Jacob & Co. Astronomia Tourbillon

Representing the pinnacle of watchmaking craftsmanship and the horological decorative arts, the Astronomia Tourbillon is an exceptional timepiece that redefines both the tourbillon and the concept of astronomical watches. This poetic astronomic watch combines a three axis tourbillon with an orbital display of the hours and minutes as well as an orbital representation of the Earth and the Moon. For the development of this highly complex mechanical system, Jacob & Co. worked with the horological atelier of Studio 7H38 –its collaborator in the development of last year’s SF24 dual time-zone watch.

The heart of the Astronomia is a four-armed carrier, which rotates once every twenty minutes. On one arm is the tourbillon, which in addition to rotating once around the dial every twenty minutes, also rotates around the dial every twenty minutes, also rotates around the axis of the arm carrying it once every five minute, and around its axis once every 60 seconds.

The tourbillon carriage is finished to the highest haute horlogerie standards, and constructed according to those standards as well, with a large, screw-poised balance beating at 18,000 vibrations per hour, and with an over coil balance spring featuring a mathematically correct Phillips terminal curve. Opposite the balance is the dial showing the hours and minutes. The open worked dial makes for a beautifully visually balanced counter point to the revolving tourbillon carriage and its Roman numerals lend a touch of classicism and formal beauty to the overall design.

The dial is mounted on a different platform which causes it to rotate as the central carrier turns this ensures that the 12:00 marker is always uppermost and that the time can always be easily read. Two celestial objects complete the composition: the Earth, and the Moon. The Moon is represented by a spherical, briolette-cut diamond which, in addition to rotating around the dial once every 20 minutes on the carrier, also rotates its own axis once every 60 seconds, with each of its 56 facets constantly catching and refracting the light, produce a spectacular kinetic display of diamond’s radiance.

The earth, which rotates once every seconds on its own axis is represented by a globe made of white gold, with the oceans represented by deep blue, translucent grand feu champlevé enamel.

The backdrop to this tour-de-force display of mechanical art is a dial of deep blue aventurine – a precious stone that contains tiny inclusions of sparkling minerals that give it the appearance of a midnight sky dusted with stars.  The entire dazzling mechanical display takes place under a complex, highly domed sapphire crystal, almost hemispherical in shape.

The  47mm  case  is  kept  both  light,  and  strong,  through  the  use  of  a sophisticated polycarbonate composite strengthened with diamond dust, and is enhanced with 18k rose gold.

Technical details
Model: Astronomia Tourbillon
Ref. 750.100.94.AB.SD.1NS
Limited edition of 9 pieces

Movement
Exclusively manual wind Jacob & Co. JCEM01, 72-hour power reserve
Frequency:  18’800 vib/h (2.5 Hz); 42 jewels
Diameter 40mm; height 15.9mm
Barrel with “Motor Barrel” construction
235 components
Gravitational Orbital Tourbillon system

Movement finishing
Plate and bridges: hand angled and polished, flank draw, Circular graining, polished sink; hand-polished screws
Barrel: Circular graining
Pinions:  Wood grinding-wheel polished
Balance spring: Philips curve; PE 3000

Functions
Hours, minutes dial rotating in 20 minutes on the central axe
Differential gears system
Briolette diamond rotating in 60 seconds on 2 axes (56 faceted round diamond, weight:  1 carat)
Enamel globe 18K white gold hand engraved rotating in 60 seconds on two axes

Case
Diameter: 47mm
Thickness: 18mm
18K rose gold; diamond micro-particule polycarbonate fibre
Winding and time setting via 18K rose gold lift-out rotating “bows” at case back
Sky layer front case
Aventurine gold fluss and 18 K rose gold

Dial & hands
Hand engraved, lacquered indexes, diamond finish
Hands: hand finished gunned blue

Strap & Clasp
Alligator, 18K rose gold folding buckle

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