A. Lange & Söhne’s 1815 stands for noble understatement at the pinnacle of horology. Its three-day movement has now been paired with a power-reserve mechanism. In the new 1815 Up/Down, an additional blued-steel hand at 8 o’clock indicates how long the watch will continue to run before having to be rewound.

The display with AUF for the fully wound and AB for the fully unwound movement is a traditional A. Lange & Söhne characteristic that dates back to a patent granted in 1879.

The principle employed in the 1815 Up/Down also relies on a patent filed by Otto Lange, one of the grandsons of the manufactory’s founder. His invention was specially conceived for slender watches: a planetary gear system integrated in the movement drives the display without requiring extra vertical space. Lange adopted the same approach for the power-reserve indicator of the 1815 Up/Down.

On the plate side, two additional gold chatons in the three-quarter plate made of German silver refer to the presence of the power-reserve mechanism. Despite the supplementary 57 parts, the L051.2 manufacture movement has exactly the same dimensions as that of the 1815 without the Up/Down indicator: a height of 4.6 millimetres and a diameter of 30.6 millimetres.

Beneath the hand-engraved balance cock, a classic screw balance and an indexless oscillator assure optimised rate accuracy together with a balance spring developed and manufactured in-house, which is calibrated to a frequency of 21,600 semi- oscillations per hour.

With its 245 parts lavishly finished by hand, manufacture calibre L051.2 features a host of hallmarks that underscore Lange’s watchmaking artistry: they include chamfered and polished edges, Glashütte ribbing on the three-quarter plate, gold chatons secured with blued screws, the polished endpiece of the escape-wheel cock, and winder wheels decorated with solarisation that are visibly integrated in the plate.

The case and prong buckle of the 1815 Up/Down are crafted from 18-carat yellow, white, or pink gold; all model variations have an argenté dial made of solid silver. Superb legibility is guaranteed thanks to black numerals and blued-steel hands. With a railway- track minute scale, Arabic numerals, and symmetrically arranged subsidiary dials for the power-reserve indicator and the small seconds, the 1815 Up/Down pays tribute to the style elements of Lange’s acclaimed pocket watches, now transposed in a contemporary way to the dimensions of a wristwatch.

Movement	:	Lange manufacture calibre L051.2, 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	:	245
Jewels	:	29
Screwed gold chatons	:	7
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	:	72 hours when fully wound
Functions	:	Time indicated in hours, minutes, and subsidiary seconds with stop seconds; power-reserve indicator
Operating elements	:	Crown for winding the watch and setting the time
Case dimensions
Diameter	:	39.0 millimetres
Height	:	8.9 millimetres
Movement dimensions
Diameter	:	30.6 millimetres
Height	:	4.6 millimetres
Crystal and caseback	:	Sapphire crystal (hardness 9)
Reference	:	234.021
Case	:	Yellow gold
Dial	:	Solid silver, argenté
Hands	:	Blued steel
Strap	:	Hand-stitched crocodile strap, middle-brown
Buckle	:	Prong buckle in yellow gold
Reference	:	234.026
Case	:	White gold
Dial	:	Solid silver, argenté
Hands	:	Blued steel
Strap	:	Hand-stitched crocodile strap, black
Buckle	:	Prong buckle in white gold
Reference	:	234.032
Case	:	Pink gold
Dial	:	Solid silver, argenté
Hands	:	Blued steel
Strap	:	Hand-stitched crocodile strap, reddish-brown
Buckle	:	Prong buckle in pink gold