Since its introduction in 2015 — and subsequent award for Best Calendar Watch at the 2016 GPHG — MB&F’s Legacy Machine (LM) Perpetual has run the gamut of case materials in its various incarnations, all of them very limited in number — rose gold, white gold, platinum, and titanium. For the latest, founder Max Büsser (the “MB”) and his talented team of “friends” (the “F”) have turned to a more classical precious metal, 18k yellow gold, pairing it with an of-the-moment blue dial for the latest 25-piece limited edition of the LM Perpetual.
Designed and developed in cooperation with Irish independent watchmaker Stephen McDonnell, the Legacy Machine Perpetual not only boasts a high-complication movement built entirely from the ground up — no base caliber, no module — but also puts its revolutionary design on full display on the dial side, ensconced beneath a large suspended balance. The manually wound, 581-part caliber in the LM Perpetual differs from traditional perpetual calendar movements in a few significant respects. Instead of using a 31-day month as the “default” and fast-forwarding through the unnecessary days in the shorter months, as is the common system, it uses a default 28-day month (as in a non-leap-year February) and adds extra days as required, thus no skipping ahead of dates, which has the potential to jam gears. Traditional perpetual calendar mechanisms can also be easily damaged if the owner makes an inadvertent adjustment while the date is changing; in MB&F’s caliber, the adjustment pushers automatically deactivate during calendar changes, so this risk is avoided.
The movement accomplishes these feats with the use of a “mechanical processor” in place of the grand levier (big lever) system more commonplace in perpetual calendar calibers, which also drives the leap-year adjustment by means of a simple quick-set pusher. The huge balance wheel oscillating on the dial side is connected to the escapement in the back via an extra-long balance staff (probably the world’s longest, according to MB&F); under that massive balance are the subdials, which appear to float above the exposed mechanisms beneath them. At 12 o’clock, framed by the arches of the balance bridge, the hours and minutes are displayed on a traditional white subdial with Roman numerals and blued hands. Moving clockwise around the dial, the three other skeletonized subdials, mounted on hidden studs, display the day of the week at 3 o’clock, the month at 6 o’clock, and the date at 9 o’clock. At 4 o’clock is an arc-shaped indicator for the watch’s 72-hour power reserve and at 7 o’clock, another indicator for the leap year, equipped with a retrograde hand.
The back of the 44-mm-diameter, 3N yellow gold case has a sapphire exhibition window, with the same nonreflective coating as the front crystal, offering a view of the movement’s rear side, notably its double mainspring barrels and the haute horlogerie decorations on its bridges, including côtes de Genève, polished bevels and angles, and hand-made engravings. The case — itself comprising no less than 69 parts — is mounted on a hand-stitched alligator strap with a yellow-gold folding buckle. Its U.S. retail price is $167,000.