The A. Lange & Sohne Datograph Perpetual Tourbillon is comes in a precious platinum case framing a black solid-silver dial. It exhibits at SIHH 2016 which produced in just 100 pieces.
The chronograph function is here combined to a perpetual calendar with a moon-phase display where all indications – outsize date, day-of-week, month, and leap-year – switch instantaneously for precise reading. If marching without interruptions, the first correction of the mechanism by one day will only be needed the first day of March in year 2100. The moon-phase display will only deviate from the true lunation by a single day after 122.6 years.
The rapid-correction pusher at 10 o’clock can be used to advance all calendar displays at the same time while three recessed correctors on the caseband allow the separate adjustment of the day of the week, the month, and the moon phases.As if it was not enough, the sapphire-crystal caseback reveals the tourbillon mechanism with the escapement rotating about A. Lange & Sohne Datograph Perpetual Tourbillon axis once a minute inside the filigreed cage.
For the first time in a Lange tourbillon, the balance beats at a rate of 18,000 vibrations per hour (2.5 Hz) instead of the conventional 21,600. Consequently, stopped times can be displayed with an accuracy of one-fifth of a second. The 55-hour power-reserve indicator is integrated at the end of the tachymeter scale.
The patented stop-seconds mechanism instantaneously brings the balance wheel inside the tourbillon cage to a standstill when the crown is pulled. This allows the A Lange &Sohne watch to be set with one-second accuracy.
This ultra complicated hand-wound movement – calibre L952.2 – is composed of an impressive number of parts 729. The aesthetic result is mind-blowing with flawless finishes which confirm the exceptional mastery of Lange’s watchmakers.
