Duality by Philippe Dufour

A prodigious double regulator movement, silvered dial,

"dauphin" hands, second hand off-set at 7:30,

sapphire crystal and caseback, hand stitched

croco leather strap.

The original idea for using a double regulator goes back to Louis-Abraham Breguet. He envisioned putting this device into a clock but did not follow through on his inspiration. A century and a half later, the idea was taken up by the Technical School in Le Sentier, Switzerland and in the 1930s, the school's watchmakers put the double regulator into a pocket watch. And now, some 60 years later, Philippe Dufour is the first to adapt the concept to the wristwatch.

The double regulator is in some ways a "competitor" to the tourbillon because it also tries to compensate for the effects of gravity on the regulating components of the watch. In fact, this devise involves a complex system of a differential, mounted with the two escapements, on the seconds wheel. The two balance wheels function independently of each other. The differential system compensates for the deviation between them thus reducing by half the potential working error.

Dufour explains it like this, "These two balance wheels are like two hearts which work together to help each other." Extremely complex to make, the differential system alone is composed of 21 parts (twice as many as the tourbillon), not including the regulating organs. Yet, the whole device measures only 30mm in diameter and 4mm in thickness!

Working alone, Philippe Dufour makes each component part himself and has therefore limited the production to 25 pieces. The finished movement is then placed into a 34mm diameter case which is made of platinum of 18K yellow, rose or gray gold.

The differential system