Bonfils, Immanuel Ben Jacob:

By: Richard Gottheil , Isaac Broydé

Physician, mathematician, and astronomer; lived at Orange, France, and later at Tarascon, in the fourteenth century. He was the contemporary of the astronomer Levi ben Gerson of Bagnols. At one time Bonfils taught astronomy and mathematics at Orange. He was the author of the following works: (1) a treatise on the relation between the diameter and the circumference, followed by rules for extracting the square root, and with an explanation of a passage of the "Book of Creation," dealing with arithmetic (Bibliothèque Nationale, Paris, MS. No. 1290, 5); (2) arithmetical propositions respecting division, and extraction of the square root, and notes on astronomy ( ib. No. 1081, 1, 2); (3) "Derek Ḥilluḳ" (Way of Division), notes on the decimal numbers ( ib. No. 1054, 6); (4) "Bi'ur me-Luḥot," treatise on the middle course of the planets ( ib. No. 1054, 6); (5) table for the calculation of the declination of the sun; (6) "Luaḥ Mattanah Ṭobah" (Table of Good Gift), on the determination of the planet Venus from 1300 to 1357; (7) "Bi'ur Asiyat ha-Istrolab," on the construction of the astrolabe ( ib. Nos. 1050, 6; 1054, 2); (8) note on the cycles (Neubauer, "Cat. Bodl. Hebr. MSS." No. 1483, 4); (9) "Kanfe Nesharim" (Wings of Eagles), or "Shesh Kenafayim" (Six Wings), a treatise on conjunctions, appositions, eclipses, etc. (this work enjoyed great popularity in the Middle Ages, being translated into Latin in 1406, commented upon by Chrysocca, and the Hebrew text published by Naḥmu Bibowitz, Jitomir, 1872); (10) "Ma'amar 'Erek ha-Ḥilluf" (Treatise on the Value of Inequalities), dealing with the inequalities of the course of the sun and the moon, and the necessity of taking into consideration these inequalities in calculating conjunctions, appositions, eclipses, etc. (Bibliothèque Nationale, Paris, MS. No. 1054, 13); (11) astrological treatise on the seven constellations ( ib. No. 1048, 4); (12) a commentary on a passage of Ibn Ezra's commentary on Ex. xxx. 2, relative to the Tetragrammaton ( ib. No. 825, 8; MSS. Munich, Nos. 343, 386); (13) "Bi'ur 'al M'ozene Ḥanok," commentary on the balances of Enoch and Hermes, mentioned in Abraham ibn Ezra's "Sefer ha-Moladot" ( ib. No. 903, 1); (14) note on the nine comets, attributed to Ptolemy, but be lieved to belong to Bonfils; (15) "Toledot Alexander," the legend of Alexander, translated from the "Historia de Prœliis" of Leon.