Clair de Lune: Arnold & Son’s Fern Green Perpetual Moon Shines Bright

Arnold & Son is no stranger to playing with the moonphase complication. We’ve seen the brand get three-dimensional with models like the Luna Magna, which launched in 2021 showcasing one of the largest spherical moonphase indicators. However, the Maison has also taken a more traditional approach to the complication with collections like the Perpetual Moon, first unveiled back in 2013.

For its latest Perpetual Moon, Arnold & Son takes inspiration from the green ferns that grow in abundance in the gardens of Cornwall, England, birthplace of the legendary English clockmaker John Arnold (1736-1799), the brand’s historic founder.

Limited to 28 pieces, the Perpetual Moon 41.5 Platinum, Fern Green edition “Clear Skies” marries a botanical green engraved dial with a shimmery mother-of-pearl moon against a deep blue starry sky all framed within a gleaming platinum case.

Since its initial debut more than a decade ago, the design of the Perpetual Moon has wowed with its expansive moonphase display that dramatically spans the top of the dial from 10 to 2 o’clock. In this latest version, the oversized white mother-of-pearl moon is set on a grained midnight-blue PVD night sky and coated with Super-LumiNova that lights up the wrist after dark.
 

The dial serves as the perfect contrast to make the signature moon display shine. It features radial “Stellar Rays,” achieved by an irregular engraving pattern with various depths and widths to catch the light. Here, several layers of transparent lacquer add depth and enhance the playfulness of reflections on the dial.

In a nod to John Arnold’s legacy in producing precise marine chronometers used to navigate the high seas in the 18th century, the moon is surrounded by the constellations Ursa Major and Cassiopeia. Hand-painted and treated with luminescent material, the two constellations historically served as landmarks in the night sky.
 

In between them is Polaris, or the North Star. Given its positioning directly above the North Pole, Polaris moves very little over the course of the night, making it a touchstone for navigators to reliably pinpoint north. In addition, its elevation angle can be used to estimate distance from the equator or latitude.

Arnold & Son’s A&S1512 calibre is showcased through the clear sapphire caseback. The movement’s secondary moonphase features a scale and the representative moon cycle, allowing for quick and easy adjustment to the accurate moon age.

Developed and produced at the brand’s manufacture in La Chaux-de-Fonds, Switzerland, the manually wound calibre features a 90-hour power reserve and tracks the moon so accurately that if it were, theoretically, continually kept fully wound, 122 years would pass before it would accumulate a 24-hour discrepancy between the display and astronomical reality.
 

Decorative finishing touches include radiating Côtes de Genève stripes on the main plate, polished and chamfered bridges, satin-finished wheels, and blued and chamfered screws with polished heads.

The Limited Edition Perpetual Moon 41.5 Platinum, Fern Green edition “Clear Skies” is produced in a series of just 28 pieces. It’s available today and priced at $48,300. For more information and to purchase, head over to Arnold & Son’s website.