Ferdinand Berthoud Chronomètre FB 1L.4 Limited edition of 10 pieces

The Ferdinand Berthoud Chronomètre FB 1L.4, also known as the “Far Side of the Moon,” is a remarkable achievement in contemporary chronometric watchmaking. Inspired by the marine chronometers created by Ferdinand Berthoud during the 18th century, its distinctive 44mm octagonal case incorporates anthracite ceramised titanium with sandblasted 18-carat white gold and two sapphire crystal portholes, creating a striking combination of technical materials and traditional precious metal craftsmanship. The case measures 13.95mm thick and is water resistant to 30 metres.

The black PVD-coated sandblasted dial presents the hours and minutes on a dedicated subdial at 12 o’clock, while central seconds and an innovative display of the moon’s age and phases provide the watch with its unmistakable astronomical character. A specially developed feeler-spindle mechanism follows an age-of-the-moon cam, allowing the moon-age indication to achieve extraordinary precision. The system is accurate to within just one day over 577 years of continuous operation, making it significantly more precise than conventional moon-phase displays.

At the heart of the Ferdinand Berthoud FB 1L.4 is the manually wound Calibre FB-T.FC.L, an entirely in-house movement featuring a suspended fusee-and-chain construction designed to deliver constant force to the escapement throughout the 53-hour power reserve. The movement also incorporates a one-minute tourbillon with direct-drive central seconds, while the power-reserve indication is displayed on the back of the movement. The calibre measures 37.30mm in diameter and 9.38mm thick, contains 1,240 components and 55 jewels, and operates at 21,600 vibrations per hour. Each movement is COSC-certified as a chronometer.

Completed with a hand-stitched black alligator leather strap and folding clasp, the Ferdinand Berthoud Chronomètre FB 1L.4 is an exceptionally rare collector’s timepiece limited to only 10 individually numbered pieces. Combining constant-force technology, a fusee-and-chain mechanism, tourbillon regulation, astronomical moon indications, and Ferdinand Berthoud’s distinctive marine-chronometer-inspired architecture, the FB 1L.4 stands as a remarkable example of independent haute horlogerie and chronometric innovation.