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Milne, John . Earthquakes and Other Earth Movements

在約翰·米爾恩（John Milne）的《地震與其他地球運動》一書中，讀者將得到對地震和其他地質事件現象的全面和詳盡的探索。米爾恩的書深入探討了這些自然事件背後的科學解釋和機制，以清晰簡潔的方式呈現了大量資訊。這本書以學術但易於理解的風格撰寫，將經驗數據與理論分析相結合，使其成為地質愛好者和研究人員的寶貴資源。米爾恩的工作置於19世紀科學話語的背景之中，為早期地震學和板塊構造研究提供了見解。這部經典著作至今仍然具有重要意義，為地質學領域的現代研究奠定了基礎。約翰·米爾恩是一位著名的地質學家和地震學家，以其對地震研究的開創性貢獻而聞名。他對這一主題的專業知識和熱情在《地震與其他地球運動》中得以體現，使其成為該領域的重要著作。我強烈推薦這本書給所有對地球動態地質過程和塑造我們星球的力量感興趣的人。

CHAPTER II. SEISMOMETRY 第二章 地震儀

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.

地震振動的性質----許多被稱為地震儀的儀器實際上只是地震示波器----東方的地震示波器、柱體、投影地震儀----裝滿液體的容器----帕爾米耶里的水銀管----船用地震示波器----卡恰托雷地震儀----克雷爾、華格納、尤因和格雷的擺動儀器----支架地震儀----韋斯特的平行運動儀器----格雷的錐形擺、滾動球和圓柱體----弗貝克的球板地震儀----佩里和艾爾頓的原理----垂直運動儀器----記錄接收器----時間記錄裝置----格雷和米爾恩的地震儀。

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.

在討論地震運動的性質之前，現代地震學研究的目標就是確定這一性質。讀者自然會希望了解記錄這種擾動的各種儀器。如果要描述即使是僅在日本使用的地震儀器，可能需要一本厚重的書。因此，我們只能簡要描述一些較重要儀器的主要特點。為了更好地理解這些儀器的相對優劣，我們可以大致說明，現代研究表明，典型的地震由一系列小震動組成，隨後是一次或一系列衝擊，再接著是或多或少不規則的地面振動。這些振動的周期和幅度通常都不規則，持續時間從幾秒鐘到幾分鐘不等。我們將在以後的章節中展示實際地震的記錄，但與此同時，必須摒棄地震只由一次衝擊組成的觀念。

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 .

要構造一種在地震時能夠移動並記錄其運動的儀器，難度並不大。這類裝置稱為地震示波器。然而，如果我們希望知道構成地震的每次振動的周期、幅度和方向，則面臨相當大的困難。能夠以這種方式測量或記錄地球運動的儀器稱為地震儀或地震計。

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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.

許多配有電磁裝置和鐘錶裝置的精密儀器，當我們仔細檢查時，會發現它們其實只是被誤稱為地震儀的複雜地震示波器。
目前所發明的唯一接近真正地震儀的儀器，毫無疑問，是近幾年在日本使用的那些。然而，將不同的儀器分類為地震示波器、地震計和地震儀是有些武斷的，因為某些儀器所提供的記錄有時只是地震示波性的，而在其他時候則是地震計性的，取決於擾動的性質。例如，許多儀器可以相當準確地記錄單次突發運動，但對持續震動卻無法提供可靠的資訊。

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:--

東方地震示波器
有歷史記錄的最早地震示波器源於一位名叫張衡的中國人。它發明於公元136年。在中國的歷史書《後漢書》中有對該裝置的描述，其翻譯內容如下：

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），一位名叫張衡的中國人發明了地震儀，其示意圖如附圖所示。該儀器由一個直徑八尺的球形銅器組成，頂部覆蓋，形狀類似酒瓶。外部裝飾有各種鳥獸圖案和古怪的文字。在儀器內部，有一根可以向八個方向移動的柱子。瓶內還有一種裝置，可以根據柱子的移動記錄地震。在瓶子的外側有八個龍頭，每個龍頭嘴裡含著一個球。在這些龍頭下方有八隻青蛙，呈現出仰望龍頭的姿態，隨時準備接住掉落的球。使柱子撞擊龍嘴中球的所有裝置都巧妙地隱藏在瓶子內部。

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.

當地震發生時，瓶子受到震動，龍頭立即掉下球，接住球的青蛙會劇烈振動。觀察這個儀器的人可以很容易地察覺到地震的發生。

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.

通過這種裝置，雖然一個龍頭可能會掉下一個球，但如果運動並非來自所有方向，其他七個龍頭就不會掉球。這樣我們就能輕鬆判斷地震的方向。

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，一個龍頭掉下了球，但當時沒有觀察到地震，因此人們認為這個儀器沒什麼用。然而，兩三天後，收到了一則消息，說洛陽發生了地震。聽到這個消息，那些懷疑這個儀器作用的人又重新開始相信它了。自從張衡發明了這個巧妙的儀器後，中國政府明智地任命了一位秘書來專門觀察地震。

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.
這個儀器不僅因其古老而引人注目，還因為它與許多現代儀器有著驚人的相似之處。另一種同樣起源於東方的地震儀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年那次毀滅性地震的夜晚，這場地震摧毀了東京的大片區域。當時，淺草區一家眼鏡店的店主觀察到，一塊磁鐵掉下了幾枚原本吸附在其上的舊鐵釘和鑰匙。由於這一現象，店主認為磁鐵由於年代久遠，失去了磁力。然而，大約兩小時後，發生了那場大地震，隨後發現磁鐵又恢復了磁力。這一現象引發了地震儀的構思，這種儀器在一本名為《安政見聞錄》的書中有所描述，該書記錄了1855年地震的情況，目前在東京仍能看到這種儀器的實例。

這些儀器由一塊磁性鐵礦石組成，鐵礦石上吸附著類似釘子的一塊鐵片。鐵片通過一根繩子連接到一個時鐘機構，並與一個報警器相連。如果鐵片掉下，卡扣會被釋放，時鐘機構開始運轉，鈴聲響起以發出警報。然而，似乎這種儀器從未成功地發揮過作用。

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。地震儀的一種常見形式，並且被廣泛使用，由一個圓柱體組成，可以是木製、金屬或其他合適的材料，垂直放置在一個水平面上，並被鬆散的沙子等軟材料包圍，以防它被推倒後滾動。這樣一個柱子的倒下表明發生了震動或衝擊。有人嘗試使用不同尺寸的多個柱子來使這些指示具有地震測量意義，但它們很少能提供關於震動強度或方向的可靠資訊。關於強度的指示因以下事實而失真：長時間的輕微震動可能會推倒一個能夠承受相當大突發衝擊的柱子，而多個柱子倒下的方向往往不一致，因為震動會對它們產生旋轉運動。此外，地震的運動方向在整個擾動過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.
一種極其敏感且同時簡單的地震儀形式，可以通過將玻璃條、針或其他容易被推倒的物體靠在適當放置的支撐物上來製作。通過這種方式，可以安排這些物體，儘管它們只能朝一個方向倒下，但其倒下所需的運動遠遠小於推倒任何能夠在沒有橫向支撐下站立的柱子所需的運動。

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.
投影地震儀。與依靠物體傾覆的地震儀和地震計密切相關。馬萊特描述了兩套儀器，它們的指示取決於物體投射的距離。其中一套由兩個相似的部分組成，按直角排列，兩顆金屬球分別位於兩個類似槽道下部的止擋兩側。在這個位置，每個球都完成了一個電路。通過震動，球被投射或滾上槽道，其上升的高度通過電路斷開的相應間隔記錄下來。運動的垂直分量通過壓縮支撐此裝置的台子上的彈簧來測量。

第二套儀器中，兩個球被依次投射，一個由震動的前擺投射，另一個由後擺投射。它們附著著形成電路端子的鬆散電線。球落入金屬槽道內的濕沙床中，形成電路的另一端。通過測量球在沙中的投擲距離，以及通過與電路閉合相關的特殊裝置顯示的連續投射時間差，觀察者可以計算出震波的方向、速度及其他擾動相關的元素。需要注意的是，這套儀器的設計假定地震由一個獨立的單一震動組成。

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年卡查地震的報告結尾，奧德姆建議使用一種基於類似原理的儀器。在他的儀器中，四個類似子彈的球被放置在插入地面的方形樁上端角落的凹槽中。

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]
液體容器。另一種簡單的地震儀形式是部分填充液體的容器。液體沿容器壁上升的高度被視為震動強度的指示，而連接最大運動指示點的線被視為震動的方向。如果所有地震的持續時間相同，且由相同周期的振動組成，這種儀器可能會有用。然而，這類儀器從很早就開始使用。1742年，人們發現用盛水的碗來測量當年使利沃諾居民感到恐慌的地震。同一時期，牧師S. Chandler在寫到里斯本的地震時告訴我們，可以用一個直徑約三到四英尺的球形碗來測量地震，其內部在撒上粉塵後，輕輕地裝滿水。馬萊特、巴貝奇和德拉比克也推薦過同樣的裝置，但儘管如此，這種裝置被公正地批評為"荒謬且完全不切實際"。

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.
帕爾米耶里著名儀器的一個重要部分由水平管組成，這些管的兩端向上彎曲，並部分填充汞。為了放大汞的運動，鐵制的小浮子放在汞的表面。通過線將這些浮子連接到帶有指示器的滑輪上，指示器在一個刻度盤前移動。我們由此可以讀取地震的強度，以度數表示，這意味著管內汞上下運動的毫米數。運動方向由給出最大指示的管的方位角決定，多個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.
這種儀器形式似乎是由馬萊特提出的，他在1846年對其進行了描述。由於這種管中的汞的升降取決於其深度、地震的周期及其持續時間，我們可以看到，儘管從特定儀器獲得的結果可以為我們提供對不同地震相對強度的近似比較手段，但它遠遠不能提供任何絕對的測量。

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.
另一種用於放大和記錄容器內液體運動的方法是將一艘木筏或船漂浮在液體表面，從船上豎起一根高高的桅杆。由於木筏的微小運動，桅杆頂端會在相當大的範圍內振動。然後，通過安裝在桅杆頂端的合適裝置記錄下桅杆的運動方向和幅度。

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.
一種非常簡單的液體地震儀由一個木製的圓形槽組成，槽的邊緣開有凹口。槽內裝滿水銀至凹口的高度。當地震發生時，最大量的水銀會沿著震動最大的方向溢出凹口。這種儀器在義大利已經使用很久了，被稱為Cacciatore，以其發明者的名字命名。它是組成著名的Palmieri地震儀設備集合中的一個重要特點。

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.
擺儀器。Mallet提到擺地震儀和地震記錄儀是"可能最古老的地震測量儀器，早在義大利和南歐就已經設置。"1841年，我們發現這些儀器被用來記錄蘇格蘭Comrie的地震擾動。

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.'
這些儀器可以分為兩類：第一類是在震動時擺動，從而記錄運動方向的儀器；第二類是旨在保持靜止，從而提供"穩定點"的儀器。

To obtain an absolutely 'steady point' at the time of an earthquake, has been one of the chief aims of all recent seismological investigations.
在地震發生時獲得一個絕對的"穩定點"一直是所有近期地震學研究的主要目標之一。

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.
在地震發生時，為了獲得一個絕對的"穩定點"，可以在這個穩定點上伸出一個指針，指向一個由地球前後移動的表面。通過表面自身的運動，它會記錄其所附著的地面的運動。反之，從移動的地面向上伸出的指針可以在提供穩定點的裝置上記錄運動，這類儀器中的穩定點通常是擺錘的球體。在中等強度地震時，讓擺錘擺動並不難，但要獲得一個在這樣的時間不會擺動的擺錘卻相當困難。

近年來，長度在四十英尺、重量為八十磅的擺錘，以及長度為八分之一英寸、重如槍彈的小擺錘，在各種情況下都進行了實驗。有時，這些擺錘的支撐結構儘可能地用磚和灰泥建造得非常堅固，而有時它們被故意做得鬆散且靈活。記錄這些擺錘運動的指針形狀和種類與擺錘本身一樣多樣化。其中，一種較受歡迎的記錄指針形式是一個小針，通過兩個小孔垂直滑動，其下端 resting 在一塊煙燻玻璃表面上，因其摩擦力極小而廣受青睞。

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.
自由擺錘的使用有兩個目的：首先，通過擺動的方向確定運動的方向；其次，通過在一系列不同長度的擺錘中找出擺動最劇烈的一個，來估算地球運動的周期。擺動最劇烈的那個擺錘可能是其自然擺動周期最接近地震振蕩周期的擺錘。

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.
由於所有鐘擺在擺動時都有改變其振蕩平面的趨勢，並且我們現在知道地震期間的運動方向並不總是恆定的，因此通常用這些儀器得到的關於地球運動方向的結果是不令人滿意的。由於各種原因，通過一系列不同長度的鐘擺獲得的結果也同樣不令人滿意。

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.
關於用來提供穩定點的鐘擺，這些穩定點可以記錄地球表面上某點的相對運動，鐘擺的形式有很多種。其中最古老的形式之一是鐘擺的擺錘向下伸出一個筆尖，使其觸及一層沙子。有時，在鐘擺下方放置一個凹面，通過鉛筆在其上追蹤記錄。可能最好的形式是使用一個能夠自由上下滑動的針，在煙燻玻璃板上標記地球與鐘擺擺錘之間的相對水平運動。

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，在中等強度的地震發生時，這些儀器的所有部分都會被啟動，部分原因是鐘擺支點的運動，部分原因是書寫點在板上的摩擦力。

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.
這些鐘擺中可以提到Cavallieri、Faura、Palmieri、Rossi及眾多其他人的鐘擺。可能某些鐘擺的發明者本來意圖讓它們通過擺動來記錄。如果是這樣，那麼在確定地震運動的實際性質方面，它們屬於低於本文所提及設備的一個等級。

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.
鐘擺裝置的一個重大改進歸功于格拉斯哥的托馬斯·格雷先生，他建議對鐘擺的自由擺動施加大量的摩擦阻力，使其在小幅度擺動時變得"停止擺動"。通過實施這一建議，鐘擺儀器被提升到地震儀的水平。以下是對一種鐘擺儀器的描述，這種儀器還配備了一個指示器，可以放大地球的運動，以便更好地理解摩擦的應用方式。

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 是一個高113厘米，底部為30厘米乘18厘米的長方形箱子。在這個箱子內部，有一個直徑17厘米、厚度3厘米的鉛環 r ，作為鐘擺懸掛在螺絲 s 上。螺絲穿過一個小的黃銅板 p p ，這個黃銅板可以在箱子頂部的一個孔上水平移動。通過調整懸掛點的這些運動，可以調整鐘擺。

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.
懸掛在擺錘頂部的是一個木製手臂w，上面有兩個滑動指針h h，這些指針放置在擺錘頂部的玻璃板上。指針的作用是提供前面提到的摩擦阻力。如果這個摩擦板被燻黑，摩擦指針將在其上記錄大地震的痕跡，這些記錄獨立於由正式指針記錄的記錄，正式指針只能在普通強度的震動情況下給出令人滿意的記錄。在擺錘內部r橫穿有一個黃銅棒，在m處有一個小的圓錐形孔。通過m的有一根硬鋼絲，形成了指針i的上部分，其下部分是薄的竹片。固定在鋼絲上有一個小的黃銅球，球 resting在第二個同樣有圓錐形孔的黃銅板上方，這個黃銅板固定在橫穿盒子的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.
如果在地震時，指針的上部 i 保持在 m 處靜止，那麼由於 o 處的運動，帶有滑動針 g 的指針下端將以 m o : o g 的比例放大地面的運動。在這個儀器中，o g 約為 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 .
針 g 作用於一塊熏制過的玻璃上。為了在不受干擾的情況下使玻璃與針接觸，玻璃安裝在一條木條 k 上，木條的後端通過鉸鏈固定在箱子的背面，前端由一塊鬆動的木塊 y 支撐。當移除 y 時，玻璃會隨同 k 一起下落，與針脫離接觸。箱子通過木條 c c 支撐在地上，並用木樁 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.
擺式地震儀在固定底板上工作的巨大優勢在於，其記錄能夠立即顯示運動方向是恆定的還是變化的。還可以很容易地獲得各個方向上的最大運動幅度。

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.
該儀器的缺點在於，當發生大地震時，也許由於擺動輕微而導致記錄被不當地放大。

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.
在這種情況下，然而，通過摩擦指示器可能可以得到相當不錯的記錄，前提是它們工作的板子事先已經塗上了菸灰。也許最好使用兩個這樣的儀器，一個摩擦阻力相對較高，因此對大位移具有"減震"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.
已經有很多嘗試將擺式地震儀與記錄接收表面結合使用，地震發生時，記錄接收表面應該由發條保持運動。希望通過這種方式分離地震的各種振動，從而避免當擺索的指針在靜止的平板上記錄其前後運動時所出現的較大或較小混亂。迄今為止，在這個方向上的所有嘗試，使用了單個放大指針，都因為移動的平板將指針沿著其運動方向拖動了一小段距離，然後讓它回到其正常位置，而導致失敗。

In connection with this subject we may mention the pendulum seismographs of Kreil, Wagener, Ewing, and Gray.
關於這個話題，我們可以提到 Kreil、Wagener、Ewing 和 Gray 的擺動地震儀。

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的擺的鉛球里裝有發條，這導致擺軸上的圓盤不斷旋轉。在這個不斷旋轉的表面上，與地球固定的樣式描繪出一個完整的圓圈。在地震發生時，通過樣式的運動，這個圓圈將會被打破並繪製出線條。這些線條的數量和長度將指示出震動的長度和強度。

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.
格雷的擺由一個扁平而沉重的圓盤組成，其上表面裝有一塊煙燻玻璃板。這塊板子形成了擺的重物，由一根鋼琴線支撐著。當準備好接收地震時，這根線被扭曲，並且用一個裝置將擺的重物固定住，這樣在地震發生時，裝置會釋放，擺的重物就能夠通過支撐線的解扭纏而緩慢轉動。在這個旋轉圓盤的表面上，放置著兩個乘法指數，用來記錄地球運動的兩個分量。

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.
在華格納和尤因的儀器中，發條和移動表面不是鐘擺的一部分，而是獨立地放置在與地球剛性連接的支架上。在華格納的儀器中，僅使用一個指標，而在尤因的儀器中，使用兩個指標來記錄運動的記錄。

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.
所有擺錘機器都存在一個明顯的困難，即當這樣一個擺錘的重物被偏移時，它傾向於回到正常位置。因此，要使擺錘完美，就需要一些補償安排，使得擺錘在小位移時處於中性平衡狀態，並且避免擺動引起的誤差。

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.
有幾種方法被提出用於使普通擺錘在小偏移時保持無靜摩擦狀態。格雷提出的一種方法是在擺錘中固定一個液體的圓槽，這個槽的曲率有適當的形式。另一種方法是建議將一個垂直螺旋彈簧連接到離擺錘軸稍低於懸掛點的地方，並連接到上方的固定點，這樣當擺錘偏轉時就會引入一個力矩。

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.
尤因教授建議通過一種安排，使擺錘部分由拉伸的螺旋彈簧部分懸掛，並同時由垂直放置的支撐杆從下方部分支撐，支撐杆承載的重量與彈簧承載的重量之比為它們各自長度的比例。至於當這些安排實施時會產生怎樣的作用，目前還有待觀察。

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.
另一個重要的儀器類別是倒置擺。這些是由金屬或木材製成的垂直彈簧，在其上端裝有一塊重金屬質量的裝置。這種安排在其上端配備有一支鉛筆以書寫在凹曲表面上的器械，曾於1841年用於記錄蘇格蘭康布里地區的地震。在日本，它們被大量使用成系列，每個系列成員具有不同的振動周期。這些安排的目的是確定哪個擺動，與給定的地震記錄了最大的運動，假設被扔進最猛烈擺動的那個最接近地震周期。這些實驗的結果顯示，通常是振動周期慢的那些受到最大幹擾。

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.
支撐式地震儀。一組近期出現並取得良好成果的儀器是支撐式地震儀。這些儀器似乎是由幾位研究者獨立發明的：它們的發源地可能是著名的佐爾納教授的水平擺。在日本，它們首先由查普林教授使用。隨後，它們被尤因教授和格雷先生使用。它們基本上由一個沉重的重物支撐在一個水平支架的末端，該支架在其另一端可以繞垂直軸線自由轉動。當攜帶此軸線的架構沿除了與支撐支架的長度平行的任何方向移動時，重物會使支架繞著被稱為支架瞬時軸線的線旋轉，該軸線對應於固定軸的運動。因此，該線上的任何點都可以作為支撐支架長度垂直方向運動的穩定點。必須同時使用兩個相互垂直放置的這些儀器，並將地面的運動記錄為兩個矩形分量。在尤因教授的儀器形式中，支架的輕微延伸形成放大的表示運動的指標，而重物則圍繞其中心的垂直軸旋轉。

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 .
在附圖中，b 是一個沉重的重物，樞軸在一個小支架 c a k 的末端，該支架可自由轉動在上方的刀口 k 上，並在下方的支架 s 中有一個樞軸 a。在地震時，b 保持穩定，指針 p 與支架連續，放大了支架的運動，比例為 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.
在一種名為雙支架地震儀的儀器中，由格雷先生髮明，我們有兩個支架相互鉸接，其中一個連接到一個固定架構上。這兩個支架的平面放置成直角，以便在外支架末端支撐的重物具有兩個水平自由度。

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.
在所有的括號機器中，特別是那些攜帶樞軸重物的機器中，是否重物提供了一個相對於記錄所寫的板上在與臂的運動方向平行的運動中確實穩定的點，這是值得懷疑的。

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 .
平行運動儀器。一種機器，它將其記錄寫成兩個組成部分，並且承諾具有很高的穩定性，這是由C. D. West教授提出的一種建議。就像括弧機一樣，它由放置在彼此垂直的兩個相似部分組成，具體如下：一根鐵桿a由輕型臂在c c處的兩側懸掛，這些臂在黑色點處相互鉸接，位於剛性架構bc的上部和下部之間。這些臂的長度設計得足夠長，使得對於沿著鐵桿長度的小位移，cc幾乎沿直線運動，並且鐵桿處於中立平衡狀態。鐵桿的輕型延長部d操作著輕型指示器e的上端，它通過剛性支撐f作為萬向節穿過。第二個指示器e′從與之垂直的鐵桿上穿過f。這些指示器的乘法端被耦合在一起，以在煙化玻璃板s上寫出結果運動。

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.
圓錐擺。另一組也提供了寶貴記錄的儀器是圓錐擺地震儀。首次提出並付諸實踐使用圓錐擺的擺球在地震模擬機中提供穩定點的想法是格雷先生。所使用的地震儀由一對懸掛在彼此垂直平面上的圓錐擺組成。這些擺球的每個吊球都固定在一個輕槓桿的末端附近一小段距離處，該槓桿形成書寫指示器，短端作為支撐靠在固定在地球中的柱子一側。重量由一根細線或絲線支撐，其上端固定在距離槓桿固定端垂直方向上的一個點上。

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.
滾動球體和圓柱體。在圓錐擺式地震儀之後，後者聲稱比支架機器有幾個重要優點，我們來到了一組被稱為滾動球體地震儀的儀器。在這裡，我們再次看到了一類儀器，對於它們的各種形式，我們要感謝格雷先生的聰明才智。

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.
這些儀器之一的總體結構和原理可以從隨附的圖中很容易理解。s 是一個大球的一部分，其中心接近於 c。略低於這個中心處，有一個重物 b，可以是一個鉛環，它被樞軸支撐著。在地震時，c 是穩定的，地球的運動通過指針 c a n 被放大，放大比例為 c a：a n。這個指針或指標的工作類似於擺鐘中的指針。

Closely connected with the rolling sphere seismographs, are Gray's rolling cylinder seismographs.
與滾動球形地震儀密切相關的是格雷的滾動圓柱地震儀。

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.
這是兩個圓柱體，它們靜置在一個表面平板上，它們的軸互相垂直。在每個圓柱體的最高點附近，當表面平板前後移動時，這一點保持幾乎不變，連接著一個輕型指示器的末端。這些指示器再次在與表面平板連接的軸線上的末端附近短距離處樞軸。為了使這兩個指示器可以平行，其中一個在第二個樞軸處彎曲。

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.
球盤式地震儀。另一種地震儀，與剛剛描述的兩種儀器密切相關，是Verbeck的球盤式地震儀。它由一個表面板放置在三個硬球上組成，這些球再放在第二個表面板上。當下面的板移動時，上面的板傾向於保持靜止，因此可以用作穩定的質量來移動一個指示器。

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.
佩里和艾爾頓原理。一種具有科學原理意義的儀器是由佩里教授和艾爾頓教授提出的一種地震儀，他們建議用三根彈簧支撐一個重球，這些彈簧應該足夠堅硬，以具有極快的振動周期。通過連接在球上的槓桿上的鉛筆，球的運動將被記錄在一張移動的紙帶上。結果將是由彈簧的小振動與較大、較慢的地震波形運動疊加而成的記錄，通過分析可以分離出前者，從而得知後者。儘管我們目前對地震運動的認識表明，這樣的記錄的分析經常會給我們帶來難以克服的困難，但這個儀器值得注意，因為它涉及的原理是新穎的，正如作者所指出的，在地震測量中一直是一個被"忽視"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.
記錄垂直運動的儀器。 用於記錄垂直運動的儀器幾乎和用於記錄水平運動的儀器一樣多。 最早用於此目的的儀器形式是由重物拉伸的螺旋彈簧，由於其慣性，據信在震動時保持穩定。 從這些儀器中從未獲得過令人滿意的結果，主要是因為要製造足夠長的彈簧以允許足夠的拉伸，以提供長時間的振動周期非常不方便。 類似的評論也適用於水平放置的彈性杆，其中一端固定在牆上，而另一端則裝有重物。 這些裝置配備有鉛筆，用於在垂直表面上書寫記錄，1842年在康萊使用過，我們在Palmieri的裝置的一部分中也看到了同樣的原理應用。 這類裝置既不能給出垂直運動的真實振幅，因為它們很容易被設置為振蕩狀態；也不能指示擾動的持續時間，因為一旦開始運動，它們會在實際地震結束後仍然依靠其慣性繼續運動。 它們只能被視為地震示波器。

The most satisfactory instrument which has yet been devised for recording vertical motion is Gray's horizontal lever spring seismograph.
迄今為止，用於記錄垂直運動的最令人滿意的儀器是格雷的水平槓桿彈簧地震儀。

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.
通過附帶的草圖可以更好地理解這一儀器。垂直彈簧s的上端通過螺母n固定，螺母n放置在架構f的頂部，並用來將彈簧稍微上下移動，以作為橫臂a位置的最後調整。臂a的一端放在兩個尖點p上，一個尖點放在錐形孔中，另一個尖點放在V形槽中；臂a在b處由彈簧s支撐，在c處用鉛環r加重。在c點的銷釘上放置了一根線環支架，它支撐著一個小槽t。槽t在a點有一個樞軸，附有指針i（通過一條堅韌的紙帶在h處鉸接，並通過一個細銷釘固定在玻璃板g上），槽內部分充滿了水銀。

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.
另一種獲得垂直運動穩定點的方法是由華格納博士提出的，他使用部分浸入水容器中的浮標。格雷先生對此進行了相當大的改進，他建議使用一個浮標，除了一個長而細的部分外，其餘部分全部沉入水中。

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.
在用於記錄垂直運動的其他裝置中，可以提到一種帶有橡膠或其他柔性底部的容器，這些容器部分裝滿了水或其他液體。當容器上下移動時，底部傾向於保持原位，從而提供一個相對穩定的點。與此相連接的是一個輕質指針，該指針又與一個與地面相連的剛性架構鉸接。這類儀器已經提供了良好的記錄。

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.
記錄接收器。已經提到過許多地震儀，現在需要考慮記錄其運動的裝置。早期形式的地震儀，如前所述，在沙床上記錄它們的運動；其他則用鉛筆在紙張上記錄它們的運動。當我們有放大地球運動的地震儀時，可以觀察到上述方法會涉及很大的摩擦阻力，導致地震儀假定的穩定點產生運動。其中一種最完美的儀器是通過光線反射將記錄指針的運動以攝影方式記錄下來。然而，這樣的儀器難以製造且難以操作。最實用的記錄裝置之一是在煙燻玻璃表面上書寫記錄。之後可以覆蓋一層攝影師用的清漆，然後通過工程師熟知的"藍圖法"進行攝影。

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.
要獲取地震的所有振動記錄，必須確保地震儀書寫的表面在地震發生時處於運動狀態。記錄接收設備有三種類型。首先是連續運動的類型。常見形式是一塊圓形玻璃板，類似於舊式計時器，通過發條持續驅動。在這塊玻璃板上，地震儀的指針不斷地在相同的圓周上描繪。地震發生時，指針來回移動，穿過這些理論上是細線的圓周，留下地震的記錄。除了圓形玻璃板外，還可以使用覆蓋煙紙的鼓，這種鼓在地震後展開時，記錄呈直線，而不是像圓形玻璃板那樣記錄在圓周上。這類記錄容易保存，但較難拍照。

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.
第二種儀器是在震動時啟動的裝置。這可以是類似前面描述的裝置，或者是一塊安裝在滑架上的直線煙燻玻璃板。通過一種稱為"啟動器"的電氣或機械裝置（已有許多形式被設計出來），地震會釋放一個止動裝置，從而啟動移動記錄接收器的機制。

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.
連續運動機器的一個巨大優勢是通常可以確定地獲取衝擊的開始和結束，同時避免了"啟動器"作用的不確定性。當然，自啟動機器具有簡單和廉價的優點，同時也不存在由於指針下的記錄板後續運動而導致記錄被抹去的危險。

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.
記錄時間的設備。與記錄地面運動的儀器同樣重要的是那些記錄運動發生時間的儀器。當確定地震的起源時，時間記錄的巨大價值將在後面展示。與時間觀測相關的最重要的結果是確定擾動從一個點傳到另一個點所花費的時間間隔。由於這些擾動有時以極快的速度傳播，因此需要非常精確地進行這些觀測。舊的方法是將一個裝置連接到一個鐘錶上，當受到震動時，使鐘錶停止運轉，除非觀測站之間距離相當遠，否則這種方法價值不大。這一點可以通過回想擾動可能以每秒一英里的速度傳播，它在任何一個站點的持續時間可能經常超過一分鐘，而一個站點的設備可能在擾動開始時停止，另一個則在擾動結束時停止來理解。因此，滿意的時間記錄設備不僅需要能夠停止鐘錶的裝置，還需要一種裝置，在停止鐘錶的同時，在地震儀記錄的圖表上做一個標記。這樣，我們就能知道在震動的哪個部分記錄了時間。

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.
帕爾米埃里通過關閉一個電路來停止地震儀上的時鐘。馬萊特提出通過一根繩子與時鐘擺相連的柱子的倒塌來停止時鐘。只要柱子站立，繩子就是松的，擺可以自由擺動；但當柱子倒塌時，繩子就會拉緊，擺就會停止。出現的困難是獲得一個會因輕微干擾而倒塌的柱子。用於使柱子倒塌的最佳裝置形式，也可以用於拉出一個擋板以減輕記錄接收器的機械壓力，如附圖所示。

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是一個半徑約為4.5厘米的球段，其中心略高於c。l是一個直徑約為7厘米的鉛盤，放置在球段上方。在其上方有一個長約30厘米的輕指針p。在指針頂部平衡著一個小鐵圓柱w，並通過繩子與待解除的掛鉤相連。當放置wps的桌子被震動時，近似於c處發生旋轉，基礎s的運動在指針的上端被放大，並使重物翻倒。這個掛鉤可以用來釋放一個齒條，其一端軸承在上面，上面有一個突出的銷從擺錘球體的面上突出。當這個齒條下降時，它會抓住突出的銷並固定擺錘。

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.
緩解齒條的另一種方法是將其反方向埠托舉起來，使其軸心處於懸掛在圓錐擺的重錘上的水平線的末端上----例如，懸掛在圓錐擺地震儀的一個標尺上。整個裝置可以用幾便士的成本製造，大小足夠小以適應普通的鐘表箱內。

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.
所有這些停鍾安排所產生的困難在於，遠處站點的觀察者很難重新啟動他們的時鐘，以便他們的時間差能夠準確地知道。即使每個觀察者都配備了一個精確調校的計時器，他們可以用它進行比較，這些儀器的評定對於所有普通人來說都是一項極其麻煩的操作。

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.
為了避免這種困難，作者近年來採用了一種獲取時間的方法，而無需停止時鐘。為此，採用一台帶有中心秒針的時鐘，並將時針和分針延長並稍微彎曲，使其在面部的末端呈直角，其中時針略長一些。然後，每個指針的末端都塗抹了一塊軟材料，如軟木，其塗抹了一層甘油墨水。一個輕巧的扁平環，上面劃分有與時鐘面相對應的刻度，安排在這樣一個位置，即在發生衝擊時，可以快速前進以觸摸時鐘指針上的墨水墊，然後撤回。這是通過適當的機械裝置完成的，該裝置通過電磁鐵或其他裝置來釋放，以撤回抓取物。這樣，可以在盤上得到三個點的形式的印記，並且知道時間，而無需停止或明顯減慢時鐘。

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.
對於普通觀察者來說，如果不使用時間記錄器與記錄接收器結合使用，通過瞥一眼普通手錶也可以獲得與普通停鍾設備獲得的同樣好的結果。隨後，應該將觀察所用的手錶與一些良好的時間記錄器進行比較，然後大致知道發生衝擊的當地時間。

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.
從現在所說的內容可以看出，對於完整的地震儀，我們需要三套不同的設備--一套記錄水平運動的設備，一套記錄垂直運動的設備，以及一套記錄時間的設備。水平和垂直運動必須寫在同一個記錄器上，並且如果可能的話，應該並列在一起，同時，時間記錄被製作的瞬間必須在由地震儀繪製的圖表邊緣上做一個標記。這樣的地震儀已經被製造出來，並且現在已經在日本建立起來。它在附圖中有所示。

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 .
格雷和米爾恩地震儀。在這個裝置中，地球的水平運動的兩個互相垂直的分量被記錄在一張環繞在一個由鐘錶機構保持連續運動的滾筒 d 上的煙燻紙上，通過兩個圓錐擺地震儀 c 。垂直運動則通過一個補償彈簧地震儀 s l m b 在同一張紙上記錄。

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.
地震發生的時間是通過使兩個電磁鐵的電路閉合而確定的。其中一個磁鐵釋放了一個機制，該機制是時間記錄器的一部分，它導致時鐘的鐘盤突然前進並然後移回原來的位置。指針上裝有墨盒，它們在鐘盤上標記它們的位置，從而指示電路閉合時的小時、分鐘和秒。第二個電磁鐵導致指針在接收運動記錄的紙上做出標記。這個標記指示了電路閉合時地震的部分。

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.
地震的持續時間是根據煙燻紙上的記錄長度和滾筒運動的速度來估計的。從紙上繪製的曲線可以得到不同運動的性質和周期。

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.
格雷先生後來對這個裝置進行了很大修改，特別是引入了一條足夠長的紙帶，可以在不重複的情況下記錄二十四小時的數據。記錄是通過細小的虹吸管用墨水寫成的。通過這種方式，這個對水平變化非常敏感的儀器不僅可以顯示地震，還可以顯示最近受到了很多關注的長周期的脈動。

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