Initially, Cox assisted his father who ran the Law Times newspaper, and later took over the management of his father's properties. His father died in 1879 and he took over permanently, moving to the home he inherited at Moat Mount, Mill Hill, Middlesex. His wife, whom he married in 1865, was the daughter of the Vicar of Mill Hill.
Recreations
Cox had many recreations, including angling and shooting; at Moat Mount, he began to conserve game for shooting. Among those who visited to enjoy the sport was Sir Robert Baden-Powell. Developing the family newspaper business, Cox also became proprietor of The Field, and also edited the annual Angler's Diary under the initials "I.E.B.C.".
Politics
When it was established in 1889, Cox was elected to Middlesex County Council as a Conservative, and became an Alderman in 1901. He enjoyed local government and was High Sheriff of the County for the year 1898 to 1899, also becoming a Deputy Lieutenant. Meanwhile, he was Chairman of the Petty Sessional Division of Gore from 1894. When the sitting Member of Parliament for Harrow, William Ambrose, was appointed a Judge, Cox was unanimously selected to follow him. Although standing as a Conservative, Cox pledged to vote against the Conservative government's Street Traffic Bill which regulated bus transport. Cox won the election despite an energetic challenge from the Liberal candidate.
Parliament
Cox was a self-described "strong supporter of Mr. Balfour's government", and he also went along with Joseph Chamberlain's campaign for tariff reform. However, Cox did not entirely enjoy Parliamentary life; although re-elected at the 1900 general election, no speech by him in the House of Commons is recorded. He announced in 1904 his decision to stand down before the next election and his name rarely appears in Division Lists after then. He went back to writing books on angling and shooting, and also hosted fox hunting. Cox died in 1922 at the age of 84.
Works edited
The Angler's Diary: or, Forms for Registering the Fish Taken During the Year; to which is Prefixed, a List of Fishing Stations in England - The Angler's Diary and Tourist Fisherman's Gazetteer
The Shooter's Diary: or, Forms for Registering Game Killed During the Year; to Which is Prefixed, a List of Some of the Principal Shooting Districts in the World
Facts and Useful Hints Relating to Fishing and Shooting: Being a Collection of Various Methods for Capturing Birds, Beasts, Vermin, and Fish; Together with a Great Variety of Recipes of all Kinds Useful to the Fisherman and Sportsman
The Country House: A Collection of Useful Information and Recipes. Adapted to the Country Gentleman and his Household, and of the Greatest Utility to the Housekeeper Generally
The Farm, Garden, Stable, and Aviary: to Which is Added some Useful Information Relating to the Poultry-Yard, Bee-Keeping, and Natural History