uropa Star: For centuries, watchmakers have been looking for ways to measure time with ever greater precision.

Denis Asch: The balance spring is 350 years old. The escapement, in a form adapted to watches, is 270 years old. The revolution in materials, alloys and manufacturing processes has been going on for a long, long time and progress is still being made. Why? Because watchmakers are inventors at heart, determined to reach their “grail” in terms of mechanical precision. Many have come close but are always confronted with the same problem: how to maintain consistent, stable timekeeping in a watch when it is worn.

So the real question is how to maintain chronometric precision over the long term?

Regardless of whether it is issued by an official body, such as COSC, METAS or another, whether it’s carried out by the brands themselves or independently, certification records results that correspond to a specific point in time.

The vast majority of brands test reliability and ageing using their own processes, simulating the type of movements and accelerations a watch can experience on the wrist. On day one for the customer, on the day of purchase, those characteristics will be as stated.

To what extent is chronometric performance important to collectors?

Not all collectors have the same expectations. Some don’t pay much attention to chronometric performance. For others, it’s essential that their watch maintain a consistent level of performance over the medium and long term, whereas others are more concerned with their grandes complications and want the reassurance they will be able to have them serviced into the future. A lot of the movements that equip this type of watch, meaning ones that focus on optimal chronometry, are by no means conventional. Often, they’re the result of extensive research by independent master watchmakers who, if they are to reassure collectors, also need to prepare for the handover, for passing on their expertise.

Having said that, large industrial brands also carry out advanced research, with the advantage that they have more resources and can take longer to scientifically and industrially confirm their innovations, where independents take a more “empirical” approach.

More specifically, what areas of mechanical chronometry are currently being explored?

Research into ideal chronometry is a carefully balanced combination of solving technical problems and compensating unwanted effects. The most inventive, most ingenious watchmakers are all fighting the same natural enemies—shocks, magnetism, gravity, friction, variations in temperature and water-resistance—and have been ever since watches have been worn on the wrist. That said, the means at their disposal have evolved, even if the fundamental theory is the same, with a few exceptions such as at Grand Seiko.

What are these means?

Progress has been made in many areas. Take magnetism as an example. Watches today are considerably more exposed to magnetic fields but at the same time, watchmakers have doubled down on research into how to protect them. New alloys, treatments, silicon… there are many avenues turning up new solutions to the “enemies” of chronometry, whether with regard to friction, lubrication or weight. To give another example, it’s been almost 50 years since the first cases in titanium, yet it was a long time before titanium made its way into movements, even though titanium components are substantially lighter than many other materials and therefore need far less energy to set them moving: a distinct advantage from a chronometry perspective. Think of it as a car or a plane: the heavier they are, the harder the engine has to work to move them.

There are other areas we could mention, too: component geometry, managing the energy supply, etc., etc.

Not forgetting silicon which revolutionised, or at least solved, some of the recurrent problems watchmakers face, in particular lubrication and resistance to magnetic fields.

Silicon has been part of our watches for a quarter of a century and can be treated to diminish its natural fragility. Silicon has numerous qualities but still implies certain constraints, despite recent research. For example, unlike the majority of materials used in watchmaking, silicon is hard to adjust or repair. Also, we haven’t yet developed a fully reliable oscillator entirely in silicon.

Listening to you, it seems we’ll never truly get to the bottom of the problem.

Well it’s certainly a never-ending story. But we have seen, and are still seeing, fascinating research and very real progress. In this journey towards lasting and ultimate precision, and I insist on the word “lasting”, we still have to confirm advances made in numerous areas, such as power reserve, robustness, water-resistance and magnetic-resistance.

You mentioned independents, who often lean towards “complex” solutions, and certain large brands that focus on “simplification” and more industrial solutions. Is one preferable to the other?

It all depends what you’re looking for, what interests you. And what you need. Personally, I have huge admiration and respect for many of the avenues explored by some highly innovative independents. At the same time, there’s no denying the remarkable chronometric performance achieved by brands such as Rolex and Omega. And, taking Rolex as an example, this considerable progress, close to zero variation in rate, has been made on “standard” movements, if you can call them that, meaning a classic gear train, barrel, lever escapement, escape wheel and balance.

Where next for mechanical chronometry?

Chronometry, as it stands, is based on principles that were established several centuries ago, many by an English carpenter and self-taught watchmaker. In this respect, watchmaking is an exception. It is the product of a long and uninterrupted line of men and women who, step by step, have made improvements to the art and science of mechanisms. The techniques and understanding passed along this line are key to this progress. For as long as we are assured of this continuity of knowledge, mechanical watches have a bright future.