Elements of geometry / from the Latin translation of Commandine. To which is added, a treatise of the nature of arithmetic of logarithms, likewise another of the elements of plain and spherical trigonometry; with a preface ... By Doctor John Keil ... The whole revised ... [with a] preface, by Samuel Cunn.

Euclid

Date:: 1741

Credit: Elements of geometry / from the Latin translation of Commandine. To which is added, a treatise of the nature of arithmetic of logarithms, likewise another of the elements of plain and spherical trigonometry; with a preface ... By Doctor John Keil ... The whole revised ... [with a] preface, by Samuel Cunn. Source: Wellcome Collection.

11/465

$ufelefs 5 fitch, for Example, as Prop. 27, 28, andiy, o f the fixth Book, and fome others, whofe Ufies they might not know. Farther, where-ever they ufe demonfirac¬ tions of their own, inftead ^/’EuclidV, in thofie demonfir at ions they are faulty in their Re a fining, and deviate very much from the Goncifenefs of the Antients. In the fifth Book, they have vjholly re- jeffiedHLx\cX\&sdemonflrations, and have given a definition of Proportion diffe¬ rent from EuclidV; and which compre¬ hends but one of the two Species of Pro¬ portion, taking in only commenfiurable Qiiantities. Which great Fault no Lo¬ gician or Geometrician would have ever pardoned, had not thofe Authors done laudable Things in their other Mathe¬ matical Writings. Indeed, this Fault of theirs is common to all Modern Wri¬ ters of Elements, who all fplit on the fame Rock; and to phew their Skill, blame Euclid, for what, on the contrary, he ought to be commended5 I mean thf definition of proportional Quantities, wherein he pews an eajy Property of thofe Quantities, taking in both com¬ menfurable and incommenfurable ones, and from which all the other Properties of Proportionals do e a fly follow - Some Geometricians, forjooth, want a demonfir at ion of this Property in Eu¬ clid j and undertake to J'upply the defi¬ ciency by one of their own. Here, again,$

Licence and re-use

Contents