The Beverly Clock is a

clock A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and t ...

in the 3rd-floor lift

foyer A lobby is a room in a building used for entry from the outside. Sometimes referred to as a foyer, reception area or an entrance hall, it is often a large room or complex of rooms (in a theatre, opera house, concert hall, showroom, cinema, etc. ...

of the Department of Physics at the

University of Otago , image_name = University of Otago Registry Building2.jpg , image_size = , caption = University clock tower , motto = la, Sapere aude , mottoeng = Dare to be wise , established = 1869; 152 years ago , type = Public research collegiate ...

Dunedin Dunedin ( ; mi, Ōtepoti) is the second-largest city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from , the Scottish Gaelic name for Edinburgh, the capital of Scotland. Th ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. The clock is still running despite never having been manually wound since its construction in 1864 by

Arthur Beverly Arthur Beverly (22 March 1822 – 25 October 1907) was a New Zealand watchmaker, mathematician and astronomer. He was born the son of farmer George Beverly in Stonehaven, Aberdeenshire, Scotland and was educated at home and by a local shoemak ...

Operation

The clock's mechanism is driven by variations in

atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...

, and by daily

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

variations; of the two, temperature variations are more important. Either causes the air in a airtight box to expand or contract, which pushes on a diaphragm. A temperature variation of over the course of each day creates approximately enough pressure to raise a one- pound weight by one inch (equivalent to ), which drives the clock mechanism. A similar mechanism in a commercially available clock that operates on the same principle is the

Atmos clock Atmos is the brand name of a mechanical torsion pendulum clock manufactured by Jaeger-LeCoultre in Switzerland which does not need to be wound manually. It gets the energy it needs to run from temperature and atmospheric pressure changes in the ...

, manufactured by the Swiss watchmaker

Jaeger-LeCoultre Manufacture Jaeger-LeCoultre SA, or simply Jaeger-LeCoultre (), is a Swiss luxury watch and clock manufacturer founded by Antoine LeCoultre in 1833 and is based in Le Sentier, Switzerland. Since 2000, the company has been a fully owned subsidiary ...

. While the clock has not been wound since it was made, 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. Also, on occasions when the ambient temperature does not fluctuate sufficiently to supply the requisite amount of energy, the clock will not function. However, after environmental parameters readjust, the clock begins operating again.

References

;Citations ;General * * * {{refend History of physics University of Otago Clocks in New Zealand 1864 works

Operation

See also

References