Charles Frodsham, like John, was son of William Frodsham. In 1842 he founded his own business and made chronometers for British Navy.
Charles Frodsham history, see website of Charles Frodsham and Co, http://www.frodsham.com/index.aspx :
"Charles Frodsham, the founder of the company, was the son of William Frodsham an established London clockmaker. Charles was born on the 15th April 1810 and at the age of 14 he was apprenticed to his father for seven years. At twenty, Charles distinguished himself by submitting one of his first marine chronometers to the Premium trials at Greenwich Observatory, receiving the second prize of £170. In 1834 he was made a fellow of the Royal Astronomical Society. Shortly after and doubtless encouraged by his recent successes, Charles ventured out on his own establishing his business in London.
Charles gained an enviable reputation for the manufacture of precision timekeepers, both as a supplier of marine chronometers to the Admiralty, and as provider of fine watches and regulators to discerning clients worldwide. He later acquired three prestigious businesses, that of, J.R. Arnold, Vulliamy and William Johnson late of Grimalde & Johnson."