PRINTED BOOKS, ETC, BEFORE 1734 53 



Principia^ published first in the Year 1687, which 

 almost vvhoUy depends upon the Use of the said 

 Calculus. But the Method of Mr. Leibnitz'z is 

 much more easy and expeditious, on account of 

 the Notation he uses. . . ." 



In the preface of " The Translator to the Reader " 

 Stone points out that the work he is bringing out 

 '*becomes the more necessary, because there are 

 but two EngHsh Treatises on the Subject . . . the 

 one being Hay's Introduction to Mathematical 

 Philosophy, and the other, Ditton's Institutio7i of 

 Fluxions'' \ the former " too prolix," the latter 

 "much too sparing in Examples " and " too re- 

 dundant " in the explanation of fluxions, so that " it 

 is next to impossible for one who has not been 

 conversant about Infinites to apprehend it. That 

 of our Author is much easier, tho less Geo- 

 metrica!, who calls a Differentia] (or Fluxion) the 

 infinitely small Part of a Magnitude. " " But," con- 

 tinues Stone, ' ' I would not bere be thought in any 

 wise to lessen the Value of Sir Isaac Newton's 

 Definition : When the Learner has made some 

 Progress, I would bave him then make himself 

 Master of it." Stone then proceeds to explain the 

 nature of fluxions, foUowing closely Newton's 

 language in his Quadrature of Curves. 



71. In De l'Hospital's treatise, as translated by 

 Stone, we read : 



"The infinitely small Part whereby a variable 

 Quantity is continually increased or decreas'd, is 

 called the Fluxion of that Ouantity." 



