Skip to main content

Bonfils, Immanuel ben Jacob


BONFILS, IMMANUEL BEN JACOB (14th century), of Tarascon (in Provence, France), mathematician and astronomer. He is chiefly known for his astronomical tables called Shesh-Kenafayim ("Six Wings" – cf. Isa. 6:2) which were written in Hebrew about 1365 and which were subsequently translated into both Latin (in 1406) and Byzantine Greek (c. 1435). These tables are preserved in many manuscript copies and the Hebrew version was published (Zhitomir, 1872). The author is often referred to in Hebrew as Ba'al ha-Kenafayim ("Master of Wings"). Each "wing" contains a number of astronomical tables concerning the movements of the sun and the moon for determining the times and magnitudes of solar and lunar eclipses as well as the day of the new moon. The tables themselves are largely based on the tables of the ninth-century Arab astronomer al-Battānī (known in Latin as Albategnius), as the author acknowledges in the preface. But they are presented according to the Jewish calendar and adapted to the longitude and latitude of Tarascon. These tables were consulted by European scholars as late as the seventeenth century. Bonfils is also known to have made astronomical observations, and his discussion of decimal fractions is among the earliest presentations of the subject.


Renan, Ecrivains, 692–99; je, 3 (1902), 306; M. Steinschneider, Mathematik bei den Juden (1964), 155ff.; The Hexapterygon [Six Wings] of Michael Chrysokokhes, ed. and tr. by P.C. Solon (unpublished thesis, Brown University, 1968); Gandz, in: Isis, 25 (1936), 16–45; Saidan, ibid., 57 (1966), 475–89; Petri Gassendi Opera Omnia, 5 (1964), 313.

[Bernard R. Goldstein]

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Bonfils, Immanuel ben Jacob." Encyclopaedia Judaica. . 25 Mar. 2019 <>.

"Bonfils, Immanuel ben Jacob." Encyclopaedia Judaica. . (March 25, 2019).

"Bonfils, Immanuel ben Jacob." Encyclopaedia Judaica. . Retrieved March 25, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.