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William the Englishman


(fl. France, thirteenth century)

astronomy, astrology.

All that is known of William’s life is that he was a physician who lived in Marseilles during the first half of the thirteenth century. Of the works that have been variously attributed to him, four, De urina non visa, an Astrologia, a Summa super quarto libro metheorum, and a treatise on the astrolabium Arzachelis, or saphea, may be considered to be his with some certainly. All four may be dated between 1220 and 1231. A number of other works may be less clearly ascribed to William.

Of the tracts known to be by William (Guillelmus Anglicus Civis Marsiliensis), the first, De urina non visa (“Ne vel ignorancie vel potius invidie redarguar mi germane . . .”), is a brief argument that an astrologer’s prognostication of an illness, based on astral conjuctions, may have the same validity as that of a physician who has been able to observe the symptomatology of the patient. William here cites the case of a patient whom he himself had examined, and for whom he would live for another two months and eight days; his prediction proved correct. The planetary positions upon which he based it indicate that the diagnosis could have been made only in the last days of the year 1219; the De urina non visa cannot have been written before 1220, and the date 1219 that occurs in one manuscript must have meant anno completo.1

The text of William’s Astrologia is undated, but a manuscript in the Biblioteca Capitular Colombina in Seville ascribes it to 1220. This treatise, which begins “Quoniam astrologie speculatio prima figuram ipsius . . .,” is a theory of the planets that follows, like a commentary, the canons of the Toledan Tables, although they are never referred to specifically. The work opens with a description of the astrolabe and some of its uses, then reviews the principles of stereographic projection, together with a note on the construction of an instrument azimatal for taking meridian altitudes. William does not give any exact information about the eccentricities of the planets, the length of the radii of the epicycles, or the duration of their revolutions; his materials on the conjunctions of the sun and moon and on eclipses is, however, developed at some length. The examination of the movement of the eighth sphere-that is, the motion of “accession and recession” -was discussed at the end of the treatise, as in the canons of al-Zarqālī.

The only known manuscript of the Summa super quarto libro metheorum, which begins “Rerum corruptibilium effectus ut ad nutum et voluntatem . . .,” gives 1230 as the date of the text. This rather brief text is organized into three parts, of which the first deals with terrestrial phenomena, both those originating within the earth (water, gems, and minerals) and those found upon its surface (as, for example), alums and salts). The second section treats of aerial, or meteorological matters, including evaporation, dew, rain and snow, ice, winds, earthquakes, and rainbows, while the concluding portion discusses the ethereal region of shooting stars, thunder, lightning, and comets, William drew the hypothesis that the Flood had resulted from the joining together of the waters that fall from the sky and the waters that well up from the depths of the earth. He further attributed the Passiones etheris to vapors rising from the earth, the nature of the phenomenon being dependent upon the nature and form of the ascendant vapor-thus, dry vapors moving directly upward create shooting stars.

William’s treatise on the saphea, or astrolabium Arzachelis, beginning “Siderei motus et effectus motuum speculator . . .,” represents the introduction of this instrument into the Latin West. Invented in the eleventh century by ‘Alī ibn Khalaf or by al-Zarqālī,2 the saphea is, like the astrolabe, conceived on the principle of the stereographic projection of both the movable sphere of the stars and the zodiac and a fixed sphere of celestial reference; it differs from the astrolabe in that the pole of projection is one of the points of intersection of the ecliptic and the zodiac, while the plane of projection is that of the colure of the solstices.

Contrary to what is generally believed, William’s treatise on the saphea is not an abridgment of al-Zarqālī’s, which became known in the Latin West only through Ibn Tibbon’s translation of 1263. It is likely that William knew of this kind of projection only by hearsay and had never seen it put into practice, since the method he himself proposes and upon which he says he worked for six years is at best rather clumsy. William attempted to construct the almucantars of the horizon by piercing small holes on the limb of his instrument and holding strings parallel to the diameter by which this horizon was projected. Thus the instrument he describes is characterized by both the sterographic projection proper to the saphea and by the orthographic projection invented by J. de Rojas in the middle of the sixteenth century.3 The saphea devised by al-Zarqālī, which became known to the West in 1263, used the almucantars of the equator as a provisional coordinate system: a reference point could then be selected on this system and moved to that of the horizon by means of a ruler. He remained true to the tradition of the astrolabe, inscribing twenty stars on his saphea although they have no purpose on it. Their positions were taken directly from al-Zarqālī’s table, which had been established according to Ptolemy’s positions, with the addition to the longitudes of a constant of 14°7′s.4

In addition to these works, a number of others attributed to William remain problematical. Confusions and improbable identifications with other Williams, notably Guillaume Grisaunt and William of Aragon5 have further wrongly extended the list. A De virtute aquile attributed to a “Guillelmus Anglicus” is known in only one manuscript.6 While the sixteenth-century bibliographer John Bale composed a list of nine titles, of which six are given with their incipits,7 only one corresponds to a genuine work, the Astrologia. The other works ascribed by Bale to William are all to some degree suspect. A De quadratura circuli (“Aristoteles in eo qui de categoriis . . .”) is found in other manuscripts only under the name of Campanus;8 a De motu captis (“Motum accessionis et recessionis . . .”) and a De magnitudine solis (“Dico quod sol apparet mag . . .”) have not been located; a De qualitatibus signorum (“Cum humana corpora sint omnia . . .”) has been erroneously cited by E. Zinner in a manuscript at Bamberg which does not contain the incipit given;9 a De significatione signorum cannot be identified for lack of an incipit; a De urina non visa has an aberrant incipt (“De corpore quidem humano Satur . . .”); and a De judicio patientis and a De causa ignorancie are probably doublets of the De urina.10

The attribution to a “W. A.” by Wellcome manuscript 175 of a pseudotranslation of Abū-l-Qāsim ‘Ammor’s (Conamusoli) De infirmitate oculorum likewise cannot be maintained,11 while the De stellis fixis that P. Duhem has put forward as William’s translation of a treatise by al-Zarqālī is in fact only the star table appended to the treatise on the saphea. The Scripta Marsiliensis or Scripta super canones Azarchelis (beginning “Cum,” or “Quoniam, cujuslibet actionis; liber iste scilicet canones tabularum . . .”),12 a commentary on the canons of the Toledan Tables, cannot be by William, although sometimes ascribed to him, since it alludes to the turquet, and therefore cannot have been written earlier than the end of the thirteenth century. (The first treatise on this instrument was in fact written by either Francon of Poland in 1284 or by Bernard of Verdun at a slightly earlier date.)13 It is further worth noting that the Scripta Marsiliensis suggests, especially in certain aspects of the development of its treatment of the movement of the eighth sphere, the commentary on these same canons written by John of Sicily in 1291.14


1. L. Thorndike, A History of Magic and Experimental Science, II, 485–486, n. 5. Simon de phares, Recueil des plus célébres astrologues . . ., E. Wickersheimer, ed. (Paris, 1929), 180, 191, devoted two accounts to William the Englishman: one for the beginning of the twelfth century, in which he also attributed to the author of the De urina non visa a prediction of the destruction of Liége, and one for 1219, in which he alludes to a “book of astrology” the first words of which (“De ignorantie . . .”) recall those of De urina.

2. J.-M. Millás Vallicrosa, Estudios sobre Azarquiel (Madrid-Granada. 1943–1950), 438–447. On the theory of the saphea, see S. Garcĺa Franco, Catalogo crĺtico de astrolabios existentes en España (Madrid, 1945), 64–65; H. Michel, Traité de l’astrolabe (Paris, 1947), 95–97.

3. Michel. op. cit., 20, 105–107; and F. Maddison, Hugo Helt and the Rojas Astrolabe Projection (Coimbra, 1966: Agrupamento de Estudos de Cartografia Antiga, no. 12).

4. The MS tradition of William’s star table is so mediocre that its origin is difficult to uncover; on this table see P. Kunitzsch, Typen von Sternverzeichnissen in astronomischen Handschriften des 10. bis 14. Jahrhunderts (Wiesbaden, 1966), 77.

5. Thorndike, op. cit., 301.

6.Ibid., 487.

7. J. Bale, Scriptorum illustrium Majoris Brytannie, I (Basel, 1557), 446; the same information can be found in Bale’s Index Britanniae scriptorum, R. L. Poole and M. Bateson, eds. (Oxford, 1902), 114–115.

8. This attribution is examined and the text is edited by M. Clagett, Archimedes in the Middle Ages, I (Madison, Wis., 1964), 581–609; to the twelve MSS cited add Columbia University Smith add. 1, fols. 138v-139.

9. E. Zinner, Verzeichnis des astronomischen Handschriften des deutschen Kulturgebietes (Munich, 1925), 4034.

10. J. Bale, Scriptorum, II (1559), 46, also notes a Guillelmus Anglicus who is the author of a De incarnatione verbi and of a Commentarium de anima that are hardly likely to be by the citizen of Marseilles. C. H. Lohr, “Medieval Latin Aristotle Commentaries,” in Traditio,24 (1968), 194, who has not identified this William, does not indicate the author of the commentary on the fourth book of the Meteorology.

11. See G. Sarton, Introduction to the History of Science, I (Baltimore, 1927), 729.

12. A short extract was published by M. Curtze. “Urkunden zur Geschichte des Trigonometrie im christlichen Mittelalter,” in Bibliotheca mathematica, 3rd ser., 1 (1900), 321–416: no. 3 (347–353), “Aus den Scripta Marsiliensis super canones Azarchelis.” MSS are Berlin F. 246, fols. 144–154v; Erfurt F. 394, fols. 111v-119.

13. E. Poulle. “Bernard de Verdun et le turquet,” in Isis.55 (1964), 200–208.

14. The following text (188–190) that Sédillot published does not belong to the treatise of William the Englishman; it is the first chapter of Ibn Tibbon’s translation (in 1263) of the treatise by al-Zarqālī.


I. Original Works. The De urina non visa is preserved in numerous MSS; to those cited in L. Thorndike, A History of Magic and Experimetnal Science, II (New York, 1923, 485–486, add Berlin F. 246, fols. 252v-254v; Cracow 551, fols. 122–124; Oxford, Hertford Coll. 4, fols. 44–46v. A French trans. of this text is cited by J. Camus, “Un manuscrit namurois du XVe siècle,” in Revue des langues romanes,38 (1895), 31–32. The Astrologia is preserved in the following MSS: Erfurt F. 394, fols. 136–140v; Erfurt 4° 357, fols. 1 “21; Paris lat, 7298, fols. 111v-124v; Seville 5-I-25, fols. I-33; Vienna 5311, fols. 42–51v. Of the Summa super quarto libro metheorum, only one MS is known: Paris lat. 6552, fols. 39v-41v.

As for the treatise on the saphea, the section on its construction was published by L. A. Sédillot, “Mémoire sure les instruments astronomiques des Arabes,” in Mémoires présentés par dives savants à l’Académie des inscriptions et belles-lettres, 1st ser., 1 (1844), 185- 188, text repr. in R. T. Gunther, The Astrolabes of the World, I (Oxford, 1932), 259–262; and that on its uses by P. Tannery, “Le traité du quadrant de maitre Robert Anglés,” in Notices et extraits des manuscrits de la Bibliothéque nationale, 35, pt. 2 (1897), 75–80, repr. in his Mémories scientifiques, V, 190–197.

II. Secondary Literature. Brief accouts of William are in P. Duhem, Le systéme du monde, III (Paris, 1915), 287–291; L. Thorndike, A History of Magic and Experimental Science, II (New York, 1923), 485–487; E. Wickersheimer, Dictionnaire biographique des médecins en France au moyenâge (Paris, 1936), 224–225; and C. H. Talbot and E. A. Hammond, The Medical Practitioners in Medieval England (London, 1965), 381- 382.

Emmanuel Poulle

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Englishman, William the

Englishman, William the (fl. 1174–d. c.1214). English master-mason. He worked under William of Sens on the rebuilding of Canterbury Cathedral, Kent, from 1174, and continued the works after 1177 (when Sens was injured) until 1184. He was responsible for innovations at Canterbury, as the Trinity Chapel and the Corona (circular chapel at the east) show. He may also have been involved at Chichester Cathedral (1187–99), and perhaps the Abbey of St Radigund, Dover, Kent.


J. Harvey (1987)

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William the Englishman

William the Englishman (fl. 1174–d. c.1214). See Sens.

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