The 1815 Rattrapante Perpetual Calendar by A. Lange & Söhne incorporates a multitude of complications, such as rattrapante chronograph, perpetual calendar, moon-phase display, and power-reserve indicator. This timepiece is equipped with the Lange manufacture calibre L101.1, the eighth chronograph calibre developed by the Saxon manufacture.
Since the presentation of the Datograph in 1999, the eminent Saxon manufactory had repeatedly raised the bar in the design of sophisticated chronographs with no fewer than seven proprietary calibres, including milestones such as the Double Split and the Tourbograph “Pour le Mérite”.
The A. Lange & Söhne 1815 Rattrapante Perpetual Calendar belongs to the top league of chronographs, the so-called rattrapante or split-seconds chronographs.
Visible through the sapphire-crystal caseback, the rattrapante function can be activated by the push piece at the 10 o’clock position. Stopping elapsed or lap times is handled precisely in the classic manner with two column wheels.
The central, superposed chronograph hand and rattrapante hand make it possible to measure any number of lap times within the course of a minute. The minute-counter and power-reserve displays are located at 12 o’clock.
The longer blued-steel hand indicates the count of stopped seconds. Conversely, the shorter golden hand in the inner circle tells the owner of the watch when the time has come to replenish the energy of the mainspring via the winding crown.
Of the 631 individual parts of the newly developed manufacture calibre L101.1, more than 200 components are part of the perpetual calendar mechanism. It not only knows the durations of all months in the course of a calendar year but also indicates all leap years until the year 2100.
The paired calendar indications are positioned at 9 and 3 o’clock. The subsidiary dial on the left indicates the date and the day of the week, the one on the right the month and the leap year.
The newly designed solid-gold lunar disc beneath the subsidiary seconds dial at 6 o’clock emulates the synodic lunation so precisely that it only needs to be corrected by one day every 122 years.
Arabic numerals, a railway-track minute scale, gold and blued hands as well as four round subsidiary dials in a clover-leaf configuration characterise the design of the 1815 Rattrapante Perpetual Calendar.
It is the classic design mantra of the 1815 watch family that has its roots in A. Lange & Söhne’s grand pocket watch tradition. The prominent case in platinum or pink gold with a diameter of 41.9 millimetres rounds out the impressive personality of this horological masterpiece.
Model: A. Lange & Söhne 1815 Rattrapante Perpetual Calendar
Reference 421.025: Platinum case, Solid silver rhodié dial and Black crocodile strap
Reference 421.032: 18K Pink gold case, Solid silver, argenté dial and reddish-brown crocodile strap
Lange manufacture calibre L101.1, manually wound, crafted to the most exacting Lange quality standards, decorated and assembled by hand; precision-adjusted in five positions; plates and bridges made of untreated German silver; balance cock engraved by hand
Movement parts: 631
Screwed gold chatons: 4
Diameter: 32.6 millimetres
Height: 9.1 millimetres
Escapement: Lever escapement
Oscillator: Shock-resistant screw balance, superior-quality balance spring manufactured in-house, frequency 21,600 semi-oscillations per hour, precision beat adjustment system with lateral setscrew and whiplash spring
Power reserve: 42 hours when fully wound
Time indicated in hours, minutes, and subsidiary seconds; rattrapante chronograph with minute counter; perpetual calendar with date, day of week, month, moon phase and leap year; power-reserve indicator
Crown for winding the watch and setting the time; two chronograph push pieces, one push piece to operate the rattrapante mechanism; separate correction push pieces for adjusting the date, day, month, and moon phase
Material: Platinum or 18K Pink gold
Diameter: 41.9 millimetres
Height: 14.7 millimetres
Crystal and caseback: Sapphire crystal (hardness 9)
Platinum version: Solid silver rhodié dial; hours, minutes, minute-counter and rattrapante hands in blued steel; chronograph seconds hand in gold-plated steel; other hands in rhodiumed gold
Pink gold version: solid silver argenté dial; minute-counter and rattrapante hands in blued steel; chronograph seconds hand in gold-plated steel, other hands in pink gold
Hand-stitched crocodile strap, black or reddish-brown
Buckle: Lange deployant buckle in platinum or pink gold
Image Credit: Lange Uhren GmbH