[233] Rabbi ben Ezra (1092-1168) used both
גלגל
, galgal (the Hebrew for wheel), and
ספרא
, sifra. See M. Steinschneider, "Die Mathematik bei den Juden," in Bibliotheca Mathematica, 1893, p. 69, and Silberberg, Das Buch der Zahl des R. Abraham ibn Esra, Frankfurt a. M., 1895, p. 96, note 23; in this work the Hebrew letters are used for numerals with place value, having the zero.
[234] E.g., in the twelfth-century Liber aligorismi (see Boncompagni's Trattati, II, p. 28). So Ramus (Libri II, 1569 ed., p. 1) says: "Circulus quæ nota est ultima: nil per se significat." (See also the Schonerus ed. of Ramus, 1586, p. 1.)
[235] "Und wirt das ringlein o. die Ziffer genant die nichts bedeut." [Köbel's Rechenbuch, 1549 ed., f. 10, and other editions.]
[236] I.e. "circular figure," our word notation having come from the medieval nota. Thus Tzwivel (1507, f. 2) says: "Nota autem circularis .o. per se sumpta nihil vsus habet. alijs tamen adiuncta earum significantiam et auget et ordinem permutat quantum quo ponit ordinem. vt adiuncta note binarij hoc modo 20 facit eam significare bis decem etc." Also (ibid., f. 4), "figura circularis," "circularis nota." Clichtoveus (1503 ed., f. XXXVII) calls it "nota aut circularis o," "circularis nota," and "figura circularis." Tonstall (1522, f. B_3) says of it: "Decimo uero nota ad formam
