John Roger Arnold (1769-1843)was apprenticed in Paris to A. L. Breguet in 1792. He was admited as a member of the Clockmaker's Company in 1796, and became Master in 1817. After the death of his father, John Roger remained in business on his own until 1830, maintening the reputation gained by his father, as one of the foremost makers of his time. In 1830 he moved to 84 Strand and entered into a partnership agreement for ten years with E. J. Dent, during which period the business flourished. Much experimental work was also caried out during this period particularly on the influence of magnetism on chronometers. In 1840 Dent left Arnold, setting up next door at 82 Strand. For the following three years Arnold continued business on his own but died in Febuary 1843. Immediately, Charles Frodsham purchased the business working under the name Arnold and Frodsham until 1858.