Montblanc Tourbillon Cylindrique Geosphères Functions

Other than having a cylindrical tourbillon as a grand complication (covered in Part One of my post), the Montblanc Tourbillon Cylindrique Geosphères can also features a double timezone and a worldtime feature (although as Nicolas mentioned, it is hard to really read the globes as a worldtime – it is a lot more artisanal than functional per se in terms of the worldtime function).


Functions: Double time zone and Worldtime explained


The two beautifully handpainted globes on the dial are actually fixed to the movement and they do not move. It is the two 24-hour worldtime indicator discs with a day/night indicator that rotates once per day around the two globes. The discs poetically illustrate the passage of day and night around the two hemispheres, with the silvery rhodium plated part of the disc depicting Day and the black rhodium plated part depicting night.
 




The disc on the Northern Hemisphere turns clockwise whereas the disc associated with the Southern Hemisphere globe rotates anti-clockwise. Using the meridians of longitude, the owner of this watch can read the current hour in various cities or parts of the world, although to be honest as discussed, it is not so legible and one has to estimate the location of the city on the map and hence estimate the time on that city. For this reason, I personally feel the worldtime function is more artisanal (from all the live pictures and testimonies of those who saw the watch in the metal, the globes and the whole dial is beautiful!) than functional.

The Home time, local time and 24 hour discs around the two 3D globes all move together as time passes. The worldtime around the two discs can be set through the crown whereas the home time (at 6 o’clock is adjusted independently through a dedicated home time corrector.

Time zones globally are either expressed as positive or negative offsets from the Universal Time Coordinated (UTC). By tradition, London is the timezone of reference, marked by <<0>>, symbolized by the white meridian of longitude on each of the 3D globes.



In addition, for this watch, the time zones can also be referenced on the case back and determined by adding or subtracting the number of hours specified by the UTC time offset, ranging from UTC – 12:00 in the west to UTC +12:00 in the east. The picture below illustrates how this works. Personally, I feel this feature won’t be used by the lucky owners of this watch – it is too cumbersome. If I were one of the lucky owners, I will just stare at the beautiful dial and watch the cylindrical tourbillon dances J







The caliber MB M68.40

Some technical details of the movement provided by Montblanc below:  
Movement: MB M68.40
Features: Manually wound movement with 1-minute cylindrical tourbillon Home and Local time display, Worldtime and Day/Night indication for each hemispheres

Technical Features: 288 components

18'000 semi-oscillations per hour (2.5 hertz)

Screw balance, Ø 14.5 mm; 59 mg.cm2

Power reserve: Approx. 48 hours

Thickness: 10,50 mm

Diameter: 38,40 mm 16 lines 3/4


The movement on both the back and the dial side is breathtaking from these pics. I am sure if I can see them in person with a loupe, it will be an awesome experience! I will be covering on the 3D globes handpainting and various aspects of the artisanal craftsmenship in another post with more details


See the components below. There are 73 parts dedicated to the Worldtime function (left side) and 91 parts for the cylindrical tourbillon (right stack of components).



I feel the hand-made artisanal finishing of the Montblanc Tourbillon Cylindrique Geosphères deserves a separate post on its own and will write about it in Part 3 of this series of posts. There is just so much to share about this part (my favorite aspect of any Montblanc Villeret watch is indeed their artisanal qualities from movement finishing to the crafting of the dial). There are some nice pictures which Montblanc has shared so stay tuned for Part 3!


Cheers

robin