The Latin phrase "Pereunt et Imputantur", a favourite motto for clocks and sundials was written by the Latin poet Martial. It is usually translated as "they perish and are reckoned to our account", referring to the hours that we spend, wisely or not. The original clockwork mechanism was much modified, repaired, and neglected until it was replaced in the early 20th century. The door below the clock has a round hole near its base. This was cut in the early 17th century to allow entry for the Bishop's cat to deter vermin. The vermin were attracted to the animal fat used to lubricate the clock mechanism.