Abstract

In this paper, we analyze the astronomical tables for 1340 by Immanuel ben Jacob Bonfils who flourished 1340–1365, based on four Hebrew manuscripts. We discuss the relation of these tables principally with those of al-Battānī, Abraham Bar Ḥiyya, and Levi ben Gerson, as well as with Bonfils’s better known tables, called Six Wings. An unusual feature of this set of tables is that there are two kinds of mean motion tables, one arranged for Julian years from 1340 to 1380, months, days, hours, and minutes of an hour, and the other arranged in the Hebrew calendar for the times of conjunctions and oppositions of the Sun and the Moon only, with subtables for 19-year cycles, single years in a 19-year cycle, and months. The latter arrangement is found in Bonfils’s Six Wings for solar and lunar motions only, whereas in his Tables for 1340, this arrangement applies to all planets. Notably absent are tables for the trigonometric functions, etc., that are generally found in such sets of astronomical tables.