A Lange and Söhne: Grand Lange 1 ‘Lumen’

This timepiece reveals the numbers that other watches hide. It is also inspired by a 171-year-old clock

This watch could have been a skeleton, but it is not. It has a translucent dial, but does not reveal the movement. What it reveals is the new outsized date mechanism that Lange had launched some years ago. Back then, this mechanism was kept neatly hidden below the dial. It has since been used in several other watches. Its makers must value this date mechanism a lot, because they now reveal it in a manner that ensures it doesn’t get lost with the 400 parts that comprise the watch movement. If you want to admire its internals, you can do it through its transparent caseback.

The date mechanism is inspired by the Five-Minute Clock in Dresden’s Semper Opera House, 1841, to which Ferdinand A Lange had contributed. This watch has a platinum case, the dial is made of silver, and its hands are solid rhodium gold. It has been launched in a limited edition of 200.

Parts of its dial consist of semi-transparent sapphire crystal. Only the outer ring and surfaces of the hours, minutes, and small seconds displays are made of blackened silver. The sapphire crystal surfaces reveal the disc mechanism of the outsize date that glows in the dark. Time and power reserve indicators are also clearly visible in the dark.

To gain luminosity, these have to be exposed to light for some time. While the ten’s place of the date is fine with this limitation, the units place—which changes daily in the middle of the night—needed some innovation. Lange’s workaround was to print the units on a glass disc and have it rotate in front of a luminous window that is always exposed.

The sapphire crystal sections of the dial are treated with a special coating that blocks most of the visible spectrum of light. To invisible UV light, however, it presents no barrier. This creates an interesting effect as the ‘hidden’ units on its date plate glow with lesser luminosity than its large, current date indicators.

Last year, Lange made another small modification to this watch—to give it a slimmer profile. It rearranged the parts a bit and gave the watch a manual movement instead of an automatic one. This has not affected the power reserve, which is now at 72 hours. It is just that you have to remind yourself to wind it regularly.

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