Arnold & Son

The history of wristwatches with a precise, so-called astronomical moonphase display in the Arnold & Son collection in its modern incarnation began with the True Moon model, which was introduced in 2007. The caliber A1788 for this moonphase watch, which accumulates a deviation of one day over 122 years, was developed in collaboration with the brand’s partner, the Swiss movement factory Jaquet-Baume (now La Joux-Perret) of La Chaux-de-Fonds, on the basis of the Eta self-winding movement, presumably 2893 (Sotheby’s points this out), whereby the mechanism of the second time zone was modified to use it as moonphase display. Arnold & Son’s close collaboration with Jaquet-Baume and La Joux-Perret continues to this day, even after the acquisition of both companies by Citizen Watch in 2012.

Subsequently, Arnold & Son abandoned the use of third-party movements in its moonphase watches and concentrated on the movements manufactured by La Joux-Perret. Launched in 2013, the HM Perpetual Moon, a model with a newly designed astronomical precision moonphase display which is very large and actually occupies the entire dial, is based on the A&S1001 caliber with manual winding and two barrels introduced in 2011, which offers a power reserve of 80 or even 90 hours. Its moonphase version is designated A&S1512 and, in addition to the large moonphase on the dial, also has another on the back of the watch. Arnold & Son claims that this was done to facilitate the precise adjustment of this display, whereas the display on the dial was not equipped with a means of precise adjustment, making for a spectacularly clean and impressive design. Like the True Moon, the HM Perpetual Moon with caliber A&S1512 has a 122-year calculated accuracy of moonphase indication.

With this Arnold & Son Perpetual Moon 41.5 in platinum with a salmon-colored dial, the focus is on the classic moonphase complication. The brand, which is associated with the name of the great English watchmaker, inventor and chronometer maker, was re-established in Switzerland in 1995 and has been offering exceptional moonphase watches since 2007. In this Perpetual Moon 41.5, the moonphase display stands out for its size, which turns into a breathtaking spectacle at dusk thanks to the luminescent material applied to the moon disk. Moreover, the display is precise and gives 122 years to accumulate a deviation of one day. Finally, this is perhaps the most attractive of the Arnold & Son moonphase watches, as it uses a charismatic and collectible combination of a platinum case and a salmon-colored dial.