Arnold & Son HM Double Hemisphere Perpetual Moon
For the first time, the HM Double Hemisphere Perpetual Moon displays the moon phases as they can be seen both from the northern and southern hemispheres respectively, all in a single watch.
The moonphase has one day’s deviation every 122 years. The first aperture displays the moon phase as seen in the northern hemisphere, a mirror image of the moon phase also shows the state of the moon in the southern hemisphere. Additionally, these large moons are one of the most visually stunning recreations of the moon because they are three-dimensional sculptured moons that were first hand-engraved and then duplicated for the series. The two sculptured moons are then inserted into the disc. From the technical side, in addition to the HM Double Hemisphere Perpetual Moon being so precise, it is also an intriguing complication in that it is not simply a module added to the movement, but, in fact, is fully integrated into the calibre. The watch also has a unique easy-to-set feature thanks to the ingenious addition of a third moon phase indication installed at the back of the movement. This third moon display, visible via a transparent case back, features a graduated dial and a pointer hand that allows for a more exact setting.
The case, in 18kt red gold, measures 42mm. It has double AR-coated sapphire crystals and it is water resistant to 30 meters.
Movement is the Swiss manual-wind Arnold & Son in-house caliber A&S1512 with 27 jewels, 12,600 vph and a power reserve of 90 hours. Functions are: hours, minutes, two big perpetual moon phase indications on the front, diameter disc: 29 mm, diameter moons: 11.20 mm, third moon phase indication on the back for setting purposes.
Movement decoration: nickel-silver movement, rhodium treated with Haute Horlogerie finishing: manually chamfered bridges with polished edges, fine circular graining and Côtes de Genève rayonnantes, and blued screws
The dial is translucent blue lacquered guilloché, translucent blue lacquered guilloché moon disc with golden moon and stars; back dial: fine circular graining, rhodium treated, rendition of the 8 phases of the moon.
It comes on a hand-stitched black or brown alligator leather strap with 18kt red gold buckle.