Jacob & Co. Astronomia Maestro

Unveiled at Baselworld 2018, the Astronomia Maestro from Jacob & Co. Astronomia Tourbillon collection successfully merges two high-horology complications – the brand’s acclaimed gravitational triple axis tourbillon movement and a minute repeater carillon with elevated spiral gongs – in addition to its basic timekeeping function and the spectacular astronomical display.

Dressed in a massive 50mm rose gold case with sapphire apertures on sides, this grand complication watch was realized by Jacob & Co. Founder Jacob Arabo in partnership with master watchmaker Luca Soprana. Masters in their respective fields, the duo worked together to conceive and develop the entire span of the Astronomia collection’s movements (including the original Astronomia’s first-ever vertically-constructed watch caliber constantly revolving around a center axis and the Astronomia Sky’s sidereal time display) over the past four years, dedicated a total of two years to bring the Astronomia Maestro to life. Due to the complexity of its composition and the intricacy of its design, the Astronomia Maestro is a limited edition model, offering only 18 individually numbered pieces.

The highly complex minute repeater mechanism complication, which has been mastered by only a handful of watchmakers worldwide, is complemented by overall sophistication of the Astronomia Maestro. The Astronomia Maestro, whose minute repeater is equipped with a patented fusée barrel with a ratchet and pawl system, also distinguishes itself as a first in watchmaking: the three gongs delivering the cathedral carillon melody crisscross above the plate, into a clearly visible spiral.

To make this seemingly impossible mechanism a reality, many elements of the Astronomia Maestro had to be newly devised. The Astronomia caliber’s distinct concept, as well as the space available in its sapphire dome case, enabled Arabo and Soprana to enhance the chiming function. Chiming the hours, quarter hours, and minutes from a low to high pitch, the Maestro’s minute repeater incorporates three hammers to simplify the aural indication of time. Together, the three hammers generate the harmonious melody of a “cathedral carillon” with the finest, purest of tones.

The watch’s sapphire dome and sides allow for a crystal clear sound. The required energy is provided by a rapid-rotation barrel and the minute repeater function is secured through a patented system which protects the mechanism from any handling mishap.

Aside from the acoustic performance of its minute repeater carillon, the Astronomia Maestro is considered a cutting edge timepiece because of its gravitational triple axis tourbillon. Although initially designed to counteract the effects of terrestrial gravitation on the caliber’s mobile components, the system gains in effectiveness by rotating on three axes: the cage housing the escapement goes around the balance wheel axis in 60 seconds and completes a revolution over itself in 2.5 minutes, while the entire tourbillon covers a full cycle around the watch’s central axis in 10 minutes. The triple rotation ensures the extreme precision of this exclusive Jacob & Co. JCEM03 caliber.

Honoring the primary function of a watch, the Astronomia Maestro’s dial, which indicates the hours and minutes, is positioned at the heart of the four axes rather than its typical position on one of the axes. The tip of the axis which normally houses the dial in the Astronomia collection is thus freed in the Maestro and has found a new function; it holds a moon phase rotating around the movement in 10 minutes and over itself in 31 days. While the date is displayed through a traditional index, the moon phase is shown through the rotation of a 288-facets Jacob-cut diamond that is half black and half white.

Coming to the astronomical display, under the sapphire dome, which resembles a porthole of an interplanetary vessel, one can follow the course of the Earth as it travels around the timepiece. Placed on one of the axes the lacquered magnesium globe rotates on itself in 30 seconds while simultaneously revolving around the main axis. Juxtaposed next to this movement is the sculpture of an astronaut, floating weightlessly within the Astronomia universe. The miniature sculpture weighs a mere 0.2 grams and revolves on itself in 30 seconds, as well as, around the watch’s face in 10 minutes.

Technical details
Model: Astronomia Maestro
Limited Edition: 18 Pieces; Individually Numbered Pieces
Reference: AM500.40.AC.SD.B

Caliber: Manufacture Jacob&Co. Manual Winding JCEM03
Diameter: 39.7mm; Height: 19.6mm; Components: 601
Material: Titanium and Maillechort
Functions: Hours and Minutes, Minute Repeater Carillon with elevated
Spiral Gongs, Moon Phase and Date
System: Vertical Movement with 4 Arms, Full Revolution in 10 min around a
Central Axis
• Gravitational Triple Axis Tourbillon, 1st Cage rotating in 60 sec and 2nd Cage in 2.5 min
• Lacquered Magnesium Globe rotating in 30 sec; Weight: 0.3g
• Hand-Made Magnesium and Hand-Painted Astronaut rotating in 30 sec; Weight: 0.3g
• Moon Phase and Date, 2 Half Sphere Jacob Cut® Diamonds:
1 Carat Total
Minute Repeater striking: Hours, 15 minutes and Minutes (Music Notes: Do, Re, Mi), Carillon Gong with 3
Hammers at 6 O’clock
Patented Double Mechanical Safety℗ Feature During a Chiming Sequence
First in Watchmaking: the Three Gongs Crisscross above the Plate, into a clearly Visible Spiral combined with a Triple Axis Tourbillon
Hours Gong Diameter: 44.7mm; 15-Minutes Gong Diameter: 43.5mm; Minutes Gong Diameter: 44.1mm
Power Reserve: 60-Hours; Frequency: 21’600 vib/h (3 Hz); Jewels: 56
Finishing: Plate and Bridges: Hand Angled and Polished, Flank Draw, Circular Graining, Polished Sink; Hand Polished Screws; Barrel: Circular Graining; Pinions: Conical Pinions, 4 Mechanical Ball Bearing Devices; Flat Balance Spring

Case, dial and strap
Diameter: 50mm; Height: 26mm; Material: 18K Rose Gold; Sapphire Apertures on Sides
Case Back: Double Case Back to Enhance the Sound, Winding and Time-Setting via rotating Bows, Rotating
Wheel to set the Moon Phase
Crystal: Unique Domed Sapphire with Anti-Reflective Treatment
Water resistance: 30m
Dial: Aluminum and Titanium, Lacquered Indexes; Hands: Gun Blue Finish
Strap: Alligator
Clasp: 18K Rose Gold Folding Buckle


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