information:extraction, structural:reformatting, structural:summarization, stylistic:style_transfer
Kater's pendulum

The precision of the early gravity measurements above was limited by the difficulty of measuring the length of the pendulum, L. L was the length of an idealized simple gravity pendulum (described at top), which has all its mass concentrated in a point at the end of the cord. In 1673 Huygens had shown that the period of a rigid bar pendulum (called a compound pendulum) was equal to the period of a simple pendulum with a length equal to the distance between the pivot point and a point called the center of oscillation, located under the center of gravity, that depends on the mass distribution along the pendulum. But there was no accurate way of determining the center of oscillation in a real pendulum. Huygens' discovery is sometimes referred to as Huygens' law of the (cycloidal) pendulum.