The Grand Lange 1 "Luna Mundi":
A short presentation

by Alex G
© April 2003

The first time I saw the A. Lange & Söhne Lange 1 Luna Mundi in the press kits, I was very disappointed. The watch just did not look right and it seemed to me that Lange was playing on the Lange 1 success much too much and God forbid it was in a 42mm case AND all displays were overlapping! How can they do this to such an icon! I thought.

But, as usual, Lange timepieces have to be seen "in the metal" to fully appreciate them.

Not only because they always look better in reality, but also because only by holding a Lange can you feel the exquisite craftsmanship, the love of detail and human effort that has gone into manufacturing the timepiece.

The Luna Mundi is no exception. Here is a watch I wanted to hate, but couldn’t because, as usual, Lange did things with class and cut no corners.

With this model Lange & Söhne have actually rethought the whole philosophy of the Lange 1 and have slowly modified the icon to appeal to the tastes of the 21st century watch enthusiast.

Very few brands can boast such strong designs that can be easily attributed to the company, the Audemars Piguet Royal Oak, Rolex Oyster and Panerai Lumior coming to mind. Lange could have rested on its laurels and left such a perfect and recognised design alone but this is where they prove their boldness

Where, as legend puts it, Messrs. Blumlein and Meis locked themselves up in a room all night working on a dial presenting the indications for hours, minutes, seconds, big date and power reserve with NO indications overlapping, in the new Grand Lange 1 ALL indications overlap! And it still looks good. The dial somewhat makes me think of 18th century English astronomical pocket watches.

The Luna Mundi, the first model with the new Grand Lange 1 design, comes in an exclusive set of two watches (limited to 101 pieces) with the correct depiction of the moon phases – in white gold for the Northern Hemisphere and pink gold for the Southern Hemisphere.

The waxing and waning of the moon in the Northern Hemisphere is the exact opposite of the progression seen from a standpoint in the Southern Hemisphere. Only the full moon and the new moon look the same on both sides of the equator

The watchmaking industry, traditionally in the Northern Hemisphere, has always ignored this fact and until now all our moonphase timepieces displayed the correct moonphase but only in the Northern Hemisphere.

Lange decided to right this historical error :-) by introducing this set.

The two prominent constellations in the northern and southern skies, the Big Dipper and the Southern Cross, are shown as stellar symbols on the dial and the respective moon-phase disc.

Both watches in the enlarged 41.9mm case also feature the continuous moon-phase drive of the LANGE 1 which was presented a year ago. The mechanism is incorporated in both calibre versions, the L901.8 for the Northern Hemisphere and the L901.7 for the Southern Hemisphere. In the latter, an additional wheel reverses the rotation of the moon disc. Thus, both watches of the set share the moon-phase display implemented in the Lange 1 Moonphase for the first time in 2002: It is probably the most realistic depiction of the progression of lunar phases, because the waxing and waning moon is always in motion as long as the watch runs. The moon-phase display is not advanced merely once or twice every 24 hours but instead is coupled with the continuum of the hour wheel and therefore moves steadily, albeit at a speed that is indiscernible to the human eye.

Moonphase mechanism for the Southern Hemisphere (Lange stock drawing):

Moonphase mechanism for the Northern Hemisphere (Lange stock drawing):

Because of the extremely high accuracy of the gear train, the synodic orbit of the moon around the earth, averaging 29 days, 12 hours, 44 minutes, and 3 seconds, is emulated so precisely that the gear-ratio-related display error is a scant 1.9 seconds per day, or 57 seconds per lunation. This eventually adds up to one full day in 122.6 years. The push-piece recessed in the case between 7 and 8 o’clock makes it possible to readjust the moon-phase display if required or in case the watch has been stopped for a prolonged period of time.

On the compact celestial stage framed by the off-centre subsidiary seconds dial, the moon is accompanied by either of the two constellations.

In the Northern Hemisphere, it is the Big Dipper (Ursa Major), the third-largest constellation. Its seven brightest stars form the Great Chariot, as it is called in central Europe, or the Great Bear in British vernacular.

The Southern Cross is a somewhat smaller constellation in astronomical terms, but certainly the most famous one in the Southern Hemisphere. It is in the middle of the bright band of the Milky Way. In the Ptolemaic era, it was believed to be one of the centaurs, but the seafarers of the 16th century willingly adopted it as an important reference point in navigation because it points the way south.

The sapphire-crystal caseback exposes all the characteristic hallmarks of Lange quality: the Glashütte three-quarter plate made of untreated, cross-laminated German silver, screwed gold chatons, manually blued steel screws, the hand-engraved balance cock with the whiplash precision index adjuster and the shock-proofed screw balance that vibrates at 21,600 semi-oscillations per hour, manually chamfered and polished plate edges, and lavishly decorated surfaces in the Lange tradition.

On the wrist the watch, even though a bit too big to my taste, sits perfectly well, and the dial is mesmerising! Lange & Söhne may not have introduced this year the big WOW piece every one was waiting for, but instead of a run for complications and technical mastery they have introduced a timepiece with a poetic appeal that no ultra complication would have had.

Data sheet GRAND LANGE 1 "Luna Mundi"


Lange manufacture calibres L901.7 ("Luna Mundi/ Southern Cross") and L901.8 ("Luna Mundi/Ursa Major"); manually wound; adjusted in five positions; twin mainspring barrels; patented outsize date; power-reserve indicator; plates and bridges made of untreated cross-laminated German silver; balance cock engraved by hand
Number of parts:

398 ("Luna Mundi/Ursa Major")
402 ("Luna Mundi/Southern Cross")
Frequency: 21,600 semi-oscillations per hour
Jewels: 54
Screwed gold chatons: 9
Escapement: Lever escapement

Shock-proofed Glucydur screw balance, Nivarox balance spring, patented micrometer-screw index adjuster with whiplash spring
Power reserve: More than 72 hours when fully wound

Hours, minutes, small seconds with stop seconds, patented outsize date, power-reserve indicator

Moon-phase display for Northern Hemisphere with clockwise and Southern Hemisphere with anti-clockwise moon disc rotation for correct presentation of visible lunar orbit.
Accuracy of display: One day deviation from synodic lunation in 122.6 years
Operating elements:

Crown for winding the movement and setting the time, push-piece for switching the patented outsize date, recessed push-piece for correction of the moon-phase display

Diameter 41.9 millimeters, 18-carat white gold ("Luna Mundi/Ursa Major") and 18-carat pink gold ("Luna Mundi/Southern Cross")
Glass and caseback: Sapphire crystal (hardness 9)

Solid silver, argenté, with rhodiumed- or pink-gold appliqués, depending on model
Hands: Rhodiumed or pink gold, depending on model
Water resistance: 30 metres

Hand-stitched crocodile strap with precious-metal Lange prong buckle in white or pink gold, depending on model
Edition: Limited to 101 sets (two watches each)


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Copyright April 2003 - AlexG and - all rights reserved