Plato Thales and others to fetch Philosophy into Greece But long before that time abundance of them went into Assyria and had their Towns and Lands assigned them also there and were by the Hebrews called Chaldies A. Why so B. I cannot tell but I finde in Martinius Lexicon they were called Chasdim and Chesdim and as he saith from one Chesed the son of Nachor but I finde no such man as Chesed amongst the issue of Noah in the Scripture Nor do I finde that there was any certain Country called Chaldaea though a Town where any of them inhabited were called A Town of the Chaldies Martinius saith further that the same word Chasdim did signifie also Demons A. By this reckoning I should conjecture they were called Chusdim as being a Race of Ethiopians For the Land of Chus is Aethiopia and so the name degenerated first into Chuldim and then into Chaldim so that they were such another kinde of people as we call Gypsies saving that they were admired and feared for their Knavery and the Gypsies counted Rogues B. Nay pray except Claudius Ptolomaeus Author of that great Work of Astronomy the Almegest A. I grant he was excellent both in Astronomy and Geometry and to be commended for his Almegest but then for his Judiciar Astrologie annexed to it he is again a Gypsie But the Greeks that travelled you say into Egypt what Philosophy did they carry home B. The Mathematiques and Astronomy But for that sublunary Physiques which is commonly called Natural Philosophy I have not read of any Nation that studied it earlier than the Greeks from whom it proceeded to the Romans Yet both Greeks and Romans were more addicted to Moral than to Natural Philosophy in which kinde we have their Writings but loosly and incoherently written upon no other Principles than their own Passions and Presumptions without any respect to the Laws of Common-wealth which are the ground and measure of all true Morality So that their Books tend rather to teach men to censure than to obey the Laws Which has been a great hinderance to the Peace of the Western world ever since But they that seriously applied themselves to Natural Philosophy were but few as Plato and Aristotle whose Works we have and Epicurus whose Doctrine we have in Lucretius The Writings of Philolaus and many other curious Students being by fire or negligence now lost though the Doctrine of Philolaus concerning the Motion of the Earth have been revived by Copernicus and explained and confirmed by Galileo now of late A. But methinks the Natural Philosophy of Plato and Aristotle and the rest should have been cultivated and made to flourish by their Disciples B. Whom do you mean the Successors of Plato Epicurus Aristotle and the other first Philosophers It may be some of them may have been learned and worthy men But not long after and down to the time of our Saviour and his Apostles they were for the most part a sort of needy ignorant impudent cheating fellows who by the profession of the Doctrine of those first Philosophers got their living For at that time the name of Philosophy was so much in fashion and honour amongst great persons that every rich man had a Philosopher of one Sect or another to be a Schoolmaster to his Children And these were they that faining Christianity with their disputing and readiness of talking got themselves into Christian Commons and brought so many Heresies into the Primitive Church every one retaining still a tang of what they had been us'd to teach A. But those Heresies were all condemned in the first Council of Nice B. Yes But the Arrian Heresie for a long time flourished no less than the Roman and was upheld by divers Emperours and never fully extinguished as long as there were Vandals in Christendom Besides there arose daily other Sects opposing their Philosophy to the Doctrine of the Councils concerning the Divinity of our Saviour as how many Persons he was how many Natures he had And thus it continued till the time of Charlemain when he and Pope Leo the third divided the Power of the Empire into Temporal and Spiritual A. A very unequal division B. Why Which of them think you had the greater share A. No doubt the Emperour For he onely had the Sword B. When the Swords are in the hands of men whether had you rather command the Men or the Swords A. I understand you For he that hath the hands of the Men has also the use both of their Swords and strength B. The Empire thus divided into Spiritual and Temporal the freedom of Philosophy was to the power Spiritual very dangerous And for that cause it behoved the Pope to get Schools set up not onely for Divinity but also for other Sciences especially for Natural Philosophy Which when by the power of the Emperour he had effected out of the mixture of Aristotle's Metaphysicks with the Scripture there arose a new Science called School-Divinity which has been the principal Learning of these Western parts from the time of Charlemain till of very late A. But I finde not in any of the Writings of the School-men in what manner from the causes they assigne the Effect is naturally and necessarily produced B. You must not wonder at that For you enquire not so much when you see a change of any thing what may be said to be the cause of it as how the same is generated which generation is the entire progress of Nature from the efficient cause to the Effect produced Which is always a hard Question and for the most part impossible for a man to answer to For the alterations of the things we perceive by our five Senses are made by the motion of Bodies for the most part either for distance smalness or transparence invisible A. But what need had they then to assigne any cause at all seeing they could not shew the Effect was to follow from it B. The Schools as I said were erected by the Pope and Emperour but directed by the Pope onely to answer and confute the Heresies of the Philosophers Would you have them then betray their Profession and Authority that is to say their Livelihood by confessing their ignorance Or rather uphold the same by putting for causes strange and unintelligible words which might serve well enough not onely to satisfie the people whom they relied on but also to trouble the Philosophers themselves to finde a fault in A. Seeing you say that Alteration is wrought by the Motion of Bodies pray tell me first what I am to understand by the word Body B. It is a hard Question though most men think they can easily answer it as that it is whatsoever they can see feel or take notice of by their Senses But if you will know indeed what is body we must enquire first what there is that is not Body You have seen I suppose the Effects of Glasses how they multiply and magnifie the Object of our sight as when
Licensed May 26. 1677. Ro. L'strange Decameron Physiologicum OR TEN DIALOGUES OF NATURAL Philosophy By THOMAS HOBBES of Malmsbury To which is added The Proportion of a straight Line to half the Arc of a Quadrant By the same AUTHOR LONDON Printed by J. C. for W. Crook at the Green Dragon without Temple-Bar 1678. The Contents Dial. 1. OF the Original of Natural Philosophy Pag. 1. 2. Of the Principles and Method of Natural Philosophy p. 14. 3. Of Vacuum p. 23. 4. Of the Systeme of the World p. 31. 5. Of the Motions of Water and Air. p. 46. 6. Of the Causes and Effects of Heat and Cold. p. 58. 7. Of Hard and Soft and of the Atomes that fly in the Air. p. 72. 8. Of Gravity and Gravitation p. 84. 9. Of the Loadstone and its Poles and whether they shew the Longitude of Places on the Earth p. 104. 10. Of Transparence Refraction and of the Power of the Earth to produce living Creatures p. 121. The Proportion of a straight Line to half the Arc of a Quadrant by the same Author p. 133. CAP. I. Of the Original of Natural Philosophy A. I Have heard exceeding highly commended a kinde of thing which I do not well understand though it be much talkt of by such as have not otherwise much to do by the name of Philosophy And the same again by others as much despised and derided So that I cannot tell whether it be good or ill nor what to make of it though I see many other men that thrive by it B. I doubt not but what so many do so highly praise must be very admirable and what is derided and scorn'd by many foolish and ridiculous The honour and scorn falleth finally not upon Philosophy but upon the Professors Philosophy is The knowledge of Natural Causes And there is no Knowledge but of Truth And to know the true Causes of things was never in contempt but in admiration Scorn can never fasten upon Truth But the difference is all in the Writers and Teachers Whereof some have neither studied nor care for it otherwise than as a Trade to maintain themselves or gain Preferment and some for Fashion and to make themselves fit for ingenious Company and their study hath not been meditation but acquiescence in the Authority of those Authors whom they have heard commended And some but few there be that have studied it for Curiosity and the delight which commonly men have in the acquisition of Science and in the mastery of difficult and subtil Doctrines Of this last sort I count Aristotle and a few others of the Ancients and some few Moderns and to these it is that properly belong the Praises which are given to Philosophy A. If I have a minde to study for example Natural Philosophy must I then needs read Aristotle or some of those that now are in request B. There 's no necessity of it But if in your own meditation you light upon a difficulty I think 't is no loss of time to enquire what other men say of it but to rely onely upon Reason For though there be some few Effects of Nature especially concerning the Heavens whereof the Philosophers of old time have assigned very rational Causes such as any man may acquiesce in as of Eclipses of the Sun and Moon by long observation and by the Calculation of their visible Motions yet what is that to the numberless and quotidian Phaenomena of Nature Who is there amongst them or their Successors that has satisfied you with the Causes of Gravity Heat Cold Light Sense Colour Noise Rain Snow Frost Winds Tides of the Sea and a thousand other things which a few mens lives are too short to go through and which you and other curious Spirits admire as quotidian as they are and fain would know the Causes of them but shall not finde them in the Books of Naturalists and when you ask what are the Causes of any of them of a Philosopher now he will put you off with mere words which words examined to the bottom signifie not a jot more than I cannot tell or Because it is Such as are Intrinsecal quality Occult quality Sympathy Antipathy Antiperistasis and the like Which pass well enough with those that care not much for such wisdom though wise enough in their own ways but will not pass with you that ask not simply what 's the Cause but in what manner it comes about that such Effects are produced A. That 's Cozening What need had they of that When began they thus to play the Charletants B. Need had they none But know you not that men from their very birth and naturally scramble for every thing they covet and would have all the world if they could to fear and obey them If by fortune or industry one light upon a Secret in Nature and thereby obtain the credit of an extraordinary Knowing man should he not make use of it to his own benefit There is scarce one of a thousand but would live upon the charges of the people as far as he dares What poor Geometrician is there but takes pride to be thought a Conjurer what Mountebank would not make a living out of a false opinion that he were a great Physician And when many of them are once engaged in the maintenance of an Errour they will joyn together for the saving of their Authority to decry the Truth A. I pray tell me if you can how and where the study of Philosophy first began B. If we may give Credit to old Histories the first that studyed any of the Natural Sciences were the Astronomers of Aethiopia My Author is Diodorus Siculus accounted a very faithful Writer who begins his History as high as is possible and tells us that in Aethiopia were the first Astronomers and that for their Predictions of Eclipses and other Conjunctions and Aspects of the Planets they obtained of their King not onely Towns and Fields to a third part of the whole Land but were also in such veneration with the People that they were thought to have discourse with their Gods which were the Stars and made their Kings thereby to stand in awe of them that they durst not either eat or drink but what and when they prescribed no nor live if they said the Gods commanded them to die And thus they continued in subjection to their false Prophets till by one of their Kings called Ergamenes about the time of the Ptolemies they were put to the Sword But long before the time of Ergamenes the Race of these Astrologers for they had no Disciples but their own Children was so numerous that abundance of them whether sent for or no I cannot tell transplanted themselves into Egypt and there also had their Cities and Lands allowed them and were in request not onely for Astronomy and Astrologie but also for Geometry And Egypt was then as it were an University to all the world and thither went the curious Greeks as Pythagoras
a Glass of a certain Figure will make a Counter or a Shilling seem twenty though you be well assured there is but one And if you set a mark upon it you will finde the mark upon them all The Counter is certainly one of those things we call Bodies Are not the others so too A. No without doubt For looking through a Glass cannot make them really more than they are B. What then be they but fancies so many fancies of one and the same thing in several places A. 'T is manifest they are so many Idols mere Nothings B. When you have look'd upon a Star or Candle with both your eyes but one of them a little turn'd awry with your finger has not there appeared two Stars or two Candles And though you call it a deception of the sight you cannot deny but there were two Images of the Object A. 'T is true and observed by all men And the same I say of our faces seen in Looking-glasses and of all Dreams and of all Apparitions of dead mens Ghosts and wonder since 't is so manifest I never thought upon 't before for it is a very happy encounter and such as being by every body well understood would utterly destroy both Idolatry and Superstition and defeat abundance of Knaves that cheat and trouble the world with their devices B. But you must not hence conclude that whosoever tells his Dream or sometimes takes his direction from it is therefore an Idolater or Superstitious or a Cheater For God doth often admonish men by Dreams of what they ought to do yet men must be wary in this case that they trust not Dreams with the conduct of their lives further than by the Laws of their Country is allow'd For you know what God says Deut. 13. If a Prophet or a Dreamer of Dreams give thee a signe or a wonder and the signe come to pass yet if he did thee serve other Gods let him be put to death Here by serving other Gods since they had chosen God for their King we are to understand revolting from their King or disobeying of his Laws Otherwise I see no Idolatry nor Superstition in following a Dream as many of the Patriarches in the Old Testament and of the Saints in the New Testament did A. Yes Their own Dreams But when another man shall dream or say that he has dream'd and require me to follow that he must pardon me if I ask him by what Authority especially if he look I should pay him for it B. But if commanded by the Laws you live under you ought to follow it But when there proceed from one Sound divers Echoes what are those Echoes And when with fingers cross'd you touch a small Bullet and think it two and when the same Herb or Flower smells well to one and ill to another and the same at several times well and ill to your self and the like of Tastes what are those Echoes Feelings Odours and Tastes A. 'T is manifest they are all but Fancies But certainly when the Sun seems to my eye no bigger than a Dish there is behinde it somewhere somewhat else I suppose a real Sun which creates those fancies by working one way or other upon my eyes and other Organs of my Senses to cause that diversity of Fancy B. You say right and that is it I mean by the word Body which briefly I define to be any thing that hath a Being in it self without the help of Sense A. Aristotle I think meaneth by Body Substance or Subjectum wherein Colour Sound and other Fancies are as he says inherent For the word Essence has no affinity with Substance And Seneca says he understands it not And no wonder for Essence is no part of the Language of mankinde but a word devised by Philosophers out of the Copulation of two names as if a man having two Hounds could make a third if 't were need of therâ— Couples B. 'T is just fo For having said in themselves for example A Tree is a Plant and conceiving well enough what is the signification of those Names knew not what to make of the word Is that couples those Names nor daring to call it a Body they called it by a new name derived from the word est Essentia and Substantia deceived by the Idiome of their own Language For in many other Tongues and namely in the Hebrew there is no such Copulative They thought the Names of things sufficiently connected when they are placed in their natural consequence and were therefore never troubled with Essences nor other Fallacy from the Copulative Est. CAP. II. Of the Principles and Method of Natural Philosophy A. THis History of the old Philosophers has not put me out of love but out of hope of Philosophy from any of their Writings I would therefore try if I could attain any knowledge therein by my own meditation But I know neither where to begin nor which way to proceed B. Your desire you say is to know the Causes of the Effects or Phaenomena of Nature and you confess they are Fancies and consequently that they are in your self so that the Causes you seek for onely are without you and now you would know how those external Bodies work upon you to produce those Phaenomena The beginning therefore of your enquiry ought to be at What it is you call a Cause I mean an Efficient Cause For the Philosophers make four kindes of Causes whereof the Efficient is one Another they call the Formal Cause or simply the form or essence of the thing caused as when they say Four equal Angles and four equal Sides are the Cause of a Square Figure or that Heaviness is the Cause that makes heavie Bodies to descend But that 's not the Cause you seek for nor any thing but this It descends because it descends The third is the Material Cause as when they say The Walls and Roof c. of a house are the cause of a House The fourth is the Final Cause and hath place onely in Moral Philosophy A. We will think of Final Causes upon some other occasion of Formal and Material not at all I seek onely the Efficient and how it acteth from the beginning to the production of the Effect B. I say then that in the first place you are to enquire diligently into the nature of Motion For the variations of Fancies or which is the same thing of the Phaenomena of Nature have all of them one Universal Efficient Cause namely the variety of Motion For if all things in the world were absolutely at rest there could be no variety of Fancy but living Creatures would be without sense of all Objects which is little less than to be dead A. What if a Childe new taken from the Womb should with open eyes be exposed to the Azure-Sky do not you think it would have some sense of the Light but that all would seem unto him Darkness B. Truly if he had no memory of any
may have made you hot Is Motion therefore hot No. You are to consider the Concomitants of your heat as that you are more faint or more ruddy or that you sweat or feel some Endeavour of Moisture or Spirits tending outward and when you have found the Causes of those Accidents you have found the Causes of Heat which in a living Creature and specially in a Man is many times the Motion of the parts within him such as happen in sickness anger and other passions of the minde which are not in the Sun nor in Fire A. That which I desire now to know is what Motions and of what Bodies without me are the Efficient Causes of my Heat B. I shewed you yesterday in discoursing of Rain how by this compounded Motion of the Suns Body the Air was every way at once thrust off West and East so that where it was contiguous the small parts of the water were forced to rise for the avoiding of Vacuum Think then that your hand were in the place of water so exposed to the Sun Must not the Sun work upon it as it did upon the Water Though it break not the skin yet it will give to the inner Fluids and looser parts of your hand an Endeavour to get forth which will extend the skin and in some climates fetch up the bloud and in time make the skin black The Fire also will do the same to them that often sit with their naked skins too neer it Nay one may sit so neer without touching it as it shall blister or break the skin and fetch up both spirits and bloud mixt into a putrid oyly matter sooner than in a Furnace Oyl can be extracted out of a Plant. A. But if the Water be above the Fire in a Kettle what then will it do Shall the particles of water go toward the Fire as it did toward the Sun B. No. For it cannot But the Motion of the parts of the Kettle which are caused by the Fire shall dissipate the Water into Vapour till it be all cast out A. What is that you call Fire Is it a hard or Fluid Body B. It is not any other Body but that of the shining coal which coal though extinguished with Water is still the same Body So also in a very hot Furnace the hollow spaces between the shining coals though they burn that you put into them are no other Body than Air moved A. Is it not Flame B. No. For flame is nothing but a multitude of Sparks and Sparks are but the Atomes of the Fewel dissipated by the incredible swift Motion of the Movent which makes every Spark to seem a hundred times greater than it is as appears by this That when a man swings in the Air a small stick fired at one end though the Motion cannot be very swift yet the Fire will appear to the eye to be a long streight or crooked Line Therefore a great many sparks together flying upward must needs appear unto the sight as one continued Flame Nor are the sparks striken out of a Flint any thing else but small particles of the stone which by their swift Motion are made to shine But that Fire is not a substance of it self is evident enough by this that the Sun-beams passing through a Globe of Water will burn as other fire does Which beams if they were indeed Fire would be quenched in the passage A. This is so evident that I wonder so wise men as Aristotle and his followers for so long a time could hold it for an Element and one of the primary parts of the Universe But the Natural heat of a man or other living Creature whence proceedeth it Is there any thing within their Bodies that hath this compounded Motion B. At the breaking up of a Deer I have seen it plainly in his Bowels as long as they were warm And it is called the Peristaltique Motion and in the Heart of a Beast newly taken out of his Body and this Motion is called Systole and Diastole But they are both of them this compounded Motion whereof the former causeth the food to Winde up and down through the guts and the later makes the Circulation of the Blood A. What kind of Motion is the Cause of Cold Methinks it should be contrary to that which causeth Heat B. So it is in some respect For seeing the Motion that begets Heat tendeth to the separation of the parts of the Body whereon it acteth it stands with reason that the Motion which maketh Cold should be such as sets them closer together But contrary Motions are to speak properly when upon two ends of a Line two Bodies move towards each other the Effect whereof is to make them meet But each of them as to this Question is the same A. Do you think as many Philosophers have held and now hold that Cold is nothing but a privation of Heat B. No. Have you never heard the Fable of the Satyre that dwelling with a Husbandman and seeing him blow his fingers to warm them and his Pottage to cool it was so scandalized that he ran from him saying he would no longer dwell with one that could blow both Hot and Cold with one breath Yet the Cause is evident enough For the Air which had gotten a Calefactive power from his vital parts was from his mouth and throat gently diffused on his fingers and retained still that power But to cool his Pottage he streightened the passage at his lips which extinguished the Calefactive Motion A. Do you think Wind the general Cause of Cold If that were true in the greatest Winds we should have the greatest Frosts B. I mean not any of those uncertain Winds which I said were made by the Clouds but such as a Body moved in the Air makes to and against it self For it is all one Motion of the Air whether it be carried against the Body or the Body against it Such a Wind as is constant if no other be stirring from East to West made by the Earth turning dayly upon its own Centre Which is so swift as except it be kept off by some hill to kill a man as by Experience hath been found by those who have passed over great Mountains and specially over the Andies which are opposed to the East And such is the Wind which the Earth maketh in the Air by her Annual Motion which is so swift as that by the Calculation of Astronomers to go Sixty miles in a minute of an hour And therefore this must be the Motion which makes it so cold about the Poles of the Ecliptique A. Does not the Earth make the Wind as great in one part of the Ecliptique as in another B. Yes But when the Sun is in Cancer it tempers the Cold and still less and less but least of all in the Winter-Solstice where his beams are most oblique to the Superficies of the Earth A. I thought the greatest Cold had been about the Poles of the
straight line from my Eye to the Sun terminated in the East B. 'T is not due East but partly East partly South For the Earth being but a point compared to the Sun all the parallels to D E the Aequator such as are e a f b e g if they be produced will fall upon the Body of the Sun And therefore A b is North-East A a East North-East And A c North North-East A. Proceed now to the Cause of Attraction B. Suppose now that the Internal parts of the Loadstone had the same Motion with that of the Internal parts of the Sun which make the Annual Motion of the Earth from West to East but in a contrary way for otherwise the Loadstone and the Iron can never be made to meet Then set the Loadstone at a little distance from the Earth marked with z and the Iron marked with x upon the superficies of the Earth Now that which makes x rise to z can be nothing else but Air for nothing touches it but Air. And that which makes the Air to rise can be nothing but those small circles made by the parts of the Earth such as are at a b c for nothing else touches the Air. Seeing then the Motion of each point of the Loadstone is from East to West in Circles and the motion of each point of the Iron from West to East it follows that the Air between the Loadstone and the Iron shall be cast off both East and West and consequently the place left empty if the Iron did not rise up and fill it Thus you see the Cause that maketh the Loadstone and the Iron to meet A. Hitherto I assent But why they should meet when some Heterogeneous Body lyes in the Air between them I cannot imagine And yet I have seen a Knife though within the Sheath attract one end of the Needle of a Mariners Compass and have heard it will do the same though a Stone-wall were between B. Such Iron were indeed a very and vigorous Loadstone But the Cause of it is the same that causeth Fire or hot Water which have the same compounded Motion to work through a Vessel of Brass For though the Motion be altered by restraint within the Heterogeneous Body yet being continued quite through it restores it self A. What is the Cause why the Iron rub'd over by a Loadstone will receive the vertue which the Loadstone hath of drawing Iron to it B. Since the Motion that brings two Bodies to meet must have contrary ways and that the Motions of the Internal parts of the Magnet and of the Iron are contrary the rubbing of them together does not give the Iron the first Edeavour to rise but multiplies it For the Iron untouch'd will rise to a Loadstone but if touch'd it becomes a Loadstone to other Iron For when they touch a piece of Iron they pass the Loadstone over it only one way viz. from Pole to Pole not back again for that would undo what before had been done also they press it in passing to the very end of the Iron and somewhat hard So that by this pressing Motion all the small Circles about the points a b c are turned the contrary way And the halves of those small Circles made on the Arch D B will be taken away and the Poles changed so as that the North-Poles shall point South and the South Poles North as in the Figure A. But how comes it to pass that when a Loadstone hath drawn a piece of Iron you may add to it another as if they begat one another Is there the like Motion in the generation of Animals B. I have told you that Iron of it self will rise to the Loadstone Much more then will it adhere to it when it is armed with Iron and both it and the Iron have a plain Superficies For then not only the points of Contact will be many which make the coherence stronger but also the Iron wherewith it is armed is now another Loadstone differing a little which you perhaps think as Male and Female But whether this compounded Motion and confrication causeth the generation of Animals how should I know that never had so much leasure as to make any observation which might conduce to that A. My next Question is seeing you say the Loadstone or a Needle touch'd with it naturally respecteth the Poles of the Earth but that the variation of it proceedeth from some accidents in the Superficies of the Earth what are those accidents B. Suppose there be a Hill upon the Earth for example at r then the stream of the Air which was between z and x Westward coming to the Hill shall go up the Hills side and so down to the other side according to the crooked Line which I have mark'd about the Hill by points and this infallibly will turn the North-point of the Needle being on the East side more toward the East and that on the other side more towards the West than if there had been no Hill And where upon the Earth are there not Eminencies and depressions except in some wide Sea and a great way from Land A. But if that be true the Variation in the same place should be always the same For the Hills are not removed B. The Variation of the Needle at the same place is still the same but the Variation of the Variation is partly from the Motion of the Pole it self which by the Astronomers is called Motus trepidationis and partly from that that the Variation cannot be truly observ'd for the Horizontal Needle and the Inclinatory Needle incline alike but cannot incline in due quantity For whether set upon a Pin or an Axis their Inclination is hindred in the Horizontal Needle by the Pin it self If upon an Axis if the Axis be just it cannot move if slack the weight will hinder it But chiefly because the North Pole of the Earth draws away from it the North Pole of the Needle For two like Poles cannot come together And this is the cause why the Variation in one place is East and another West A. This is indeed the most probable reason why the Variation varies that ever I heard given And I should presently acknowledge that this parallel Motion of the Axis of the Earth in the Ecliptick supposed by Copernicus is the true Annual Motion of the Earth but that there is lately come forth a Book called Longitude found which makes the Magnetical Poles distant from the Poles of the Earth eight Degrees and a half B. I have the Book 'T is far from being demonstrated as you shall find if you have the patience to see it examined For wheresoever his demonstration is true the conclusion if rightly inferred will be this that the Poles of the Loadstone and the Poles of the Earth are the same And where on the contrary his demonstrations are fallacies it is because sometimes he fancieth the Lines he hath drawn not where they are sometimes because he mistakes