In a starry sky, a large moon alternates between light and dark as it moves through its phases. Luna Magna is the largest rotating moon ever built into a wristwatch.
Gallery
diaphaneous presence
Arnold & Son explores the theme of moon-phases with its constant eye for detail and decoration, taking advantage of the watchmaker’s developments in cases, dials, and finishes.
precious material
Perpetual Moon cases in 18-carat (5N) red gold or 950 platinum have been specifically designed. The cases measuring either 41.5 mm or 38 mm leave a large place for the dial, drawing attention to its finishes and its vast moon.
The collection
realistic moon
Except for jewellery models, the large moon is realistically depicted with hand-painted shadows, enhanced with a luminescent material that is particularly intense in darkness yet invisible in daylight, giving way to the white mother-of-pearl disc. It is set against the sky and is surrounded by the constellations of the Big Dipper and Cassiopeia, also hand-painted and coated with Super-LumiNova.
navigation at sea
The constellations have been chosen to directly reference John Arnold’s history as a maker of naval chronometers. Navigators in the Northern Hemisphere have used the Big Dipper and Cassiopeia since time immemorial to find their bearings and locate the North Star (Polaris). The latter’s position defines the North and its angular altitude, or position in the North-South plane, and allows the distance to the equator, i.e., latitude, to be estimated.
second moon-phase indicator
On the case back of 41.5 mm diameter models, a secondary indicator allows the moon-phase to be adjusted quickly and precisely. The hand-wound calibre that powers it can track the development of its segments with exceptional precision. A complete lunar cycle lasts 29 days, 12 hours, 44 minutes and 2.8 seconds. Arnold & Son has succeeded in representing it so that it would take 122 years for this movement, if regularly wound, to accumulate a day’s difference between its display and celestial reality. Like all Arnold & Son movements, the calibres have been entirely developed, manufactured, decorated, assembled, adjusted and cased at the Manufacture in La Chaux-de-Fonds. They feature two barrels and an oscillation frequency of 3 Hz, providing a power reserve of 90 hours.