Page:A History Of Mathematical Notations Vol I (1928).djvu/235

He says also (p. 175): “Si igitur ut √:3×6: significat terminum medium inter 3 et 6 in progressione Geometrica aequabili 3, 6, 12, etc. (continue multiplicando 3×2×2 etc.) ita ]7T: 1 [f: significet terminum medium inter 1 et -f in progressione Geometrica decrescente 1, -§, YS etc. (continue multiplicando lX-fXf, etc.) erit □=]?T:l|f: Et propterea circulus est ad quadratum diametri, ut 1 ad W:l%” He uses this symbol again in his Treatise of Algebra (1685), pages 296, 362. 7 a Ve,Notation! CAP, IX. * 'G ' v Petcfta j f f«u Nomina, 'Charafteres* Radix •~r K A' a a!'■ Quadratum u * V. a a a t 2 Cub us qo C Ac aaa a* 3 Quad, quid rat tim £4 44 4* 4Surdefolkkim r* S Aqc 3ic. a 5 $ Quad. Cub?. yr SC Acc a* 6 Surdefblidum. Bp bS Aqqc ■■ rN 7 Quad. quad.quad. SSS- h v c a* 8 Cubi cubu» . CC Accc a 5 9 Quad. Surdefol. y,« ■ £>S Aqqcc 4 t9 JO 3 ™ Surdefolidqm ■ c8 Aqccc it Quad- quad, cubi yyr Accec 12 4 m Surdefolidum D(* d S Aqqccc a ^ *3 Qua d. 2 l Surdefol. ■ m i* S Aqqccc a ** *4 Cubu* Surdefol. C S Accc.cc Quad.quad.quad.q uad. Aqqcc.cc <3 1 * Fig. 98.—From John Wallis, Operuvi mathematicorum pars prirna (Oxford, 1657), p. 72. The absence of a special sign for division shows itself in such pas1 2D sages as (p. 135): “Ratio rationis hujus ad illam puta 2/2D □ , erit. ” He uses Oughtred’s clumsy notation for decimal fractions, even though Napier had used the point or comma in 1617. On page 166 Wallis comes close to the modern radical notation; he writes for VR. Yet on that very page he uses the old designa¬ tion “i/qqR” for 1 R.