(b. Winchcomb, England, ca 1300; d. ca. 1372)
mathematics, astronomy, medicine.
Originally a fellow of Balliol College, Oxford, Bredon moved to merton College and was a fellow there in 1330, becoming junior proctor of the university in 1337 and keeper of the Langton chest about 1339. In 1348 he left Merton to become vicar of Rustington, Susssex, and thereafter held a succession of church appointments. His will, probated in 1372, listed the contents of his library, which covered theology, law, medicine, mathematics, and astronomy, as well as grammar and dialectic.
Bredon’s earliest writings were concerned with philosophy, but he soon turned to mathematics and produced an explanation of Boethius’ Arithmetic. This he split up into two parts, the first dealing with numbers, including multiplication, the second concerned with geometrical figures—triangles, squares, pentagons, hexagons, etc. In his copy of William Rede’s astronomical tables for 1341–1344 he jotted down five conclusions on square numbers, which he considered useful for the squaring of the circle. These were followed by two criticisms of statements made by Vitello in his book on perspective, which Bredon dubbed “marvellous but false”. His possession of Richard of Wallingford’s book on sines and John Maudith’s table of chords shows him to have taken an interest in trigonometry, but his own writings on these subjects have not survived except for a few brief notes; therefore it is not possible to assess his contribution in this field.
Bredon’s works on astronomy are better attested. He wrote a treatise on the use of the astrolabe, giving detailed instructions how to find the altitude, degree, and declination of the sun; the latitude of any region; the degree of eclipse; and so on. The opening paragraph, entitled “Nomina instrumentorum”, is not his work, but a borrowing from Messehallach. His Theorica planetarum, sometimes attributed to Walter Brytte, a contemporary at Merton, sometimes to Gerardo da Sabbionetta, is largely a paraphrase of the latter’s treatise although it lacks the two final sections on the latitude of the planets and the invection of the aspects of the planets. The text De equationibus planetarum formerly ascribed to Bredon has been shown to belong to Chaucer.
Bredon wrote a commentary on the first three books of Ptolemy’s Almagest. No complete copy survives, but the work can be reconstructed from two incomplete manuscripts, both of which were annotated by Thomas Allen and John Dee. According to a marginal note in MS Digby 179, Bredon also made a new translation of Ptolemy’s Quadrepartitum, probably to be identified with the Astronomia judiciaria mentioned in John Bale’s Index Britanniae scriptorum. This translation is inserted into the lower margins of the version done by Egidius de Thebaldis of Parma, a copy of which was in Bredon’s library. He drew up tables for the declination of the sun and the ascension of the signs and gave the longitude of Oxford as 14°5′. Bale ascribes three other works to him—Super introductorio Alcabitii, Astronomia calculatoria, and Astronomia judiciaria—without giving incipits.
Bredon’s most ambitious work was the Trifolium, a medical compilation modeled on Avicenna’s Canon. Only one–twelfth of it survives, dealing with the prognostication of disease from feces and urine, and with the composition of medicines. He was physician to Richard, Earl of Arundel, in 1355 and treated Joanna, Queen of Scots, in 1358.
I. Original Works. Bredon’s writings are Questiones in X libros Ethicorum Aristotelis; Vienna, Bibl. Monast B.V.M. ad Scotos MS 278.
De arithmetica: Oxford, Digby MS 98, fols. 109–117; Digby MS 147, fols. 92–103; Corpus Christi Coll. MS 118, fols. 101–118; Cambridge, Univ. Lib. MS Ee. iii, 61, fols. 92–101; Univ. of Alabama, MS 1, fols. 1–16; Boston Public Lib. MS 1531. On the last, see Margaret Munsterberg, “An unpublished Mathematical Treatise by Simon Bredon”, in More Books, The Bulletin of the Boston Public Library, 19 (1944), 411.
Conclusiones quinque de numero quadrato; Digby MS 178, fols. 11v-14.
Massa compoti (of Alexandre de Ville Dieu, not of Grosseteste, as ascribed by Bale): Digby MS 98, fols. 11–21, “bene correctus secundum sententiam Bredone”.
Theorica planetarum: London, British Museum Egerton MS 847, fols. 104–122; Egerton MS 889; Oxford, Digby MS 48; Digby MS 93; Digby MS 98. The following MSS listed by Lynn Thorndike do not contain Bredon’s work, but the treatise by Gerardo da Sabbionetta: London, B.M. Royal 12 C.ix; Royal 12 C.xvii; Royal 12 E.xxv; oxford, Digby MS 47; Digby MS 168; Digby Ms 207
Commentum… Almagesti: Oxford, Digby MS 168, fols. 21–39; Digby MS 178, fols. 42–87; Cambridge, Univ. Lib. Ee.iii, 61, art. 8.
Astrolabii usus et declaracio: London, B.M. Harl, 321, fols. 24v–28.
Liber Quadrepartiti Ptolemei: Digby MS 179. See Axel Anthon Björnbo, “Die Mittelalterlichen lateinischen Übersetzungen aus dem Griechischen aug dem Gebiete der mathematischen Wissenschaften”, in Archiv für Geschichte der Naturwissenschaften und der Technik, 1 (1909), 391 ff.
Trifolium: Oxford, Digby MS 160, fols. 102–233.
Bredon is quoted in Thomas Werkworth, Tractatus de motu octavae spherae (1396): Dibgy MS 97, fol. 143.
Two letters addressed to him are in London, B.M. Royal 12 D.xi, fols. 25r, 35r. His longitude for Oxford is in Royal 12 D.v, fol. 50r.
II. Secondary Literature. Full biographical details are in A. B. Emden, A. Biographical Register of the University of Oxford to A.D. 1500, I (Oxford, 1957), 257–258; R.T. Gunther, Early Science in Oxford, II (Oxford, 1923), 52–55; and Lynn Thorndike, A History of Magic and Experimental Science, III (New York, 1934), 521–522. See also C. H. Talbot, “Simon Bredon (c. 1300–1372), Physician, Mathematician and Astronomer”, in British Journal of the History of Science, 1 (1962–1963), 19–30; and J. A. Weisheipl, “Early 14th Century Physics and the Merton School”, Bodl. Lib. MS D. Phil. d.1776. A list of the contents of Bredon’s library is in F.M. Powicke, The Mediaeval Books of Merion College (Oxford, 1931), pp. 82–86, 138–142.
C. H. Talbot