Monochrome Watches
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Graham Tourbillon Orrery Looks to the Heavens

| By Max E. Reddick | 4 min read |
Graham Geo Tourbillon Orrery

In 1713, George Graham built a clock, which used a mechanical movement to power a heliocentric model of the planets. The mechanical solar system, presented to the fourth Earl of Orrery, was called an Orrery, and because of its precision, all subsequent planetary models retained the name Orrery. Exactly three hundred years later, the Graham watch company unveils the Graham Tourbillon Orrery watch, bringing the company’s heritage to the wrist.

When we think of Graham, we think of oversized chronographs with triggers like the Chronofighter (see here or here), but with the Tourbillon Orrery, Graham enters haute horology. Not only is this watch a tribute to watchmaker George Graham, the company’s namesake, but thanks to the collaboration with Christophe Claret, it is an equally impressive mechanical achievement.

Original Smaller Orrery by George Graham
Original Orrery Clock by George Graham

When Eric Loth, Graham Founder, first learned of the Orrery Clock, he went to see it in England’s Museum of the History of Science. He was already thinking of a watch. Eric Loth developed the many calculations needed to simultaneously represent the orbits of Earth and Mars around the sun as well as the Moon’s orbit around earth. Despite 20 years of dogged persistence, he was unable to perfect the movement, so with the approach of the 300th anniversary, he enlisted the expertise of Christophe Claret to finalize the calculations and build the model. Graham showed the watch, one of only twenty, at Baselworld this year.

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Graham Geo Tourbillon Orrery

Inside the 48mm pink gold case is a portable Orrery. Looking at the dial is like visiting a planetarium. The center tourbillon cage represents the sun, and at its zenith is a real diamond to fix the tourbillon, reminiscent of pre-ruby movements, because only diamonds were used 300 years ago. This cage holding the 3hz tourbillon has a George Graham specific design of two Phoenix heads facing each other. Moving outward, the earth is the blue planet (blue sapphire) with its silver moon (rhodium) close at hand, and on the periphery is the red planet Mars (ruby). The Moon’s orbit is approximately a monthly calculation, the Earth’s orbit – an annual calculation, and Mars’ orbit is more than a year because of its slower movement. The orbits are embedded in a calendar read counter-clockwise by Earth’s position, indicating both the Gregorian and Zodiac dates. All the orbits, moving around the dial (or should we say the sun), are accurate to 100 years, needing only minor corrections.

Graham Geo Tourbillon Orrery

These corrections happen according to schedule. The Moon is corrected every 7 years; Mars is corrected every 25 years; and the Earth is corrected only every 1156 years. The perimeter of the caseback crystal indicates the years for needed correction. Two additional caseback crystals, provide the graduations for 300 years total accuracy. As the company says, “Designed to last a lifetime and longer.” The watch has two crowns, one at 2 o’clock and the other at 3 o’clock, with a lunar pin at 4 o’clock and a Mars pin at 10 o’clock. The 3 o’clock crown is for manual winding and setting the time on the hands, which sit off-center, on the edge of the sun. The 2 o’clock crown is the planets crown, and can set Earth, Moon and Mars.

Instead of a watch for the next generation, this is a watch for the next evolution.

Graham Sundial



  • Manual Tourbillon Orrery, mechanical solar system model with 100 year calendar (two additional graduations of 100 years – 300 years in total). Year counter on the case back with planet correction indicators. (Moon: 7 years, Earth: 1156 years, Mars: 25 years)
  • Hours, Minutes


  • G1800, high precision mechanical movement exclusively made for GRAHAM by Christophe Claret with Haute Horlogerie finishing, circular “Côtes de Genève” decoration, Tourbillon Orrery (solar system mechanism), 21’600 A/h (3Hz), Incabloc shock absorber
  • 35 Jewels
  • Power reserve: 72 hours – 2 barrels


  • 48 mm in diameter, 17.60 mm thick, pink gold, right hand control crowns (planets’ crown at 2 o’clock, manual winding and time crown at 3 o’clock), Moon corrector at 4 o’clock, Mars corrector at 10 o’clock, domed sapphire crystal with anti-reflective coating on both sides
  • See-through sapphire crystal case back with 100-year scale, Moon and Mars correction indicators and serial number hand-engraved
  • Water Resistance 160 feet / 50 m / 5 bar


  • Black dial with Geo.Graham Tourbillon Orrery inscription at 4 o’clock
  • 3 scales – from the outside to the center: hours and minutes scale, Gregorian calendar (365.25 days – Earth indicates the date), Zodiac scale (12 astrological signs – Earth indicates the zodiac sign). Counter-clockwise reading.
  • Solar system: The Moon (rhodium, Ø0.90 mm); The Earth (blue sapphire, Ø3.20 mm); Mars (ruby, Ø1.70 mm); The Sun (pink gold (18K) – hand-engraved Tourbillon bridge with 2 Phoenix heads inspired by George Graham decoration and a close set diamond at the center (Ø2.50mm). Counter-clockwise reading.
  • Off-center skeleton pink gold (18K) hands with black Super-LumiNova coating

For more information, you can visit the Graham website.

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