[194] As when we use three dots (...).
[195] "The Hindus call the nought explicitly śūnyabindu 'the dot marking a blank,' and about 500 A.D. they marked it by a simple dot, which latter is commonly used in inscriptions and MSS. in order to mark a blank, and which was later converted into a small circle." [Bühler, On the Origin of the Indian Alphabet, p. 53, note.]
[196] Fazzari, Dell' origine delle parole zero e cifra, Naples, 1903.
[197] E. Wappler, "Zur Geschichte der Mathematik im 15. Jahrhundert," in the Zeitschrift für Mathematik und Physik, Vol. XLV, Hist.-lit. Abt., p. 47. The manuscript is No. C. 80, in the Dresden library.
[198] J. G. Prändel, Algebra nebst ihrer literarischen Geschichte, p. 572, Munich, 1795.
[199] See the table, p. 23. Does the fact that the early European arithmetics, following the Arab custom, always put the 0 after the 9, suggest that the 0 was derived from the old Hindu symbol for 10?
[200] 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 ο 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 ο, without the notion of place value, by the Greeks.
[201] Al-Battānī sive Albatenii opus astronomicum. Ad fidem codicis escurialensis arabice editum, latine versum, adnotationibus instructum a Carolo Alphonso Nallino, 1899-1907. Publicazioni del R. Osservatorio di Brera in Milano, No. XL.
[202] Loc. cit., Vol. II, p. 271.
[203] C. Henry, "Prologus N. Ocreati in Helceph ad Adelardum Batensem magistrum suum," Abhandlungen zur Geschichte der Mathematik, Vol. III, 1880.