One major difficulty lay in housing the Calibre 3655 and its 1,521 components in a reasonably sized case that would comfortably fit the wrist. Mission accomplished by the watchmaker, who succeeded in tucking the movement into a case measuring 45mm in diameter with a height of only 14.99mm – a watchmaking tour-de-force.

This watch occupies a special place in horology, notably for its five innovative astronomical complications, four of which relate to the course of the Sun across the sky. Thanks to an innovative mechanism, the display shows the position of the Sun in real time, its height, time of culmination and angle of declination – astronomical feats for a mechanical wristwatch.

Given the concentration of complications, a major challenge was ensuring legibility. Four counters are positioned on the front, two of which display up to five complications each, while the back combines a sky map and chronograph functions. The watch face features a sophisticated interplay of white, black, and grey tones for a striking contrast that enhances ease of reading.