Arnold & Son Nebula 38 Steel

Carl Eady reviews the Arnold & Son Nebula 38 Steel – a spectacular timepiece which lays bare its mechanical soul with modern materials in a stunningly symmetric ensemble.


In the world of horological history, there are few names to match the status of English watchmaker and inventor, John Arnold. Born in the Cornish town of Bodmin in 1736, Arnold spent his early working life apprenticed to his father, himself an accomplished clockmaker. At 19 years of age, he travelled to the Netherlands to gain further experience and in doing so, picked up a command of the German language, which would later stand him in good stead at the Hanoverian court of George III.

Circa 1762, Arnold set up his watchmaking premises in Deveraux Court on The Strand, thanks to a loan from a wealthy customer for whom he had repaired a repeating watch. By 1764 he had gained favour with the Royal Court after presenting his king with a ring containing a perfectly executed ‘half-quarter’ repeater. Arnold’s renown and success grew significantly as a result, with the British Admiralty notably enlisting Arnold’s timekeeping expertise in their goal to determine longitude at sea.

As Arnold pursued the quest for increased accuracy and stability in movements, his endeavours attracted much interest from his contemporaries, so much so that he was forced to register a number of protective patents for inventions, including helical and overcoil balance springs and a detent escapement.

During his much-documented friendship with the French master Abraham Louis-Breguet, he was less protective of his ideas and the pair freely traded secrets, such was their respect for each other.  Arnold’s son, John Roger Arnold, was first tutored by his father and then sent to Breguet for a further two years of expert tutelage before assuming the reins of his father’s business. He ran it with considerable commercial success until his own death in 1843. Charles Frodsham kept the name alive for several more years after which it sadly lay dormant for well over a century.

In 1995, ‘British Masters’ resurrected the Arnold & Son name and began producing collections uniting British inspired designs with high quality swiss movements, creating one of the most exciting independent brands in today’s market.

Arnold & Son first presented the ‘Nebula’ back in 2016 to much acclaim. The move towards smaller case sizes has prompted a re-issue of the Nebula in a smaller, more inclusive case size.

Dial / Movement

The Arnold & Son Nebula 38 Steel is a visually stunning timepiece, captivating onlookers with its celestially inspired openworked calibre AS5101. In astronomical terms, a nebula is a giant cloud of dust and gas emanating from an exploded dying star. Arnold and Son brilliantly capture the essence of this phenomenon by cleverly placing seven bridges around the dial perimeter giving an aura of explosive energy. Each bridge is secured with a mirror-polished screw and is expertly finished with NAC coating, polished edges and chamfering, adding contrast with the ADLC coated mainplate.

One of the hardest challenges with skeletonised watches is to present enough symmetry to please the eye. The simple yet ingenious design of the AS5101’s mainplate enables Arnold & Son to display each of the key components with harmonious equilibrium.  Two imposing mainspring barrels are positioned at the 10 and 2 o’clock positions. The primary mainspring drives the gear train until its torque falls below a certain level, at which point the secondary mainspring ‘kicks in’ to compensate.  This clever combination delivers an admirable 90-hours power reserve, a rare performance for a hand-wound movement.

Arnold & Son Nebula 38 Steel

The Nebula’s aesthetic balance is continued by symmetrically mirroring the seconds chapter ring (at 7 o’clock) and balance mechanism (at 4 o’clock) directly below the mainspring barrels.  Save for the 24 jewels on display, only the golden animation of the free-sprung balance wheel offers any contrast to the array of black and silver.

The well-proportioned ‘Modernes’ style hands display ‘pen nib’ shaped tips and are nicely faceted to enhance legibility, subtly complementing the corresponding hour markers.

On the reverse, the Arnold & Son Nebula 38 Steel is equally well proportioned and the hollows of the mainplate enable closer inspection of the winding mechanism, gear-train and escapement.  Most of the wheels within the movement are three-spoked, a respectful nod to watchmaking from Arnold’s era.

At this price point, few Swiss brands can match the combination of technical prowess and enviable aesthetics as seen in the AS5101 movement.


Originally presented as a 41.5mm case, the brand has clearly kept its ear to the ground and opened up the Nebula design to a much wider audience.  At 38mm wide and just 8.91mm deep, the case dimensions make the timepiece suitable as a dress watch and more desirable for those individuals with slimmer wrists. The highly polished stainless-steel case has a slender perimeter and short but elegant stepped lugs. Both sides of the Nebula’s spectacular movement can be viewed through sapphire crystals, with the top domed window enhanced with anti-reflective coating on both sides for supreme legibility. The case is equipped with a well-proportioned winding crown, fitted with a double seal, contributing to the model’s 10-bar water resistance, and features Arnold and Son’s familiar Crown and Anchor logo.


With such a sophisticated movement on display, Arnold & Son has chosen a plain calfskin black leather strap, however, there are several alternative options available to suit customer requirements. In my opinion, most prospective purchasers will naturally opt for the black strap in order to complement the watch’s predominantly noir features. A simple stainless steel ‘pin and buckle’ secures the strap with minimal fuss and maximum comfort.

Closing thoughts

Since the Arnold & Son name was revived in 1995, the brand has created some exceptionally striking and innovative watches. Although these designs are perhaps more avant-garde, they clearly take inspiration from their legendary British namesakes. The Arnold & Son Nebula 38 Steel is a wonderfully honest timepiece, divulging all of its horological secrets via its spectacular skeletonised architecture. Whilst openworked dials will never garner universal acclaim, there are some designs that clearly command respect. In this instance, Arnold and Sons has understood the human eye’s subliminal need for symmetry and admirably balanced the key components of the A&S5101 movement. When coupled with the commendable standards of finishing, modern materials and an ’on trend’ case size, this version of the Nebula will undoubtedly help Arnold & Son attract even more admiring fans.

Further reading

Technical specification

  • Model: Arnold & Son Nebula 38 Steel
  • Reference: 1NECS.B01A
  • Case: Stainless steel case; diameter 38.00 mm; height 8.91mm; water resistance 3ATM (30 metres); sapphire crystal to front and exhibition caseback
  • Functions: Hours; minutes; small seconds
  • Movement: Calibre A&S5101: hand-wound mechanical; frequency 21,600 VpH (3Hz); 24 jewels; power reserve 90 hours
  • Strap: Calfskin strap (various colours available) and steel pin buckle
  • Price: £12,500 (RRP as at 29.6.2020)

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