|Son of Robert Were Fox, a shipping agent, and Elizabeth, daughter of Joseph Tregellen of Falmouth. Educated privately, showing a special aptitude in mathematics, and taught to study natural phenomena by his mother. In 1814, during his wedding trip on the continent, he formed lasting friendships with Humboldt and other foreign scientists. His researches began in 1812 with Joel Lean, when they performed a series of experiments hoping to improve Watt's engines which were used in Cornish mines. In 1815 Fox began his researches into the internal temperature of the earth, which continued throughout his life. Facilities were provided for this by his lifelong connection with Cornish mines. Fox was the first to prove definitively that heat increased with depth, and that this increase was in diminishing ratio as depth increased. Fox was also interested in magnetic phenomena, especially relating to the earth's magnetism, and constructed a new dipping needle of great sensitivity and accuracy which was later used by Sir James Clark Ross in his voyage to the Antarctic in 1837 and by Captain Nares in the expedition to the North Pole in 1875-1877. Fox was one of the founders of the Royal Cornwall Polytechnic Society in 1833, and was Vice President several times. He died at his house near Falmouth in 1877 and was buried at the Friends' burial ground at Budock.