A. Lange & Söhne Marks 20 Years of the Datograph Perpetual with 50-Piece Limited Edition

A. Lange & Söhne marks the 20th anniversary of its Datograph Perpetual collection with a new limited-edition model. The 20th anniversary edition is limited to 50 pieces.

Technical Specifications

The watch features a 41mm 950 platinum case and matching platinum bracelet. It measures 41mm in diameter and 13.5mm in height. The watch is powered by the manually wound calibre L952.1 with a 36-hour power reserve.

The L952.1 calibre is a manually wound manufacture caliber with 556 parts. The movement operates at 2.5 Hz (18,000 vibrations per hour) and is visible through a sapphire-crystal caseback.

Dial and Display Details

The dial is black and rhodié-colored 925 silver with eleven baguette-cut diamond hour markers. It has 11 hand-applied baguette-shaped diamond hour markers. The dial is made of 925 silver and coated with black rhodium.

The dial omits indices at 4 and 8 o’clock to accommodate prominent rhodié auxiliary dials. The outsize date at 12 o’clock forms the tip of an equilateral triangle with the two main subdials.

Complications and Functions

The watch includes a column-wheel flyback chronograph and perpetual calendar functions. The chronograph measures elapsed time to one-fifth of a second. The perpetual calendar automatically accounts for months of different lengths and leap years.

The perpetual calendar mechanism is accurate until March 2100. It will not require correction until March 1, 2100. The subdial at 9 o’clock tracks small seconds, day of the week, and day/night indicator. The subdial at 3 o’clock displays the jumping minute counter, month, and leap-year cycle.

Adjusting displays uses a single rapid-correction pusher at 10 o’clock or individual recessed correctors. The watch includes a moon-phase display at 6 o'clock. The moon-phase display deviates by one day after 122.6 years if the watch runs continuously.

Design Evolution

The original Datograph Perpetual had a silver dial, while the anniversary edition has a black dial. The bracelet design differs from the original, featuring a squarer, more modern style compared to the original curvier links.

The watch is the only Datograph model with a bracelet option, as bracelets are no longer offered on most modern Lange watches. The new Datograph Perpetual (Ref. 410.136E) is limited to 50 pieces. Its perpetual calendar will remain accurate until March 2100.