ferdinand berthoud chronometer fb1l


This limited edition is a homage to erudition, with a constant-force module powering an unusual astronomic feature.

A display of the moon cycles is an exercise mastered by many watchmakers. But the complication generally has more of an aesthetic than a practical function, since the moon phases are not accurate enough to be of use to astronomy fans. To improve the complication, the Ferdinand Berthoud team took a long look at some precision timekeeping studies carried out by the inventive master watchmaker of the same name. In the 18th century, Berthoud conducted several research projects with a surprising instrument used to measure angular distances, the repeating circle. Earlier, in 1752, the German astronomer Tobias Mayer had used the tool to compose his Lunar Tables, pinpointing the exact position of the Earth’s satellite. The Chronomètre FB 1L embodies the scientific progress of the Age of Enlightenment with an indicator of the moon age and phases together with a chronometer.

ferdinand berthoud chronometer fb1l dark closeupIn the dial’s southern hemisphere, the display of the age of the moon in days is shown with a hand moving along a scale numbered from 1 to 14. The number 1 is for the first day after a new moon, with the number 14 for a full moon. The mechanism is coupled with an original display of the moon phases. You can see if the moon is waxing or waning at a glance. This ingenious feature is made without a disc and will not need correcting for 577 years!

ferdinand berthoud chronometer fb1l clear closeupA chain and fusee tourbillon calibre was used to obtain this result. The complex movement including 1,240 elements is housed in a grey-gold 44-mm-wide case. Two models with ten pieces each are available. The first, Near Side of the Moon, comes in light colours. The second, Far Side of the Moon, takes us to a much darker world.

ferdinand berthoud chronometer fb1l caseback closeupPrice: 250,000 CHF (titanium) – 265,000 CHF (white gold)

By Dan Diaconu