High Quality Content by WIKIPEDIA articles! A Kater`s pendulum is a reversible freeswinging pendulum invented by British physicist and army captain Henry Kater in 1817 for use as a gravimeter instrument to measure the local acceleration of gravity. Its advantage is that, unlike previous pendulum gravimeters, the pendulum`s centre of gravity and center of oscillation don`t have to be determined, allowing greater accuracy. For about a century, until the 1930s, Kater`s pendulum and its various refinements remained the standard method for measuring the strength of the Earth`s gravity during geodetic surveys. It is now used only for demonstrating pendulum principles.