The Perimeter Of The Earth Is About

Eureka, Eureka! (i Found It, I Found It!).

Equal Weights At Equal Distances Are In Equilibrium And Equal Weights At Unequal Distances Are Not In Equilibrium But Incline Towards The Weight Which Is At The Greater Distance.

I Am Persuaded That This Method [for Calculating The Volume Of A Sphere] Will Be Of No Little Service To Mathematics. For I Foresee That Once It Is Understood And Established, It Will Be Used To Discover Other Theorems Which Have Not Yet Occurred To Me, By Other Mathematicians, Now Living Or Yet Unborn.

The Perimeter Of The Earth Is About 3,000,000 Stadia And Not Greater.

It Follows At Once From The Last Proposition That The Centre Of Gravity Of Any Triangle Is At The Intersection Of The Lines Drawn From Any Two Angles To The Middle Points Of The Opposite Sides Respectively.