As well as being a much-loved makers of super-chic dress watches, including the Reverso, its Art Deco-inspired design icon, and the Memovox, its mesmerising family of chiming watches, Jaeger-LeCoultre is known for producing one truly unique timepiece: the Atmos Clock.

As astute readers will have spotted, this is a clock not a watch.

The Atmos Clock is as about as close to magic as you’re likely to come in horology. Its ingenious, near-perpetual mechanical movements are driven by air temperature changes, and nothing more. It's appeared in various different shapes and sizes: all have been pushing at the avant-garde of design since the 1930s.

The clock is driven by a mainspring, which is wound by the expansion and contraction of liquid and gaseous ethyl chloride in a hermetically sealed metal bellows. The ethyl chloride vaporises into an expansion chamber as the temperature rises, compressing a spiral spring. With a fall in temperature the gas then condenses and the spiral spring expands, winding the mainspring.

This action constantly winds the clock.

Developing this type of “perpetual motion” clock – one that would run and stay wound without any direct mechanical influences – was a peculiar obsession of Jean-Léon Reutter, a Swiss engineer, who in the 1920s made a prototype, one whose movement reacted to the slightest variations in temperature and air pressure, to constantly keep itself wound.

Reutter’s invention caught the eye of Jacques-David LeCoultre, the eponymous watch company, who eventually bought the patent.

There have been many Atmos clocks ever since, of many designs, often seemingly produced with the unwritten brief to be madder than the one that preceded it.

Jaeger-LeCoultre has collaborated on Atmos clocks with Marc Newson, German industrial designer Luigi Colani of Fiat and Alfa Romeo car and the luxury house Hermès, to name three.

For 2022 it has unveiled the Atmos Hybris Mechanica Calibre 590, also called the Atmos Tellurium, which the company says is the most complicated Atmos clock ever created.

We're in no position to disagree.

The tellurium (also written as tellurion) is a three-dimensional mechanical mobile that illustrates the relative positions and movements of Earth and the Moon in relation to the Sun.

Part sculpture, part work of art, a temperature variation of just one degree Celsius provides sufficient energy to "wind" the new clock for 48 hours, enabling it to run perpetually – as long as it's kept under normal everyday conditions.

Forget watch straps made of reclaimed bottle tops, biodegradable packaging, etc. This is ahead-of-its-time environmentally conscious timekeeping, of the most mind-boggling kind.

In a limited edition of 10, the Atmos Hybris Mechanica Calibre 590 can be yours for €500,000 (excluding VAT). jaeger-lecoultre.com