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Milne, John . Earthquakes and Other Earth Movements

在约翰·米尔恩（John Milne）的《地震与其他地球运动》一书中，读者将得到对地震和其他地质事件现象的全面和详尽的探索。米尔恩的书深入探讨了这些自然事件背后的科学解释和机制，以清晰简洁的方式呈现了大量信息。这本书以学术但易于理解的风格撰写，将经验数据与理论分析相结合，使其成为地质爱好者和研究人员的宝贵资源。米尔恩的工作置于19世纪科学话语的背景之中，为早期地震学和板块构造研究提供了见解。这部经典著作至今仍然具有重要意义，为地质学领域的现代研究奠定了基础。约翰·米尔恩是一位著名的地质学家和地震学家，以其对地震研究的开创性贡献而闻名。他对这一主题的专业知识和热情在《地震与其他地球运动》中得以体现，使其成为该领域的重要著作。我强烈推荐这本书给所有对地球动态地质过程和塑造我们星球的力量感兴趣的人。

CHAPTER II. SEISMOMETRY 第二章 地震仪

Nature of earthquake vibrations--Many instruments called seismometers only seismoscopes--Eastern seismoscopes, columns, projection seismometers--Vessels filled with liquid--Palmieri's mercury tubes--The ship seismoscope--The cacciatore--Pendulum instruments of Kreil, Wagner, Ewing, and Gray--Bracket seismographs--West's parallel motion instrument--Gray's conical pendulums, rolling spheres, and cylinders--Verbeck's ball and plate seismograph--The principle of Perry and Ayrton--Vertical motion instruments--Record receivers--Time-recording apparatus--The Gray and Milne seismograph.

地震振动的性质----许多被称为地震仪的仪器实际上只是地震示波器----东方的地震示波器、柱体、投影地震仪----装满液体的容器----帕尔米耶里的水银管----船用地震示波器----卡恰托雷地震仪----克雷尔、瓦格纳、尤因和格雷的摆动仪器----支架地震仪----韦斯特的平行运动仪器----格雷的锥形摆、滚动球和圆柱体----弗贝克的球板地震仪----佩里和艾尔顿的原理----垂直运动仪器----记录接收器----时间记录装置----格雷和米尔恩的地震仪。

Before we discuss the nature of earthquake motion, the determination of which has been the aim of modern seismological investigation, the reader will naturally look for an account of the various instruments which have been employed for recording such disturbances. A description of the earthquake machines which have been used even in Japan would form a bulky volume. All that we can do, therefore, is to describe briefly the more prominent features of a few of the more important of these instruments. In order that the relative merits of these may be better understood, we may state generally that modern research has shown a typical earthquake to consist of a series of small tremors succeeded by a shock, or series of shocks, separated by more or less irregular vibrations of the ground. The vibrations are often both irregular in period and in amplitude, and they have a duration of from a few seconds to several minutes. We will illustrate the records of actual earthquakes in a future chapter, but in the meantime the idea that an earthquake consists of a single shock must be dismissed from the imagination.

在讨论地震运动的性质之前，现代地震学研究的目标就是确定这一性质。读者自然会希望了解记录这种扰动的各种仪器。如果要描述即使是仅在日本使用的地震仪器，可能需要一本厚重的书。因此，我们只能简要描述一些较重要仪器的主要特点。为了更好地理解这些仪器的相对优劣，我们可以大致说明，现代研究表明，典型的地震由一系列小震动组成，随后是一次或一系列冲击，再接着是或多或少不规则的地面振动。这些振动的周期和幅度通常都不规则，持续时间从几秒钟到几分钟不等。我们将在以后的章节中展示实际地震的记录，但与此同时，必须摒弃地震只由一次冲击组成的观念。

To construct an instrument which at the time of an earthquake shall move and leave a record of its motion, there is but little difficulty. Contrivances of this order are called seismoscopes . If, however, we wish to know the period, extent, and direction of each of the vibrations which constitutes an earthquake, we have considerable difficulty. Instruments which will in this way measure or write down the earth's motions are called seismometers or seismographs .

要构造一种在地震时能够移动并记录其运动的仪器，难度并不大。这类装置称为地震示波器。然而，如果我们希望知道构成地震的每次振动的周期、幅度和方向，则面临相当大的困难。能够以这种方式测量或记录地球运动的仪器称为地震仪或地震计。

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Many of the elaborate instruments supplemented with electro-magnetic and clockwork arrangements are, when we examine them, nothing more than elaborate seismoscopes which have been erroneously termed seismographs.
The only approximations to true seismographs which have yet been invented are without doubt those which during the past few years have been used in Japan. It would be a somewhat arbitrary proceeding, however, to classify the different instruments as seismoscopes, seismometers, and seismographs, as the character of the record given by certain instruments is sometimes only seismoscopic, whilst at other times it is seismometric, depending on the nature of the disturbance. Many instruments, for instance, would record with considerable accuracy a single sudden movement, but would give no reliable information regarding a continued shaking.

许多配有电磁装置和钟表装置的精密仪器，当我们仔细检查时，会发现它们其实只是被误称为地震仪的复杂地震示波器。
目前所发明的唯一接近真正地震仪的仪器，毫无疑问，是近几年在日本使用的那些。然而，将不同的仪器分类为地震示波器、地震计和地震仪是有些武断的，因为某些仪器所提供的记录有时只是地震示波性的，而在其他时候则是地震计性的，取决于扰动的性质。例如，许多仪器可以相当准确地记录单次突发运动，但对持续震动却无法提供可靠的信息。

Eastern Seismoscopes. The earliest seismoscope of which we find any historical record is one which owes its origin to a Chinese called Chôko. It was invented in the year a.d. 136. A description is given in the Chinese history called 'Gokanjo,' and the translation of this description runs as follows:--

东方地震示波器
有历史记录的最早地震示波器源于一位名叫张衡的中国人。它发明于公元136年。在中国的历史书《后汉书》中有对该装置的描述，其翻译内容如下：

In the first year of Yōka, a.d. 136, a Chinese called Chôko invented the seismometer shown in the accompanying drawing. This instrument consists of a spherically formed copper vessel, the diameter of which is eight feet. It is covered at its top, and in form resembles a wine-bottle. Its outer part is ornamented by the figures of different kinds of birds and animals, and old peculiar-looking letters. In the inner part of this instrument a column is so suspended that it can move in eight directions. Also, in the inside of the bottle, there is an arrangement by which some record of an earthquake is made according to the movement of the pillar. On the outside of the bottle there are eight dragon heads, each of which holds a ball in its mouth. Underneath these heads there are eight frogs so placed that they appear to watch the dragon's face, so that they are ready to receive the ball if it should be dropped. All the arrangements which cause the pillar to knock the ball out of the dragon's mouth are well hidden in the bottle.

在永嘉元年（公元136年），一位名叫张衡的中国人发明了地震仪，其示意图如附图所示。该仪器由一个直径八尺的球形铜器组成，顶部覆盖，形状类似酒瓶。外部装饰有各种鸟兽图案和古怪的文字。在仪器内部，有一根可以向八个方向移动的柱子。瓶内还有一种装置，可以根据柱子的移动记录地震。在瓶子的外侧有八个龙头，每个龙头嘴里含着一个球。在这些龙头下方有八只青蛙，呈现出仰望龙头的姿态，随时准备接住掉落的球。使柱子撞击龙嘴中球的所有装置都巧妙地隐藏在瓶子内部。

When an earthquake occurs, and the bottle is shaken, the dragon instantly drops the ball, and the frog which receives it vibrates vigorously; any one watching this instrument can easily observe earthquakes.

当地震发生时，瓶子受到震动，龙头立即掉下球，接住球的青蛙会剧烈振动。观察这个仪器的人可以很容易地察觉到地震的发生。

With this arrangement, although one dragon may drop a ball, it is not necessary for the other seven dragons to drop their balls unless the movement has been in all directions; thus we can easily tell the direction of an earthquake.

通过这种装置，虽然一个龙头可能会掉下一个球，但如果运动并非来自所有方向，其他七个龙头就不会掉球。这样我们就能轻松判断地震的方向。

Once upon a time a dragon dropped its ball without any earthquake being observed, and the people therefore thought the instrument of no use, but after two or three days a notice came saying that an earthquake had taken place at Rōsei. Hearing of this, those who doubted the use of this instrument began to believe in it again. After this ingenious instrument had been invented by Chōko, the Chinese Government wisely appointed a secretary to make observations on earthquakes.

曾有一次，一个龙头掉下了球，但当时没有观察到地震，因此人们认为这个仪器没什么用。然而，两三天后，收到了一则消息，说洛阳发生了地震。听到这个消息，那些怀疑这个仪器作用的人又重新开始相信它了。自从张衡发明了这个巧妙的仪器后，中国政府明智地任命了一位秘书来专门观察地震。

Not only is this instrument of interest on account of its antiquity, but it is also of interest on account of the close resemblance it bears to many of the instruments of modern times. Another earthquake instrument also of Eastern origin is the magnetic seismoscope of Japan.
这个仪器不仅因其古老而引人注目，还因为它与许多现代仪器有着惊人的相似之处。另一种同样起源于东方的地震仪器是日本的磁性地震示波器。

On the night of the destructive earthquake of 1855, which devastated a great portion of Tokio, the owner of a spectacle shop in Asakusa observed that a magnet dropped some old iron nails and keys which had been attached to it. From this occurrence the owner thought that the magnet had, in consequence of its age, lost its powers. About two hours afterwards, however, the great earthquake took place, after which the magnet was observed to have regained its powers. This occurrence led to the construction of the seismoscope, which is illustrated in a book called the 'Ansei-Kembun-Roku,' or a description of the earthquake of 1855, and examples of the instrument are still to be seen in Tokio. These instruments consist of a piece of magnetic iron ore, which holds up a piece of iron like a nail. This nail is connected, by means of a string, with a train of clockwork communicating with an alarm. If the nail falls a catch is released and the clockwork set in motion, and warning given by the ringing of a bell. It does not appear that this instrument has ever acted with success.
在1855年那次毁灭性地震的夜晚，这场地震摧毁了东京的大片区域。当时，浅草区一家眼镜店的店主观察到，一块磁铁掉下了几枚原本吸附在其上的旧铁钉和钥匙。由于这一现象，店主认为磁铁由于年代久远，失去了磁力。然而，大约两小时后，发生了那场大地震，随后发现磁铁又恢复了磁力。这一现象引发了地震仪的构思，这种仪器在一本名为《安政见闻录》的书中有所描述，该书记录了1855年地震的情况，目前在东京仍能看到这种仪器的实例。

这些仪器由一块磁性铁矿石组成，铁矿石上吸附着类似钉子的一块铁片。铁片通过一根绳子连接到一个时钟机构，并与一个报警器相连。如果铁片掉下，卡扣会被释放，时钟机构开始运转，铃声响起以发出警报。然而，似乎这种仪器从未成功地发挥过作用。

Columns. One of the commonest forms of seismoscope, and one which has been very widely used, consists of a round column of wood, metal, or other suitable material, placed, with its axis vertical, on a level plane, and surrounded by some soft material such as loose sand to prevent it rolling should it be overturned. The fall of such a column indicates that a shaking or shock has taken place. Attempts have been made by using a number of columns of different sizes to make these indications seismometric, but they seldom give reliable information either as to intensity or direction of shock. The indications as to intensity are vitiated by the fact that a long-continued gentle shaking may overturn a column which would stand a very considerable sudden shock, while the directions in which a number of columns fall seldom agree owing to the rotational motion imparted to them by the shaking. Besides, the direction of motion of the earthquake seldom remains in the same azimuth throughout the whole disturbance.
柱子。地震仪的一种常见形式，并且被广泛使用，由一个圆柱体组成，可以是木制、金属或其他合适的材料，垂直放置在一个水平面上，并被松散的沙子等软材料包围，以防它被推倒后滚动。这样一个柱子的倒下表明发生了震动或冲击。有人尝试使用不同尺寸的多个柱子来使这些指示具有地震测量意义，但它们很少能提供关于震动强度或方向的可靠信息。关于强度的指示因以下事实而失真：长时间的轻微震动可能会推倒一个能够承受相当大突发冲击的柱子，而多个柱子倒下的方向往往不一致，因为震动会对它们产生旋转运动。此外，地震的运动方向在整个扰动过程中很少保持在同一方位。

An extremely delicate, and at the same time simple form of seismoscope may be made by propping up strips of glass, pins, or other easily overturned bodies against suitably placed supports. In this way bodies may be arranged, which, although they can only fall in one direction, nevertheless fall with far less motion than is necessary to overturn any column which will stand without lateral support.
一种极其敏感且同时简单的地震仪形式，可以通过将玻璃条、针或其他容易被推倒的物体靠在适当放置的支撑物上来制作。通过这种方式，可以安排这些物体，尽管它们只能朝一个方向倒下，但其倒下所需的运动远远小于推倒任何能够在没有横向支撑下站立的柱子所需的运动。

Projection Seismometers. Closely related to the seismoscopes and seismometers which depend on the overturning of bodies. Mallet has described two sets of apparatus whose indications depend on the distance to which a body is projected. In one of these, which consisted of two similar parts arranged at right angles, two metal balls rest one on each side of a stop at the lower part of two inclined like troughs. In this position each of the balls completes an electric circuit. By a shock the balls are projected or rolled up the troughs, and the height to which they rise is recorded by a corresponding interval in the break of the circuits. The vertical component of the motion is measured by the compression of a spring which carries the table on which this arrangement rests. In the second apparatus two balls are successively projected, one by the forward swing, and the other by the backward swing of the shock. Attached to them are loose wires forming terminals of the circuits. They are caught in a bed of wet sand in a metal trough forming the other end of the circuit. The throw of the balls as measured in the sand, and the difference of time between their successive projections as indicated by special contrivances connected with the closing of the circuits, enables the observer to calculate the direction of the wave of shock, its velocity, and other elements connected with the disturbance. It will be observed that the design of this apparatus assumes the earthquake to consist of a distinct isolated shock.
投影地震仪。与依靠物体倾覆的地震仪和地震计密切相关。马莱特描述了两套仪器，它们的指示取决于物体投射的距离。其中一套由两个相似的部分组成，按直角排列，两颗金属球分别位于两个类似槽道下部的止挡两侧。在这个位置，每个球都完成了一个电路。通过震动，球被投射或滚上槽道，其上升的高度通过电路断开的相应间隔记录下来。运动的垂直分量通过压缩支撑此装置的台子上的弹簧来测量。

第二套仪器中，两个球被依次投射，一个由震动的前摆投射，另一个由后摆投射。它们附着着形成电路端子的松散电线。球落入金属槽道内的湿沙床中，形成电路的另一端。通过测量球在沙中的投掷距离，以及通过与电路闭合相关的特殊装置显示的连续投射时间差，观察者可以计算出震波的方向、速度及其他扰动相关的元素。需要注意的是，这套仪器的设计假定地震由一个独立的单一震动组成。

Oldham, at the end of his account of the Cachar earthquake of 1869, recommends the use of an instrument based on similar principles. In his instrument four balls like bullets are placed in notches cut in the corners of the upper end of a square stake driven into the ground.
在1869年卡查地震的报告结尾，奥德姆建议使用一种基于类似原理的仪器。在他的仪器中，四个类似子弹的球被放置在插入地面的方形桩上端角落的凹槽中。

Vessels filled with liquid. Another form of simple seismoscope is made by partially filling a vessel with liquid. The height to which the liquid is washed up the side of the vessel is taken as an indication of the intensity of the shock, and the line joining the points on which maximum motion is indicated, is taken as the direction of the shock. If earthquakes all lasted for the same length of time, and consisted of vibrations of the same period, such instruments might be of service. These instruments have, however, been in use from an early date. In 1742 we find that bowls of water were used to measure the earthquakes which in that year alarmed the inhabitants of Leghorn. About the same time the Rev. S. Chandler, writing about the shock at Lisbon, tells us that earthquakes may be measured by means of a spherical bowl about three or four feet in diameter, the inside of which, after being dusted over with Barber's puff, is filled very gently with water. Mallet, Babbage, and De la Bêche have recommended the same sort of contrivance, but, notwithstanding, it has justly been criticised as 'ridiculous and utterly impracticable.' [7]
液体容器。另一种简单的地震仪形式是部分填充液体的容器。液体沿容器壁上升的高度被视为震动强度的指示，而连接最大运动指示点的线被视为震动的方向。如果所有地震的持续时间相同，且由相同周期的振动组成，这种仪器可能会有用。然而，这类仪器从很早就开始使用。1742年，人们发现用盛水的碗来测量当年使利沃诺居民感到恐慌的地震。同一时期，牧师S. Chandler在写到里斯本的地震时告诉我们，可以用一个直径约三到四英尺的球形碗来测量地震，其内部在撒上粉尘后，轻轻地装满水。马莱特、巴贝奇和德拉比克也推荐过同样的装置，但尽管如此，这种装置被公正地批评为"荒谬且完全不切实际"。

An important portion of Palmieri's well-known instrument consists of horizontal tubes turned up at the ends and partially filled with mercury. To magnify the motion of the mercury, small floats of iron rest on its surface. These are attached by means of threads to a pulley provided with indices which move in front of a scale of degrees. We thus read off the intensity of an earthquake as so many degrees, which means so many millimetres of washing up and down of mercury in a tube. The direction of movement is determined by the azimuth of the tube which gives the maximum indication, several tubes being placed in different azimuths.
帕尔米耶里著名仪器的一个重要部分由水平管组成，这些管的两端向上弯曲，并部分填充汞。为了放大汞的运动，铁制的小浮子放在汞的表面。通过线将这些浮子连接到带有指示器的滑轮上，指示器在一个刻度盘前移动。我们由此可以读取地震的强度，以度数表示，这意味着管内汞上下运动的毫米数。运动方向由给出最大指示的管的方位角决定，多个管子被放置在不同的方位角上。

This form of instrument appears to have been suggested by Mallet, who gives an account of the same in 1846. Inasmuch as the rise and fall of the mercury in such tubes depend on its depth and on the period of the earthquake together with its duration, we see that although the results obtained from a given instrument may give us means of making approximate comparisons as to the relative intensity of various earthquakes, it is very far from yielding any absolute measurement.
这种仪器形式似乎是由马莱特提出的，他在1846年对其进行了描述。由于这种管中的汞的升降取决于其深度、地震的周期及其持续时间，我们可以看到，尽管从特定仪器获得的结果可以为我们提供对不同地震相对强度的近似比较手段，但它远远不能提供任何绝对的测量。

Another method which has been employed to magnify and register the motions of liquid in a vessel has been to float upon its surface a raft or ship from which a tall mast projected. By a slight motion of the raft, the top of the mast vibrated through a considerable range. This motion of the mast as to direction and extent was then recorded by suitable contrivances attached to the top of the mast.
另一种用于放大和记录容器内液体运动的方法是将一艘木筏或船漂浮在液体表面，从船上竖起一根高高的桅杆。由于木筏的微小运动，桅杆顶端会在相当大的范围内振动。然后，通过安装在桅杆顶端的合适装置记录下桅杆的运动方向和幅度。

A very simple form of liquid seismoscope consists of a circular trough of wood with notches cut round its side. This is filled with mercury to the level of the notches. At the time of an earthquake the maximum quantity of mercury runs over the notches in the direction of greatest motion. This instrument, which has long been used in Italy, is known as a Cacciatore, being named after its inventor. It is a prominent feature in the collection of apparatus forming the well-known seismograph of Palmieri.
一种非常简单的液体地震仪由一个木制的圆形槽组成，槽的边缘开有凹口。槽内装满水银至凹口的高度。当地震发生时，最大量的水银会沿着震动最大的方向溢出凹口。这种仪器在意大利已经使用很久了，被称为Cacciatore，以其发明者的名字命名。它是组成著名的Palmieri地震仪设备集合中的一个重要特点。

Pendulum instruments. Mallet speaks of pendulum seismoscopes and seismographs as 'the oldest probably of seismometers long set up in Italy and southern Europe.' In 1841 we find these being used to record the earthquake disturbances at Comrie in Scotland.
摆仪器。Mallet提到摆地震仪和地震记录仪是"可能最古老的地震测量仪器，早在意大利和南欧就已经设置。"1841年，我们发现这些仪器被用来记录苏格兰Comrie的地震扰动。

These instruments may be divided into two classes: first, those which at the time of the shock are intended to swing, and thus record the direction of movement; and second, those which are supposed to remain at rest and thus provide 'steady points.'
这些仪器可以分为两类：第一类是在震动时摆动，从而记录运动方向的仪器；第二类是旨在保持静止，从而提供"稳定点"的仪器。

To obtain an absolutely 'steady point' at the time of an earthquake, has been one of the chief aims of all recent seismological investigations.
在地震发生时获得一个绝对的"稳定点"一直是所有近期地震学研究的主要目标之一。

With a style or pointer projecting down from the steady point to a surface which is being moved backward and forward by the earth, such a surface has written upon it by its own motions a record of the ground to which it is attached. Conversely, a point projecting upwards from the moving earth might be caused to write a record on the body providing the steady point, which in the class of instruments now to be referred to is supposed to be the bob of a pendulum. It is not difficult to get a pendulum which will swing at the time of a moderately strong earthquake, but it is somewhat difficult to obtain one which will not swing at such a time. During the past few years, pendulums varying between forty feet in length and carrying bobs of eighty pounds in weight, and one-eighth of an inch in length, and carrying a gun-shot, have been experimented with under a great variety of circumstances. Sometimes the supports of these pendulums have been as rigid as it is possible to make a structure from brick and mortar, and at other times they have intentionally been made loose and flexible. The indices which wrote the motions of these pendulums have been as various as the pendulums themselves. A small needle sliding vertically through two small holes, and resting its lower end on a surface of smoked glass, has on account of its small amount of friction been perhaps one of the favourite forms of recording pointers.
在地震发生时，为了获得一个绝对的"稳定点"，可以在这个稳定点上伸出一个指针，指向一个由地球前后移动的表面。通过表面自身的运动，它会记录其所附着的地面的运动。反之，从移动的地面向上伸出的指针可以在提供稳定点的装置上记录运动，这类仪器中的稳定点通常是摆锤的球体。在中等强度地震时，让摆锤摆动并不难，但要获得一个在这样的时间不会摆动的摆锤却相当困难。

近年来，长度在四十英尺、重量为八十磅的摆锤，以及长度为八分之一英寸、重如枪弹的小摆锤，在各种情况下都进行了实验。有时，这些摆锤的支撑结构尽可能地用砖和灰泥建造得非常坚固，而有时它们被故意做得松散且灵活。记录这些摆锤运动的指针形状和种类与摆锤本身一样多样化。其中，一种较受欢迎的记录指针形式是一个小针，通过两个小孔垂直滑动，其下端 resting 在一块烟熏玻璃表面上，因其摩擦力极小而广受青睐。

The free pendulums which have been employed, and which were intended to swing, have been used for two purposes: first, to determine the direction of motion from the direction of swing, and second, to see if an approximation to the period of the earth's motion could be obtained by discovering the pendulum amongst a series of different lengths which was set in most violent motion, this probably being the one which had its natural period of swing the most nearly approximating to the period of the earthquake oscillations.
自由摆锤的使用有两个目的：首先，通过摆动的方向确定运动的方向；其次，通过在一系列不同长度的摆锤中找出摆动最剧烈的一个，来估算地球运动的周期。摆动最剧烈的那个摆锤可能是其自然摆动周期最接近地震振荡周期的摆锤。

Inasmuch as all pendulums when swinging have a tendency to change the plane of their oscillation, and also as we now know that the direction of motion during an earthquake is not always constant, the results usually obtained with these instruments respecting the direction of the earth's motion have been unsatisfactory. The results which were obtained by series of pendulums of different lengths were, for various reasons, also unsatisfactory.
由于所有钟摆在摆动时都有改变其振荡平面的趋势，并且我们现在知道地震期间的运动方向并不总是恒定的，因此通常用这些仪器得到的关于地球运动方向的结果是不令人满意的。由于各种原因，通过一系列不同长度的钟摆获得的结果也同样不令人满意。

Of pendulums intended to provide a steady point, from which the relative motion of a point on the earth's surface could be recorded, there has been a great variety. One of the oldest forms consisted of a pendulum with a style projecting downwards from the bob so as to touch a bed of sand. Sometimes a concave surface was placed beneath the pendulum, on which the record was traced by means of a pencil. Probably the best form was that in which a needle, capable of sliding freely up and down, marked the relative horizontal motion of the earth and the pendulum bob on a smoked glass plate.
关于用来提供稳定点的钟摆，这些稳定点可以记录地球表面上某点的相对运动，钟摆的形式有很多种。其中最古老的形式之一是钟摆的摆锤向下伸出一个笔尖，使其触及一层沙子。有时，在钟摆下方放置一个凹面，通过铅笔在其上追踪记录。可能最好的形式是使用一个能够自由上下滑动的针，在烟熏玻璃板上标记地球与钟摆摆锤之间的相对水平运动。

It generally happens that at the time of a moderately severe earthquake the whole of these forms of apparatus are set in motion, due partly to the motion of the point of support of the pendulum, and partly to the friction of the writing point on the plate.
通常，在中等强度的地震发生时，这些仪器的所有部分都会被启动，部分原因是钟摆支点的运动，部分原因是书写点在板上的摩擦力。

Among these pendulums may be mentioned those of Cavallieri, Faura, Palmieri, Rossi, and numerous others. It is possible that the originators of some of these pendulums may have intended that they should record by swinging. If this is so, then so far as the determination of the actual nature of earthquake motion is concerned, they belong to a lower grade of apparatus than that in which they are here included.
这些钟摆中可以提到Cavallieri、Faura、Palmieri、Rossi及众多其他人的钟摆。可能某些钟摆的发明者本来意图让它们通过摆动来记录。如果是这样，那么在确定地震运动的实际性质方面，它们属于低于本文所提及设备的一个等级。

A great improvement in pendulum apparatus is due to Mr. Thomas Gray of Glasgow, who suggested applying so much frictional resistance to the free swing of a pendulum that for small displacements it became 'dead beat.' By carrying out this suggestion, pendulum instruments were raised to the position of seismographs. The manner of applying the friction will be understood from the following description of a pendulum instrument which is also provided with an index which gives a magnification of the motion of the earth.
钟摆装置的一个重大改进归功于格拉斯哥的托马斯·格雷先生，他建议对钟摆的自由摆动施加大量的摩擦阻力，使其在小幅度摆动时变得"停止摆动"。通过实施这一建议，钟摆仪器被提升到地震仪的水平。以下是对一种钟摆仪器的描述，这种仪器还配备了一个指示器，可以放大地球的运动，以便更好地理解摩擦的应用方式。

b b b b is a box 113 cm. high and 30 cm. by 18 cm. square. Inside this box a lead ring r , 17 cm. in diameter and 3 cm. thick, is suspended as a pendulum from the screw s . This screw passes through a small brass plate p p , which can be moved horizontally over a hole in the top of the box. These motions in the point of suspension allow the pendulum to be adjusted.
b b b b 是一个高113厘米，底部为30厘米乘18厘米的长方形箱子。在这个箱子内部，有一个直径17厘米、厚度3厘米的铅环 r ，作为钟摆悬挂在螺丝 s 上。螺丝穿过一个小的黄铜板 p p ，这个黄铜板可以在箱子顶部的一个孔上水平移动。通过调整悬挂点的这些运动，可以调整钟摆。

Projecting over the top of the pendulum there is a wooden arm w carrying two sliding pointers h h , resting on a glass plate placed on the top of the pendulum. These pointers are for the purpose of giving the frictional resistance before referred to. If this friction plate is smoked, the friction pointers will write upon it records of large earthquakes independently of the records given by the proper index, which only gives satisfactory records in the case of shocks of ordinary intensity. Crossing the inside of the pendulum r there is a brass bar perforated with a small conical hole at m . A stiff wire passes through m and forms the upper portion of the index i , the lower portion of which is a thin piece of bamboo. Fixed upon the wire there is a small brass ball which rests on the upper side of a second brass plate also perforated with a conical hole, which plate is fixed on the bar o o crossing the box.
悬挂在摆锤顶部的是一个木制手臂w，上面有两个滑动指针h h，这些指针放置在摆锤顶部的玻璃板上。指针的作用是提供前面提到的摩擦阻力。如果这个摩擦板被熏黑，摩擦指针将在其上记录大地震的痕迹，这些记录独立于由正式指针记录的记录，正式指针只能在普通强度的震动情况下给出令人满意的记录。在摆锤内部r横穿有一个黄铜棒，在m处有一个小的圆锥形孔。通过m的有一根硬钢丝，形成了指针i的上部分，其下部分是薄的竹片。固定在钢丝上有一个小的黄铜球，球 resting在第二个同样有圆锥形孔的黄铜板上方，这个黄铜板固定在横穿盒子的o o杆上。

If at the time of an earthquake the upper part of the index i remains steady at m , then by the motion at o , the lower end of the index which carries a sliding needle at g , will magnify the motion of the earth in the ratios m o : o g . In this instrument o g is about 17 cm.
如果在地震时，指针的上部 i 保持在 m 处静止，那么由于 o 处的运动，带有滑动针 g 的指针下端将以 m o : o g 的比例放大地面的运动。在这个仪器中，o g 约为 17 厘米。

The needle g works upon a piece of smoked glass. In order to bring the glass into contact with the needle without disturbance, the glass is carried on a strip of wood k , hinged at the back of the box, and propped up in front by a loose block of wood y . When y is removed the glass drops down with k out of contact with the needle. The box is carried on bars of wood c c , which are fixed to the ground by the stakes a a .
针 g 作用于一块熏制过的玻璃上。为了在不受干扰的情况下使玻璃与针接触，玻璃安装在一条木条 k 上，木条的后端通过铰链固定在箱子的背面，前端由一块松动的木块 y 支撑。当移除 y 时，玻璃会随同 k 一起下落，与针脱离接触。箱子通过木条 c c 支撑在地上，并用木桩 a a 固定在地面上。

The great advantage of a pendulum seismograph working on a stationary plate is, that the record shows at once whether the direction of motion has been constant, or whether it has been variable. The maximum extent of motion in various directions is also easily obtained.
摆式地震仪在固定底板上工作的巨大优势在于，其记录能够立即显示运动方向是恒定的还是变化的。还可以很容易地获得各个方向上的最大运动幅度。

The disadvantage of the instrument is, that at the time of a large earthquake, owing perhaps to a slight swing in the pendulum, the records may be unduly magnified.
该仪器的缺点在于，当发生大地震时，也许由于摆动轻微而导致记录被不当地放大。

On such occasions, however, fairly good records may be obtained from the friction pointers, provided that the plates on which they work have been previously smoked. It might perhaps be well to use two of these instruments, one having a comparatively high frictional resistance, and hence 'dead beat' for large displacements.
在这种情况下，然而，通过摩擦指示器可能可以得到相当不错的记录，前提是它们工作的板子事先已经涂上了烟灰。也许最好使用两个这样的仪器，一个摩擦阻力相对较高，因此对大位移具有"减震"作用。

Many attempts have been made to use a pendulum seismograph in conjunction with a record-receiving surface, which at the time of the earthquake should be kept in motion by clockwork. In this way it was hoped to separate the various vibrations of the earthquake, and thus avoid the greater or less confusion which occurs when the index of the pendulum writes its backward and forward motion on a stationary plate. Hitherto all attempts in this direction, in which a single multiplying index was used, have been unsuccessful because of the moving plate dragging the index in the direction of its motion for a short distance, and then allowing it to fall back towards its normal position.
已经有很多尝试将摆式地震仪与记录接收表面结合使用，地震发生时，记录接收表面应该由发条保持运动。希望通过这种方式分离地震的各种振动，从而避免当摆索的指针在静止的平板上记录其前后运动时所出现的较大或较小混乱。迄今为止，在这个方向上的所有尝试，使用了单个放大指针，都因为移动的平板将指针沿着其运动方向拖动了一小段距离，然后让它回到其正常位置，而导致失败。

In connection with this subject we may mention the pendulum seismographs of Kreil, Wagener, Ewing, and Gray.
关于这个话题，我们可以提到 Kreil、Wagener、Ewing 和 Gray 的摆动地震仪。

In the bob of Kreil's pendulum there was clockwork, which caused a disc on the axis of the pendulum to continuously rotate. On this continually revolving surface a style fixed to the earth traced an unbroken circle. At the time of an earthquake, by the motion of the style, the circle was to be broken and lines drawn. The number and length of these lines were to indicate the length and intensity of the disturbance.
Kreil的摆的铅球里装有发条，这导致摆轴上的圆盘不断旋转。在这个不断旋转的表面上，与地球固定的样式描绘出一个完整的圆圈。在地震发生时，通过样式的运动，这个圆圈将会被打破并绘制出线条。这些线条的数量和长度将指示出震动的长度和强度。

Gray's pendulum consisted of a flat heavy disc carrying on its upper surface a smoked glass plate. This, which formed the bob of the pendulum, was supported by a pianoforte steel wire. When set ready to receive an earthquake, the wire was twisted and the bob held by a catch so arranged that at the time of the earthquake the catch was released, and the bob of the pendulum allowed to turn slowly by the untwisting of the supporting wire. Resting on the surface of this rotating disc were two multiplying indices arranged to write the earth's motions as two components.
格雷的摆由一个扁平而沉重的圆盘组成，其上表面装有一块烟熏玻璃板。这块板子形成了摆的重物，由一根钢琴线支撑着。当准备好接收地震时，这根线被扭曲，并且用一个装置将摆的重物固定住，这样在地震发生时，装置会释放，摆的重物就能够通过支撑线的解扭缠而缓慢转动。在这个旋转圆盘的表面上，放置着两个乘法指数，用来记录地球运动的两个分量。

In the instruments of Wagener and Ewing, the clockwork and moving surface do not form part of the pendulum, but rest independently on a support rigidly attached to the earth. In Wagener's instrument one index only is used, while in Ewing's two are used for writing the record of the motion.
在瓦格纳和尤因的仪器中，发条和移动表面不是钟摆的一部分，而是独立地放置在与地球刚性连接的支架上。在瓦格纳的仪器中，仅使用一个指标，而在尤因的仪器中，使用两个指标来记录运动的记录。

A difficulty which is apparent in all pendulum machines is that when the bob of such a pendulum is deflected it tends to fall back to its normal position. To make a pendulum perfect it therefore requires some compensating arrangement, so that the pendulum, for small displacements, shall be in neutral equilibrium, and the errors due to swinging shall be avoided.
所有摆锤机器都存在一个明显的困难，即当这样一个摆锤的重物被偏移时，它倾向于回到正常位置。因此，要使摆锤完美，就需要一些补偿安排，使得摆锤在小位移时处于中性平衡状态，并且避免摆动引起的误差。

Several methods have been suggested for making the bob of an ordinary pendulum astatic for small displacements. One method proposed by Gray consists in fixing in the bob of a pendulum a circular trough of liquid, the curvature of this trough having a proper form. Another method which was suggested, was to attach a vertical spiral spring to a point in the axis of the pendulum a little below the point of suspension, and to a fixed point above it, so that when the pendulum is deflected it would introduce a couple.
有几种方法被提出用于使普通摆锤在小偏移时保持无静摩擦状态。格雷提出的一种方法是在摆锤中固定一个液体的圆槽，这个槽的曲率有适当的形式。另一种方法是建议将一个垂直螺旋弹簧连接到离摆锤轴稍低于悬挂点的地方，并连接到上方的固定点，这样当摆锤偏转时就会引入一个力矩。

Professor Ewing has suggested an arrangement so that the bob of the pendulum shall be partly suspended by a stretched spiral spring, and at the same time shall be partly held up from below by a vertically placed strut, the weight carried by the strut being to the weight carried by the spring in the ratio of their respective lengths. As to how these arrangements will act when carried into practice yet remains to be seen.
尤因教授建议通过一种安排，使摆锤部分由拉伸的螺旋弹簧部分悬挂，并同时由垂直放置的支撑杆从下方部分支撑，支撑杆承载的重量与弹簧承载的重量之比为它们各自长度的比例。至于当这些安排实施时会产生怎样的作用，目前还有待观察。

Another important class of instruments are inverted pendulums . These are vertical springs made of metal or wood loaded at their upper end with a heavy mass of metal. An arrangement of this sort, provided at its upper end with a pencil to write on a concave surface, was employed in 1841 to register the earthquakes at Comrie in Scotland. In Japan they were largely employed in series, each member of a series having a different period of vibration. The object of these arrangements was to determine which of the pendulums, with a given earthquake, recorded the greatest motion, it being assumed that the one which was thrown into the most violent oscillation would be the one most nearly approximating with the period of the earthquake. The result of these experiments showed that it was usually those with a slow period of vibration which were the most disturbed.
另一个重要的仪器类别是倒置摆。这些是由金属或木材制成的垂直弹簧，在其上端装有一块重金属质量的装置。这种安排在其上端配备有一支铅笔以书写在凹曲表面上的器械，曾于1841年用于记录苏格兰康布里地区的地震。在日本，它们被大量使用成系列，每个系列成员具有不同的振动周期。这些安排的目的是确定哪个摆动，与给定的地震记录了最大的运动，假设被扔进最猛烈摆动的那个最接近地震周期。这些实验的结果显示，通常是振动周期慢的那些受到最大干扰。

Bracket Seismographs. A group of instruments of recent origin which have done good work, are the bracket seismographs. These instruments appear to have been independently invented by several investigators: the germ from which they originated probably being the well-known horizontal pendulum of Professor Zöllner. In Japan they were first employed by Professor W. S. Chaplin. Subsequently they were used by Professor Ewing and Mr. Gray. They consist essentially of a heavy weight supported at the extremity of a horizontal bracket which is free to turn on a vertical axis at its other end. When the frame carrying this axis is moved in any direction excepting parallel to the length of the gate-like bracket, the weight causes the bracket to turn round a line known as the instantaneous axis of the bracket corresponding to this motion of the fixed axis. Any point in this line may therefore be taken as a steady point for motions at right angles to the length of the supporting bracket. Two of these instruments placed at right angles to each other have to be employed in conjunction, and the motion of the ground is written down as two rectangular components. In Professor Ewing's form of the instrument, light prolongations of the brackets form indices which give magnified representations of the motion, and the weights are pivoted round a vertical axis through their centre.
支撑式地震仪。一组近期出现并取得良好成果的仪器是支撑式地震仪。这些仪器似乎是由几位研究者独立发明的：它们的发源地可能是著名的佐尔纳教授的水平摆。在日本，它们首先由查普林教授使用。随后，它们被尤因教授和格雷先生使用。它们基本上由一个沉重的重物支撑在一个水平支架的末端，该支架在其另一端可以绕垂直轴线自由转动。当携带此轴线的框架沿除了与支撑支架的长度平行的任何方向移动时，重物会使支架绕着被称为支架瞬时轴线的线旋转，该轴线对应于固定轴的运动。因此，该线上的任何点都可以作为支撑支架长度垂直方向运动的稳定点。必须同时使用两个相互垂直放置的这些仪器，并将地面的运动记录为两个矩形分量。在尤因教授的仪器形式中，支架的轻微延伸形成放大的表示运动的指标，而重物则围绕其中心的垂直轴旋转。

In the accompanying sketch b is a heavy weight pivoted at the end of a small bracket c a k , which bracket is free to turn on a knife-edge, k , above, and a pivot a , below, in the stand s . At the time of an earthquake b remains steady, and the index p , forming a continuation of the bracket, magnifies the motion of the stand, in the ratio of a c : c n .
在附图中，b 是一个沉重的重物，枢轴在一个小支架 c a k 的末端，该支架可自由转动在上方的刀口 k 上，并在下方的支架 s 中有一个枢轴 a。在地震时，b 保持稳定，指针 p 与支架连续，放大了支架的运动，比例为 a c：c n。

In an instrument called a double-bracket seismograph, invented by Mr. Gray, we have two brackets hinged to each other, and one of them to a fixed frame. The planes of the two brackets are placed at right angles, so as to give to a heavy mass supported at the end of the outer bracket two degrees of horizontal freedom.
在一种名为双支架地震仪的仪器中，由格雷先生发明，我们有两个支架相互铰接，其中一个连接到一个固定框架上。这两个支架的平面放置成直角，以便在外支架末端支撑的重物具有两个水平自由度。

In all bracket machines, especially those which carry a pivoted weight, it is doubtful whether the weight provides a truly steady point relatively to the plate on which the record is written for motion parallel to the direction of the arm.
在所有的括号机器中，特别是那些携带枢轴重物的机器中，是否重物提供了一个相对于记录所写的板上在与臂的运动方向平行的运动中确实稳定的点，这是值得怀疑的。

Parallel motion Instrument. A machine which writes its record as two components, and which promises great stability, is one suggested by Professor C. D. West. Like the bracket machines it consists of two similar parts placed at right angles to each other, and is as follows: A bar of iron a is suspended from both sides on pivots at c c by a system of light arms hinging with each other at the black dots, between the upper and lower parts of the rigid frame b c . The arms are of such a length that for small displacements parallel to the length of the bar, c c practically move in a straight line, and the bar is in neutral equilibrium. A light prolongation of the bar d works the upper end of the light index e , passing as a universal joint through the rigid support f . A second index e′ from the bar at right angles also passes through f . The multiplying ends of these indices are coupled together to write a resultant motion on a smoked glass plate s .
平行运动仪器。一种机器，它将其记录写成两个组成部分，并且承诺具有很高的稳定性，这是由C. D. West教授提出的一种建议。就像括弧机一样，它由放置在彼此垂直的两个相似部分组成，具体如下：一根铁杆a由轻型臂在c c处的两侧悬挂，这些臂在黑色点处相互铰接，位于刚性框架bc的上部和下部之间。这些臂的长度设计得足够长，使得对于沿着铁杆长度的小位移，cc几乎沿直线运动，并且铁杆处于中立平衡状态。铁杆的轻型延长部d操作着轻型指示器e的上端，它通过刚性支撑f作为万向节穿过。第二个指示器e′从与之垂直的铁杆上穿过f。这些指示器的乘法端被耦合在一起，以在烟化玻璃板s上写出结果运动。

Conical Pendulums. Another group of instruments which have also yielded valuable records are the conical pendulum seismographs. The idea of using the bob of a conical pendulum to give a steady point in an earthquake machine was first suggested and carried into practice by Mr. Gray. The seismograph as employed consists of a pair of conical pendulums hung in planes at right angles to each other. The bob of each of these pendulums is fixed a short distance from the end of a light lever, which forms the writing index, the short end resting as a strut against the side of a post fixed in the earth. The weight is carried by a thin wire or thread, the upper end of which is attached to a point vertically above the fixed end of the lever.
圆锥摆。另一组也提供了宝贵记录的仪器是圆锥摆地震仪。首次提出并付诸实践使用圆锥摆的摆球在地震模拟机中提供稳定点的想法是格雷先生。所使用的地震仪由一对悬挂在彼此垂直平面上的圆锥摆组成。这些摆球的每个吊球都固定在一个轻杠杆的末端附近一小段距离处，该杠杆形成书写指示器，短端作为支撑靠在固定在地球中的柱子一侧。重量由一根细线或丝线支撑，其上端固定在距离杠杆固定端垂直方向上的一个点上。

Rolling Spheres and Cylinders. After the conical pendulum seismographs, which claim several important advantages over the bracket machines, we come to a group of instruments known as rolling sphere seismographs. Here, again, we have a class of instruments for the various forms of which we are indebted to the ingenuity of Mr. Gray.
滚动球体和圆柱体。在圆锥摆式地震仪之后，后者声称比支架机器有几个重要优点，我们来到了一组被称为滚动球体地震仪的仪器。在这里，我们再次看到了一类仪器，对于它们的各种形式，我们要感谢格雷先生的聪明才智。

The general arrangement and principle of one of these instruments will be readily understood from the accompanying figure. s is a segment of a large sphere with a centre near c . Slightly below this centre a heavy weight b , which may be a lead ring, is pivoted. At the time of an earthquake c is steady, and the earth's motions are magnified by the pointer c a n in the proportion of c a : a n . The working of this pointer or index is similar to that of the pointer in the pendulum.
这些仪器之一的总体结构和原理可以从随附的图中很容易理解。s 是一个大球的一部分，其中心接近于 c。略低于这个中心处，有一个重物 b，可以是一个铅环，它被枢轴支撑着。在地震时，c 是稳定的，地球的运动通过指针 c a n 被放大，放大比例为 c a：a n。这个指针或指标的工作类似于摆钟中的指针。

Closely connected with the rolling sphere seismographs, are Gray's rolling cylinder seismographs.
与滚动球形地震仪密切相关的是格雷的滚动圆柱地震仪。

These are two cylinders resting on a surface plate with their axes at right angles to each other. Near to the highest point in each of these cylinders, this point remaining nearly steady when the surface plate is moved backwards and forwards, there is attached the end of a light index. These indices are again pivoted a short distance from their ends on axes connected with the surface plate. In order that the two indices may be brought parallel, one is cranked at the second pivot.
这是两个圆柱体，它们静置在一个表面平板上，它们的轴互相垂直。在每个圆柱体的最高点附近，当表面平板前后移动时，这一点保持几乎不变，连接着一个轻型指示器的末端。这些指示器再次在与表面平板连接的轴线上的末端附近短距离处枢轴。为了使这两个指示器可以平行，其中一个在第二个枢轴处弯曲。

Ball and Plate Seismograph. Another form of seismograph, which is closely related to the two forms of apparatus just described, is Verbeck's ball and plate seismograph. This consists of a surface plate resting on three hard spheres, which in turn rests upon a second surface plate. When the lower plate is moved, the upper one tends to remain at rest, and thus may be used as a steady mass to move an index.
球盘式地震仪。另一种地震仪，与刚刚描述的两种仪器密切相关，是Verbeck的球盘式地震仪。它由一个表面板放置在三个硬球上组成，这些球再放在第二个表面板上。当下面的板移动时，上面的板倾向于保持静止，因此可以用作稳定的质量来移动一个指示器。

The Principle of Perry and Ayrton. An instrument which is of interest from the scientific principle it involves is a seismograph suggested by Professors Perry and Ayrton, who propose to support a heavy ball on three springs, which shall be sufficiently stiff to have an exceedingly quick period of vibration. By means of pencils attached to the ball by levers, the motions of the ball are to be recorded on a moving band of paper. The result would be a record compounded of the small vibrations of the springs superimposed on the larger, slower, wave-like motions of the earthquake, and, knowing the former of these, the latter might be separated by analysis. Although our present knowledge of earthquake motion indicates that the analysis of such a record would often present us with insuperable difficulties, this instrument is worthy of notice on account of the novelty of the principle it involves, which, the authors truly remark, has in seismometry been a 'neglected' one.
佩里和艾尔顿原理。一种具有科学原理意义的仪器是由佩里教授和艾尔顿教授提出的一种地震仪，他们建议用三根弹簧支撑一个重球，这些弹簧应该足够坚硬，以具有极快的振动周期。通过连接在球上的杠杆上的铅笔，球的运动将被记录在一张移动的纸带上。结果将是由弹簧的小振动与较大、较慢的地震波形运动叠加而成的记录，通过分析可以分离出前者，从而得知后者。尽管我们目前对地震运动的认识表明，这样的记录的分析经常会给我们带来难以克服的困难，但这个仪器值得注意，因为它涉及的原理是新颖的，正如作者所指出的，在地震测量中一直是一个被"忽视"的原理。

Instruments to record Vertical Motion. The instruments which have been devised to record vertical motion are almost as numerous as those which have been devised to record horizontal motion. The earliest form of instrument employed for this purpose was a spiral spring stretched by weight, which, on account of its inertia, was supposed at the time of a shock to remain steady. No satisfactory results have ever been obtained from such instruments, chiefly on account of the inconvenience in making a spring sufficiently long to allow of enough elongation to give a long period of vibration. Similar remarks may be applied to the horizontally placed elastic rods, one end of which is fixed to a wall, whilst the opposite end is loaded with a weight. Such contrivances, furnished with pencil on the weight to write a record upon a vertical surface, were used in 1842 at Comrie, and we see the same principle applied in a portion of Palmieri's apparatus. Contrivances like these neither give us the true amplitude of the vertical motion, insomuch as they are readily set in a state of oscillation; nor do they indicate the duration of a disturbance, for, being once set in motion, they continue that motion in virtue of their inertia long after the actual earthquake has ceased. They can only be regarded as seismoscopes.
记录垂直运动的仪器。 用于记录垂直运动的仪器几乎和用于记录水平运动的仪器一样多。 最早用于此目的的仪器形式是由重物拉伸的螺旋弹簧，由于其惯性，据信在震动时保持稳定。 从这些仪器中从未获得过令人满意的结果，主要是因为要制造足够长的弹簧以允许足够的拉伸，以提供长时间的振动周期非常不方便。 类似的评论也适用于水平放置的弹性杆，其中一端固定在墙上，而另一端则装有重物。 这些装置配备有铅笔，用于在垂直表面上书写记录，1842年在康莱使用过，我们在Palmieri的装置的一部分中也看到了同样的原理应用。 这类装置既不能给出垂直运动的真实振幅，因为它们很容易被设置为振荡状态；也不能指示扰动的持续时间，因为一旦开始运动，它们会在实际地震结束后仍然依靠其惯性继续运动。 它们只能被视为地震示波器。

The most satisfactory instrument which has yet been devised for recording vertical motion is Gray's horizontal lever spring seismograph.
迄今为止，用于记录垂直运动的最令人满意的仪器是格雷的水平杠杆弹簧地震仪。

This instrument will be better understood from the accompanying sketch. A vertical spring s is fixed at its upper end by means of a nut n , which rests on the top of the frame f , and serves to raise or lower the spring through a short distance as a last adjustment for the position of the cross-arm a . The arm a rests at one end on two sharp points, p , one resting in a conical hole and the other in a v slot; it is supported at b by the spring s , and is weighted at c with a lead ring r . Over a pin at the point c a stirrup of thread is placed which supports a small trough, t . The trough t is pivoted at a , has attached to it the index i (which is hinged by means of a strip of tough paper at h , and rests through a fine pin on the glass plate g ), and is partly filled with mercury.
通过附带的草图可以更好地理解这一仪器。垂直弹簧s的上端通过螺母n固定，螺母n放置在框架f的顶部，并用来将弹簧稍微上下移动，以作为横臂a位置的最后调整。臂a的一端放在两个尖点p上，一个尖点放在锥形孔中，另一个尖点放在V形槽中；臂a在b处由弹簧s支撑，在c处用铅环r加重。在c点的销钉上放置了一根线环支架，它支撑着一个小槽t。槽t在a点有一个枢轴，附有指针i（通过一条坚韧的纸带在h处铰接，并通过一个细销钉固定在玻璃板g上），槽内部分充满了水银。

Another method of obtaining a steady point for vertical motion is that of Dr. Wagener, who employs a buoy partly immersed in a vessel of water. This was considerably improved upon by Mr. Gray, who suggested the use of a buoy, which, with the exception of a long thin style, was completely sunk.
另一种获得垂直运动稳定点的方法是由瓦格纳博士提出的，他使用部分浸入水容器中的浮标。格雷先生对此进行了相当大的改进，他建议使用一个浮标，除了一个长而细的部分外，其余部分全部沉入水中。

Among the other forms of apparatus used to record vertical motion may be mentioned vessels provided with india-rubber or other flexible bottoms, and partially filled with water or some other liquid. As the vessel is moved up and down, the bottom tends to remain behind and provides a more or less steady point. Pivoted to this is a light index, which is again pivoted to a rigid frame in connection with the earth. Instruments of this description have yielded good records.
在用于记录垂直运动的其他装置中，可以提到一种带有橡胶或其他柔性底部的容器，这些容器部分装满了水或其他液体。当容器上下移动时，底部倾向于保持原位，从而提供一个相对稳定的点。与此相连接的是一个轻质指针，该指针又与一个与地面相连的刚性框架铰接。这类仪器已经提供了良好的记录。

Record Receivers. A large number of earthquake machines having been referred to, it now remains to consider the apparatus on which they write their motions. The earlier forms of seismographs, as has already been indicated, recorded their movements in a bed of sand; others wrote their records by means of pencils on sheets of paper. Where we have seismographs which magnify the motion of the earth, it will be observed that methods like the above would involve great frictional resistances, tending to cause motion in the assumed steady points of the seismographs. One of the most perfect instruments would be obtained by registering photographically the motions of the recording index by the reflection of a ray of light. Such an instrument would, however, be difficult to construct and difficult to manipulate. One of the best practical forms of registering apparatus is one in which the record is written on a surface of smoked glass. This can afterwards be covered with a coat of photographer's varnish, and subsequently photographed by the 'blue process' so well known to engineers.
记录接收器。已经提到过许多地震仪，现在需要考虑记录其运动的装置。早期形式的地震仪，如前所述，在沙床上记录它们的运动；其他则用铅笔在纸张上记录它们的运动。当我们有放大地球运动的地震仪时，可以观察到上述方法会涉及很大的摩擦阻力，导致地震仪假定的稳定点产生运动。其中一种最完美的仪器是通过光线反射将记录指针的运动以摄影方式记录下来。然而，这样的仪器难以制造且难以操作。最实用的记录装置之一是在烟熏玻璃表面上书写记录。之后可以覆盖一层摄影师用的清漆，然后通过工程师熟知的"蓝图法"进行摄影。

To obtain a record of all the vibrations of an earthquake it is necessary that the surface on which the seismograph writes should at the time of an earthquake be in motion. Of record-receiving machines there are three types. First, there are those which move continuously. The common form of these is a circular glass plate like an old form of chronograph, driven continuously by clockwork. On this the pointers of the seismograph rest and trace over and over again the same circles. At the time of an earthquake they move back and forth across the circles, which are theoretically fine lines, and leave a record of the earthquake. Instead of a circular plate, a drum covered with smoked paper may be used, which, after the earthquake, possesses the advantage, after unrolling, of presenting the record in a straight line, instead of a record written round the periphery of a circle, as is the case with the circular glass plates. Such records are easily preserved, but they are more difficult to photograph.
要获取地震的所有振动记录，必须确保地震仪书写的表面在地震发生时处于运动状态。记录接收设备有三种类型。首先是连续运动的类型。常见形式是一块圆形玻璃板，类似于旧式计时器，通过发条持续驱动。在这块玻璃板上，地震仪的指针不断地在相同的圆周上描绘。地震发生时，指针来回移动，穿过这些理论上是细线的圆周，留下地震的记录。除了圆形玻璃板外，还可以使用覆盖烟纸的鼓，这种鼓在地震后展开时，记录呈直线，而不是像圆形玻璃板那样记录在圆周上。这类记录容易保存，但较难拍照。

The second form of apparatus is one which is set in motion at the time of a shock. This may be a contrivance like one of those just described, or a straight smoked glass plate on a carriage. By means of an electrical or a mechanical contrivance called a 'starter,' of which many forms have been contrived, the earthquake is caused to release a detent and thus set in motion the mechanism which moves the record receiver.
第二种仪器是在震动时启动的装置。这可以是类似前面描述的装置，或者是一块安装在滑架上的直线烟熏玻璃板。通过一种称为"启动器"的电气或机械装置（已有许多形式被设计出来），地震会释放一个止动装置，从而启动移动记录接收器的机制。

The great advantage of continuously-moving machines is that the beginning and end of the shock can usually be got with certainty, while all the uncertainty as to the action of the 'starter' is avoided. Self-starting machines have, of course, the advantage of simplicity and cheapness, while there is no danger of the record getting obliterated by the subsequent motion of the plate under the index.
连续运动机器的一个巨大优势是通常可以确定地获取冲击的开始和结束，同时避免了"启动器"作用的不确定性。当然，自启动机器具有简单和廉价的优点，同时也不存在由于指针下的记录板后续运动而导致记录被抹去的危险。

Time-recording Apparatus. Of equal importance with the instruments which record the motion of the ground, are those instruments which record the time at which such motion took place. The great value of time records, when determining the origin from which an earthquake originates, will be shown farther on. The most important result which is required in connection with time observations, is to determine the interval of time taken by a disturbance in travelling from one point to another. On account of the great velocity with which these disturbances sometimes travel, it is necessary that these observations should be made with considerable accuracy. The old methods of adapting an apparatus to a clock which, when shaken, shall cause the clock to stop, are of little value unless the stations at which the observations are made are at considerable distances apart. This will be appreciated when we remember that the disturbance may possibly travel at the rate of a mile per second, that its duration at any station may often extend over a minute, and that one set of apparatus at one station may stop, perhaps, at the commencement of the disturbance, and the other near the end. A satisfactory time-taking apparatus will therefore require, not only the means for stopping a clock, but also a contrivance which, at the same instant that the clock is stopped, shall make a mark on a record which is being drawn by a seismograph. In this way we find out at which portion of the shock the time was taken.
记录时间的设备。与记录地面运动的仪器同样重要的是那些记录运动发生时间的仪器。当确定地震的起源时，时间记录的巨大价值将在后面展示。与时间观测相关的最重要的结果是确定扰动从一个点传到另一个点所花费的时间间隔。由于这些扰动有时以极快的速度传播，因此需要非常精确地进行这些观测。旧的方法是将一个装置连接到一个钟表上，当受到震动时，使钟表停止运转，除非观测站之间距离相当远，否则这种方法价值不大。这一点可以通过回想扰动可能以每秒一英里的速度传播，它在任何一个站点的持续时间可能经常超过一分钟，而一个站点的设备可能在扰动开始时停止，另一个则在扰动结束时停止来理解。因此，满意的时间记录设备不仅需要能够停止钟表的装置，还需要一种装置，在停止钟表的同时，在地震仪记录的图表上做一个标记。这样，我们就能知道在震动的哪个部分记录了时间。

Palmieri stops a clock in his seismograph by closing an electric circuit. Mallet proposes to stop a clock by the falling of a column which is attached by a string to the pendulum of the clock. So long as the column is standing the string is loose and the pendulum is free to move; but when the column falls, the string is tightened and the pendulum is arrested. The difficulty which arises is to obtain a column that will fall with a slight disturbance. The best form of contrivance for causing a column to fall, and one which may also be used in drawing out a catch to relieve the machinery of a record receiver, is shown in the accompanying sketch.
帕尔米埃里通过关闭一个电路来停止地震仪上的时钟。马莱特提出通过一根绳子与时钟摆相连的柱子的倒塌来停止时钟。只要柱子站立，绳子就是松的，摆可以自由摆动；但当柱子倒塌时，绳子就会拉紧，摆就会停止。出现的困难是获得一个会因轻微干扰而倒塌的柱子。用于使柱子倒塌的最佳装置形式，也可以用于拉出一个挡板以减轻记录接收器的机械压力，如附图所示。

s is the segment of a sphere about 4·5 cm. radius, with a centre slightly above c . l is a disc of lead about 7 cm. in diameter resting upon the segment. Above this there is a light pointer, p , about 30 cm. long. On the top of the pointer a small cylinder of iron, w , is balanced, and connected by a string with the catch to be relieved. When the table on which w p s rests is shaken, rotation takes place near to c , the motion of the base s is magnified at the upper end of the pointer, and the weight overturned. This catch may be used to relieve a toothed bar axled at one end, and held up above a pin projecting from the face of the pendulum bob. When this falls it catches the projecting pin and holds the pendulum.
s是一个半径约为4.5厘米的球段，其中心略高于c。l是一个直径约为7厘米的铅盘，放置在球段上方。在其上方有一个长约30厘米的轻指针p。在指针顶部平衡着一个小铁圆柱w，并通过绳子与待解除的挂钩相连。当放置wps的桌子被震动时，近似于c处发生旋转，基础s的运动在指针的上端被放大，并使重物翻倒。这个挂钩可以用来释放一个齿条，其一端轴承在上面，上面有一个突出的销从摆锤球体的面上突出。当这个齿条下降时，它会抓住突出的销并固定摆锤。

Another way of relieving the toothed bar is to hold up the opposite end to that at which it is axled by resting it on the extremity of a horizontal wire fixed to the bob of a conical pendulum--for example, one of the indices of a conical pendulum seismograph. The whole of this apparatus, which may be constructed at the cost of a few pence, can be made small enough to go inside an ordinary clock case.
缓解齿条的另一种方法是将其反方向端口托举起来，使其轴心处于悬挂在圆锥摆的重锤上的水平线的末端上----例如，悬挂在圆锥摆地震仪的一个标尺上。整个装置可以用几便士的成本制造，大小足够小以适应普通的钟表箱内。

The difficulty which arises with all these clock-stopping arrangements is that it is difficult for observers situated at distant stations to re-start their clocks so that their difference in time shall be accurately known. Even if each observer is provided with a well-regulated chronometer, with which he can make comparisons, the rating of these instruments is for all ordinary persons an extremely troublesome operation.
所有这些停钟安排所产生的困难在于，远处站点的观察者很难重新启动他们的时钟，以便他们的时间差能够准确地知道。即使每个观察者都配备了一个精确调校的计时器，他们可以用它进行比较，这些仪器的评定对于所有普通人来说都是一项极其麻烦的操作。

In order to avoid this difficulty the author has of late years used a method of obtaining the time without stopping the clock. To do this a clock with a central seconds hand is taken, and the hour and minute hands are prolonged and bent out slightly at their extremities at right angles to the face, the hour hand being slightly the longest. Each hand is then tipped with a piece of soft material like cork, which is smeared with a glycerine ink. A light flat ring, with divisions in it corresponding to those on the face of the clock, is so arranged that at the time of a shock it can be quickly advanced to touch the inked pads on the hands of the clock and then withdrawn. This is accomplished by suitable machinery, which is relieved either by an electro-magnet or some other contrivance which will withdraw a catch. In this way an impression in the form of three dots is received on the disc, and the time known without either stopping or sensibly retarding the clock.
为了避免这种困难，作者近年来采用了一种获取时间的方法，而无需停止时钟。为此，采用一台带有中心秒针的时钟，并将时针和分针延长并稍微弯曲，使其在面部的末端呈直角，其中时针略长一些。然后，每个指针的末端都涂抹了一块软材料，如软木，其涂抹了一层甘油墨水。一个轻巧的扁平环，上面划分有与时钟面相对应的刻度，安排在这样一个位置，即在发生冲击时，可以快速前进以触摸时钟指针上的墨水垫，然后撤回。这是通过适当的机械装置完成的，该装置通过电磁铁或其他装置来释放，以撤回抓取物。这样，可以在盘上得到三个点的形式的印记，并且知道时间，而无需停止或明显减慢时钟。

For ordinary observers, if a time-taker is not used in conjunction with a record receiver, as good results as those obtained by ordinary clock-stopping apparatus are obtainable by glancing at an ordinary watch. Subsequently the watch by which the observation was made should be compared with some good time-keeper, and the local time at which the shock took place is then approximately known.
对于普通观察者来说，如果不使用时间记录器与记录接收器结合使用，通过瞥一眼普通手表也可以获得与普通停钟设备获得的同样好的结果。随后，应该将观察所用的手表与一些良好的时间记录器进行比较，然后大致知道发生冲击的当地时间。

From what has now been said it will be seen that for a complete seismograph we require three distinct sets of apparatus--an apparatus to record horizontal motion, an apparatus to record vertical motion, and an apparatus to record time. The horizontal and vertical motions must be written on the same receiver, and if possible side by side, whilst the instant at which the time record is made a mark must be made on the edge of the diagram which is being drawn by the seismograph. Such a seismograph has been constructed and is now erected in Japan. It is illustrated in the accompanying diagram.
从现在所说的内容可以看出，对于完整的地震仪，我们需要三套不同的设备--一套记录水平运动的设备，一套记录垂直运动的设备，以及一套记录时间的设备。水平和垂直运动必须写在同一个记录器上，并且如果可能的话，应该并列在一起，同时，时间记录被制作的瞬间必须在由地震仪绘制的图表边缘上做一个标记。这样的地震仪已经被制造出来，并且现在已经在日本建立起来。它在附图中有所示。

The Gray and Milne Seismograph. In this apparatus two mutually rectangular components of the horizontal motion of the earth are recorded on a sheet of smoked paper wound round a drum, d , kept continuously in motion by clockwork, w , by means of two conical pendulum seismographs, c . The vertical motion is recorded on the same sheet of paper by means of a compensated-spring seismograph, s l m b .
格雷和米尔恩地震仪。在这个装置中，地球的水平运动的两个互相垂直的分量被记录在一张环绕在一个由钟表机构保持连续运动的滚筒 d 上的烟熏纸上，通过两个圆锥摆地震仪 c 。垂直运动则通过一个补偿弹簧地震仪 s l m b 在同一张纸上记录。

The time of occurrence of an earthquake is determined by causing the circuit of two electro-magnets to be closed by the shaking. One of these magnets relieves a mechanism, forming part of a time-keeper, which causes the dial of the timepiece to come suddenly forwards on the hands and then move back to its original position. The hands are provided with ink-pads, which mark their positions on the dial, thus indicating the hour, minute, and second when the circuit was closed. The second electro-magnet causes a pointer to make a mark on the paper receiving the record of the motion. This mark indicates the part of the earthquake at which the circuit was closed.
地震发生的时间是通过使两个电磁铁的电路闭合而确定的。其中一个磁铁释放了一个机制，该机制是时间记录器的一部分，它导致时钟的钟盘突然前进并然后移回原来的位置。指针上装有墨盒，它们在钟盘上标记它们的位置，从而指示电路闭合时的小时、分钟和秒。第二个电磁铁导致指针在接收运动记录的纸上做出标记。这个标记指示了电路闭合时地震的部分。

The duration of the earthquake is estimated from the length of the record on the smoked paper and the rate of motion of the drum. The nature and period of the different movements are obtained from the curves drawn on the paper.
地震的持续时间是根据烟熏纸上的记录长度和滚筒运动的速度来估计的。从纸上绘制的曲线可以得到不同运动的性质和周期。

Mr. Gray has since greatly modified this apparatus, notably by the introduction of a band of paper sufficiently long to take a record for twenty-four hours without repetition. The record is written in ink by means of fine siphons. In this way the instrument, which is extremely sensitive to change of level, can be made to show not only earthquakes, but the pulsations of long period which have recently occupied so much attention.
格雷先生后来对这个装置进行了很大修改，特别是引入了一条足够长的纸带，可以在不重复的情况下记录二十四小时的数据。记录是通过细小的虹吸管用墨水写成的。通过这种方式，这个对水平变化非常敏感的仪器不仅可以显示地震，还可以显示最近受到了很多关注的长周期的脉动。

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