One of the athletes covered was runner Christopher Chataway, the employee at Guinness who recommended them to Sir Hugh Beaver. After an interview in which the Guinness directors enjoyed testing the twins' knowledge of records and unusual facts, the brothers agreed to start work on the book that became "The Guinness Book of Records" in 1954. In August 1955, the first slim green volume – 198 pages long – was at the bookstalls, and in four more months it was Britain's No. 1 nonfiction best-seller.