"In October 1672 ... had sailed to the South American island of ... While there, he noticed that the he had brought... ran ever so slightly slower than it did in Paris. ...When he shortened the three-foot pendulum by just one twelfth of an inch, it corrected the error. ... Isaac Newton, he immediately guessed the cause. The island of Cayenne, situated almost on the Equator, was farther from the center of the Earth's gravitational pull... As the pendulum reached the top of its swing... the gravitational pull would be slightly less... Richer's discovery revealed that the Earth almost certainly bulged at the Equator... one of the first observational confirmations of Newton's theory of gravity. Meanwhile, for Buffon at least, it established that when the world formed, it was molten."