The Arnold & Son HM Dual Hemisphere Perpetual Moon’s crystal is anti-reflective sapphire and also the case back allows for more precise adjustments to the moon phase by showing a third moon through eight distinct phases. Once set, the accuracy should hold for 122 decades, and an easy adjustment will ensure it for another 122 years. The hand-wound motion is an Arnold & Son manufacture A&S1512 that defeats at 21,600 bph with a 90-hour power book. The motion itself is 5.35mm thick and contains 27 jewels, while the instance is rated for 30 meters of water resistance. As if the case back were not amazing enough, the C?tes de Genève revealed during the movement is merely lovely.The Arnold & Son HM Double Hemisphere Perpetual Moon includes either a brown or black hand-stitched alligator strap and is guaranteed to catch the attention of many an eye buff. When trying to fix a problem, the beginning is always a good place to start. That’s exactly the process followed by Arnold & Son in their attempt to get rid of isochronal mistake from one of the newest pieces, the Arnold & Son Constant Force Tourbillon. Arnold & Son’s heritage exists in the legacy of John Arnold and his son, two of the greatest watchmakers to ever come out of England. Having packed his son off to learn in the knee of the maestro, Arnold turned his attentions to the problem of these times: the quest for chronometric accuracy at sea.
Arnold & Son’s latest timepiece is the Double Tourbillon Escapement, displaying two time zones and regulated by twin tourbillons.
The Arnold & Son Double Tourbillon Escapement (DTE) works on a simple premise – it has has two tourbillon regulators, two gear trains and consequently, two indepdendent time displays. Each time display is regulated by its own tourbillon and independent of the other. Both tourbillons, however, are driven together by a pair of twin barrels, which give the watch a 90 hour power reserve. Though unusual, the twin regulator or gear train approach is not unique or new in watchmaking. In fact, it is growing more common as watchmakers are able to pack more complications in smaller spaces. Each time zone is displayed on separate white lacquered dials, one with Roman numerals and the other with Arabics. The dial is almost perfectly symmetrical, and reminiscent of the MB&F Legacy Machine 1. Because the time displays are independently adjustable, each can be set right down to the minute, meaning this can accommodate the odd time zones which are offset by 15 or 45 minutes. The lack of a date or day and night indicator, however, reduce the practicality of this as a true travel watch.
The DTE is a limited edition of 28 pieces, with a 43.5 mm red gold case and a retail price of 199,800 Swiss francs, equivalent to about US$227,000.