Big Ben

           Big Ben is the nickname for the great bell of the clock at the north end of the Palace of Westminster in London and is generally extended to refer to the clock or the clock tower (officially known simply as Clock Tower) as well.The clock tower holds the largest four-faced chiming clock in the world and is the third-tallest free-standing clock tower. It celebrated its 150th anniversary on 31 May 2009,during which celebratory events took place. The tower was completed in 1858 and has become one of the most prominent symbols of both London and England, often in the establishing shot of films set in the city.

Tower
The Palace of Westminster, the Clock Tower and Westminster Bridge The present Clock Tower  metonymically referred to as Big Ben, and historically confused with St Stephen's Tower was raised as a part of Charles Barry's design for a new palace, after the old Palace of Westminster was largely destroyed by fire on the night of 16 October 1834. The new Parliament was built in a Neo-gothic style. Although Barry was the chief architect of the Palace, he turned to Augustus Pugin for the design of the Clock Tower, which resembles earlier Pugin designs, including one for Scarisbrick Hall. The design for the Clock Tower was Pugin's last design before his final descent into madness and death, and Pugin himself wrote, at the time of Barry's last visit to him to collect the drawings: "I never worked so hard in my life for Mr Barry for tomorrow I render all the designs for finishing his bell tower & it is beautiful. The tower is designed in Pugin's celebrated Gothic Revival style, and is 316 feet (96.3 m) high (roughly 16 storeys). The bottom 200 feet (61 m) of the Clock Tower's structure consists of brickwork with sand coloured Anston limestone cladding. The remainder of the tower's height is a framed spire of cast iron. The tower is founded on a 49-foot (15 m) square raft, made of 9.8-foot (3 m) thick concrete, at a depth of 13 feet (4 m) below ground level. The four clock dials are 180 feet (55 m) above ground. The interior volume of the tower is 164,200 cubic feet (4,650 cubic metres). Despite being one of the world's most famous tourist attractions, the interior of the tower is not open to overseas visitors, though United Kingdom residents are able to arrange tours (well in advance) through their Member of Parliament.However, the tower has no lift, so those escorted must climb the 334 limestone stairs to the top. Due to changes in ground conditions since construction (notably tunnelling for the Jubilee Line extension), the tower leans slightly to the north-west, by roughly 8.66 in (220 millimetres) at the clock dials, giving an inclination of approximately 1/250. Due to thermal effects it oscillates annually by a few millimetres east and west.

Great Bell
The second 'Big Ben' (centre) and the Quarter Bells from The Iustrated News of the World 4 December 1858 A modern picture of 'Big Ben'The main bell, officially known as the Great Bell, is the largest bell in the tower and part of the Great Clock of Westminster. The bell is better known by the nickname Big Ben.The original bell was a 16.3-tonne (16 ton) hour bell, cast on 6 August 1856 in Stockton-on-Tees by John Warner & Sons.The bell was named in honour of Sir Benjamin Hall, and his name is inscribed on it.However, another theory for the origin of the name is that the bell may have been named after a contemporary heavyweight boxer Benjamin Caunt. It is thought that the bell was originally to be called Victoria or Royal Victoria in honour of Queen Victoria, but that an MP suggested the nickname during a Parliamentary debate; the comment is not recorded in Hansard.Since the tower was not yet finished, the bell was mounted in New Palace Yard. Cast in 1856, the first bell was transported to the tower on a trolley drawn by sixteen horses, with crowds cheering its progress. Unfortunately, it cracked beyond repair while being tested and a replacement had to be made. The bell was recast on 10 April 1858 at the Whitechapel Bell Foundry as a 13.76-tonne (13½ ton) bell.[30][1] This was pulled 200 ft (61 m) up to the Clock Tower’s belfry, a feat that took 18 hours. It is 2.2 metres tall and 2.9 metres wide. This new bell first chimed in July 1859. In September it too cracked under the hammer, a mere two months after it officially went into service. According to the foundry's manager, George Mears, Denison had used a hammer more than twice the maximum weight specified.For three years Big Ben was taken out of commission and the hours were struck on the lowest of the quarter bells until it was reinstalled. To make the repair, a square piece of metal was chipped out from the rim around the crack, and the bell given an eighth of a turn so the new hammer struck in a different place.Big Ben has chimed with an odd twang ever since and is still in use today complete with the crack. At the time of its casting, Big Ben was the largest bell in the British Isles until "Great Paul", a 17 tonne (16¾ ton) bell currently hung in St Paul's Cathedral, was cast in 1881.