AFP - Big Ben, arguably the world's most famous clock which towers over London, marked its 150th anniversary Sunday.
The clock started ticking on May 31 1859 and has continued with only occasional interruptions for maintenance, bad weather and even bird strikes ever since.
The clock, housed in St Stephen's Tower which adjoins Britain's House of Commons, is one of the capital's most popular tourist attractions and boasts some amazing statistics.
Each of the four Gothic clock faces is seven metres wide, with a minute hand over four metres long which travels the equivalent of 190 kilometres per year.
A Latin inscription is carved beneath each one -- "Domine salvam fac Reginam nostrum Victoriam primam" which means: "O Lord, save our Queen Victoria the First." Queen Victoria was on the throne in Britain at the time.
The 96 metre-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.
A competition was opened in 1846 to decide who should build the clock, but it took seven years to decide a winner.
Eventually, the winner was named as Edward Dent, who had already made a chronometer for the HMS Beagle, the ship which carried Charles Darwin on a worldwide voyage which led him to the theory of evolution.
The clock cost 2,500 pounds to build and was completed in 1854 but it was not installed until the clock tower was finished five years later.
Even then, there was a last-minute hitch -- the original cast-iron minute hands were too heavy and had to be replaced with copper ones.
The famous bell chimes -- which are used at the start of many television and radio news bulletins in Britain -- did not sound for another six weeks afterwards.
The name Big Ben originally referred to the bell in the clocktower, but has come to be used for the tower and the clock as well.
It is not entirely clear where the name Big Ben comes from -- some say refers to Sir Benjamin Hall, an MP at the time, while others claim it was after heavyweight boxer Benjamin Caunt.