We’re just back from one of the central events of the watch lover’s (and watch journalist’s) year: the Salon International Haute Horlogerie in Geneva, where luxury watch brands under the aegis of the Richemont Group (as well as a few other brands that prefer the relative calm of the SIHH to the rugby-scrum hurly-burly of the Other Watch Fair, BaselWorld) show what’s new and (we hope) exciting for 2012. It’s a whirlwind –five days, literally hundreds of watches, and the near-impossible task of trying to keep everything you’ve seen in mind once you’re home.
Every year, though, there are a few watches that it’s no trouble to recall, and one of the most memorable this year (and one of the most talked about watches among attendees) was the Jaeger LeCoultre Sphérotourbillon, one of JLC’s new complicated watches based on the “Dual Wing” concept. The basic idea behind the Dual Wing watches is to have two independent power sources (essentially, two separate mainsprings.) One mainspring powers the timekeeping gear train and the other is used to supply energy to whatever complication has been built into the watch. The reason behind this construction is simple: a complication has the potential to disrupt the accuracy of a watch by stealing energy, when it’s in use, from the escapement, which requires as constant torque as possible to work well. (Chronographs, for instance, may run at a different rate when the chronograph is switched on than when it’s not.)
The solution in traditional watchmaking is to simply exercise great care in the construction of the complication, so as to reduce the amount that torque varies when the complication is running. Jaeger LeCoultre, however, has opted for another solution –one which has allowed them to incorporate several novel and useful features into the Sphérotourbillon.
The Sphérotourbillon is, as is obvious from the name, a tourbillon wristwatch. A reminder: the tourbillon is a device intended to combat the disruptive effects of gravity on the accuracy of a watch, by placing the escapement in a rotating carriage that prevents the escapement from ever staying in one position too long. Tourbillons, however, were invented over 200 years ago when wristwatches were still over a century in the future, and what works in a pocket watch works less well in a wristwatch. To address this problem, the multiple axis tourbillon was developed, in which the tourbillon rotates around more than one center. Originally pioneered by English watchmakers Randall and Good, multi-axis tourbillons are extremely rare, with notable models made by independent watchmaker Thomas Prescher and by Greubel Forsey, which made the first inclined multi-axis tourbillon wristwatches, in which the central axis of the tourbillon is tilted relative to the watch, in order to further reduce the chances of the escapement finding itself compromised by gravity. Jaeger LeCoultre is no stranger to multi-axis tourbillons itself, having made the Gyrotourbillon I and II, both of which feature a double tourbillon cage.
The Sphérotourbillon is the first inclined, dual-axis tourbillon produced by Jaeger LeCoultre and also the first JLC tourbillon to use the Dual Wing system. It’s a match made in heaven. The tourbillon is an exotic. There are two cages –the inner rotates once every 30 seconds, and the outer once every 15 seconds. The tourbillon is inclined at a 20 degree angle, and the balance spring is cylindrical –an extremely rare shape, usually reserved for use only in ship’s chronometers. We’re unaware of any other tourbillon wristwatch with a cylindrical balance spring except Jaeger LeCoultre’s own Gyrotourbillon II.
The fact that there are two separate power supplies also allowed Jaeger LeCoultre to solve a long-standing problem in tourbillon design, which is that despite their declared purpose of improving accuracy, it is impossible to set most tourbillons to the nearest second (this is usually done with a stop-seconds feature, sometimes called “hacking,” which stops the seconds hand when the crown is pulled out.) A pusher built into the Sphérotourbillon’s case instantly re-sets the seconds hand to zero, allowing it to be coordinated with an external time reference –all without stopping the watch from running, which is possible only because there are two independent power sources.
All this is delivered in a beautifully classic chassis –the Sphérotourbillon despite its complexity and the inherently large size of the tourbillon mechanism, is only 42mm in diameter and a surprisingly svelte 14.1mm thick. For real connoisseurs of both the pursuit of greater accuracy in mechanical watches, and for those who delight in real horological rarity, the Sphérotourbillon is magic in motion.
The Jaeger LeCoultre Sphérotourbillon is available in red gold only, and in addition to the tourbillon also features a date and second time zone display, as well as power reserve indications for each power source. Price $262,000.00 USD.