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The Beverly Clock as it now stands in the Physics Department at the University of Otago

The inner mechanism of the Beverly clock showing chain, sprockets and torsional pendulum

The Beverly Clock is a clock situated in the foyer of the Department of Physics at the University of Otago, Dunedin, New Zealand. The clock is still running despite never having been wound since its construction in 1864 by Arthur Beverly. It is a contender for the title of longest continuously running scientific experiment.

The clock mechanism is driven by variations in atmospheric pressure and by daily temperature variations; of the two, the temperature variations are the more important. Either causes the air in a one cubic-foot air-tight box to expand and contract, pushing on a diaphragm. A six-degree Celsius temperature variation over the course of each day creates enough pressure to raise a one-pound weight by one inch (energy extracted = .11 joules), which drives the clock mechanism.

A similar commercial example of this mechanism is known as the Atmos clock.

Whilst the clock has not been wound since it was made by Arthur Beverly in 1864, it has stopped on a number of occasions, when its mechanism needed cleaning, when there was a mechanical failure, when the Physics Department moved to new quarters, and on occasions when the ambient temperature has not fluctuated sufficiently. After environmental parameters readjust, the clock begins operating again.

[edit] See also

• Pitch drop experiment
• Oxford Electric Bell
• Cox's timepiece

[edit] References

• L.E.S. Amon, A. Beverly, and J.N. Dodd (1984). "The Beverly clock" (abstract). European Journal of Physics 5: 1957–197. doi:10.1088/0143-0807/5/4/002. http://www.iop.org/EJ/abstract/0143-0807/5/4/002. 
• Marc Abrahams (2001). "The Latest on Long-Running Experiments" (^{[dead link]} – ^{Scholar search}). Annals of Improbable Research 7 (3). http://www.improbable.com/airchives/paperair/volume7/v7i3/long-run-7-3.html. 
• L.E.S. Amon and Hardwicke Knight (2005-07-07). "Beverly, Arthur 1822 – 1907". Dictionary of New Zealand Biography. http://www.dnzb.govt.nz/dnzb/Essay_Body.asp?PersonEssay=1B20&QuickSearch=true.