F. P. Journe, Tourbillon Souverain d'égalité n° 108/01T, circa 2001. photo Sotheby's

A fine and rare platinum tourbillon wristwatch with constant force remontoire and power reserve * cal. 1498 manual wind movement with constant force remontoir, 25 jewels, mono-metallic compensation balance within a one-minute tourbillon carriage * 18k gold dial plate, eccentric guilloché mean time dial, two apertures revealing the remontoire fly regulator at 6 o'clock and tourbillon carriage at 9 o'clock, sector for power reserve * sapphire crystal display back secured by six screws * case, dial and movement signed * platinum F. P. Journe buckle * Certificate of Authenticity, instruction booklet, box and packaging - diameter 38 mm - Est. 60,000—80,000 USD - Sold 74,500 USD

NOTE: First created by Jost Burgi at the end of the 16th Century, the remontoire acts as a buffer to limit the effect of variances in power of the going train on the escapement and re-distributes varying levels of energy as a constant force. While originally created to counter the effects of wind on the movement of tower clocks, its application in a wristwatch prevents the variation in the winding level of the mainspring from interfering with the consistency of time-keeping.

Launched in 1999, the Tourbillon Souverain d'Egalité marked the first usage of a constant force remontoire in a wristwatch. The combination of both remontoire and tourbillon is a tribute to F. P. Journe's technical genius in the creation of complicated modern wristwatches firmly rooted in horological tradition.

This model was created in small quantities and has now been discontinued. It was replaced by the Tourbillon Souverain with dead seconds.

Sotheby's Important Watches, Clocks and Automata. 20 Oct 09. New York www.sothebys.com