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June 27, 2013
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| The Rolling Ball Clock was designed by Sir William Congreve in 1820. Although an unreliable timekeeper, the design was used by a number of clock makers. The steel ball takes 30 seconds to roll from one end of the table to the other. At each end a catch is released, enabling the mechanism to tip the table the other way so the ball rolls back. The ball travels about 2,500 miles each year. |
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