SIHH 2014: A. Lange & Söhne 1815 Tourbillon Written byWatchTimeJanuary 21, 2014 The tourbillon has long been something of an enigma. It is offered as the ultimate in timekeeping precision, and its owners pay dearly for a watch that is supposed to be the ultimate in accuracy. Yet because of its construction, tourbillon watches are almost impossible to set precisely – to the second- with the current time. That’s because they lack basics like stop-seconds and zero reset functions. Until now. With the 1815 Tourbillon, Lange presents the first tourbillon armed with these twin guarantors of precision setting.When the crown is pulled, the balance inside the tourbillon cage stops instantaneously and the seconds hand jumps to the zero position. The watch can then be perfectly synchronized with a reference watch or a time signal. In 2008, Lange’s movement designers succeeded in directly braking the balance inside the rotating tourbillon cage, but without zero reset. That stop-seconds mechanism works as follows: When the crown is pulled, a complex lever mechanism presses a movable V-shaped spring onto the balance wheel and stops it instantaneously. The new 1815 Tourbillon goes one step further. Lange’s movement developers paired the stop mechanism with the brand’s zero-reset mechanism. Both the stop seconds and zero-rest systems are patented. The 1815 Tourbillon’s case measures 39.5 mm in diameter and 11.1 mm high. It will be available in pink gold, priced at 132,500 euros, and in a limited edition of 100 pieces in platinum priced at 162,500 euros.