Hands-on – Arnold & Son HM Perpetual Moon, in steel with a striking blue dial (live pics, specs & price)

The Moon has always been a huge source of fascination for us, mere mortals. From its association with Antique Gods, to its first attempt of explanations by Greek scientists, to all the different symbolisms it had through history, the Moon has always fascinated men – a fascination that came to a pinnacle in 1969, when Mankind finally achieved to walk on what has always been its closest but yet unknown sister. Still today, we all have a certain relation with this satellite and wearing a watch with the age of the moon displayed on the dial is a sort of poetical, quite magical. And if you’re looking for a display that feels even more striking, the Arnold & Son HM Perpetual Moon won’t disappoint. Here is its steel and blue dial version.

Moon phase watches are among the most classical complications used in horology, and for decades. Early watchmakers, as well educated people, some being physicians or mathematicians, knew the influence of our satellite on both the earth and us, humans. Part of the astronomical complications, together with the calendars or the equation of time, the age of the moon is usually displayed by a disc with two moon faces, one appearing after the other, in a semi-circular window – but a window that tends to be small, measuring a few millimeters large. With its HM Perpetual Moon, Arnold & Son puts the moon at the center stage, with one of the largest displays on the market, and a photorealistic, three-dimensional sculptured moon.

On the Arnold & Son HM Perpetual Moon, the display of the age of the moon is located on the upper half of the dial, in a window that measures an immense 29mm diameter – and that’s certainly one of the largest, if not the largest moon display we’ve seen in a wristwatch. Still about this display, not only the size impress but also the execution, with a moon that measures 11.2mm (that’s probably the average size of the entire moon phase display in classical watches…), with a superb 3D engraved satellite. This moon was first hand-engraved to look as realistic as possible and then duplicated with a stamping process for the commercial watches. This moon, large and visually striking, is then inserted in a guilloche disc, with a printed constellation.

Not only the moon display of the Arnold & Son HM Perpetual Moon is impressive in terms of visual execution, but it is also pretty precise, to say the least. Indeed, once correctly adjusted and if the watch is kept running all the time, it will offer extremely accurate moon phases display, with only one day’s deviation every 122 years. Of course, some others achieved even better results (see the Andreas Strehler Sauterelle à Lune Perpétuelle 2M, with a correction required every 2.060 million years…), however, let’s agree that the HM Perpetual Moon already brings more than you need in terms of precision – a lot more, to be frank. One of the reason of this precision is the fact that the moon phase display is not a module added to the movement but it fully integrated into the calibre, right from its conception.

Still on the technical side, the Arnold & Son HM Perpetual Moon solves one big issue of the moon phase watches: setting. Indeed, trying to get the right position of the moon on the dial with a classical display is rather difficult – if you’re the owner of a timepiece with moon phase, you should know what we’re talking about. The solution brought by Arnold & Son is located on the back, on top of the movement: an additional display of the moon, this time with a dial showing the age of the moon, pointed by a hand on a graduated track. No errors possible anymore. The rest of the movement is also enjoyable, with a nice finishing (rayonnante Geneva stripes, thermally blued screws, manually bevelled and polished angles, fine circular graining) and some interesting technical specifications, including a 90 hours power reserve (thanks to two barrels, always good for the precision) and a restrained thickness of 5.35mm.

Of course, while the moon phase indication is the main attraction, the rest of the Arnold & Son HM Perpetual Moon shouldn’t be forgotten. Already available in several editions (red gold with blue dial, red gold with cream dial or steel with black dial), it comes since this year in what is, to us, the most visually appealing combination: a stainless case (always good in front of the banker…) with a translucent blue dial, hiding a superb guilloche pattern. The dial is first engraved with a concentration wave pattern, with a traditional, hand-made engine-turned process. Then, a blue lacquer is applied. However, this lacquer is not plain but translucent, letting the guilloche pattern appear underneath, while the surface remain entirely flat and shining. It is discreet at first and then become fascinating when look closely, in different light conditions.

The Arnold & Son HM Perpetual Moon comes in a reasonable 42mm case, here made out of stainless steel, with an entirely polished finishing, to the exception of the small brushed inserts on the sides of the lugs. The design of this case is traditional, with a thin cambered bezel and strong lugs, with double-step design. This case tapers from top to bottom, the widest section accommodating the extra-large glass with the lower part narrowing to virtually refine the profile of the watch. On the wrist, the Arnold & Son HM Perpetual Moon has a strong presence, due to the large diameter of the dial and the combination of this bright blue color and large moon display, however it remains elegant in every situation.

The Arnold & Son HM Perpetual Moon in steel with a blue dial is secured to the wrist by a black or brown alligator leather strap, with steel pin-buckle. It is priced at $17,200. More details and retailers can be found on the website of Arnold & Son.

Specifications of the Arnold & Son HM Perpetual Moon

• Case: 42mm diameter – stainless steel – sapphire crystal on the front and on the back – 30m water resistant
• Movement: Calibre A&S1512, in-house – manual winding – 90h power reserve – 21,600 vibrations/h – hours, minutes and large moon phase indication
• Strap: black or brown alligator leather strap on steel pin-buckle