...inertia, and on opposite sides of that point, such that the time of oscillation is the same for each, the distance between them is the length of the equivalent simple pendulum. Kater made use of this proposition in his determination of the length of the second's pendulum, under...

...must coincide with 5. Hence the center of suspension and the center of oscillation are interchangeable and the distance between them is the length of the equivalent simple pendulum. This is the principle of Kater's pendulum. 121. Energy Changes. The resultant force of gravity acts...