What is congreve rolling ball clock?

Congreve rolling ball clock is a type of clock that uses rolling steel balls to indicate time. It was invented by Sir William Congreve in the early 19th century.

The clock consists of a large frame, usually made of mahogany or oak, with a series of ramps and troughs in it. The steel balls are placed on the ramps and are guided by the troughs as they roll down.

The time is indicated by the number of balls that fall into a series of cups at the bottom of the frame. Each cup represents an hour, with twelve cups in total.

The clock also has a mechanism that lifts the balls back up to the top of the frame, allowing them to roll down again and indicate the passage of time.

Congreve rolling ball clocks are considered highly collectible and are valued for their intricate design and craftsmanship. They are also known for their accuracy and ability to run for long periods of time without needing to be wound.