24, namely, 3..2::72..48. Curious notations are given in Rich. Balam’s Algebra, London, 1653. [116]Chr. Clavii Operum mathematicorum tomus secundus, Mayence, 1611, Algebra, p. 39. [117]Invention nouvelle en l’algèbre, by Albert Girard, Amsterdam, 1629, p. 17. [118]La géométrie et pratique générale d’icelle, par I. Errard de Bar-le-Duc, Ingénieur ordinaire de sa Majesté, 3d ed., revised by D. H. P. E. M., Paris, 1619, p. 216. [119]Novae geometriae clavis algebra, authore P. Jacobo de Billy, Paris, 1643, p. 157; also an Abridgement of the Precepts of Algebra. Written in French by James de Billy, London, 1659, p. 346. [120]Miscellanies: or Mathematical Lucubrations, of Mr. Samuel Foster, Sometime publike Professor of Astronomie in Gresham Colledge in London, London, 1659, p. 7. [121]Quarterly Jour. of Pure and Applied Math., Vol. XLVI (London, 1915), p. 191. [122]Pietro Cossali, Origine, trasporto in Italia primi progressi in essa dell’ algebra, Vol. I, Parmense, 1797, p. 52. [123]In Is. Bullialdi astronomiae philolaicae fundamenta inquisitio brevis, Auctore Setho Wardo, Oxford, 1653, p. 1. [124]John Wallis, Algebra, London, 1685, p. 321, and in some of his other works. He makes greater use of Harriot’s symbols. [125]Euclidis data, 1657, p. 1; also Euclidis elementorum libris XV, London, 1659, p. 1. [126]John Kersey, Algebra, London, 1673, p. 321. [127]E. Wells, Elementa arithmeticae numerosae et speciosae, Oxford, 1698, p. 142. [128]Cocker’s Decimal Arithmetick, perused by John Hawkins, London, 1695 (preface dated 1684), p. 278. [129]Th. Baker, The Geometrical Key, London, 1684, p. 15. [130]Richard Sault, A New Treatise of Algebra, London (no date). [131]Richard Rawlinson in a pamphlet without date, issued sometime between 1655 and 1668, containing trigonometric formulas. There is a copy in the British Museum. [132]F. Dulaurens, Specima mathematica, Paris, 1667, p. 1. [133]J. Milnes, Sectionum conicarum elementa, Oxford, 1702, p. 42. [134]Cheyne, Philosophical Principles of Natural Religion, London, 1705, p. 55. [135]J. Craig, De calculo fluentium, London, 1718, p. 86. [136]Jo. Wilson, Trigonometry, 2d ed., Edinburgh, 1724, p. v. [137]Commercium Epistolicum, 1712, p. 20. [138]C. Le Paige, “Sur l’origine de certains signes d’opération,” Annales de la société scientifique de Bruxelles, 16th year, 1891-92, Part II, pp. 79-82. [139]Gravelaar, “Over den oorsprong van ons maalteeken (×),” Wiskundig Tijdschrift, 6th year. We have not had access to this article. [140]H. Bosmans, op. cit., p. 40. [141]Claudii Ptolemaei . . . . annotationes, Bâle, 1551. This reference is taken from the Encyclopédie des sciences mathématiques, Tome I, Vol. I, Fasc. 1, p. 40.