A Rare John R. Arnold Antique Chronometer

Theodore Bruce Auctioneers is delighted to bring to auction a rare antique Chronometer by 19th century watchmaker, John Roger Arnold. Working with his father, the celebrated watchmaker John Arnold, John Roger’s pocket watches and chronometers accompanied notable explorers including David Livingstone – and they continue to be prized for their precision, beauty and history.

A Rare John. R. Arnold, London, One Day Chronometer No. 275, c.1805

A Family of Watchmakers

John Roger Arnold (1769-1843) was the son and apprentice of John Arnold of Bodmin, Cornwall (1736-1799), the most celebrated watchmaker of the 18th Century. His innovations had included his ‘Pocket Watch 1/36’, trialled at the Royal Observatory in Greenwich in 1779 and praised for its accuracy, as well as early marine chronometers.

John Roger Arnold gained insight into clockmaking techniques both from his father – whose inventions included the Detent escapement, a bimetallic balance and a helical balance spring – and leading French watchmaker, Abraham-Louis Breguet, a close friend of the senior Arnold. When in 1808 Breguet developed his first tourbillon escapement (a device to increase accuracy), he mounted it in an Arnold pocket chronometer and presented it to John Roger.

John Roger joined his father in business in 1764, with Arnold & Son chronometers accompanying marine and land explorers – including Dr David Livingstone on his 1858 expedition to Africa. He filed a patent for a ‘U’-shaped balance and became a predominant supplier to the Admiralty. In 1817 he was elected Master of the Worshipful Company of Clockmakers, and in 1830 he partnered with Edward John Dent to form John R Arnold & Dent. The Arnold & Son brand was relaunched in La Chaux-de-Fonds in 1995 and continues today.

A Rare John. R. Arnold, London, One Day Chronometer No. 275, c.1805Making History with Marine Chronometers

Whilst the earliest sailors were successfully able to determine latitude at sea by using the position of the sun, longitude posed a much greater challenge. Navigators were able to gauge an estimate of their position only by tracking how long a vessel had been travelling in a particular direction. The British Government though it such an issue that Parliament passed The Longitude Act in 1714, with the newly established Board of Longitude offering monetary rewards to those able to demonstrate accurate measuring devices.

John Arnold presented his first marine chronometers to the board in 1770, and whilst they did not meet the strict accuracy requirements at that time, he was awarded £200 to assist further development. Just two years later, his chronometers would accompany Captain James Cook on his second global voyage aboard the ships, Resolution and Adventure.

The development of the chronometer changed the course of naval exploration – and chronometers crafted by both John Arnold and John Roger Arnold played a key role in global expeditions of the 18th and 19th centuries.


We are delighted to bring to auction this Rare John. R. Arnold, One Day Chronometer No. 275, c.1805. Signed ‘Arnold, London, No.275’, the movement features Arnold’s spring detent escapement and ‘Z’ balance with helical balance spring.

It is signed on the top plate, ‘John R. Arnold, London, invt. et fecit, No. 275’. The brass case is gimballed in a mahogany box with a sliding top lid.

A Rare John R. Arnold Chronometer

Wednesday 10 July | 6pm
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A Rare John R Arnold Chronometer at Auction 10 July

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