AFP - Big Ben, one of London's most familiar landmarks, celebrates the 150th anniversary of its first chiming on Saturday.
The Great Bell, housed in Saint Stephen's Tower which adjoins Britain's House of Commons, first struck the hour on July 11, 1859, and has been interrupted only occasionally for maintenance and bad weather ever since.
To mark the anniversary, the message "Happy Birthday Big Ben, 150 years, 1859 - 2009" will be projected on the tower.
These days, the name Big Ben is frequently used to describe the tower, one of the British capital's most photographed sites, but the nickname was first given to the bell alone.
The origin of the name is thought to come from Sir Benjamin Hall, the First Commissioner of Works and Public Buildings, whose name is inscribed on the bell.
Mike McCann, Keeper of the Great Clock, said: "After 150 years, Big Ben still holds a special place in the hearts of Londoners and the world as a magnificent example of engineering and building genius."
The 96-metre (315-foot) high tower which houses the clock was built as part of the rebuilding of the Houses of Parliament by architects Charles Barry and Augustus Pugin following a major fire in 1843.