15933, ‘Onyx’ Skeletonized Chronograph, Yellow Gold Explorer II The 1815 Chronograph built on

The 1815 Chronograph built on the foundation of the Datograph

Its architecture is inspired by mid-century Patek Philippe observatory chronometers

a technical challenge that was pioneered entirely in Beat's Thun workshop

A remarkably well-preserved 'Four-Liner' gilt dial ref

15933, ‘Onyx’ Skeletonized Chronograph, Yellow Gold Explorer II The 1815 Chronograph built onAn extremely rare ref. 15933 Onyx Lemania 2310 bauche chronograph, the only surviving onyx example known, thought to be one of three ever made. The 39mm case is unique to this reference, highly intricate with 3 piece construction, a bezel inlaid with polished onyx, hobnail exhibition caseback, and flared, stepped lugs. Its movement is finely finished with freehand engraving in floral motif, mirror anglage, and aggressive skeletonization, leaving