The Tourbillon cancels out the variations in rate due to gravity. It consists of a circular mobile carriage carrying all the escapement organs, with the regulating organ in its centre. Clearly exposed through the large dial opening, the carriage completes one revolution per minute and this rotation compensates for the negative effects of gravity on the escapement and in particular on the balance.

The Arnold & Son calibre A1767 powering your Sir John Tourbillon timekeeper features an extremely refined « one-minute » tourbillon, a balance with screws oscillating at a cadence of 21’600 vibrations per hour, a polished and hand-bevelled carriage, and an English shape and finishing – bridge.

Limited edition of 25 pieces the whole range