The Chronomètre FB 3SPC draws its stylistic, technical and aesthetic inspiration from a rare and exceptional creation, the No. 26 decimal watch, made in 1793 by Louis Berthoud. Calibre FB-SPC is based on a cylindrical balance-spring, a rare watchmaking speciality. It is the only one of its kind to satisfy the chronometric (precision timekeeping) criteria of the COSC: ISO 3159 certification made possible only by the precision adjustments performed by the Manufacture’s watchmakers. The FB 3SPC.1, one of the two versions available, is equipped with an 18-carat white gold case, 2N pale yellow gold movement components and an eggshell-coloured dial in sandblasted silver-toned brass.
Appearing at 9 o’clock, the three main escapement organs – the balance-wheel, pallet-lever and escape-wheel – are thus individualised, distinct and prominent. This ample space dedicated to the regulating organ enables its operation to be admired in full, and the cylindrical balance-spring to be seen beating throughout the three-day power reserve, including through a large water-resistant porthole created in the case middle. Its round case, available in 18-carat white or rose gold, recalls the curves of pocket watches from the early 19th century, such as the decimal watch No. 26, made in 1793 by Louis Berthoud and now on display within the Chronométrie Ferdinand Berthoud heritage collection in Fleurier. The mainplate is placed at the heart of Calibre FB-SPC and the components are assembled on either side of it. On the dial side, a close-knit array of six bridges traces curves and lines directly inspired by the work of Louis Berthoud. They are echoed on the back by ten other bridges forming an intimately juxtaposed mosaic.