Big Ben Celebrates Its 150th Anniversary

• The Royal Air Force Red Arrows fly in formation with four Typhoon aircraft over central London with Big Ben in the foreground. The bells in Big Ben are fixed and struck by hammers from outside rather than swinging and being struck from inside by clappers.
  
  
  

  Cate Gillon, Getty Images

• A seagull flies past technicians as they begin maintenance and cleaning work the clock face of Big Ben.
  
  
  

  Daniel Berehulak, Getty Images

• Mike McCann, Keeper of the Great Clock, looks up at the arm mechanism on the south face of the Great Westminster Clock, more commonly known as Big Ben. In August 2007, the iconic clock underwent cleaning and maintenance, the first time some parts of the clock have been taken apart for 150 years.
  
  
  

  Adrian Dennis, AFP / Getty Images

• St. Stephen's Tower, widely known as Big Ben, is visible from a window in the bell tower of St. Margaret's Church on May 15, 2009 in London.
  
  
  

  Peter Macdiarmid, Getty Images

• The name Big Ben actually refers not to the clock-tower itself, but to the 13-ton bell hung within. The bell was named after the first commissioner of works, Sir Benjamin Hall.
  A man walks by as Big Ben is reflected on the pavement in London.
  
  
  

  Daniel Berehulak, Getty Images

• The Great Westminster Clock is the largest striking, most powerful and most accurate clock in the world. The first blow on the bell Big Ben indicates the correct time, which is broadcast by the BBC worldwide. Currently the clock is being temporarily driven by an electrical backup system.
  
  
  

  Ian Walton, Getty Images

• Souvenir models of Saint Stephen's Tower, commonly known as Big Ben, are sold on a traders stall in Westminster, London.
  
  
  

  Leon Neal, AFP / Getty Images

• There are even cells within the clock tower where Members of Parliament can be imprisoned for a breach of parliamentary privilege. This is rare, though; the last recorded case was in 1880.
  
  
  

  Leon Neal, AFP / Getty Images

• During the second world war in 1941, an incendiary bomb destroyed the Commons chamber of the Houses of Parliament, but the clock tower remained intact and Big Ben continued to keep time and strike away the hours, its unique sound was broadcast to the nation and around the world, a welcome reassurance of hope to all who heard it.
  St Stephen's Tower, also known as Big Ben, is visible from a window in the bell tower of St. Margaret's Church in London.
  
  
  

  Peter Macdiarmid, Getty Images

• Shafts of sunlight cross in front of St. Stephen's Tower, which houses the Big Ben bell in London.
  
  
  

  Kirsty Wigglesworth, AP