The Hindu-Arabic Numerals c11.163

c11.163

Four Englishmen — Adelhard of Bath (c. 1130), Robert of Chester (Robertus Cestrensis, c. 1143), William Shelley, and Daniel Morley (1180) — are known¹ to have journeyed to Spain in the twelfth century for the purpose of studying mathematics and Arabic. Adelhard of Bath made translations from Arabic into Latin of Al-Khowārazmī's astronomical tables² and of Euclid's Elements,³ while Robert of Chester is known as the translator of Al-Khowārazmī's algebra.⁴ There is *Computus* by the same author and bearing the date given. It contains chapters “De additione,” “De diminutione,” “De mediatione,” “De divisione,” and part of a chapter on multiplication. The numerals are in the usual medieval forms except the 2, which, as will be seen from the illustration,¹ is somewhat different, and the 3, which takes the peculiar shape ⠃, a form characteristic of the twelfth century.