Beverly Clock

The Beverly Clock is a clock situated in the 3rd floor lift foyer of the Department of Physics at the University of Otago, Dunedin, New Zealand. The clock is still running despite never having been manually wound since its construction in 1864 by Arthur Beverly.   The clock's mechanism is driven by variations in atmospheric pressure, and by daily temperature variations; of the two, temperature variations are more important. Either causes the air in a one cubic-foot (28 liter) air-tight box to expand or contract, which pushes on a diaphragm. A temperature variation of six degree Fahrenheit (3.3 °C) over the course of each day creates approximately enough pressure to raise a one-pound weight by one inch, which drives the clock mechanism.   A similar clock mechanism operating on the same principle is known as the Atmos clock.   While the clock has not been wound since it was made by Arthur Beverly in 1864, it has stopped on a number of occasions, such as when its mechanism needed cleaning or there was a mechanical failure, and when the Physics Department moved to new quarters. As well, on occasions when the ambient temperature has not fluctuated sufficiently to absorb the requisite amount of energy, the clock will not function. However, after environmental parameters readjust, the clock begins operating again.