[425] Cunningham, loc. cit., p. 186.
[426] J. R. Green, Short History of the English People, New York, 1890, p. 66.
[427] W. Besant, London, New York, 1892, p. 43.
[428] Baldakin, baldekin, baldachino.
[429] Italian Baldacco.
[430] J. K. Mumford, Oriental Rugs, New York, 1901, p. 18.
[431] Or Girbert, the Latin forms Gerbertus and Girbertus appearing indifferently in the documents of his time.
[432] See, for example, J. C. Heilbronner, Historia matheseos universæ, p. 740.
[433] "Obscuro loco natum," as an old chronicle of Aurillac has it.
[434] N. Bubnov, Gerberti postea Silvestri II papae opera mathematica, Berlin, 1899, is the most complete and reliable source of information; Picavet, loc. cit., Gerbert etc.; Olleris, Œuvres de Gerbert, Paris, 1867; Havet, Lettres de Gerbert, Paris, 1889 ; H. Weissenborn, Gerbert; Beiträge zur Kenntnis der Mathematik des Mittelalters, Berlin, 1888, and Zur Geschichte der Einführung der jetzigen Ziffern in Europa durch Gerbert, Berlin, 1892; Büdinger, Ueber Gerberts wissenschaftliche und politische Stellung, Cassel, 1851; Richer, "Historiarum liber III," in Bubnov, loc. cit., pp. 376-381; Nagl, Gerbert und die Rechenkunst des 10. Jahrhunderts, Vienna, 1888.