,Clock Tower ,The Clock Tower is a turret t:rit（角楼，塔楼）clock structure at the north-eastern end of the Houses of Parliament building in Westminster, London, England. It is popularly known as Big Ben, but this name is actually a nickname nik,neim（绰号,浑名）for the clocks main bell. The tower has also been referred to as St. Stephens Tower or The Tower of Big Ben, in reference refrns （提及;涉及） to its bell.,Structure Reliability Culture,The tower was raised as a part of Charles Barrys design for a new palace, after the old Palace of Westminster was destroyed by fire on the night of October 16, 1834. The tower is designed in the Victorian Gothic style, and is 96.3 meters high.,Structure,The first 61 meters of the structure is the clock tower, consisting of brickwork brikw:k砖结构with stone cladding kldi包覆; the remainder of the towers height is a framed freim架构,骨架;结构 spire spai螺旋形上升 of cast iron. The tower is founded on a 15 by 15 meter raft, made of 3-metre thick concrete knkri:t混凝土,at a depth dep深度,厚度 of 7 meters below ground level. The four clock faces are 55 meters above ground.,Due to ground conditions present since construction, the tower leans li:n倾斜slightly to the north-west, by roughly rfli 大约220 millimeters .Due to thermal :ml保暖的effects it oscillates si,leit摆动annually njuli 每年一次by a few millimeters east and west.,Clock faces The main bell Other bells,Clock faces,The clock faces were once large enough to allow the Clock Tower to be the largest four-faced clock in the world. The clock mechanism meknizm机构;结构itself was completed by 1854, but the tower was not fully constructed until four years later in 1858. The clock and dials dail表盘;钟盘were designed by Augustus Pugin. During World War II, the Palace of Westminster was hit by German bombing bm轰炸;轰击, destroying the House of Commons下院and causing damage to the towers western clock face.,返回,The main bell,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 name Big Ben was first given to a 14.5 tonne (16 ton) hour bell .,The bell was never officially named, but the legend on it records that the commissioner kmin长官of works, Sir Benjamin Hall, was responsible for the order .Another theory is that the bell may have been named after heavyweight boxer Benjamin Caunt who was popular at the time. Theres also a story that the bell was to be called “Victoria“ in honor of Queen Victoria, but the ceremonial ,serimunjl礼节的 speeches went on so long that some joker shouted out “Oh just call it Big Ben and have done with it!“ and the name stuck stk粘住.,返回,Other bells,Along with the main bell, the belfry belfri钟楼houses four quarter bells which play the Westminster Quarters on the quarter hours. The four quarter bells are G sharp, F sharp, E, and B. Because the low bell (B) is struck twice in quick succession sksen一连串 , there is not enough time to pull a hammer hm 锤状物 back, and it is supplied splaid有.提供的 with two hammers on opposite sides of the bell.,返回,Reliability,The clock is famous for its reliability. This is due to the skill of its designer, the lawyer and amateur horologist hrldist钟表商;钟表专家Edmund Beckett Denison, later Lord Grim Thorpe.,Instead of using the deadbeat ded,bi:t非周期的;无振荡的escapement iskeipmnt摆轮and remoter as originally designed, Denison invented the double three-legged gravity escapement. This escapement provides the best separation between pendulum pendjulm钟摆and clock mechanism. Together with an enclosed inkluzd与世隔绝的, wind-proof box sunk beneath bini:在.之下 the clock room, the Great Clocks pendulum is well isolated aisleit使脱离from external ekst:nl外来的factors like snow, ice and pigeons on the clock hands, and keeps remarkably accurate time.,Despite heavy bombing the clock ran accurately throughout the Blitz. It slowed down on New Years Eve 1962 due to heavy snow, causing it to chime taim鸣,鸣响in the new year 10 minutes late. The clock had its first and only major breakdown in 1976. The chiming mechanism broke due to metal fatigue fti:g疲劳,劳累 on 5 August 1976, and was reactivated again on 9 May 1977. On 29 October 2005, the mechanism was stopped for approximately 33 hours so that the clock and its chimes could be worked on. It was the lengthiest maintenance meintinns维持,保持shutdown in 22 years.,返回,Culture,Big Ben is a focus of New Year celebrations in the United Kingdom, with radio and TV stations tuning to its chimes to welcome the start of the year. Big Ben can be used in the classroom to demonstrate demnstreit论证,证明 the difference between the speed of light and the speed of sound. If a person visits London and stands at the bottom of the clock tower, they will hear the chimes of Big Ben approximately 1/6 of a second later than the bell being struck,