R. Immanuel Bonfils · c. 1365
Read the translation (PDF) · Editorial footnotes (PDF)
One of the most widely copied Hebrew astronomical handbooks of the late Middle Ages, composed around 1365 in Provence. Its six sets of tables — the “wings” that give the work its name — let the user compute the positions of the sun and moon, predict eclipses, and convert between calendars, each with brief instructions for use.
The book is almost entirely apparatus: a short canon explaining the method, then wing after wing of tables. The First Wing is a cycle-table, with an annual table on a twenty-eight-year cycle and monthly tables for common and leap years. The Second Wing carries the lunar ḥeq — the conjunction tables — across many folios, in degrees, with separate variant groups for leap years. Later wings give the corrected lunar reckoning, laid out in sign-panels running through the zodiac, Virgo to Libra and onward.
The manuscript’s physical character is part of the work: rubricated header bands in red and gold, diagonal panel sub-headers repeated across each panel, header-letter rows in gold and red. These tables were made to be consulted quickly, and the colour is navigational rather than decorative.
Shesh Kenafayim was a working tool, and its diffusion shows it: it survives in many copies, and was translated into both Greek and Latin — an unusual direction of travel for a Hebrew scientific text. Its most striking technical feature is the use of a decimal notation for astronomical fractions, long before such methods spread through European mathematics. Bonfils was reaching for something that would not become general practice for centuries.
This English version is drawn from an Italian manuscript copy made in 1509 — some hundred and fifty years after composition — held at the University of Pennsylvania’s Kislak Center. The work also circulated under the name Kanfei Nesharim, “Wings of Eagles.”