Setting the age and moon phase

The FB 1L collection has a complex and unique display of the age and phase of the moon. It consists of a segment numbered from 1 to 14.75 on which a needle goes back and forth continuously, depending on the current moon phase.

A second indication in the opening of the dial at 4 o'clock completes this display by indicating a waxing and waning of the moon.

Age of the moon
Day from the new moon
Moon phase
Waxing Waning

Chronomètre FB 1L.1

Setting the age and moon phase

Chronomètre FB 1L.1

Setting the age and moon phase

"Near Side of the Moon"

Imbued with the scientific spirit of the Enlightenment, the Chronomètre FB 1L.1 is at the crossroads between astronomy and chronometry. A large hand at 6 o’clock indicates the age and phases of the moon in a continuous back and forth movement. This patent-pending complication, combined with the constant force of the FB-T.FC.L calibre, ensures astronomical precision corresponding to a one-day difference in 577 years of operation. Available in a ten-piece limited edition, the FB 1L.1 “Near Side of the Moon” favours a warm and luminous approach. It features a silver-toned dial and a case made of 18-carat white gold and black ceramic lugs, housing the manufacture tourbillon movement with fusee-and-chain transmission.


The age and phases of the moon indication is a patented complication. It consists of the display of the moon's age in days, marked from 1 to 14 on a sector swept over by a hand moving back and forth. Facing these number of days, circles are spread over the same sector as the days go by. They symbolise the moon in a mathematical way: from the new moon to the full moon, passing through quarters.
Composed of a cam rotating counter clockwise, this original mechanism is inspired by a system for displaying the equation of time developed by Ferdinand Berthoud in 1752. It was based on the use of a feeler-spindle arm that followed an equation of time cam. In this instance, however, it is an age-of-the-moon cam.
The FB 1L collection pays tribute to this work and to the movements that pioneered chronometric precision. Its case is inspired by Ferdinand Berthoud's marine chronometers, turning some signature elements such as the lateral porthole into a modern interpretation.

Chronomètre FB 1L.1 in details

    • Diameter: 44 mm
    • Thickness: 13.95 mm
    • Water resistance: 30 m
    • Dynamometric crown in 18-carat white gold with black ceramic medallion
    • Knurled 18-carat white gold L/H (Moon/Time) selector
    • Octagonal case fitted with two watertight portholes in glareproofed sapphire crystal
    • Case in 18-carat white gold with black ceramic lugs elements
    • Screw-in case-back with glareproofed sapphire crystal
    • Domed, arched and glareproofed sapphire crystal
    • 10-piece limited and numbered edition
    • Mechanical hand-wound movement
    • Tourbillon with constant force device with fusee-and-chain transmission
    • Diameter : 37.30 mm
    • Thickness : 9.38 mm
    • Lines : 16 ½
    • Number of jewels : 55
    • Frequency: 21,600 vph (3 Hz)
    • Power reserve : 53 hours
    • Number or parts : 1240
    • Chain length : 285 mm
    • Chronometer-Certified by the COSC
Dial and hands
    • Moon plate (dial) in rhodium-plated sandblasted brass
    • 18-carat blued (CVD) gold hours, minutes and power reserve hands
    • Bronze blued (CVD) seconds hand
    • Steel blued (CVD) lunar-cycle hand and fixed moon-phase index (4 o'clock)
Functions and display
    • Display of the hours, minutes at 12 o'clock
    • Age and phases of the moon display at 6 o'clock
    • Waning or waxing moon phases indicator at 4 o'clock
    • Central seconds
    • Power-reserve on the back of the movement
Strap and buckle
    • Hand-sewn rolled-edge alligator leather strap
    • 18-carat white gold double-blade length-adjustable safety folding clasp
Chronomètre FB 1L.1 Chronomètre FB 1L.1
Interested in acquiring this exceptional model ?