The Eiffel Tower, symbol of innovative(革新的) technique at the end of the 19th century, has maintained its universal (全世界的) image. Even if 6 million visitors climb the Tower each year, the number of those who have set eyes on the Tower but never foot coupled1 with those who know of the Tower but have never even caught a glimpse of the monument2 are far more numerous.
Its simplified representation(表现) is but an inanimate(无生气的) object, an unchanging reference3 point. Yet, differing from many other structures built in the past,it is alive,ever changing and evolving.The most spectacular4 transformations(变化) are also those that are the most visible:it has changed color six times in its lifetime and its lighting effects have been designed at different moments to decorate the tower for a day or for longer periods of time. Following many different lighting styles, the present day system has been highlighting5 the internal structure of the Tower for more than ten years now.
Less spectacular yet visible are the developments that have been added to the different levels such as the various pavilions (亭子)and constructions on the first and second floors. Also the roofing of the galleries(走廊) and shelters(休息处) providing refuge6 from bad weather conditions including the landing stages7, covered walkways, etc., as well as the numerous technical and service quarters8andthe spaces located directly over or under these levels.The elevator and staircases(楼梯)--construction or replacement of--and the elevator platform9 could also fall into this same category10 of developments,except in cases where they have become integrated parts of the structure. Much less visible are the operations that have modified11 the original Tower's structure.
Indeed, at different periods in time, even the skeleton12 structure evolved,either little by little as the necessity arose or to reinforce certain structural members(构件) that were damaged by various causes. In the descriptive (说明的) book "The 300 meter tower" Gustave Eiffel gave precise indications concerning his calcuilations, how many were used and detailed observation(观察) notes.