Following on from his record-breaking Sauterelle à lune perpetuelle, maestro watchmaker Andreas Strehler has now made his super-precise moonphase numerically readable to the nearest 3 hours of wax or wane
Let’s face it: most of us like having a moonphase on our dial for the sheer whimsy of it; a romantic flourish that vaguely relates to horology’s origins in astronomy. Rather than using it to tell the actual phase of the moon when it’s cloudy, it’s more the other way round – we note that it’s a lovely man-in-the-moon crescent or a beaming full moon, or a pitch-black new moon, then look down at our dial for validation. “Look at that!” we say, “my moonphase was right all along!”
Well, Andreas Strehler wants his moonphases to be really right. So right in fact, that his Sauterelle à lune perpetuelle of 2014 made it into the Guinees Book of Records as the most precise, only having to be adjusted for a day off the lunar cycle every two million years, rather the couple of hundred that nearly every other moonphase watch demands.
And not only does he want his moon to be bang-on for a few hundred generations of heirs to your lovely timepiece, but now he wants us to use it numerically measure the days, and even hours that have passed during the current wane or wax. As he rightly notes, no matter how accurate your lunar watch, the only absolute is when it’s new or full moon. Anywhere in between is arbitrarily pictorial. It’s an obsession bordering on Teen Wolf levels. Stepan Sarpaneva would be impressed.
Which brings us to this year’s evolution of said obsession: the Lune Exacte. Which does exactly what it says on the handcrafted presentation case, to the nearest 3 hours.
At 6 o’clock you’ll find a subdial of concentric circular “vernier” scales. The outer scale is easy to understand – you simply read off the age of the moon from new moon onwards in days. The inner scale gives you the amount of hours “plus”, in increments of 3 hours. But how you do this is a little unintuitive (despite Strehler being impressed enough by the invention to apply for a patent..).
If the days indicated by the red arrow are in the yellow zone, look to the inner ring and find where two concentric markers are aligned in the yellow zone. That’s the approximate amount of hours to be added to the days. Similarly, if the days indicated are in the blue zone, the two markers aligned in the inner blue zone and those are your extra hours.
So, working across from left, you have: (1) New moon. (2) 5 days and 18 hours. (3) 27 days and 3 hours. Simple!
What’s more, there’s another string to the Lune Exacte’s bow, demonstrated by the three-armed seconds subdial at 11 o’clock. Look closely and you’ll see the distinctive star-shaped, sprung remontoire d’égalité patented by Strehler, delivering an even portion of energy to the seconds wheel every second – not the escapement, uniquely, as this is where the least amount of torque plays out.
Every second, the visible satellite gear provides exactly the same amount of energy to the seconds wheel and at the same time displays the seconds as dead-beat seconds. The energy is accumulated by a star-shaped satellite through a spring which is re-loaded every second. Then, the satellite wheel is released and transfers its energy to the balance. The satellite wheel then rests again against the pallet-stone.
If you’re lucky enough to be at Baselworld this year, head to Hall 2.0, find the AHCI independent’s stand and ask the man himself to see his incredible new creation. All the above might sound rather dry, but in the metal it’s a revelation.
For more information, visit astrehler.ch