1 Concerning Egyptian days during the Middle Ages, in some cases touching on mnemonic aids, see the following articles and discussions: Hampson, R. T., Medii aevi kalendarium; or, Dates, Charters, and Customs of the Middle Ages, with Kalendars from the Tenth to the Fifteenth Century (London, 1841), 152, 208–10; Loiseleur, Jules, “Les jours égyptiens: Leurs variations dans les calendriers du moyen-âge,” Mémoires de la Société Nationale des Antiquaires de France, 4th ser., 3 (1872): 198–253; Steele, Robert, “Dies Aegyptiaci,” Proceedings of the Royal Society of Medicine 12 (1918–19): 108–21; Förster, Max, “Die altenglischen Glücks- und Unglückstage,” Studies in English Philology: A Miscellany in Honor of Professor Frederick Klaeber , ed. Malone, Kemp and Rund, Martin B. (Minneapolis, 1929), 258–77, esp. 261–65; Nelson, Axel, “Dies Aegyptiaci: Ett bidrag till kännedomen om den medeltida kalendern,” in Overbibliotekar Wilhelm Munthe på femtiårsdagen 20. oktober 1933 fra fagfeller og venner , ed. Kragemo, Helge Bergh (Oslo, 1933), 185–96; Solalinde, A. G., “Fuentes de la ‘General estoria’ de Alfonso el Sabio,” Revista de filología española 22 (1936): 113–42, esp. 133–37; Bühler, Curt F., “Sixteenth-Century Prognostications: Libri impressum cum notis manuscriptis, part II,” Isis 33 (1942): 610–11; Willeumier-Schalij, J. M., “Latendagen en Dies Aegyptiaci in kalendars uit Middelnederlandse handschriften,” Het Boek, n.s., 28 (1944–46): 305–9; Hennig, John, “Versus de mensibus,” Traditio 11 (1955): 65–90; Keil, Gundolf, “Die verworfenen Tage,” Sudhoffs Archiv für Geschichte der Medizin und der Naturwissenschaften 41 (1957): 27–58; Hirsh, John C., “Why Does the Miller's Tale Take Place on Monday?” English Language Notes 13 (1975): 86–90; Puigvert, Gemma i Planagumà, , “De diebus aegyptiacis,” Annals de l'Institut d'Etudis Gironius 31 (1990): 41–52; Lange, Hanne, “Jours critiques, jours funestres, jours de Tycho Brahe: La réception en Scandinavie d'une ancienne croyance,” in Comprendre et maîtriser la nature au Moyen Âge: Mélanges d'histoire des sciences offerts à Guy Beaujouan, Hautes Études Médiévales et Modernes 73 (Paris, 1994), 285–310 (Armis gunfe cited on 299); Hirsh, John C., “Fate, Faith and Paradox: Medieval Unlucky Days as a Context for ‘Wytte Hath Wondyr,”’ Medium Aevum 66 (1997): 288–92; Wasowicz, Henryk, “Dni egipskie w ksiegach liturgicznych Krakowa i Wrocĺawia XIII–XVI wieku,” in Christianitas et cultura Europae, Ksiega Jubileuszowa Profesora Jerzego Kloczowskiego , ed. Gapski, Henryk, 1 (Lublin, 1998), 730–41; Lásló Sándor Chardonnens, Anglo-Saxon Prognostics, 900–1100: Study and Texts, Brill's Studies in Intellectual History 153 (Leiden, 2007), 330–92.Google Scholar

2 Ginzel, F. K., Handbuch der mathematischen und technischen Chronologie: Das Zeitrechnungswesen der Völker , 3 vols. (Leipzig, 1906–14), 2:178–79; Jungbauer, Gustav, “Ägyptische Tage,” in Handwörterbuch des deutschen Aberglaubens , ed. Hoffmann-Krayer, E. and Bächtold-Stäubli, Hanns (Berlin and Leipzig, 1927), 1: cols. 223–24; Mommsen, Theodor, ed., “Chronographus anni CCCLIIII,” in MGH, Auctores antiquissimi 9, Chronica minora saec. IV–VIII, 1 (Berlin, 1892), 13–148; Lommatzsch, Ernst, ed., Inscriptiones Latinae Antiquissimae ad C. Caesaris mortem (Berlin, 1893), 256–78; Strzygowski, Josef, ed., Die Calenderbilder des Chronographen vom Jahre 354, Jahrbuch des deutschen Archäologischen Instituts, Ergänzungsheft 1 (Berlin, 1888), figures 19, 20, 22–28, 30, 32. For a general introduction to the calendar of Philocalus, see Salzman, Michele Renee, On Roman Time: The Codex-Calendar of 354 and the Rhythms of Urban Life in Late Antiquity, The Transformation of the Classical Heritage 17 (Berkeley, 1990).Google Scholar

3 Rüpke, Jörg, Die Religion der Römer (Munich, 2001), 194; Wesch-Klein, Gabriele, “Der Laterculus des Polemius Silvius: Überlegungen zu Datierung, Zuverlässigkeit und historischem Aussagewert einer spätantiken Quelle,” Historia: Zeitschrift für Alte Geschichte 51 (2002): 57–88. Burgess, R. G., “Principes cum Tyrannnis: Two Studies in the Kaisergeschichte and Its Tradition,” Classical Quarterly, n.s., 43 (1993): 492: “This laterculus consisted of monthly calendars, listing festivals and holidays for every month, each followed by one of eleven short lists dealing with an amazing variety of subjects…. It was ‘modern’ because Polemius had gone through old laterculi and removed many of the difficult and outmoded (especially non-Christian) aspects, such as the pictures of the days, months, and astrological signs, the lunar letters, hebdomadals, nundials, dies Aegyptiaci, and a number of pagan festivals.” Google Scholar

4 Pseudo-Bede, , De minutione sanguinis sive de phlebotomia (PL 90:959–62): “Plures sunt dies Aegyptiaci, in quibus nullo modo nec per ullam necessitatem licet homini vel pecori sanguinem minuere, nec potionem impendere, sed ex his tribus [tres] maxime observandi, octavo Idus April, illo die lunis, intrante Augusto: illo die lunis exeunte Decembri; illo die lunis, cum multa diligentia observandum est, quia omnes venae tunc plenae sunt. Qui in istis diebus hominem aut pecus inciderit, aut statim aut in ipso die vel in tertio morietur, aut ad septimum diem non perveniet; et si potionem quis acceperit, quindecimo die morietur; et si masculus sive mulier in his diebus nati fuerint, mala morte morientur; et si quis de auca in ipsis diebus manducaverit, quindecimo die morietur.” See also Förster, Max, “Die Kleinliteratur des Aberglaubens in Altenglisch,” Archiv für das Studium der neueren Sprachen und Literaturen 110 (1903): 352–53; Payne, Joseph F., The Fitz-Patrick Lectures for 1903: English Medicine in the Anglo-Saxon Times; Two Lectures Delivered before the Royal College of Physicians of London, June 23 and 25, 1903 (Oxford, 1904), 18; Jones, Charles W., “Bedae Pseudepigrapha: Scientific Writings Falsely Attributed to Bede,” in idem, Bede, the Schools and the Computus , ed. Stevens, Wesley M. (Aldershot, 1994), 88–89. The latter is a reprint of Jones, Charles W., Bedae Pseudepigrapha: Scientific Writings Falsely Attributed to Bede (Ithaca, NY, 1939).Google Scholar

5 Stoll, Ulrich, Das “Lorscher Arzneibuch”: Ein medizinisches Kompendium des 8. Jahrhunderts (Codex Bambergensis Medicinalis 1): Text, Übersetzung und Fachglossar , Sudhoffs Archiv, Beihefte 28 (Stuttgart, 1992), 76–77.Google Scholar

6 Stuart, Heather, “A Ninth Century Account of Diets and Dies Aegyptiaci,” Scriptorium 33 (1979): 237–44.CrossRefGoogle Scholar

7 Oxford, Bodleian Library, MS Lat. Liturgy.E.10 (Summary Catalogue, no. 32942); Hirsh, , “Fate, Faith and Paradox,” 189.Google Scholar

8 Benson, Larry D., ed., The Riverside Chaucer , 3rd ed. (Boston, 1987), 255 (The Nun's Priest's Tale [B 4137–4157]); Pollard, Alfred W. et al., eds., The Works of Geoffrey Chaucer (London, 1965), 133–34. On the dating of The Nun's Priest's Tale, see Benson, , Riverside Chaucer, xxix.Google Scholar

9 Benson, , Riverside Chaucer , 345 (Book of the Duchess, vv. 1206–7); Pollard, , Works of Geoffrey Chaucer, 324 (vv. 1205–6), 752. Two other references by Chaucer to that day in the Knight's Tale and Troilus and Criseyde cannot be explained as Egyptian days. For other interpretations, see McCall, John P., “Chaucer's May 3,” Modern Language Notes 76 (1961): 201–5; Kelly, Henry Ansgar, Chaucer and the Cult of Saint Valentine, Davis Medieval Texts and Studies 5 (Leiden, 1986), 115. See also Hirsh, , “Why Does the Miller's Tale Take Place on Monday?” 86–90. In explaining Chaucer's use of the word “dismal” to refer to Egyptian days in the Book of the Duchesse, line 1206, Skeat notes an indirect connection with the Latin dies malus through “an Anglo-French phrase dis mal (= Lat. dies mali, plural), whence the [Middle English] phrase in the dismal, ‘in the evil days,’ or (more loosely), ‘on an evil day’” (Skeat, Walter, ed., The Complete Works of Geoffrey Chaucer [Oxford, 1894], 1:493). See also Spitzer, Leo, “Eng. Dismal = O.F. ∗Dism-al,” Modern Language Notes 57 (1942): 602–13. The Ten Plagues as a rationale for Egyptian days can be found in contemporary Middle English manuscripts on astrological medicine. Mooney, Linne R., “A Middle English Verse Compendium of Astrological Medicine,” Medical History 28 (1984): 406–19: “The dismall days er nogt ill for thai wer first s[o cald]; / When God chasid Egypcians that bow hym ne wald” (lines 127–28). This Middle English compendium is found in manuscripts dating from the late fourteenth and early fifteenth centuries.Google Scholar

10 Thorndike, Lynn, History of Magic and Experimental Science during the First Thirteen Centuries of Our Era (New York, 1923), 1:688 n. 1: “My impression is that some medieval astronomers also denied to these Egyptian days any astrological importance, since they always came upon the same days of the months without reference to the phases of the moon or courses of the other planets.” Google Scholar

11 Similarly, Girart d'Amiens refers to a particular Egyptian day but no dangerous hour in his Arthurian romance Escanor (ca. 1280), dedicated to Eleanor of Castile (1241–1290), wife of King Edward I (r. 1272–1307) of England. In the story, Keu (i.e., Sir Kay), seneschal of King Arthur, and Dinadan, a knight of the Round Table, delay their joust so the Egyptian day can pass. Michelant, Henri Victor, ed., Der Roman von Escanor von Gerard von Amiens , Bibliothek des Litterarischen Vereins in Stuttgart 178 (Tübingen, 1886), 33; d'Amiens, Girart, Escanor, Roman arthurien en vers de la fin du XIII^e siècle , ed. Trachsler, Richard, Textes littéraires français 449 (Geneva, 1994), 179: “Mesire Kez a l'ainz qu'il puet / Retorna vers Dynadan lors / Et dist qu'encore n'est pas hors / De la dolereuse jornee, / Qui por lui fu mal ajornee / A ce que tant li mesavient. / ‘Dix! Fait il, la nuit que ne vient / Pour ce jour devee passer!’” (vv. 1232–39).Google Scholar

12 [John David] North, J. D., Chaucer's Universe (Oxford, 1988), 467, 520–21 (quotation at 520). See also, North, J. D., “Kalenderes: Enlumyned Ben They, III,” Review of English Studies, n.s., 20 (1969): 442.Google Scholar

13 Dies caniculares are found in calendars from the early Carolingian period through the sixteenth century. For example, dies caniculares can be found in the calendar of a manuscript of 798–805 (Cologne, Dombibliothek MS 83–2) and a tenth-century manuscript (Paris, Bibliothèque Nationale de France, MS Lat. 2825). See Englisch, Brigitte, Zeiterfassung und Kalenderprogrammatik in der frühen Karolinerzeit: Das Kalendarium der Hs. Köln DB 83–2 und die Synode von Soissons 744 , Instrumenta: Herausgegeben vom Deutschen Historischen Institut Paris 8 (Stuttgart, 2002), 109, 110; Liuzza, Roy Michael, “Anglo-Saxon Prognostics in Context: A Survey and Handlist of Manuscripts,” Anglo-Saxon England 30 (2000): 208 n. 113, 225–26, notes that Egyptian days, dies malae, and/or dies caniculares were either originally incorporated into or later added to eighteen of nineteen manuscripts (the one exception is no. 17, CCCC391 = W) printed in Wormald, Francis, ed., English Kalendars before A.D. 1100, HBS 72 (London, 1934). van Wijk, W. E., Le nombre d'or: Étude de chronologie technique suivie du texte de la Massa Compoti d'Alexandre de Villedieu, avec traduction et commentaire (The Hague, 1936), 98. In a commonplace book kept in the 1470s by Robert Reynes of Acle, a minor manorial administrator in Norfolk, lucky and unlucky days are an important part of directions for bloodletting. After dealing with phlebotomy in relation to astrology and the humors, Reynes seems to refer to “dog days” and probably Egyptian days (Louis, Cameron, ed., The Commonplace Book of Robert Reynes of Acle: An Edition of Tanner MS 407, Garland Medieval Texts 1 [New York, 1980], 157–61, 378–80: “He þat schuldyn letyn man or woman blood, hym must ben avysyd of iiii poyntes. Þat is for to seyn, þat tyme be good and able, and not to oyer-hote, ne to ouer-colde, ne not in the hundyn dayes, ne on other dayes þat arn forbeden” [160]. Concerning Reynes and the village of Acle, see the introduction, 27–39).Google Scholar

14 Keil, , “Die verworfenen Tage” (n. 1 above), 32–35, 46–47; Brévart, Francis B., “The German Volkskalender of the Fifteenth Century,” Speculum 63 (1988): 328–29. A fifteenth-century Volkskalendar designated three particular Mondays as unlucky (April 30, August 1, and December 31) because they respectively commemorated the day on which Cain slew Abel, the destruction of Sodom and Gomorrah, and the birthday of Judas Iscariot. For other comparisons, see Loiseleur, , “Les jours égyptiens” (n. 1 above), 249; Lange, , “Jours critiques” (n. 1 above), 302–3; Ginzel, , Handbuch der mathematischen und technischen Chronologie (n. 2 above), 3:231. In the age of printing, lists of Egyptian days also varied. For a late example, see Garzoni, Tomaso, La piazza universale di tutte le professioni del mondo , ed. Cherchi, Paolo and Collina, Beatrice (Turin, 1996), 1:195 (“Tavola de' giorni Egizi e delle sue ore”). Equally variable were the dies critici, with which Egyptian days were often confounded. See Jacquart, Danielle, “Le temps médical au moyen âge ou l'introuvable précision,” Bibliothèque de l'École des Chartes 157 (1999): 157–70.Google Scholar

15 Michael of Rhodes's manuscript in the Burndy Library, now at San Marino, CA, Huntington Library. See Wallis, Faith, “Michael of Rhodes and Time-Reckoning: Calendar, Almanac, Prognostication,” in The Book of Michael of Rhodes: A Fifteenth-Century Maritime Manuscript , ed. Long, Pamela O., McGee, David, and Stahl, Alan M. (Cambridge, MA, 2009), 3:281–319, esp. 288, 290, 292, 296–97. These findings relate to fol. 111r–v in the Michael of Rhodes manuscript. Late medieval manuscript sources even cite Greek and Arabic unlucky days (Thorndike, , History of Magic and Experimental Science, 1:688).Google Scholar

16 This manuscript includes Notabilia bibliae et aliorum sapientum, Index librorum bibliae, and other texts. The section of Egyptian and unfortunate days is found on fols. 109v–111r. For a description, see Jemolo, Viviana and Palma, Marco, Sessoriani dispersi contributo all' identificazione di codici proviento dalla Biblioteca Romana di S. Croce in Gerusalemme , Susside Eruditi 39 (Rome, 1984), 35, no. 16. The antiquarian bookseller Les Enluminures (Paris and Chicago) offers an online description at http://textmanuscripts.com. The following introduction (fol. 109v) prefaces the list of Egyptian days: “Infrascripti sunt dies ytiachi et infelices, quos greces dixerunt dies malos, offe(?) in hiis diebus non uendas, non emas, nec aliquod edificium facias, nec incipias item nec uestes nouas induas, et qui natus fuerit pauper erat. Isti sunt lx dies; xxiiii sunt ytiachi, alii sunt infelices.” This is followed by the “Augurior decies” mnemonic verses and the two lists of days. The manuscript was later in the Fondo Sessoriano, Cistercian Abbey of Santa Croce in Gerusalemme, Rome, and in the library of Sir Thomas Phillipps (1792–1872), with the shelfmark Phillipps 12309. The author wishes to acknowledge Sandra Hindman for providing images of the relevant folios.Google Scholar

17 Graf, Fritz, Magic in the Ancient World , trans. Philip, Franklin (Cambridge, MA, 1997), 5–6, 89–92, 108–9; Fowden, Garth, The Egyptian Hermes: A Historical Approach to the Late Pagan Mind (Princeton, 1986), 14–15, 65–67.Google Scholar

18 On the Egyptian calendar and unlucky days, see Ginzel, , Handbuch der mathematischen und technischen Chronologie , 1:204–12; Porceddu, Sebastian et al., “Evidence of Periodicity in Ancient Egyptian Calendars of Lucky and Unlucky Days,” Cambridge Archaeological Journal 18 (2008): 327–39; Dawson, W. R., “Some Observations on the Egyptian Calendars of Lucky and Unlucky Days,” Journal of Egyptian Archaeology 12 (1926): 260–64; Wallis Budge, E. A., Egyptian Magic (London, 1899), 224–28.Google Scholar

19 This is seen clearly in St. Augustine, , Expositio epistolae ad Galatas 35, 2–4, in Plumer, Eric, ed., Augustine's Commentary on Galatians: Introduction, Text, Translation, and Notes, Oxford Early Christian Studies (Oxford, 2006), 187: “Quod cum tanta celebritate atque auctoritate per orbem terrarum in ecclesiis legatur, plena sunt conuenticula nostra hominibus qui tempora rerum agendarum a mathematicis accipiunt. Iam uero ne aliquid inchoetur, aut aedificiorum aut huiusmodi quorumlibet operum, diebus quos Aegyptiacos uocant saepe etiam nos monere non dubitant, nescientes, ut dicitur, ubi ambulant. Quod si locus iste de Iudaeorum superstitiosa obseruatione intelligendus est….” It is quoted in Decretum Gratiani (p. II, causa 26, quaestio 7, capitulum 16 [PL 187:1369–70]): “Non observetis dies, qui dicuntur Aegyptiaci, aut calendas Januarii…. Qui autem talibus credunt, aut ad eorum domum euntes, aut suis domibus introducunt, ut interrogent, sciant, se fidem Christianam et baptismum praevaricasse, et ut paganum et apostatam, id est retro abeuntem et Dei inimicum, iram Dei graviter in aeternum incurrisse, nisi ecclesiastica poenitentia emendatus Deo reconcilietur.” Google Scholar

20 Pseudo-Bede, , Libellus de mensura horlogii (PL 90:955): “Si tenebrae Aegyptus Graio sermone vocantur, / Inde dies mortis, tenebrosos jure vocamus. / Bis deni, binique dies scribuntur in anno, / In quibus una solet mortalibus hora timeri.” It was not uncommon in the Middle Ages for mnemonic verses to be attributed to Bede. See Baker, Peter S., “Byrhtferth's ‘Enchiridion’ and the Computus in Oxford, St. John's College 17,” Anglo-Saxon England 10 (1982): 131 n. 35; Steele, , “Dies Aegyptiaci” (n. 1 above), 112–13; Jones, , “Bedae Pseudepigrapha” (n. 4 above), 88.Google Scholar

21 Honorius of Autun, De imagine mundi libri tres (PL 172:164): “Dies Aegyptiaci ideo dicuntur, quia ab Aegyptiis sunt inventi. Et quia Aegyptus dicitur tenebrae, ipsi tenebrosi inde nominantur, eo quod incautos ad tenebras mortis perducere affirmantur.” Google Scholar

22 Duchet-Suchaux, Gaston and Pastoureau, Michel, The Bible and the Saints (Paris, 1994), 281–82.Google Scholar

23 Assmann, Jan and Livingstone, Rodney, Religion and Cultural Memory: Ten Studies (Stanford, 2006), 173: “In calendars every day was related to a mythical event and this event was used to determine whether the day had a favorable, uncertain, or dangerous augury.” Google Scholar

24 Grafton, Anthony T. and Swerdlow, Noel M., “Calendar Dates and Ominous Days in Ancient Historiography,” Journal of the Warburg and Courtauld Institutes 51 (1988): 14–42, esp. 14–15, 18.Google Scholar

25 In the order in which they appear in Exod. 7:14–12:36, the Ten Plagues are blood, frogs, lice, wild beasts or flies, pestilence, boils, hail, locusts, darkness, and death of firstborn. Accompanying the customary list of the Ten Plagues, Ps. 77:49 mentions God's sending Egypt wrath, indignation, and evil spirits as divine agents helping to bring about the plagues (“misit in eos iram indignationis suae indignationem et iram et tribulationem inmissionem per angelos malos…”). For this reason, the Evil Angel was occasionally depicted in the early medieval illuminated manuscripts. The Index of Christian Art uses the subject heading “Moses: Plague of Evil Angel” in connnection with miniatures in London, British Library, Additional MS 19352, fol. 104v, and Stuttgart, Landesbibliothek, Bibl. Fol. 23, fol. 93r (see http://ica.princeton.edu). On this larger group of plagues, see Wordsworth, Christopher, ed., The Ancient Kalendar of the University of Oxford from Documents of the Fourteenth to the Seventeenth Century: Together with Computus manualis ad usum Oxoniensium from Kyrfoth's, C. Edition, Oxon., 1519–20, Oxford Historical Society 45 (Oxford, 1904), 191: “The Jewish Rabbis reckon that there were forty or fifty plagues in Egypt, and two hundred at the Red Sea, as they multiply each of the Ten Plagues by four or five, because the Everlasting (Blessed is He) sent upon them four (or five) chastisements with each of the ten plagues.” Google Scholar

26 Comestor, Peter, Historia scholastica , 24 (PL 198:1153): “Notandum quia plures fuerunt in Aegypto plagae quam decem, quas Exodus non enumerat, sed non fuerunt adeo graves forte, et ideo tacentur. Unde quidem dies Aegyptiaci dicuntur, quia in his passa est Aegyptus, quorum duos tamen in singulis mensibus notamus ad memoriam, cum plures forte fuerint. Nec est credendum quod Aegyptii, licet astrorum periti, deprehenderunt dies hos infaustos in inchoatione operis, vel itineris, vel minutionis.” Concerning Peter Comestor and his most renowned work, see Sylwan, Agneta, ed., Petri Comestoris Scolastica historia: Liber Genesis, CCM 191 (Turnhout, 2005), x–xiv, xxxi–xxxii. Jewish arguments about the larger number of plagues are summarized in Wordsworth, , Ancient Kalendar, 191.Google Scholar

27 Seymour, M. C., et al., eds., On the Properties of Things: John Trevisa's Translation of Bartholomæus Anglicus, De proprietatibus rerum: A Critical Text , 3 vols. (Oxford, 1975–88), 1:535: “And som day is iclepid egiptiacus and some nout so; dies egiptiacus is þat day in þe whiche God sente some wreche into Egipt; and for þe dayes egiptiaci heþ foure and twenty, hit suyþ þat God sente mo wrechis vppon þe Egipcians þan ten þat beþ most famous amonge oþir. Þe dayes egiptiaci beþ iset in þe calender of holy chirche and ben iclepid dies mali ‘euel dayes’ nout for som þinge schulde b[e] spared in þilke dayes schulde nout be sparid in oþir dayes but for to haue þe miraclis and wondris of God alwei in mynde.” Concerning Bartholomeus Anglicus and his work, see Seymour, M. C., Bartholomaeus Anglicus and his Encyclopedia (Aldershot, 1992), 1–35.Google Scholar

28 Vincent of Beauvis, Speculum naturale 15, 83, in Vincentii Burgundi, ex Ordine Praedicatorum venerabilis episcopi Bellovacensis, Speculum Quadruplex (Douay, 1624) 1, col. 1143: “Dicuntur autem dies Aegyptiacim ut quidam volunt, quia in his flagelauit Dominus Aegyptum. Quamuis enim tantum decem plagae principales legantur, multae tamen secundariae feruntur.” The text may date to around 1256–59. See Gabriel, Astrik L., The Educational Ideas of Vincent of Beauvais (Notre Dame, IN, 1962), 3–4. In his Speculum historiale 2, 5, Vincent of Beauvais only mentions the Ten Plagues. See Vincentii Burgundi … Speculum Quadruplex 4, 48–49. Another argument along these lines is in the General estoria, a vernacular world history compiled at the learned court of King Alfonso X of Castile (r. 1252–84) but left unfinished at the time of his death (Solalinde, , “Fuentes de la ‘General estoria’” [n. 1 above], 132; Puigvert, i Planagumà, , “De diebus aegyptiacis” [n. 1 above], 41 n. 1). Of the plagues corresponding to the Egyptian days, a fifteenth-century Spanish manuscript (Girona Cathedral, MS 91) proclaimed, “X vero principales et XIIII collaterales.” Google Scholar

29 Concerning Baldwin of Forde (or Exeter), see Holdsworth, Christopher, “Baldwin (c.1125–1190),” in Oxford Dictionary of National Biography (Oxford, 2004), http://www.oxforddnb.com/view/article/1164 (accessed 22 June 2009).Google Scholar

30 Howlett, Richard, ed., Chronicles of the Reigns of Stephen, Henry II, and Richard I , Rerum Britannicarum Medii Aevi Scriptores (Rolls Series) 82 (London, 1884), 1:294: “Ricardus igitur, solus regum a seculo ita nominatus, Lundoniis est consecratus in regem, et sollemniter coronatus a Baluino Cantuariensi archiepiscopo tertio nonas Septembris; qui dies ex prisca gentili superstitione malus vel Aegyptiacus dicitur, tanquam quodam Judaici eventus praesagio. Dies enim ille Judaeis exitialis fuisse dignoscitur, et Aegyptiacus magis quam Anglicus; cum Anglia, in qua sub rege priore felices et incliti furant, repente illis in Aegyptum, ubi patres eorum dura perpessi sunt, Dei judicio verteretur.” Google Scholar

31 Higden, Ranulf, Polychronicon 7, 25, in Polychronicon Ranulphi Higden Monachi Cestrensis; Together with the English Translations of John Trevisa and of an Unknown Writer of the Fifteenth Century , ed. Lumby, Joseph Rawson, Rerum Britannicarum Medii Aevi Scriptores (Rolls Series) 41 (London, 1882), 7:82–83. In Higden's Latin version, “tertio nonas Septembris, qui dies ex prisca gentilium superstitione malus vel Egyptiacus dicitur, tanquam quodam Judaici eventus praesagio. Nam dies ille Judaeis Angligenis exitialis fuisse dinoscitur.” In the Middle English translation by Trevisa, John (1342–1402), “Þe þridde day of Septembre, þe whiche is accounted an evel day by þe veyn bileve and usage of mysbileved and usage of mysbileved men, as is i-cleped [in] þe kalender dayes dies Egipciacus, and dies malus, an evel day by þe veyn bileve, as it were a day of bodynge of evel happes to þe Iewes; [for þe Iewes of Engelond þat hadde evel] happes þat day.” Google Scholar

32 Thorndike, Lynn, “Computus,” Speculum 29 (1954): 232–33. In the medieval West, memory of the Ten Plagues also had a role in the magical use of the Tau cross as an emblem of divine power and protection. This use can be traced back to the symbol that God first gave to protect the Hebrews against the tenth and final plague (death of the first born). In Christian iconography, the Tau cross was used to represent the apotropaic signum that the Hebrews marked, using the paschal lamb's blood, on the lintels and doorposts of their homes (Exod. 12:12–13). Aaron was often shown painting Tau crosses on doorposts. In this way, the plague that God visited upon Egypt “passed over” their houses. The scriptural authority of Tau crosses may also rest on Ezek. 9:4, in which God said to the prophet, “Go through the midst of the city, through the midst of Jerusalem, and set a mark upon the foreheads of the men that sigh and that cry for all the abominations that shall be done in the midst thereof.” See Skemer, Don C., Binding Words: Textual Amulets in the Middle Ages, Magic in History (University Park, PA, 2006), 176–77.Google Scholar

33 Thorndike, Lynn and Kibre, Pearl, A Catalogue of Incipits of Mediaeval Scientific Writings in Latin , rev. ed., The Mediaeval Academy of America Publication 29 (London, 1963), col. 226; Mutz, Karl, “Computus chirometralis”: Spätmittelalterliches Lehrbuch für Kalenderrechnung lateinisch und deutsch, mit Kommentar, Tübinger Bausteine zur Landesgeschichte 3 (Tübingen, 2003), 108, 162–71; Smith, David Eugene, Le comput manuel de magister Anianus (Paris, 1928), 41–42 (Anianus, Computus manualis, part 2, lines 94–117); Wallis, Faith, “Medicine in Medieval Calendar Manuscripts,” in Manuscript Sources of Medieval Medicine , ed. Schleissner, Margaret R., Garland Medieval Casebooks 8, Garland Reference Library of the Humanities 1576 (New York, 1995), 107, 130–31 nn. 5, 6.Google Scholar

34 Steele, , “Dies Aegyptiaci” (n. 1 above), 112. Such calendrical mnemonics were part of the broader genre of computistic verse. On this subject, see Strecker, Karl, “Zu den komputistichen Rhythmen,” Neues Archiv 36 (1911): 317–42; Housman, A. E., “Disticha de mensibus,” Classical Quarterly 26 (1932): 129–36.Google Scholar

35 The twenty-four verses (“Prima diem primam Iani frons aspicit atram … Incursane telo ferit, articuli quoque denam) and explanatory verses were published in von Winterfeld, Paul, ed., Poetarum latinorum medii aevi , MGH 4, Poetae Latini aevi Carolini, pars prior (Berlin, 1899), 272. Concerning the author and text, see also Chartier, Yves, “Clavis operum Hucbaldi Elnonensis: Bibliographie des oeuvres d'Hucbald de Saint-Amand,” Journal of Medieval Latin 5 (1995): 209.Google Scholar

36 Steele, , “Dies Aegyptiaci,” 108–21; Hennig, , “Versus de mensibus” (n. 1 above), 65–90.Google Scholar

37 Steele, , “Dies Aegyptiaci,” 114.Google Scholar

38 Hennig, , “Versus de mensibus,” 83–84. Wormald, Francis, ed., English Benedictine Kalendars after A.D. 1100, HBS 77 (London, 1939), 95–111: “Principium Iani sancit tropicus capricornus / Iani prima dies et septima fine timetur / Prima d[i]es nona nocet hora septima quintam.” By comparison, the liturgical calendar in the Copenhagen Psalter (England, ca. 1170), Copenhagen, Kongelige Bibliotek, MS Thott 143 4°, includes “Iani principium sancit tropicus capricornus / Iani prima dies et septima a fine timetur,” but omits the dangerous hours (http://www.chd.dk/cals/th143kal.html). Chardonnens, , Anglo-Saxon Prognostics (n. 1 above), 362, identifies them in London, British Library, Caligula A.xv and Egerton 3314.Google Scholar

39 Pickering, F. P., The Calendar Pages of Medieval Service Books , Reading Medieval Studies (Reading, 1980), 11.Google Scholar

40 Steele, , “Dies Aegyptiaci,” 108; Wordsworth, , Ancient Kalendar (n. 25 above), 39; Piper, Ferdinand, Die Kalendarien und Martyrologien der Angelsachsen so wie das Martyrologium und der Computus der Herrad von Landsperg, nebst Annalen der Jahre 1859 und 1860 (Berlin, 1862), 21–24.Google Scholar

41 Wallis, , “Michael of Rhodes and Time-Reckoning” (n. 15 above), 290.Google Scholar

42 North, , “Kalenderes Enlumyned Ben They” (n. 12 above), 442 n. 1: “These evil days were carefully noted on perhaps the majority of fourteenth-century calendars.” Google Scholar

43 Thomas, Keith, Religion and the Decline of Magic: Studies in Popular Beliefs in Sixteenth and Seventeenth Century England (New York, 1997), 295, 616.Google Scholar

44 Pedersen, Olaf, “In Quest of Sacrobosco,” Journal for the History of Astronomy 16 (1985): 175–221, esp. 184–85, 206–8; Moreton, Jennifer, “John of Sacrobosco and the Calendar,” Viator 25 (1994): 229–44; Thorndike, Lynn, The Sphere of Sacrobosco and its Commentators, Corpus of Medieval Scientific Texts 2 (Chicago, 1949), 1–5.Google Scholar

45 Pedersen, , “In Quest of Sacrobosco,” 190: “Here we must remember the significant fact that Sacrobosco was never mentioned in extant documents from his own time. This points to the conclusion that he was not of great fame among the scholars of Paris while he lived and worked among them.” Google Scholar

46 Beichner, Paul E., ed., Aurora: Petri Rigae Biblia versificata: A Verse Commentary on the Bible , Publications in Mediaeval Studies 19 (Notre Dame, IN, 1965), 1:98 (Liber Exodus, verses 187–88). Vincent of Beauvais, Speculum naturale 15, 83 also associates Egyptian days with demon worship (Vincentii Burgundi … Speculum Quadruplex 1, col. 1143): “Alii dicunt quod Aegyptii sanguinem suum hiis diebus fundebant daemonibus, quorum errorem ne sequatur Ecclesia, cauet ab omnibus talibus.” Google Scholar

47 New York, New York Public Library, Manuscripts and Archives Division, MA 69. The text of De ratione anni begins on fol. 14r with a rubric (“Incipit compotus magistri Johannis de sacro buscho”) and a historiated initial that depicts Sacrobosco seated and pointing to the sun. Lucy Freeman Sandler provides an up-to-date description in Alexander, Jonathan J. G., Marrow, James H., and Sandler, Lucy Freeman, The Splendor of the Word: Medieval and Renaissance Illuminated Manuscripts at the New York Public Library (New York, 2005), 131–33, no. 74: “The manuscript is one of the earliest extant copies of the Sacrobosco texts. The material added on a formerly blank leaf now pasted down to the inside back cover, which refers to a royal marriage in Paris in 1262, is worded in a manner suggesting that it was written in or about that year, providing a terminus ante quem for the main text of the manuscript. A colophon at the end of the Computus refers to the death of Sacrobosco in 1244, fixing the terminus ante quem in that year. Convincing evidence of the date and provenance comes also from the illustrations, which are executed in a style consistent with works by Parisian ateliers in the middle of the thirteenth century, showing similarities in color, drawing, figure and facial types, and surface details to the work of lesser masters of the group around the so-called Dominican Painter.” Among other texts, the manuscript includes Sacrobosco's, Quadrans, De sphaera mundi, and Algorismus. A description based in large part on Sandler's research is available online in the Digital Scriptorium : http://app.cul.columbia.edu. The description proposes a dating of 1240–60. For another description, see Thorndike, , The Sphere of Sacrobosco, 68–69 (manuscript designated N). Thorndike expanded Sacrobosco's year of death on fol. 169v (“m xpi bis c quarto deno qu[ar]t[u]s anno”) as 1244 (i.e., four and four times ten), not 1256 (i.e., four times fourteen). In the lower left margin of fol. 26v, close to the Armis gunfe mnemonic verses, an early reader added a version of “De decem plagis,” a popular five hexameter poem by Hildebert of Lavardin (ca. 1056–1133 or 1134), which concerns the Ten Plagues: “Prima rubens unda, ranarum plaga secunda / Inde culex tristis, post mea nociuior istis / Quinta pecus sternit, viscera sexta creauit / Pone subit grando, post brucus dente nefando / Nona legit solem, primam tegit ultima prolem.” Walther, Hans, Initia carminum ac versuum medii aevi posterioris latinorum: Alphabetisches Verzeichnis der Versanfänge mittellateinischer Dichtungen (Göttingen, 1959) 1, no. 14595, identifies seventy-six copies in manuscripts. Other versions are in Wordsworth, , Ancient Kalendar, 191, 254.Google Scholar

48 Princeton University Library, Garrett MS 99, fol. 144r–v: “Armis gunfe, dei calathos, adamare dabatur, / Lixa memor, conflans gelidos, limfancia quondam, / Omne limine, aaron bagis, consorcia laudat, / Chye linkat, ei coequata, geracta lifardos.” For a description, see Thorndike, Lynn, The Sphere of Sacrobosco , 70–71, which cites Garrett MS 99 as siglum O .Google Scholar

49 Treatments in monastic infirmaries might be accompanied by ecclesiastical benedictions, also preserved in manuscripts. See Franz, Adolf, Die kirchlichen Benediktionen im Mittelalter (Freiburg im Breisgau, 1909), 1:645–46.Google Scholar

50 Thorndike, Lynn, “Unde versus,” Traditio 11 (1955): 163–93, at 170. Walther, , Initia carminum 1, no. 1496.Google Scholar

51 Concerning the art of memory, see Yates, Frances A., The Art of Memory (Chicago, 1966), 1–4, 97, 122; Carruthers, Mary, The Book of Memory: A Study of Memory in Medieval Culture (Cambridge, 1990), 80, 144, 308 n. 1; Carruthers, Mary and Ziolkowski, Jan M., eds., The Medieval Craft of Memory: An Anthology of Texts and Pictures (Philadelphia, 2002), 1–29, esp. 10; Illich, Ivan, In the Vineyard of the Text: A Commentary to Hugh's Didascalicon (Chicago, 1993), 43–47; Black, Robert, Humanism and Education in Medieval and Renaissance Italy: Tradition and Innovation in Latin Schools from the Twelfth to the Fifteenth Century (Cambridge, 2001), 55–56, 76, 81, 118–20, 168, 290.Google Scholar

52 For the word gumphus and variants, see Herrtage, Sidney J. H., ed., Catholicon anglicum , Camden Society Publications, n.s., 20 (London, 1882), 85; Latham, R. E., Revised Medieval Latin Word-List from British and Irish Sources (London, 1965), 218; Fuchs, Johan Wilhelmus, Weijers, Olga, and Gumbert-Hepp, Marijke, eds., Lexicon Latinitatis Nederlandicae medii aevi (Leiden, 1988), fasc. 29:2276.Google Scholar

53 In medieval calendars, Janus was often depicted between two doors; see Kolve, V. A., Telling Images: Chaucer and the Imagery of Narrative II (Stanford, 2009), 99–102.Google Scholar

54 Aaron's staff or flowering rod (virga Aaron), discussed in Num. 17:1–12, was his attribute in Christian art. The virga was used to perform divine miracles and unleash several of the plagues upon Egypt. But the distich Aaron bagis (sometimes spelled bigis), which could mean a two-horsed chariot, can probably not be explained as a corruption of Aaron virga. As for other words and distichs, March, adamare dabatur, could be interpreted as “dedicated to loving”; April, lixa memor, “a mindful scullion”; May, conflans gelidos, “melting frozen things”; June, limphantia quondam, “once frenzied”; September, consortia laudat, “one extols fellowship”; and November, ei coequata, “equal to it.” Two other words may be names: October, Chie, may relate to the island of Chios, and December, lifardus, to St. Liphardus or Lifard of Orleans (ca. 550).Google Scholar

55 Steele, , “Dies Aegyptiaci” (n. 1 above), 110; Wordsworth, , Ancient Kalendar, 190. In connection with the “Augurio decies” mnemonic, Christopher Wordsworth explained, “The entire alphabet would not supply sufficient numerating letters for a month of thirty days or so, but this device of counting from each end enables us to make shift with fifteen letters (the sixteenth day of a thirty-one-day month being, happily, never unlucky), and the system has the advantage of corresponding with the retrograde counting in the latter part of the monthly lines, ‘Prima dies mensis,’ etc.” Wordsworth identified the method as “Bononian.” Concerning consuetudo Bononiensis, see Grotefend, Hermann, Handbuch der historischen Chronologie des deutschen Mittelalters und der Neuzeit (Hanover, 1872), 34. Grotefend suggests origins in Bologna just before the eleventh century.Google Scholar

56 King, David A., The Ciphers of the Monks: A Forgotten Number-Notation of the Middle Ages , Boethius: Texte und Abhandlungen zur Geschichte der Mathematik der Naturwissenschaften 44 (Stuttgart, 2001), 180–81, 293–94, 306–7, 322; Menninger, Karl, Number Words and Number Symbols: A Cultural History of Numbers , trans. Broneer, Paul (Cambridge, MA, 1969), 265; Price, Derek J., ed., The Equatorie of the Planets: Edited from Peterhouse MS 75. I (Cambridge, 1955), 184.Google Scholar

57 Williams, Burma P. and Williams, Richard S., “Finger Numbers in the Greco-Roman World and the Early Middle Ages,” Isis 86 (1995): 587–608; Kusukawa, Sachiko, “A Manual Computer for Reckoning Time,” in Writing on Hands: Memory and Knowledge in Early Modern Europe , ed. Sherman, Claire Richter and Lukehart, Peter M., with contributions by Copenhaver, Brian P. and others (Carlisle, PA, 2000), 28–35; Menninger, , Number Words and Number Symbols, 208–12.Google Scholar

58 Pedersen, , “In Quest of Sacrobosco” (n. 44 above), 184–85; Jordanus: An International Catalogue of Mediaeval Scientific Manuscripts (Munich, Institute for the History of Science; Berlin, Max Planck Institute for the History of Science), http://jordanus.ign.uni-muenchen.de. Sharpe, Richard, A Handlist of the Latin Writers of Great Britain and Ireland before 1540, Publications of the Journal of Medieval Latin 1 (Turnhout, 1997), 306: “Glorieux records 15 copies out of more than a hundred known.” Google Scholar

59 Basel, Universitätsbibliothek, Cod. B.viii.27, fols. 293r–308r; and York, Minster Library, MS Add. 34, fols. 185r–189v. Mosimann, Martin, Die “Mainauer Naturlehre” im Kontext der Wissenschaftengeschichte , Basler Studien zur deutschen Sprache und Literatur 64 (Tübingen, 1994), 377–90, esp. 384, and pocket supplement Transkription und Textsynopse, 42–45, which includes the Mainauer Naturlehre and its Latin sources, especially Sacrobosco, in parallel columns. The German text gives this Latin version: “Armis gunfe. dei calatos. adamare dabatur. Lixa memor. conflans gelidos. limpfantia quosdam. Omne lumen. aaron bagis. consortia laudat. thie linkat. ei coequata. gracia liphradus.” Editions of the Mainauer Naturlehre include Wackernagel, Wilhelm, ed., Meinauer Naturlehre, Bibliothek des Litterarischen Vereins in Stuttgart 22 (Stuttgart, 1851), 18; Plant, Helmut R., Rowlands, Marie, and Burkhart, Rolf, eds., Die sogenannte “Mainauer Naturlehre” der Basler Hs. B VIII 27: Abbildung, Transkription, Kommentar, Litterae: Göppinger Beiträge zur Textgeschichte 18 (Göppingen, 1972), 27 (fol. 303r); “Mainauer Naturlehre um 1300,” in Bibliotheca Augustana , http://www.fh-augsburg.de/~harsch/germanica/Chronologie/14Jr/Naturlehre. Concerning the text, see also Deighton, Alan, “Mainauer Naturlehre,” Zeitschrift für deutsches Altertum und deutsche Literatur 126 (1997): 200–212; Brévart, Francis B., “Die ‘Mainauer Naturlehre’: Ein astronomisch-diätetisch-komputistisches Lehrbuch aus dem 14. Jahrhundert: Mit einer Quellenuntersuchung,” Sudhoffs Archiv 71 (1987): 157–79.Google Scholar

60 Schnall, Jens Eike, “Die dies mali und andere Unglückstage: Kontextualisierung, Kompilationsmuster und Wissensordnung in nordeuropäischen Handschriften des Spätmittelalters,” Opuscula 12 (2005) (= Bibliotheca Arnamagnana 44), 355–57. Copenhagen, Kongelige Bibliotek, Thott 57; Reykjavik, Stofnun Árna Magnússonar á Íslandi, AM 727.Google Scholar

61 The printed edition of the Computus ecclesiasticus by Crato, Johannes (1568) has a special half-title: Libellus Ioannis de Sacro Busto, De anni ratione, seu ut vocatur vulgo, Computus ecclesiasticus cum praefatione Philippi Melanchtonis; anno M.D.LVIII. Concerning Melanchton's edition, see Reich, Karin and Knobloch, Eberhard, “Melanchtons Vorreden zu Sacroboscos ‘Sphaera’ und zum ‘Computus ecclesiasticus,”’ in Dick, Wolfgang R. and Hamel, Jürgen, eds., Beiträge zur Astronomiegeschichte 7 Band 7 , Acta Historica Astronomiae 23 (Thun, 2004), 14–44. Concerning this and many other early editions, go to “Editions of Sacrobosco's Tractatus de Sphaera” (http://ghtc.ifi.unicamp.br/Sacrobosco/Sacrobosco-ed1.htm).Google Scholar

62 Hopton, Arthur, A Concordancy of Yeares , chapter 24 (London, 1612), 73: “Armis Gunfe, Dei Kalatos, Adamare dabatur. / Lixa memor, Constans gelidos, Infancia quosdam. / Omne limen, Aaron bagis, Concordia laudat. / Chije linkat, Ei Coequata, Gearcha Lisardus.” On 73–74, Hopton paraphrases Sacrobosco's accompanying instructions but adds additional details for clarity: “Of the words in these foure verses every two serve for one moneth, the first standing for January: If therefore you desire to know the first of the two former fatall daies in any moneth, count so many daies from the beginning of the moneth descending, as the first letter in the first word is distant from A inclusively, according to the Alphabet, & where that number ends, there is a fatall day; as in Aprill L. (beginning Lixa) is the 10[th] letter in the Alphabet, therefore the 10[th] day is fatall, and according to the number of the first letter (in the order of the Alphabet) of the second sillable, the said houre of the said day is vehemently to be suspected. But to have the second fatall day of the moneth, you must reckon so many daies from the last day of the moneth ascending, as the number of the first letter of the second word, for the moneth, commeth unto in the order of the Alphabet, as in Aprill M, for Memor, is the 11[th] letter in the Alphabet, therefore the 11[th] day before the last of Aprill is a fatall day, which is the 19[th] day of Aprill, and so as before, the first letters of the second sillable doth shew the most infortunate houre, according to the number of the Alphabet, and you must note, that H in this account is taken for no letter.” Hopton's account is quoted in Elworthy, Frederick Thomas, The Evil Eye: An Account of This Ancient and Widespread Superstition (London, 1895), 409. Concerning Hopton, a member of Clement's Inn, London, and compiler of almanacs with annual prognostications from 1607 until the year of his death, see Lee, Sidney, ed., Dictionary of National Biography (Oxford, 1908), 9:1240; De Morgan, A., “Some Incidental Writings by De Morgan,” The Mathematical Gazette 9, no. 130 (1917): 114. Schnall, , “Die dies mali und andere Unglückstage,” 356 n. 38.Google Scholar

63 Lynn Thorndike argues that the text shows Sacrobosco's mastery of astronomy and a wider reading and access to books than his Sphaera mundi and Algorismus, which the author had completed earlier. Thorndike, , The Sphere of Sacrobosco (n. 44 above), 6–11. Most scholars seem to accept Thorndike's dating of De anni ratione. Google Scholar

64 Pedersen, , “In Quest of Sacrobosco,” 193, 206.Google Scholar

65 Dales, Richard C., “The Computistical Works Ascribed to Robert Grosseteste,” Isis 80 (1989): 75: “there is a great deal of similarity among computi in general, and much of the computational instruction in both the Compotus I and De anni ratione appears nearly verbatim in dozens of twelfth- and thirteenth-century computi.” Google Scholar

66 Moreton, , “John of Sacrobosco and the Calendar” (n. 44 above), 234–39. Seven of the extant manuscripts of the Computus ecclesiasticus listed in Appendix A (pp. 240–42) are in English libraries and one in an Irish library. For example, the mnemonic is not found in the text titled Compotus ecclesiasticus, misattributed to Sacrobosco, in a thirteenth-century British manuscript (Oxford, Bodleian Library, Ashmole MS 1285, fols. 107–17). I am grateful to Prof. Ralph Hanna, Keble College, Oxford, for checking the manuscript.Google Scholar

67 These mnemonic verses had regional variants, aside from “Augurio decies audito lumine clangor liquet olus abies coluit olus oscula gallus.” For example, a twelfth-century manuscript calendar from Calahorra Cathedral, Archivio Catedral (Códice III), La Rioja region of north-central Spain, uses the mnemonic “Argue. Dicentes. Ad. Lumen. Coge. Loquentes. Ollas. Alba. Calet. Colit. Excluso. Galileo” (González, Ana Suárez, “A propósito de los días aciagos en un calendario medieval Calagurritano,” Kalakorikos 6 [2001]: 101–13, esp. 110).Google Scholar

68 Borst, Arno, The Ordering of Time: From the Ancient Computus to the Modern Computer , trans. Winnard, Andrew (Chicago, 1993), 75–76.Google Scholar

69 Steele, Robert, ed., Computus Fratris Rogeri , Opera hactenus inedita Rogeri Baconi, fasc. 6 (Oxford, 1926), 273; Van Wijk, , Le nombre d'or (n. 13 above), 55, 75.Google Scholar

70 The Augurio decies mnemonic verses, without the accompanying verses for dangerous hours, were incorporated into other texts. Vincent of Beauvais (ca. 1190–1264?), who was in Paris from around 1215 to 1220 but spent most of his life in Beauvais, used the verses “Argue discernens ad lucem coge loquelas ollas abbatum cole calibus excute gallum” in his Speculum naturale (15:83). Guillelmus Durandus included the mnemonic verses “Augurior decies audito lumine clanguor liquit olens abies coluit colus excute gallum,” in his Rationale divinorum officiorum (8:4:20), along with an explanation about their use (“In his versibus sunt xii dictiones”) to determine Egyptian days and their uniquely dangerous hours (“propter unicam horam sui”). A version of these mnemonic verses is also found in Pheffer Kuchel, a computus manual that survives in a fifteenth-century manuscript (Vatican City, Bibliotheca Apostolica Vaticana, Latin MS 1367). Thorndike, , “Computus” (n. 32 above), 226, 236: “Dies egiptiacas invenire. Scias quod unaqueque dictio istius versus desservit uni mensi (sic) Augmo decies audito lumine clango. Unquam oleis abies coluit colus escula gallus, etc. De horis eiusdem scias quod unaqueque dictio istius versus desservit uni mensi. Mimus agit sedes yskyros afflicis amphylus aufert.” These verses survived into the age of print. For example, we find them in the Compotus manualis ad usum Oxoniensium (porcio 4, lines 235–40), printed by Charles Kyrfoth in Oxford, 1519–20. The mnemonic verses were typeset using italics for the initial letters of syllables in each calendrical verse to facilitate their use in calculating Egyptian days (dies aegri) and dangerous hours. There are some differences in wording, leading to slightly different Egyptian days and dangerous hours, yet the underlying methodology and results are similar (Wordsworth, , Ancient Kalendar [n. 25 above], 173, 189–91). The Compotus manualis uses a two-part alphabet with ten letters in each half (A–G, I, K–L; and M–X), omitting the letter H in counting though included in the word habet (“Omnibus in reliquis, sed non hic H numerabis”).Google Scholar

71 Mutz, , “Computus chirometralis” (n. 33 above), 3.Google Scholar

72 Thorndike, , The Sphere of Sacrobosco , 70–71. These annotations seem to be in the same hand as a fourteenth-century annotation to Sacrobosco at the end of the first column on fol. 162r, mentioning the year 1297. Thorndike transcribed the annotation in The Sphere of Sacrobosco, 70, as follows: “1297 anno 10 indictionis 87e ita debet scribi in cartis et aliis 5 die Ianuarii explevi au[ ] librum unum. ita debet.” Thorndike noted (70 n. 75), “it would seem that this must have reference to a past transaction, whether financial, alchemical, or literary. Certainly, it is wrong if it makes Sacrobosco say in the first person that he finished the Computus in 1297…. The same hand has inserted in the Calendar three Dominican feasts: St. Thomas Aquinas, the Crown of Thorns, and the Translation of St. Dominic. As Aquinas was not canonized until 1323, it would appear that the writing is after that date.” In the collection file for Garrett MS 99 (Manuscripts Division, Department of Rare Books and Special Collections), there are three letters from Thorndike (4 January 1946; 4 February 1946; and 7 July 1947). Not mentioned by Thorndike is a marginal annotation at the bottom of fol. 154v, which reads in part, “In quo nos sumus quod est 1296.” As with New York Public Library MA 69, the annotator of Garrett MS 99 has annotated Sacrobosco's discussion of the Ten Plagues. The annotator numbered the words in Sacrobosco's mnemonic about the Ten Plagues and added an eleven-line marginal note about them. Near the top of fol. 236r is a note in another hand of the fourteenth century, pertaining to book lending, presumably by the owner of the manuscript: “[ ] habet antidotarium nicholai cum glosuliis / et habet duos illos paruos libros de astronomia / Magister johannes de pavia habet de me diascoridem.” The name of the first borrower was erased and is not readable under ultraviolet light. The second borrower was a certain John of Pavia, but the writing is too late to be the same Magister Johannes Papiensis (fl. ca. 1239) responsible for “Canones super tabulas eius que dicuntur almanach” in Oxford, Bodleian Library, Laud. Misc. 644, fols. 175r–176v. See Thorndike, Lynn, “Notes upon Some Medieval Latin Astronomical, Astrological, and Mathematical Manuscripts at the Vatican,” Isis 49 (1958): 42. The books borrowed included a glossed copy of Nicholas of Salerno (fl. ca. 1140), Antidotarium; Dioscorides (ca. 40–ca. 90 c.e.), De materia medica; and two small manuscripts of astronomical texts.Google Scholar

73 Halliwell, James Orchard, ed., Rara mathematica, or A Collection of Treatises on the Mathematics and Subjects Connected with them, from Ancient Inedited Manuscripts , 2nd ed. (London, 1841), 1–26 (Joannis de Sacro-Bosco Tractandus de arte numerandi).Google Scholar

74 For example, a thirteenth-century scribe responsible for copying Sacrobosco's De anni ratione misread the word geracta (December), which should have been divided ger|acta. Instead, the scribe wrote gersicta, which would have been divided ger|sicta. Vienna, Österreichische Nationalbibliothek, Codex Vindobonensis Palatinus, no. 2445, fol. 19v: “Armis gunfe, dei calatos / adamare dabatur, lixa memor, / conflans gelidos, limfantia quosdam / omine limen, aaron bagis, / consortia laudat, chie linkat / ei coequata, gersicta lifardus.” Google Scholar

75 Schnall, , “Die dies mali und andere Unglückstage” (n. 60 above), 351.Google Scholar

76 Pedersen, Fritz Saaby, ed., Petri Philomenae de Dacia et Petri de Audomaro: Opera quadrivialia , Corpus Philosophorum Danicorum Medii Aevi 10, 1–2 (Copenhagen, 1983–84), 10.1:222–23, 259–60.Google Scholar

77 A full description of the manuscript will be in Skemer, Don C., ed., Medieval and Renaissance Manuscripts in the Princeton University Library , 2 vols. (forthcoming). Concerning the main text, see Mütz, Karl, “Computus chirometralis.” Princeton MS 168 is not among some 100 extant Computus chirometralis manuscripts listed in Lorenz, Sönke, Studium generale Erfordense: Zum Erfurter Schulleben im 13. und 14. Jahrhundert, Monographien zur Geschichte des Mittelalters 34 (Stuttgart, 1989), 249–60. The text was probably written in Erfurt around 1330. Many manuscripts attribute the text to John of Erfurt, a Franciscan, who was also known as Johannes de Erfordia or Johannes Erfordiensis. Sönke Lorenz has argued more recently that Johannes Eligerus [or Algeri] de Gondersleuen, also of Erfurt, was the probable author. See ibid., 258, and “Johannes Algeri (Eligerus), Verfasser des Computus chirometralis: Ein Erfurter Astronom und Mathematiker der ersten Hälfte des 14. Jahrhunderts,” in Mütz, , Computus chirometralis, 184–90.Google Scholar

78 For a description of Uppsala, Universitetsbibliothek, MS C 19, see Andersson-Schmitt, Margarete and Hudlund, Monica, Mittelalterliche Handschriften der Universitetsbibliothek Uppsala, Katalog über die C-Sammlung, 1. CI-IV, 1–50 (Stockholm, 1988), 1:109–21 (“Armis gumfe” at 200). As a result of a modern binding error, the continuation of the Armis gunfe text beginning on fol. 8v is on fol. 312r (Nelson, , “Dies Aegyptiaci” [n. 1 above], 185–96, esp. 194–95).Google Scholar

79 Aberdeen, , University of Aberdeen, Library and Historic Collections, MS 123, fol. 51v: “Armis gunfe, de talathos, adomare dabuntur, / Lixa memos, conflans gelidis, limphancia quosdam, / Omen limen, aron basis, concordia laudis, / Chie lincant, ei quoequata, gerarca leperdos.” For a description of the manuscript, see Ker, N. R., Medieval Manuscripts in British Libraries (Oxford, 1977), 2:4–11 (cited at 6).Google Scholar

80 New York, Columbia University Library, Rare Books and Manuscripts Library, Smith Western Add. MS 1, fol. 49v: “Armis guffe, Dei calatos, Adamare dabatur, / Lixa memor, Conflas gelido, Linphantia quosam, / Chie linkat, Cito equatitia, Gerata lifardos.” The Computus ecclesiasticus (fols. 40r–79r) has the incipit “Dicta prius dico breviter collecta novella.” For a description of the manuscript, which was acquired by Columbia in 1952 from the estate of the New York antiquarian bookseller Wilfrid Voynich, see Digital Scriptorium (http://app.cul.columbia.edu:8080/exist/scriptorium).Google Scholar

81 Vienna, , Österreichische Nationalbibliothek, Codex Vindobonensis Palatinus, no. 2520, fol. 5v (Sacrobosco, De anni ratione): “Armis gunphe, dei calatos, / adamare dabantur, lixa memor, / conflans gelidos, limphatica quosdam, / omne limen, aron bocharis, / consorcia laudat, chie linkat, /ei coequata, geracta liphardus.” Concerning the spelling in the Icelandic manuscript, see Schnall, , “Die dies mali und andere Unglückstage,” 357.Google Scholar

82 The early printed edition used in the present article is Iohannis de Sacro Busto Libellus de sphaera: Accessit eiusdem auctoris computus ecclesiasticus, et alia quaedam, in studiosorum graiam edita; cum praefatione Philippi Melanthonis (Wittenberg, 1568), L2 verso–L3 recto. Armis gunfe is on L3: “Armis Gunfe, Dei Kalatos, adamare dabatur, / Lixa memor, conflans gelidos, linfancia quosdam, / Omine limen, Aaron bagis, concordia laudat, / Chijæ linkat, ei coequarta, gearcha lifardus.” The author acknowledges Dr. Johann Tomaschek, Admont Stiftsbibliothek, for providing a copy of Admont Cod. 442, fol. 57r, in which the mnemonic reads as follows: “Armis gunfe, dei kalathos, adamare dabatur, / Lixa memor, conflans gelidos, linfancia quosdam, / Omne lumen, aaron bagis, consorcia laudat, / Chie linkat, ei coequarta, getacta lifardus.” Google Scholar

83 Parry, William T. and Hacker, Edward A., Aristotelian Logic (Albany, NY, 1991), 282–83.Google Scholar

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85 Thorndike, Lynn, “Magic, Witchcraft, Astrology, and Alchemy,” CMH, ed. Previte-Orton, C. W. and Brooke, Z. N. (Cambridge, 1936), 8:682–83: “The Middle Ages has always been given to visions, revelations, and prophecies, especially the coming of Antichrist, but these seem to have reached their height, both in number and fantasticalness, in the troubled times of the Hundred Years' War, the Black Death, and the Great Schism.” Google Scholar

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88 The two heavily abbreviated manuscript texts have been transcribed in a modified diplomatic style. Abbreviations and contractions have been silently extended, and superscript letters have been brought down to the line. Original capitalization has been retained, but the first letter in each sentence has been capitalized for the sake of clarity. Original spelling has been retained, including the use of u for v, and j for i. The ampersand and the Tironian note 7 are transcribed as the Latin et. Word separation is normalized. In the interest of clarity, punctuation has been normalized, and references in the instructions, words quoted from the mnemonic verses, or letters of the alphabet have been italicized. Crossed-out words and interlinear additions are shown as they appear in the manuscripts.Google Scholar