MontBlanc Princesse Grace de Monaco White Mother of Pearl Diamonds Dial White Leather Ladies Watch 109274

The Montblanc Nicolas Rieussec Rising Hours for Monaco features a black dial with grain d'orge guilloche decor, which ranks among the most traditional decorative techniques in the art of watchmaking. It is encased in a 43 mm stainless steel with a glossy DLC («Diamond Like Carbon») finish.
The extremely resistant surface of the DLC coating is completed by the stainless steel material of the case, that is also especially hardened to assure that the steel, which is already very b, will be even more unyielding. A thermal treatment applied to the 0.03-mm-thick outer layer of the case's surface fuses it with additional carbon atoms to further increase the hardness of the exterior stratum to as much as 1,000 Vickers. Only afterwards is the black DLC coating applied. As a result, the case of the Montblanc Nicolas Rieussec Rising Hours for Monaco is not only significantly more resistant than the cases of standard DLC watches, it's also five times harder than a conventional stainless steel case.
The case is equipped with finely terraced horns that hold a black alligator-skin strap with a contrasting red-gold colored stitching. A triple-folding clasp made of red gold closes and opens the strap. The fluted crown, which is likewise made of 18 ct red gold, bears a mother-of-pearl inlay shaped like Montblanc's emblem.
The domed sapphire crystal above the dial is antireflective on both its surfaces. A second pane of sapphire is inserted into the screwed back to reveal the winding black rotor.
The exterior of the Rising Hours unmistakably announces that this is a Montblanc Nicolas Rieussec timepiece. Characteristic features include rotating discs under motionless pointers for the elapsed minutes and seconds, as well as a two-armed bridge at "6 o'clock" with bright red ruby bearings which makes the dial look as though it was smiling. Above it is the off-centre dial to show the ordinary time of day or night via a skeletonised minute-hand and digital hour numerals.
The day of the week appears in a semicircular aperture at its left, the date in a similar window at the right. The unoccupied spaces between and alongside these displays are embellished with grain d'orge (barleycorn) guilloche.
The Montblanc Nicolas Rieussec Rising Hours for Monaco features a special engraving on the case back: "ONLY WATCH '13 UNIQUE PIECE.
 

A difference like day and night
A digital hour display wouldn't have been anything new per se. The hour numerals simply come and go beneath a stationary index, while the minute-hand turns its circles in the conventional manner. But the way the hours are shown on the Montblanc Nicolas Rieussec Rising Hours for Monaco is technically revolutionary. Like all models of this collection, this watch too has a slightly off-centre dial for the ordinary time of day. But instead of an hour-hand, there is a circular aperture at the "12" in which a disc bearing Arabic numerals for the twelve hours turns below a little triangular index. Aficionados will no doubt have seen similar digital hour displays on other timepieces in the past, but the Nicolas Rieussec Rising Hours for Monaco goes one decisive step further: its hour numerals change color depending on the time of day or night. The numerals are blue during night time hours and black during the day. At a glance, this interesting function assigns each hour to the day or night and makes it easier to properly set the date display so that the date changes correctly at midnight rather than mistakenly at midday.
A New Montblanc manufacture calibre with a patented day/night mechanism
This unusual time display is made possible by the new manufacture calibre MB R220, which boasts an elaborate patented mechanism consisting of two rotating discs positioned one atop the other. The Arabic numerals 1 to 12 are cut from the upper disc. This twelve-hour disc turns above the bi-colour day/night disc, which is half blue and half black so that a light or dark hue appears in the skeletonised numeral in the window depending on the time of day or night.
The twelve-hour disc rotates continually, while the day/night disc turns in intervals and at variable speeds to produce the desired color change (blue for the night, black for the day) in the cut-out numerals. This complex motion is controlled with the aid of a Maltese cross mechanism consisting of two cam-like wheels. One of these cams is mounted on the propelling staff of the day/night disc; the other is affixed to an extension of the hour-staff.
Each cam's profile is specially shaped so that the cams turn idly past one another between 9 a.m. and 3 p.m. (and again between 9 p.m. and 3 a.m.); the day/night disc is accordingly motionless throughout both these intervals. Meshing begins at 3 a.m. (and 3 p.m.). This engagement causes the day/night disc to turn at an increasingly faster pace until two teeth on either side engage in a way that the day/night disc no longer accelerates but instead continues to turn synchronously with the twelve-hour disc - this occurs from 4:30 a.m. to 7:30 a.m. (and from 4:30 p.m. to 7:30 p.m.). Afterwards, the day/night disc decelerates between 7:30 a.m. and 9 a.m. (and between 7:30 p.m. and 9 p.m.) until the meshing is completely separated, whereupon the day/night disc comes to a standstill.
This patented "Rising Hours" mechanism is particularly self-explanatory twice a day: at six o'clock each morning, the pierced digit "6" appears blue on the left and black on the right to symbolize that night is ending and day is dawning; at six o'clock each evening, black daylight at the left yields to blue night-time hours at the right.
In addition to this double-disc mechanism, four other disc displays rotate in the Montblanc Nicolas Rieussec Rising Hours for Monaco. The day of the week is shown in a window at the "9" and the date appears in an aperture at the "3". Naturally, the chronograph's function likewise relies on the same unmistakable concept, with one disc to count sixty elapsed seconds and another to tally up to thirty elapsed minutes.
This chronograph has only one button, which is unconventionally but ergonomically positioned at "8 o'clock". In accord with tradition, this chronograph is controlled by a column-wheel, which couples and uncouples in a very modern and low-wear manner via a vertical friction coupling. Also noteworthy are the innovative profiles on the gear-train's teeth, which optimize energy transfer while minimizing both wear and energy consumption. The rate is regulated by a massy 10-mm-diameter screw balance, which oscillates very regularly thanks to its high moment of inertia (12 mgcm²) and its frequency of 28,800 A/h (4 Hz). The regularity of the rate is further enhanced by the double barrel, which amasses a 72-hour power reserve and maintains a very constant level of torque throughout a lengthy interval. A self-winding mechanism keeps the power reserve constantly high as long as the watch is worn.
The timepiece is presented in a special packaging and equipped with a 500 hours quality certificate.