Luna Magna – The volume of the moon
In a starry sky, a large moon alternates between light and dark as it moves through its phases. Here, Arnold & Son presents its first three-dimensional moon made of marble and aventurine. Showcased on an aventurine glass dial, the moon changes majestically and with astronomical precision. It is the largest rotating moon ever built into a wristwatch, and a creation that benefits from the first-class watchmaking and decorative techniques of the Arnold & Son Manufacture.
Luna Magna features Arnold & Son’s first three-dimensional moon. With this original timepiece, the Swiss watchmaker with English roots aims to make a lasting impression by presenting the largest rotating moon ever created in relief for a wristwatch. Beneath an off-centered dial at 12 o’clock, which constitutes one of the house’s aesthetic signatures, Arnold & Son has placed a rotating sphere that accurately represents the appearance of the quarters of the moon against a starry backdrop that is more dazzling than a midsummer night sky.
Presented in a 44 mm red-gold case, Arnold & Son has recreated one of its distinctive designs. The off-centered hours and minutes dial at 12 o’clock frees up substantial space for displaying complications, such as this spherical moon measuring 12 mm in diameter. Its size is not its only distinctive feature. Half of the moon is made of marble to represent the illuminated part of the Earth’s satellite, while the other half is made of aventurine glass to depict the darker side. Neither material has ever been used in a three-dimensional design such as this. Changing from dazzling white to a deep, starry blue, the Luna Magna’s quarters have been delicately depicted to replicate the appearance of the lunar disc.
The large moon emerges from the main plate of the A&S1021 calibre without upsetting the overall balance of the timepiece. Arnold & Son has drawn on its remarkable creativity to make Luna Magna a well-proportioned watch that showcases the incredible volume of its moon.
The lunar globe thus appears halfway up the movement, perfectly positioned between the top and bottom. The upper part is encased in a glass box. This technique has been repeated on the case-back side, where the sapphire crystal rests on the wrist.
By placing most of the volume in these sapphire crystals, the Luna Magna’s case has a total height of 15.9 mm.
Lastly, to bring the overall piece together, the deeply tapered lugs extend the curvature of the sapphire crystal to meet the natural curve of the wrist.
Arnold & Son has an ancient, long-standing relationship with the phases of the moon. Guided by the life of John Arnold and the mark he made in the Royal Navy during the 18th century, the house has frequently endeavored to depict the age of this satellite as accurately and as beautifully as possible. By completely reinventing the way the Earth’s satellite is depicted, Luna Magna elevates itself by pushing the boundaries of this astronomical and poetic watchmaking exercise.
Luna Magna is driven by the A&S1021 calibre, which has been fully developed, manufactured, assembled and adjusted in the Manufacture. This new hand-wound calibre, which has been designed with the lunar globe in mind, features a 90-hour power reserve and a regulating organ oscillating at a frequency of 3 Hz. The movement also includes a secondary display detailing the age of the moon on the case-back side. Its clearly readable markings are designed for high-precision adjustments.
The sophisticated celestial mechanics are also based on precise astronomical reality. In fact, the duration of a complete lunar cycle is 29 days, 12 hours, 44 minutes and 2.8 seconds. Arnold & Son has managed to replicate it in such a way that it will take 122 years for the movement’s display to deviate from the correct celestial reading by one day. The correction required at this time will be easy to dispense, as the Luna Magna’s moon-phase function can be accessed directly by the crown. This practical feature has been made possible by Arnold & Son’s total mastery of the watchmaking process.