The Hindu-Arabic Numerals c8.23

c8.23

⁴ Bayley, loc. cit., p. 48. From this fact Delambre (*Histoire de l'astronomie ancienne*) inferred that Ptolemy knew the zero, a theory accepted by Chasles, *Aperçu historique sur l'origine et le développement des méthodes en géométrie*, 1875 ed., p. 476; Nesselmann, however, showed (*Algebra der Griechen*, 1842, p. 138), that Ptolemy merely used o for οὐδὲν, with no notion of zero. See also G. Fazzari, "Dell' origine delle parole zero e cifra," *Ateneo*, Anno I, No. 11, reprinted at Naples in 1903, where the use of the point and the small cross for zero is also mentioned. Th. H. Martin, *Les signes numéraux etc.*, reprint p. 30, and J. Brandis, *Das Münz-, Mass- und Gewichtswesen in Vorderasien bis auf Alexander den Grossen*, Berlin, 1866, p. 10, also discuss this usage of o, without the notion of place value, by the Greeks.