[465] Picavet, loc. cit., p. 182. Weissenborn, Gerbert, p. 227. In Olleris, Liber Abaci (of Bernelinus), p. 361.
[466] Richer, in Bubnov, loc. cit., p. 381.
[467] Weissenborn, Gerbert, p. 241.
[468] Writers on numismatics are quite uncertain as to their use. See F. Gnecchi, Monete Romane, 2d ed., Milan, 1900, cap. XXXVII. For pictures of old Greek tesserae of Sarmatia, see S. Ambrosoli, Monete Greche, Milan, 1899, p. 202.
[469] Thus Tzwivel's arithmetic of 1507, fol. 2, v., speaks of the ten figures as "characteres sive numerorum apices a diuo Seuerino Boetio."
[470] Weissenborn uses sipos for 0. It is not given by Bernelinus, and appears in Radulph of Laon, in the twelfth century. See Günther's Geschichte, p. 98, n.; Weissenborn, p. 11; Pihan, Exposé etc., pp. xvi-xxii.
In Friedlein's Boetius, p. 396, the plate shows that all of the six important manuscripts from which the illustrations are taken contain the symbol, while four out of five which give the words use the word sipos for 0. The names appear in a twelfth-century anonymous manuscript in the Vatican, in a passage beginning
Ordine primigeno sibi nomen possidet igin.
Andras ecce locum mox uendicat ipse secundum
Ormis post numeros incompositus sibi primus.