Christiani Hugenii ...Theoremata De Quadratura Hyperboles, Ellipsis Et Circuli, Ex Dato Portionum Gravitatis Centro

approached both quadratures with an exquisite and completely new method, and believed that he had finished them with almost the same demonstration. But when I, having already written out my theorems, carefully examined the very extensive volumes he published on these matters (certain that if he had obtained what he intended, I would at least exhibit the centers of gravity), I finally understood that the difficult task had been attempted with greater subtlety than success, and I found a method by which I trust this can be shown most clearly. And since, among so many excellent geometers of this age, it has not yet been permitted to notice anyone who has chosen this task for himself—and consequently it could be that a long doubt might remain regarding the demonstrations, which ought to be most certain—I thought I would do something both useful to the public and not irrelevant to the reason of the proposed argument if I let appear here at the same time what seemed to be bringing new light into an obscure matter.