what is the effective length of a seconds pendulum
Seconds pendulum At standard gravity its length is 0.994 m (39.1 in). This length was determined (in toises) by Marin Mersenne in 1644. In 1660, the Royal Society proposed that it be the standard unit of length. In 1675 Tito Livio Burattini proposed that it be named the meter. In 1790, one year before the metre was ultimately based on a quadrant of the Earth, Talleyrand proposed that the metre be the length of the seconds pendulum at a latitude of 45Â°.[1] This option, with one-third of this length defining the foot, was also considered by Thomas Jefferson and others for redefining the yard in the United States shortly after gaining independence from the British Crown.[2]