A Battery at Oxford University Has Kept Bells Ringing for 180 Years, But No One Knows Exactly Why It Keeps Going
In the mid-1800s, Oxford University physics professor Robert Walker acquired a curious device. It was a battery-powered apparatus designed to vibrate a metal ball rapidly between two small bells. Today, this device, known as the Oxford Electric Bell, still chimes away after 180 years of continuous operation. Scientists estimate it has rung more than 10 billion times, according to Smithsonian Magazine.
The Oxford Electric Bell in the Clarendon Laboratory. (Photo: Wikimedia).
Built by Watkins and Hill, a London-based scientific instrument maker, the bell was delivered to Walker with a note saying simply, "Made in 1840." Today, the bell resides in the University of Oxford's Clarendon Laboratory. Researchers aren't sure exactly how this Guinness World Record-recognized "longest-lasting battery" has kept ticking for so long. Disassembling the device for study could destroy it.
The device uses a dry pile battery, an early type of electric battery first developed by Italian priest and physicist Giuseppe Zamboni in the early 1800s. Dry piles consist of alternating discs of silver, zinc, sulfur, or other materials that generate a low electrical current.
"The precise construction of the pile is not known for certain, but the exposed surface of the elements is sulfur," wrote A.J. Croft, a researcher formerly at the Clarendon Laboratory, in a 1984 paper in European Journal of Physics. "Zamboni constructed similar piles comprising about 2,000 sheets of tinfoil pasted with a paste composed of zinc sulfide on one side and manganese dioxide on the other."
The bell doesn't ring loudly like an alarm clock, but rather emits a faint buzzing sound, as the current it produces has a very low voltage. To solve the mystery of the Oxford Electric Bell, researchers will likely have to wait until the battery eventually dies or the device fails due to old age.
Summary
The Oxford Electric Bell is a battery-powered device that has been continuously ringing for 180 years. It is the world's longest-lasting battery, but scientists are still unsure how it works. The bell's battery uses a dry pile design, an early type of electric battery invented in the early 1800s. Researchers believe that the bell will continue to ring until the battery eventually dies or the device fails due to old age.