Under pressure

An app on the wrist will never call time on the traditional watch, says Adrian Hailwood

The smartphone has got us used to having a vast range of information and functions at our fingertips and its paired sibling, the smartwatch, now offers a growing range of these apps on our wrists. These developments seemingly leave the mechanical watch back in the dark ages – no matter how high the price. Even the most complicated watch in the world, Vacheron Constantin’s Tivoli with 57 complications or Patek Philippe’s Graves Super complication – the most expensive at £15million – only offer time-based features. Since clocks and watches were first created, astronomical observations and by implication calendars have been built into their mechanisms. As technology developed, the attention shifted from measuring long periods of time to splitting seconds as finely as possible. It is unusual for watch complications to be associated other than the measurement of time. Early pocket watches often had thermometers or compasses built into them but that was as far as things went. Then came watches that can measure pressure.


A dive watch is a matter of life and death. Knowing how long you have been under and at what depth is fundamental to working out decompression rates and avoiding an attack of ‘the bends’. Before digital dive computers, divers would wear a watch on one wrist and a depth gauge on the other – the Jaeger-LeCoultre Diving Pro Geo combines both functions in one. The robust titanium watchcase is designed to keep water out down to 300 metres but there is one significant area which is not titanium or sapphire crystal – a small rubber button at the 10 o’clock position. This button is sensitive to external pressure which pushes down on it a sprung lever, driving an indictor hand along a depth gauge. If the Jaeger-LeCoultre is all about rugged functionality, the Breva Genie 01 is almost a piece of mechanical art. It’s air that drives the Genie 01. Rather than keeping the elements out, the Breva has a valve that allows air into the watch. Specially designed aneroïd capsules made from memory metal drive the racks and gears of the pressure displays, expanding and contracting as the atmosphere or altitude changes. Both of these watches have, in theory, been superseded by digital technology but the sheer ingenuity of their construction makes them a joy to wear and use. And being mechanical, neither of them has to worry about a dead battery or access to a charging point!

Adrian Hailwood is director and watch specialist at Fellows Auctioneers www.fellows.co.uk