With the 1815 Rattrapante Perpetual Calendar, premiered in 2013, A. Lange & Söhne endowed three of the most sophisticated horological complications with the beautifully classic design of the 1815 product family. The equally rare and challenging combination of a split-seconds chronograph with a perpetual calendar is now presented in a new livery, featuring an 18-carat white gold case with a pink-gold dial and limited to 100 pieces. It is the third timepiece from A. Lange & Söhne to boast a watch face with this hue, which is highly sought-after by collectors, and joins the existing executions in platinum and pink gold with an argenté dial.
The rattrapante complication is considered to be one of the most ambitious in the world of high horology, since it is capable of measuring intermediate times and comparative times as well as determining minimum and maximum values in the course of one minute in addition to classic chronograph functions. As the balance wheel of the manufacture caliber L101.1 beats with six semi-oscillations per second, the stopped times can be recorded with an accuracy of one sixth of a second. Thanks to the additional graduation on the peripheral minute scale, these can be easily read.
While the rattrapante chronograph excels on the field of short-term measurement, the perpetual calendar is a long-distance champion. The complex mechanism ensures that the date, day of the week and month are correctly displayed ‒ every single day, during decades, even taking leap years into account. The calendar indications must only be corrected by one day but not until 1 March 2100 when the leap year will be skipped in accordance with the Gregorian calendar.
The high-precision moon-phase display has also been programmed with the long term in mind. It so closely emulates the duration of the synodic orbit of the earth’s satellite that it would take 122.6 years for the display to be corrected by one day.
It goes without saying that the German luxury manufacture presents these complications in a most classic design, channeling the classic aesthetics of vintage Lange pocket watches in accordance with the 1815 collection. The two pairs of combined calendar indications are arranged at 3 and 9 o’clock. The left subsidiary dial shows the date and day of the week, the right the month and leap year. Sharing an auxiliary dial with the subsidiary seconds at 6 o’clock, the moon-phase display provides an expressive colorful accent. The minute counter and power-reserve indicator are located at 12 o’clock. The shorter gold hand in the inner circle reveals when it is time to deliver new power to the movement via the winding crown. The longer hand made of blued steel imparts information about the stopped minutes.
The 1815 Rattrapante Perpetual Calendar, which has a diameter of 41mm, is powered by the manually wound movement L101.1. A feast for the eyes and a micro-mechanical gem, it totals an impressive number of 631 individual parts. The mechanism of the perpetual calendar alone requires 211 components, a further 206 account for the rattrapante-chronograph mechanism. A screw balance, which is driven by the balance spring developed and manufactured in-house, ensures high rate stability.
Lange-typical quality hallmarks such as screwed gold chatons, blued screws, an elaborate whiplash precision index adjuster and the hand-engraved balance cock are visible through the sapphire-crystal case back. The finissage of the movement, which is assembled twice as all Lange movements, displays the brand’s high standards in every detail.
Particularly pleasing to connoisseurs is the display of the chronograph mechanism, with the classic two-column wheel transmission used to control the measurement of stopped and intermediate times. As is typical for A. Lange & Söhne, technical intricacy is coupled with a high degree of artisanship. The upper surfaces of all moving parts are decorated with straight graining while the peripheral chamfers are polished. Only an experienced finisseur has the skill to polish the bevels to sharp and flat perfection.
“With three classic complications, the manufacture caliber L101.1 is one of our most complex movements. Each one in itself already constitutes a technical feat; when combined, they represent a far greater challenge. For our designers and our watchmakers in equal measure, since the tweaking and tuning process of all mechanisms requires an exceptionally high degree of dexterity and technical expertise,” explains Anthony de Haas, Director of Product Development at A. Lange & Söhne.
Pricing of the 1815 Rattrapante Perpetual Calendar is available upon request.
To learn more, visit A. Lange & Söhne, here.