Note 142 — Chapter X

The Arabs received the knowledge of the Indian numerals in the ninth century. “But the profound and important historical investigations to which a distinguished mathematician, M. Chasles, was led by his correct interpretation of the so-called Pythagorean table in the geometry of Boëthius,” says M. Humboldt, “render it more than probable that the Christians in the West were acquainted even earlier than the Arabians with the Indian system of numeration; the use of the nine figures, having their value determined by position, being known by them under the name of the System of the Abacus.” (Cosmos, vol. ii. p. 226, also note 358. See also M. Chasles, Aperçu historique des méthodes en géométrie, 464-472, and his papers in the Comptes-rendus de l’Acad. des Sciences.)