1236-1312

French Jewish mathematician and astronomer who translated several key works into Hebrew, and wrote a number of mathematical and astronomical treatises. Among the texts Jacob translated from Arabic were Euclid's (c. 325-c. 250 B.C.) Elements and Ptolemy's (c. 100-170) Almagest. In a treatise whose English title is Jacob's Quadrant, he explained the workings of a quadrant he had invented, and in his Luhot (Tables) he offered astronomical tables for the ascensions of stars over Paris. Dante Alighieri (1265-1321) mentioned the latter book in his Divine Comedy. Among the scientists influenced by Jacob's theories was Nicolas Copernicus (1473-1543).