Sights of London

The tower clock famous for its accuracy and for its massive bell (weighing more than 13 tons). It is housed in St. Stephen's Tower, at the northern end of the Houses of Parliament, in the London borough of Westminster. In coordination with the Royal Greenwich Observatory, the chimes of Big Ben have been broadcast as a feature of the BBC's daily time signal since 1924, with brief interruptions (owing to repairwork) in 1934 and 1956.

The clock was designed by Edmund Beckett Denison and built by E.J. Dent and, later, Frederick Dent. The name of the clock is said by some historians to stand for Sir Benjamin Hall, the commissioner of works. At the time of the clock and bell's installation in 1859, the name applied only to the bell, but it eventually came to indicate the clock itself.

In 1956 the clock mechanism was restored and repaired. The hands of the clock are 9 and 14 feet (2.7 and 4.3 metres) long, respectively, and the clock tower rises to 320 feet (98 metres). The bell was cast by George Mears of Whitechapel and pulled to the tower by a wagon team of 16 horses. Shortly after it was installed, it developed a crack and was kept out of service until its repair in 1862. St. Stephen's Tower once contained a prison cell where “rioters” were confined. The leader of the woman suffrage movement, Emmeline Pankhurst, was placed in the cell in 1902 after demonstrating nearby.