The Oxford Electric Bell
Images: Wikimedia Commons

The University of Oxford has a bell that’s been ringing almost continuously since 1840. A little 4-millimeter clapper oscillates between two bells, each of which is positioned beneath a dry pile, an early battery. Due to the electrostatic force, the clapper is first attracted to and then repelled by each bell in turn, so it’s been ringing them alternately for 179 years. The operation conveys only a tiny amount of charge between the bells, which explains why it’s managed to run so long. The whole apparatus is kept under two layers of glass, but the ringing is so faint that it would be inaudible in any case.

It’s estimated that the bell has produced 10 billion rings so far — it holds the Guinness World Record as “the world’s most durable battery [delivering] ceaseless tintinnabulation.”