late Antique’) De temporum mutatione. Ut autem de temporum mutatione particulariter nosse verum desideraveris, regule que iam dicentur ab animo tuo non labantur. Prima die mensis Septembris, Icarus, custos plaustri, apparet cum Solis ortu — (Quinta decima die Augusti) E<te>sie des<in>unt et est finis Cionis, id est Canis, ante unam diem. Notandum est quod cum est annus Saturni et Martis omnia signa mutationis validiora, in ceteris mi[c]tiora. Ut autem ratio inveniendi anni non deficiat… et ubi numerus defuerit, ibi est caput anni, et [si] planeta illius turris habeatur dominium totius anni.’

Bibl. C. Burnett, ‘An Unknown Latin Version of an Ancient Parapegma: The Weather-Forecasting Stars in the Iudicia of Pseudo-Ptolemy’, in Making Instruments Count. Essays on Historical Scientific Instruments Presented to Gerard L’Estrange Turner, eds R. G. W. Anderson, J. A. Bennet, W. F. Ryan, Aldershot, 1993, 27-41; C. Burnett, ‘Late Antique and Medieval Latin Translations of Greek Texts on Astrology and Magic’, in The Occult Sciences in Byzantium, eds P. Magdalino, M. Mavroudi, Genève, 2006, 325-359: 334-343; D. Lehoux, Astronomy, Weather, and Calendars in the Ancient World. Parapegmata and Related Texts in Classical and Near-Eastern Societies, Cambridge, 2007, 166-167.

Modern ed. Burnett, ‘An Unknown Latin Version’ (from MS London, BL, Harley 5402 and ed. Venice 1509); Burnett, ‘Late Antique’, 348-354 (from MSS Chantilly, Musée Condé, 322 and London, BL, Harley 5402, and ed. Venice 1509). Burnett’s first edition is reproduced, together with an English translation, by Lehoux, 425-430.