Experiment:

To determine the value of acceleration due to gravity at a place, by means of Kater’s reversible pendulum.

Kater’s pendulum,  is a physical pendulum composed of a metal rod 1.20 m in length, upon which are mounted a sliding metal weight W1, a sliding wooden weight W2, a small sliding metal cylinder w, and two sliding knife edges K1 and K2 that face each other. Each of the sliding objects can be clamped in place on the rod. 

The pendulum can suspended and set swinging by resting either knife edge on a flat, level surface. The wooden weight W2 is the same size and shape as the metal weight W1.