Pineda Johnson

“In the Clarendon Laboratory at Oxford University sits a battery-powered bell that has been ringing since the year 1840. The bell “rings” so quietly it’s almost inaudible, using only a tiny amount of charge with every motion of the clapper. Nobody knows exactly what kind of batteries it uses because nobody wants to take it apart to figure it out.”
― Randall Munroe, What If? 10th Anniversary Edition: Serious Scientific Answers to Absurd Hypothetical Questions