London watchmaker John Arnold (1736–99), was one of the true master clockmakers from what was unarguably England’s golden age of horology. Crucially Arnold was blessed with the business and social acumen to ensure that his abilities were appreciated. He is credited with several patents regarding escapement and balance spring designs and was the first to use the word “Chronometer” in the modern meaning. In 1787 he set up Arnold & Son with John Roger Arnold who served an apprenticeship with A-L Breguet. John Roger continued the business after his father’s death with John Dent. He also went on to become Master of the Clockmaker’s Company in London in 1817.