In the year 1672 John Richer, the astronomer to the Royal Academy of Sciences of Paris, was sent by Louis XIV to the island of Cayenne to make certain astronomical observations. His Parisian clock had its pendulum, slightly over 39 inches long, regulated to beat seconds. Shortly after his arrival at Cayenne, he noticed that the clock was losing time, about two and a half minutes a day. Gravity, evidently, did not act with so much force near the equator as it did at Paris. The astronomer found it necessary to shorten the pendulum nearly a quarter of an inch to get it to swing fast enough.