In a land swept by typhoons and shaken by earthquakes, how have Japan's tallest and seemingly flimsiest old buildings - 500 or so wooden pagodas - remained standing for centuries? 在日本这片屡遭台风侵袭与地震撼动的土地上，为何这些高大却貌似弱不禁风的古老建筑——500 余座木质宝塔——能够历经数个世纪仍屹立不倒？ Records show that only two have collapsed during the past 1400 years. 历史记载显示，在过去的1400 年中只有两座宝塔倒塌。 Those that have disappeared were destroyed by fire as a result of lightning or civil war. 这两座消失的宝塔是被闪电或内战引发的大火所摧毁的。 The disastrous Hanshin earthquake in 1995 killed 6,400 people, toppled elevated highways, flattened office blocks and devastated the port area of Kobe. 在1995 年发生的灾难性的阪神大地震中有6,400 人丧生，高架铁路倒塌，办公楼群被夷为平地，神户港口地区也被毁于一旦。 Yet it left the magnificent five-storey pagoda at the Toji temple in nearby Kyoto unscathed, though it levelled a number of buildings in the neighbourhood. 然而京都附近东寺院中的五层宏伟宝塔却没有受到损害，尽管其附近大量的建筑已被夷平。

Japanese scholars have been mystified for ages about why these tall, slender buildings are so stable. 长期以来，日本学者都弄不清楚为什么这些高而纤细的建筑是如此牢固。 It was only thirty years ago that the building industry felt confident enough to erect office blocks of steel and reinforced concrete that had more than a dozen floors. 也不过是在30 年前，建筑行业才有了足够的信心去建造高于12 层的钢筋混凝土办公楼群。 With its special shock absorbers to dampen the effect of sudden sideways movements from an earthquake, the thirty-six-storey Kasumigaseki building in central Tokyo - Japan's first skyscraper - was considered a masterpiece of modern engineering when it was built in 1968. 由于安装了一种特殊的减震器来削弱地震中建筑物的突然侧移，东京市中心那座高达36层的霞关大楼（号称“ 日本第一摩天大楼”）在 1968年刚刚落成时就被认为是展现现代工程技术的杰作。

Yet in 826, with only pegs and wedges to keep his wooden structure upright, the master builder Kobodaishi had no hesitation in sending his majestic Toji pagoda soaring fifty-five metres into the sky - nearly half as high as the Kasumigaseki skyscraper built some eleven centuries later. 然而在公元826 年，主建筑师Kobodaishi，在只用栓和楔保持木质结构直立的情况下，毅然决定把宏伟的东寺宝塔建到55 米高，这一高度相当于11 个世纪之后建成的霞关大楼高度的一半。 Clearly, Japanese carpenters of the day knew a few tricks about allowing a building to sway and settle itself rather than fight nature's forces. 显然，当时日本的木匠知道一些窍门，允许建筑物可以做适度摇摆却能将自身固定在地面，从而不用对抗大自然的力量。 But what sort of tricks? 但是，那究竟是一些什么样的窍门呢？

The multi-storey pagoda came to Japan from China in the sixth century. 日本多层宝塔于公元6 世纪从中国引进。 As in China, they were first introduced with Buddhism and were attached to important temples. 跟中国一样，这些塔最初是随着佛教而传入的，并且都用作重要的寺庙。 The Chinese built their pagodas in brick or stone, with inner staircases, and used them in later centuries mainly as watchtowers. 中国人用砖块或石头建成这些宝塔，并在内部设有楼梯，这些塔在后来的几百年中主要用做瞭望塔。 When the pagoda reached Japan, however, its architecture was freely adapted to local conditions - they were built less high, typically five rather than nine storeys, made mainly of wood and the staircase was dispensed with because the Japanese pagoda did not have any practical use but became more of an art object. 然而当塔传入日本时，它们变得更加本土化——塔不再建得那么高，大部分为五层而非九层。塔身主要为木质，并且没有楼梯，这主要是因为日本宝塔其实没有什么实际用处，它们更像是一种艺术品。 Because of the typhoons that batter Japan in the summer, Japanese builders learned to extend the eaves of buildings further beyond the walls. 由于日本在夏季时常受到台风的侵袭，建筑师们学会了将屋檐的长度延伸到塔壁以外。 This prevents rainwater gushing down the walls. 这样就防止了雨水溅到塔壁上。 Pagodas in China and Korea have nothing like the overhang that is found on pagodas in Japan. 日本的这种悬垂式屋檐不同于中国和朝鲜的任何宝塔。

The roof of a Japanese temple building can be made to overhang the sides of the structure by fifty per cent or more of the building's overall width. 日本寺庙的顶部通常突出整个建筑宽度的50% 或者更多。 For the same reason, the builders of Japanese pagodas seem to have further increased their weight by choosing to cover these extended eaves not with the porcelain tiles of many Chinese pagodas but with much heavier earthenware tiles. 基于同样的原因，为了进一步增加顶部的重量，日本宝塔的建筑师在覆盖这些屋檐时，不会选用中国塔常用的瓷制瓦片，而是使用更加有分量的陶制瓦片。

But this does not totally explain the great resilience of Japanese pagodas. 但是这些并不能完全解释日本宝塔的牢固性。 Is the answer that, like a tall pine tree, the Japanese pagoda - with its massive trunk-like central pillar known as shinbashira - simply flexes and sways during a typhoon or earthquake? 难道答案是这样的：日本宝塔就像一棵高大的松树，中间有根被称做Shinbashira 的像粗壮树干的立柱，一旦台风或地震来了就能随之伸缩、摇摆？ For centuries, many thought so. 几个世纪以来，许多人都这么认为。 But the answer is not so simple because the startling thing is that the Shinbashira actually carries no load at all. 但是答案并不是如此简单，因为令人吃惊的是中心支柱本身并不负重。 In fact, in some pagoda designs, it does not even rest on the ground, but is suspended from the top of the pagoda - hanging loosely down through the middle of the building. 实际上，在一些宝塔的设计中，中心柱甚至是不接触地面的，而是从塔的顶部垂下，轻松地悬在塔的中部。 The weight of the building is supported entirely by twelve outer and four inner columns. 塔本身的重量则完全由外面的12 根柱子和里面的4 根柱子所支撑。

And what is the role of the shinbashira, the central pillar? 那么Shinbashira 这个中间的立柱到底是起什么作用的呢？ The best way to understand the Shinbashira's role is to watch a video made by Shuzo Ishida, a structural engineer at Kyoto Institute of Technology. 想要弄清它的作用，最好的办法是去看看京都理工学院的结构工程师Shuzo Ishida 制作的视频短片。 Mr. Ishida, known to his students as 'Professor Pagoda' because of his passion to understand the pagoda, has built a series of models and tested them on a 'shake- table' in his laboratory. 由于Ishida先生对宝塔的钻研精神，他被学生们亲切地称为“宝塔教授”。目前他已经制作了一系列的模型，并且在他的实验室振动台上做了各种测试。 In short, the Shinbashira was acting like an enormous stationary pendulum. 简而言之，Shinbashira 就像一个巨大的被固定住的钟摆。 The ancient craftsmen, apparently without the assistance of very advanced mathematics, seemed to grasp the principles that were, more than a thousand years later, applied in the construction of Japan's first skyscraper. 古代的工匠在明显没有高超数学知识的情况下，似乎就已经掌握了那些在一千年以后才用于建造日本第一摩天大楼的原理。 What those early craftsmen had found by trial and error was that under pressure a pagoda's loose stack of floors could be made to slither to and fro independent of one another. 那些早期的工匠历经反复的尝试和失误，最终发现，在压力之下，没有被固定死的楼层之间能够独立进行来回的滑动。 Viewed from the side, the pagoda seemed to be doing a snake dance - with each consecutive floor moving in the opposite direction to its neighbours above and below. 从侧面看起来，塔呈蛇形舞动——当一个楼层移动时，与之相邻的上下楼层都会向相反的方向移动。 The shinbashira, running up through a hole in the centre of the building, constrained individual storeys from moving too far because, after moving a certain distance, they banged into it, transmitting energy away along the column. 从塔中间的孔中贯穿整个宝塔的Shinbashira 事实上只是限制了每个楼层彼此间都不能移动太远，因此当移动的距离超过一定限度后，它们会撞回到Shinbashira，从而将能量沿着柱子转移出去。

Another strange feature of the Japanese pagoda is that, because the building tapers, with each successive floor plan being smaller than the one below, none of the vertical pillars that carry the weight of the building is connected to its corresponding pillar above. 日本塔的另一个奇怪特点是，由于这种塔从下到上，慢慢变细，即每个相连楼层的设计平面都要比它下面的楼层小，因此没有一个承重的立柱与上面相应的柱子相连。 In other words, a five- storey pagoda contains not even one pillar that travels right up through the building to carry the structural loads from the top to the bottom. 换句话说，一个五层的塔中甚至没有一根贯穿塔身且能承担从顶部到底部重量的立柱。 More surprising is the fact that the individual storeys of a Japanese pagoda, unlike their counterparts elsewhere, are not actually connected to each other. 更加令人吃惊的是，不像其他地方的塔，日本塔的每个楼层之间实际上并不相连。 They are simply stacked one on top of another like a pile of hats. 它们仅仅是像一堆帽子似的一个摞在另一个的上面。 Interestingly, such a design would not be permitted under current Japanese building regulations. 有趣的是，这种设计在当今的日本建筑规定中是不被允许的。

And the extra-wide eaves? 另外那些超长的屋檐又是怎么回事呢？ Think of them as a tightrope walker's balancing pole. 我们可以把它们看成走钢丝表演者所使用的平衡杆。 The bigger the mass at each end of the pole, the easier it is for the tightrope walker to maintain his or her balance. 杆的两端越大越多，钢丝表演者就更容易保持平衡。 The same holds true for a pagoda. 宝塔也是一样的道理。 'With the eaves extending out on all sides like balancing poles,' says Mr Ishida, 'the building responds to even the most powerful jolt of an earthquake with a graceful swaying, never an abrupt shaking.' Ishida 教授说：“延伸出来的屋檐就像平衡杆，即使是面对地震中最剧烈的摇晃，塔也只会有轻微的摇摆而不会有剧烈的摇晃。” Here again, Japanese master builders of a thousand years ago anticipated concepts of modern structural engineering. 这里要重申的是，日本一千年前的建筑大师已预见到了现代结构工程学的概念。