Book II chapter 16

Showing that Movements take place by the Magnetical Vigour¹ though solid bodies lie between; and on the interposition of iron plates.

F loat a piece of iron wire on the surface of water by transfixing it through a suitable cork²; or set a versatory piece of iron on a pin or in a seaman's compass (a magnet being brought near or moved about underneath), it is put into a state of motion; neither the water, nor the vessel³, nor the compass-box offering resistance in any way. Thick boards do not obstruct168, nor earthen vessels⁵ nor marble vases, nor the metals themselves; nothing is so solid as to carry away or impede⁶ the forces excepting an iron plate. Everything which is interposed (even though it is very dense) does not carry away its influence or obstruct⁴ its path, or indeed in any way hinder, diminish, or retard⁷ it. But all the force is not suppressed by an iron plate, but it is in some measure diverted aside. For when the vigour passes into the middle of an iron plate within the orbe of the magnetick virtue⁸ or placed just opposite the pole of the stone, that virtue is scattered⁹ in very large measure towards its extremities¹⁰; so that the edges of a small round plate of suitable size allure¹¹ iron wires on every side. This is also apparent in the case of a long iron wand, which, when it has been touched by a magnet in the middle, has a like verticity at either end.



B is a loadstone, C D a long rod magnetized in the middle A; E being the Boreal pole; C is an Austral end or pole; in like manner also the end D is another Austral pole. But observe here the exactness with which a versorium touched by a pole, when a round plate is interposed, turns towards the same pole in the same way as before the interposition, only weaker; the plate not standing¹² in the way, because the vigour is diverted through the edges of the small plate, and passes out of its straight course, but yet the plate retains in the middle the same verticity, when it is in the neighbourhood of that pole, and close to it; wherefore the versorium tends towards the plate, having been touched by the same pole. If a loadstone is rather weak, a versorium hardly turns when a plate is put in between; for the vigour of the rather weak loadstone, being diffused¹³ through the extremities, passes less through the middle. But if the plate has been touched in this way by a pole in the middle and has been removed from the stone outside its orbe of virtue, then you will see the point of the same versorium tend in the contrary direction and desert the centre of the small plate, which formerly¹⁴ it desired; for outside the orbe of virtue it has an opposite verticity, in the vicinity the same; for in the vicinity it is, as it were, a part of the loadstone, and has the same pole.



A is an iron plate near the pole, B a versorium which tends with its point towards the centre of the small plate, which has been touched by the pole of the loadstone C. But if the same small plate be placed outside the orbe of magnetick virtue, the point will not turn towards its centre, but the cross E of the same versorium does. But an iron globe interposed (if it is not too large) attracts the point of the iron on the other side of the stone. For the verticity of that side is the same as that of the adjoining pole of the stone. And this turning of the cusp (that is, of the end touched by that pole) as well as of the cross-end, at a greater distance, takes place with an iron globe interposed, which would not happen at all if the space were empty, because the magnetick virtue is passed on and continued through magnetick bodies.



A is a terrella, B an iron globe; between the two bodies is F, a versorium whose point has been excited by the pole C. In the other figure A is a terrella, C its pole, B an iron globe; where the versorium tends towards C, the pole of the terrella, through the iron globe. So a versorium placed between a terrella and an iron globe vibrates more forcibly towards the pole of the terrella; because the loadstone sends an instantaneous verticity into the opposite globe. There is the same efficiency in the earth, produced from the same cause. For if a revolvable needle is shut up in a rather thick gold box (this metal indeed excels all others in density) or a glass or stone box, nevertheless that magnetick needle has its forces connected and united with the influences of the earth, and the iron will turn freely and readily (unhindered by its prison) to its desired points, North and South. It even does this when shut up in iron caverns¹⁵, if they are sufficiently¹⁶ spacious¹⁷. Whatever bodies are produced among us, or are artificially forged from things which are produced, consist of matter of the terrestrial globe; nor do those bodies hinder the prime forces of nature which are derived¹⁸ from their primary form, nor can they resist them except by contrary forms. But no forms of mixed bodies are inimical to the primary implanted earth-nature, although some often do not agree169 with one another. But in the case of all those substances which have a material cause for their inclining (as amber¹⁹, jet, sulphur), their action is impeded²⁰ by the interposition of a body (as paper, leaves, glass, or the like) when that way is impeded and obstructed²¹, so that that which exhales170 cannot reach the corpuscle to be allured²². Terrestrial and magnetick coition and motion, when corporeal²³ impediments are interposed, is demonstrated also by the efficiencies of other chief bodies due to their primary form. The moon (more than all the stars) agrees with internal parts of the earth on account of its nearness and similarity in form. The moon produces the movements of the waters and the tides of the sea; twice it fills up the shores and empties them whilst it moves from a certain definite point in the sky back to the same point in a daily revolution. This motion of the waters is incited²⁴ and the seas rise and fall no less when the moon is below the horizon and in the lowest part of the heavens, than if it had been raised at a height above the horizon. So the whole mass of the earth interposed171 does not resist the action of the moon, when it is below the earth; but the seas bordering on our shores, in certain positions of the sky when it is below the horizon, are kept in motion, and likewise stirred by its power (though they are not struck by its rays nor illuminated²⁵ by its light), rise, come up with great force, and recede²⁶. But about the reason of the tides anon172; here let it suffice to have merely touched the threshold of the question. In like manner nothing on the earth can be hidden from the magnetick disposition²⁷ of the earth or of the stone, and all magnetical bodies are reduced to order by the dominant²⁸ form of the earth, and loadstone and iron show sympathy with a loadstone though solid bodies be interposed.

1 vigour   

（=vigor）n.智力，体力，精力

参考例句：

• She is full of vigour and enthusiasm.她有热情，有朝气。
• At 40,he was in his prime and full of vigour.他40岁时正年富力强。

2 cork   

n.软木，软木塞

参考例句：

• We heard the pop of a cork.我们听见瓶塞砰的一声打开。
• Cork is a very buoyant material.软木是极易浮起的材料。

3 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

4 obstruct   

v.阻隔，阻塞(道路、通道等)；n.阻碍物，障碍物

参考例句：

• He became still more dissatisfied with it and secretly did everything in his power to obstruct it.他对此更不满意，尽在暗里使绊子。
• The fallen trees obstruct the road.倒下的树将路堵住了。

5 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

6 impede   

v.妨碍，阻碍，阻止

参考例句：

• One shouldn't impede other's progress.一个人不应该妨碍他人进步。
• The muddy roads impede our journey.我们的旅游被泥泞的道路阻挠了。

7 retard   

n.阻止，延迟；vt.妨碍，延迟，使减速

参考例句：

• Lack of sunlight will retard the growth of most plants.缺乏阳光会妨碍大多数植物的生长。
• Continuing violence will retard negotiations over the country's future.持续不断的暴力活动会阻碍关系到国家未来的谈判的进行。

8 virtue   

n.德行，美德；贞操；优点；功效，效力

参考例句：

• He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
• You need to decorate your mind with virtue.你应该用德行美化心灵。

9 scattered   

adj.分散的，稀疏的；散步的；疏疏落落的

参考例句：

• Gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来，塞进文件夹里。

10 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

11 allure   

n.诱惑力，魅力；vt.诱惑，引诱，吸引

参考例句：

• The window displays allure customers to buy goods.橱窗陈列品吸引顾客购买货物。
• The book has a certain allure for which it is hard to find a reason.这本书有一种难以解释的魅力。

12 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

13 diffused   

散布的，普及的，扩散的

参考例句：

• A drop of milk diffused in the water. 一滴牛奶在水中扩散开来。
• Gases and liquids diffused. 气体和液体慢慢混合了。

14 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。

15 caverns   

大山洞，大洞穴( cavern的名词复数 )

参考例句：

• Within were dark caverns; what was inside them, no one could see. 里面是一个黑洞，这里面有什么东西，谁也望不见。 来自汉英文学 - 家（1-26） - 家（1-26）
• UNDERGROUND Under water grottos, caverns Filled with apes That eat figs. 在水帘洞里，挤满了猿争吃无花果。

16 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

17 spacious   

adj.广阔的，宽敞的

参考例句：

• Our yard is spacious enough for a swimming pool.我们的院子很宽敞，足够建一座游泳池。
• The room is bright and spacious.这房间很豁亮。

18 derived   

vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取

参考例句：

• Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
• He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》

19 amber   

n.琥珀；琥珀色；adj.琥珀制的

参考例句：

• Would you like an amber necklace for your birthday?你过生日想要一条琥珀项链吗？
• This is a piece of little amber stones.这是一块小小的琥珀化石。

20 impeded   

阻碍，妨碍，阻止( impede的过去式和过去分词 )

参考例句：

• Work on the building was impeded by severe weather. 楼房的施工因天气恶劣而停了下来。
• He was impeded in his work. 他的工作受阻。

21 obstructed   

阻塞( obstruct的过去式和过去分词 )； 堵塞； 阻碍； 阻止

参考例句：

• Tall trees obstructed his view of the road. 有大树挡着，他看不到道路。
• The Irish and Bristol Channels were closed or grievously obstructed. 爱尔兰海峡和布里斯托尔海峡或遭受封锁，或受到了严重阻碍。

22 allured   

诱引，吸引( allure的过去式和过去分词 )

参考例句：

• They allured her into a snare. 他们诱她落入圈套。
• Many settlers were allured by promises of easy wealth. 很多安家落户的人都是受了诱惑，以为转眼就能发财而来的。

23 corporeal   

adj.肉体的，身体的；物质的

参考例句：

• The body is the corporeal habitation of the soul.身体为灵魂之有形寓所。
• He is very religious;corporeal world has little interest for him.他虔信宗教，对物质上的享受不感兴趣。

24 incited   

刺激，激励，煽动( incite的过去式和过去分词 )

参考例句：

• He incited people to rise up against the government. 他煽动人们起来反对政府。
• The captain's example incited the men to bravery. 船长的榜样激发了水手们的勇敢精神。

25 illuminated   

adj.被照明的；受启迪的

参考例句：

• Floodlights illuminated the stadium. 泛光灯照亮了体育场。
• the illuminated city at night 夜幕中万家灯火的城市

26 recede   

vi.退(去)，渐渐远去；向后倾斜，缩进

参考例句：

• The colleges would recede in importance.大学的重要性会降低。
• He saw that the dirty water had begun to recede.他发现那污浊的水开始往下退了。

27 disposition   

n.性情，性格；意向，倾向；排列，部署

参考例句：

• He has made a good disposition of his property.他已对财产作了妥善处理。
• He has a cheerful disposition.他性情开朗。

28 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。