The mechanical splendor of the Perpetual Calendar grand complication, visible through a transparent dial

In homage to the spirit of the legendary Montblanc Meisterstück Fountain Pen launched in 1924, Montblanc introduces the Montblanc Heritage Spirit Perpetual Calendar Sapphire in an innovative version. Embodying all the codes of fine watchmaking down to the last and smallest detail, it bears the signature of traditional craftsmanship, timeless design and flawless functionality.

Presented at the Watches & Wonders event, this remarkable timepiece made of 18K red gold now showcases the mechanical splendor of its perpetual calendar grand complication movement through a transparent dial of smoky sapphire crystal that combines traditional aesthetics and technical prowess.

A case with elegant lines

This elegant watch in 18-karat red gold displays harmonious proportions, with a diameter of 39 millimeters and a thickness of only 10.24 millimeters. Its case with straight, refined lines and subtly curved horns fits perfectly on the wrist, the perfect accoutrement for men wearing elegant, tight-fitting garments. Its design is embellished by the polished finish of the bezel and case-back and its satin-finished middle.

This ultra-elegant watch model reinforces its visual impact on the wrist thanks to a transparent dial made of lightly smoky sapphire crystal that displays in a highly legible manner all the information pertaining to the perpetual calendar complication, enhanced by a unique moonphase indication.

Transparent dial

The decision to display the movement under a transparent dial allows Montblanc to share with watch lovers the mechanical secrets of a grand complication normally seen only by watchmakers, and particularly appreciated for its ability to display calendar Details without the slightest possibility of error until 28 February 2100.

The connoisseur’s expert eye will thus admire delicately circular-grained main plate, some of the components of the perpetual calendar function, particularly the month and leap-year cams, the moonphase wheels, and also the levers and jumpers of the various different correctors that fix the position of the slender blued hands in their respective sub-dials.

Montblanc has particularly focused on the legibility of the transparent dial revealing the extremely sophisticated mechanism of this model, so as to ensure the highest possible quality of display of its indications. The periphery of the dial features the Roman numeral XII and the red gold-plated facetted indexes, applied by hand. They clearly enhance the anthracite grey metallic circular-grained background.

The contrasting treatment of the surfaces highlights the minute-circle so as to ensure accurate reading of the time. The calendar indications are clearly indicated in black against the surfaces of the silvery circular-grained subdials. The day of the week is displayed at 9 o’clock and the date at 3 o’clock.

The current month is pointed to by the dedicated hand in the subdial at 12 o’clock, while the leap-year indication appears at the centre of this display. In this design, the moonphase indication is displayed in a particularly spectacular way, an inventive illustration of the lunar phases.

So as to preserve all the magic of the transparent dial, Montblanc has opted to leave the entire moonphase disk visible. For ease of reading, the lower section of the moonphase subdial is adorned with a delicate circular guilloché pattern. This treatment, producing a slightly mat mirror effect, distinguishes the current moon phase (in the transparent part of the window) from the subsequent moonphase, and emphasizes the twofold golden moon travelling across a starry sky.

Operation and settings

This particularly functional perpetual calendar grand complication timepiece is integrated to a self-winding calibre MB 29.15, which can be admired through the screwed sapphire crystal case-back. For as long as the movement remains in operation, the calendar indications will require no further manual adjustment until the year 2100.

If necessary, however, should the watch not be worn for a period longer than the duration of the power reserve of 42 hours, small correctors fitted into the middle-piece of the 18 K red gold case (visible here through the dial’s smoky grey sapphire crystal) allow for rapid and easy setting of the day, date, month, leap year and moon phase   by means of a precious resin instrument specially developed for Montblanc.

Keen to present lovers of exceptional mechanisms with a timepiece corresponding to their expectations in terms of design and utmost quality, Montblanc submits each Montblanc Heritage Spirit Perpetual Calendar timepiece to 500 hours of rigorous tests at the Montblanc Manufacture in Le Locle, Switzerland. Once these have been successfully completed, this watch, worn on a black alligator-skin strap closed by a pinbuckle in 18 K red gold, will mark time to the delight of all lovers of fine watchmaking.