What is a conical pendulum?

A conical pendulum is a weight fixed on the end of a string or rod suspended from a pivot so that it can swing freely. A conical pendulum construction is similar to an ordinary pendulum; instead of swinging backward and forward, the weight moves at a constant speed in a circular motion with the string or rod tracing out a cone.

Conical pendulums were used in the 1800s as timekeeping elements in a few clockwork devices where a smooth motion was required as opposed to the rough motion provided by ordinary pendulums. They were also used as key components in centrifugal governors used to regulate the speed of steam engines.