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
Motion of the Earth For whatsoever having been asunder comes together again must come contrary ways as those that follow one another go the same way though both move upon the same Line A. What Experiment have you seen to this purpose B. I have seen a drop of glass like that of the second Figure newly taken out of the furnace and hanging at the end of an Iron rod and yet Fluid and let fall into the water and hardned The Club-end of it A A coming first to the water the tail B C following it 'T is proved before that the motion that makes it is a compounded Motion and gives an Endeavour outward to every part of it and that the Motion which maketh Cold is such as shaving the Body in every point of contact and turning it gives them all an Endeavour inward Such is this Motion made by the sinking of the hot and fluid glass into the water 'T is therefore manifest that the Motion which hardneth a Soft Body must in every point of contact be in the contrary way to that which makes a hard body Soft And further that slender tail B C shall be made much more hard than common Glass For towards the upper end in C you cannot easily break it as small as it is And when you have broken it the whole Body will fall into dust as it must do seeing the bending is so difficult For all the parts are bent with such force that upon the breaking at D by their sudden restitution to their liberty they will break together And the cause why the tail B C being so slender becomes so hard is that all the Endeavour in the great part A B is propagated to the small part B C in the same manner as the force of the Sun-beams is derived almost to a point by a Burning-glass But the Cause why when it is broken in D it breaks also in so many other places is that the Endeavour in all the other parts which is called the Spring unbends it from whence a Motion is caused the contrary way and that Motion continued bends it more the other way and breaks it as a Bow over-bent is broken into shivers by a sudden breaking of the string A. I conceive now how a Body which having been Hard and softned again may be re-hardned but how a Fluid and meer Homogeneous Body as Air or Water may be so I see not yet For the hardning of water is making a hard Body of two Fluids whereof one which is the water hath some tenacity and so a man may make a Bladder hard with blowing into it B. As for meer Air which hath no Natural Motion of it self but is moved onely by other Bodies of a greater consistence I think it impossible to be hardned For the parts of it so easily change places that they can never be fixt by any Motion No more I think can Water which though somewhat less Fluid is with an insensible force very easily broken A. It is the opinion of many learned men that Ice in long time will be turned into Christal and they alleadge Experience for it For they say that Christal is found hanging on high Rocks in the Alps like Isicles on the Eaves of a house and why may not that have formerly been Ice and in many years have lost the power of being reduced B. If that were so it would still be Ice though also Christal Which cannot be because Christal is heavier than Water and therefore much heavier than Ice A. Is there then no transubstantiation of Bodies but by mixture B. Mixture is no transubstantiation A. Have you never seen a Stone that seemed to have been formerly Wood and some like Shells and some like Serpents and others like other things B. Yes I have seen such things and particularly I saw at Rome in a Stone-cutters work-house a Billet of Wood as I thought it partly covered with bark and partly with the grain bare as long as a mans Arm and as thick as the Calf of a mans Leg which handling I found extreme heavie and saw a small part of it which was polished and had a very fine Gloss and thought it a substance between Stone and Metal but neerest to Stone I have seen also a kind of Slate painted naturally with Forest-work And I have seen in the hands of a Chymist of my acquaintance at Paris a broken Glass part of a Retort in which had been the Rozin of Turpentine wherein though there were left no Rozin yet there appeared in the piece of Glass many Trees and Plants in the ground about them such as grow in Woods and better designed than they could be done by any Painter and continued so for a long time These be great wonders of Nature but I will not undertake to shew their causes But yet this is most certain that nothing can make a hard Body of a Soft but by some Motion of its parts For the parts of the Hardest Body in the world can be no closer together than to touch and so close are the parts of Air and Water and consequently they should be equally Hard if their smallest parts had not different Natural Motions Therefore if you ask me the Causes of these Effects I answer They are different Motions But if you expect from me how and by what Motions I shall fail you For there is no kind of Substance in the World now that was not at the first Creation when the Creator gave to all things what Natural and special Motion he thought good And as he made some Bodies wondrous great so he made others wondrous little For all his works are wondrous Man can but guess nor guess further than he hath knowledge of the variety of Motion I am therefore of opinion that whatsoever perfectly Homogeneous is Hard consisteth of the smallest parts or as some call them Atomes that were made Hard in the beginning and consequently by an Eternal Cause and that the hardness of the whole Body is caused onely by the contact of the parts by pressure A. What Motion is it that maketh a hard Body to melt B. The same compounded Motion that heats namely that of Fire if it be strong enough For all Motion compounded is an Endeavour to dissipate as I have said before the parts of the Body to be moved by it If therefore hardness consist onely in the pressing Contact of the least parts this Motion will make the same parts slide off from one another and the whole to take such a figure as the weight of the parts shall dispose them to as in Lead Iron Gold and other things melted with Heat But if the small parts have such figures as they cannot exactly touch but must leave spaces between them filled with Air or other Fluids then this Motion of the fire will dissipate those parts some one way some another the Hard part still hard as in the burning of Wood or Stone into Ashes or Lime For this Motion
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
thing formerly seen or by any other sense perceived which is my supposition I think he would be in the dark For Darkness is Darkness whether it be black or blue to him that cannot distinguish A. Howsoever that be it is evident enough that whatsoever worketh is moved for Action is Motion B. Having well considered the nature of Motion you must thence take your Principles for the foundation and beginning of your Enquiry A. As how B. Explain as fully and as briefly as you can what you constantly mean by Motion which will save your self as well as others from being seduced by Aequivocation A. Then I say Motion is nothing but change of place For all the Effect of a Body upon the Organs of our Senses is nothing but Fancy Therefore we can fancy nothing from seeing it moved but change of place B. 'T is right But you must then tell me also what you understand by Place For all men are not yet agreed on that A. Well then seeing we fancy a Body we cannot but fancy it somewhere And therefore I think Place is the fancy of Here or There B. That is not enough Here and There are not understood by any but your self except you point towards it But pointing is no part of a Definition Besides though it help him to finde the Place it will never bring him to it A. But seeing Sense is Fancy when we fancy a Body we fancy also the Figure of it and the space it fills up And then I may define Place to be The precise space within which the Body is contained For Space is also part of the Image we have of the Object seen B. And how define you Time A. As Place is to a Body so I think is Time to the Motion of it and consequently I take Time to be our fancy or Image of the Motion But is there any necessity of so much niceness B. Yes The want of it is the greatest if not the onely cause of all the discord amongst Philosophers as may easily be perceived by their abusing and confounding the names of things that differ in their nature as you shall see when there is occasion to recite some of the Tenets of divers Philosophers A. I will avoid Aequivocation as much as I can And for the nature of Motion I suppose I understand it by the Definition What is next to be done B. You are to draw from these Definitions and from whatsoever Truth else you know by the light of Nature such general Consequences as may serve for Axiomes or Principles of your Ratiocination A. That is hard to do B. I will draw them my self as many as for our present discourse of Natural Causes we shall have need of so that your part will be no more than to take heed I do not deceive you A. I will look to that B. My first Axiome then shall be this Two Bodies at the same Time cannot be in one Place A. That 's true For we number Bodies as we fancy them distinct and distinguish them by their Places You may therefore adde Nor one Body at the same time in two Places And Philosophers mean the same when they say There is no penetration of Bodies B. But they understand not their own words For penetration signifies it not My second Axiome is That nothing can begin change or put an end to its own Motion For supposing it begin just now or being now in Motion change its Way or Stop I require the Cause why now rather than before or after having all that is necessary to such Motion Change or Rest alike at all times A. I do not doubt but the Argument is good in Bodies inanimate but perhaps in Voluntary Agents it does not hold B. How it holds in Voluntary Agents we will then consider when our Method hath brought us to the Powers and Passions of the minde A third Axiome shall be this Whatsoever Body being at Rest is afterwards moved hath for its Immediate Movent some other Body which is in Motion and toucheth it For since nothing can move it self the Movent must be external And because Motion is change of place the Movent must put it from its place which it cannot do till it touch it A. That is manifest and that it must more than touch it it must also follow it And if more parts of the Body are moved than are by the Movent touched the Movent is not Immediate And by this reason a continued Body though never so great if the first Superficies be prest never so little back the Motion will proceed through it B. Do you think that to be impossible I will prove it from your own words For you say that the Movent does then touch the Body which it moveth Therefore it puts it back But that which is put back puts back the next behinde and that again the next and so onward to any distance the body being continued The same is also manifest by experience seeing one that walks with a Staff can distinguish though blinde between Stone and Glass which were impossible if the parts of his Staff between the ground and his hand made no resistance So also he that in the silence of the night lays his Ear to the ground shall hear the treading of mens feet further than if he stood upright A. This is certainly true of a Staff or other hard Body because it keeps the Motion in a straight Line from diffusion But in such a Fluid Body as the Air which being put back must fill an Orb and the further it is put back the greater Orb the Motion will decrease and in time by the resistance of Air to Air come to an end B. That any Body in the world is absolutely at Rest I think not true But I grant that in a space filled every where with Body though never so Fluid if you give Motion to any part thereof that Motion will by resistance of the parts moved grow less and less and at last cease but if you suppose the space utterly void and nothing in it then whatsoever is once moved shall go on eternally Or else that which you have granted is not true viz. That nothing can put an end to its own Motion A. But what mean you by resistance B. Resistance is the Motion of a Body in a way wholly or partly contrary to the way of its Movent and thereby repelling or retarding it As when a man runs swiftly he shall feel the Motion of the Air in his face But when two hard Bodies meet much more may you see how they abate each others Motion and rebound from one another For in a space already full the Movent cannot in an instant be communicated through the whole depth of the Body that is to be moved A. What other Definitions have I need of B. In all Motion as in all Quantity you must take the beginning of your reckoning from the least supposed Motion And this I call the
every way and also continually change place to fill up the places forsaken by other parts of the Air which else would be empty there being no Vacuum to retire unto So that there would be a perpetual stream of Air and in a contrary way to the Motion of the Suns Body such as is the Motion of Water by the sides of a Ship under sail A. But this Motion of the Earth from West to East is onely Circular such as is described by a Compass about a Centre and cannot therefore repel the Air as the Sun does And the Disciples of Copernicus will have it to be the Cause of the Moons monthly motion about the Earth B. And I think Copernicus himself would have said the same if his purpose had been to have shewn the Natural Causes of the Motions of the Stars But that was no part of his designe which was onely from his own observations and those of former Astronomers to compute the times of their Motions partly to foretel the Conjunctions Oppositions and other Aspects of the Planets and partly to regulate the times of the Churches Festivals But his followers Kepler and Galileo make the Earths Motion to be the Efficient Cause of the Monthly motion of the Moon about the Earth which without the like Motion to that of the Sun in LM is impossible Let us therefore for the present take it in as a necessary Hypothesis which from some Experiment that I shall produce in our following discourses may prove to be a certain truth A. But seeing A is the Centre both of the Suns Body and of the Annual Motion of the Earth How can it be as all Astronomers say it is that the Orb of the Annual Motion of the Earth should be Excentrique to the Suns Body For you know that from the Vernal Aequinox to the Autumnal there be 187 days but from the Autumnal Aequinox to the Vernal there be but 178 days What Natural Cause can you assigne for this Excentricity B. Kepler ascribes it to a Magnetique vertue viz. that one part of the Earths Superficies has a greater kindness for the Sun than the other part A. I am not satisfied with that It is Magical rather than Natural and unworthy of Kepler Tell me your own opinion of it B. I think that the Magnetical vertue he speaks of consisteth in this that the Southern Hemisphere of the Earth is for the greatest part Sea and that the greatest part of the Northern Hemisphere is dry Land But how it is possible that from thence should proceed the Excentricity the Sun being neerest to the Earth when he is in the Winter-Solstice I shall shew you when we come to speak of the Motions of Air and Water A. That 's time enough For I intend it for our next meeting In the mean time I pray you tell me what you think to be the Cause why the Equinoctial and consequently the Solstitial points are not always in one and the same point of the Ecliptique of the Fixt Stars I know they are not because the Sun does not rise and set in points diametrally opposite For if it did there would be no difference of the Seasons of the year B. The cause of that can be no other than that the Earth which is l m hath the like Motion to that which I suppose the Sun to have in L M compounded of streight and circular from West to East in a day as the Annual Motion hath in a year so that not reckoning the Excentricity it will be moved through the Ecliptiques one Revolution as Copernicus proveth about one degree Suppose then the whole Earth moved from H to I which is half the year circularly but falling from I to i in the same time about 30 minutes and as much in the other Hemisphere from H to k then draw the line i k which will be equal and parallel to H I and be the Diameter of the Aequator for the next year But it shall not cut the Diameter of the Ecliptick B Z in A which was the Equinoctial of the former year but in o 36 seconds from the first degree of Aries Suppose the same done in the Hemisphere under the Plain of the paper and so you have the double of 36 seconds that is 72 seconds or very neer for the progress of the Vernal Equinox in a year The cause why I suppose the Arch I i to be half a degree in the Ecliptique of the Earth is that Copernicus and other Astronomers and Experience agree in this that the Aequinoctial points proceed according to the order of the Signes Aries Taurus Gemini c. from West to East every 100 year one degree or very neer A. In what time do they make the whole Revolution through the Ecliptique of the Sky B. That you may reckon For we know by Experience that it hath proceeded about one degree that is 60 minutes constantly a long time in a hundred years But as 100 years to one degree so is 36000 years to 360 degrees Also as 100 years to one degree so is one year to the hundred part of one degree or 60 minutes which is 60 100 or 36 seconds for the progress of one year which must be somewhat more than a degree according to Copernicus who lib. 3. cap. 2. saith That for 400 years before Ptolomie it was one degree almost constantly Which is well enough as to the Natural Cause of the Precession of the Aequinoctial points which is the often-said compounded Motion though not an exact Astronomical Calculation A. And 't is a great signe that his Supposition is true But what is the Cause that the Obliquity of the Ecliptique that is the distance between the Aequinoctial and the Solstice is not always the same B. The necessity of the Obliquity of the Ecliptique is but a consequence to the Precession of the Aequinoctial points And therefore if from C the North-Pole you make a little Circle C u equal to 15 minutes of a degree upon the Earth and another u s equal to the same which will appear like this Figure 8 that is as Copernicus calls it a Circle twined the Pole C will be moved half the time of the Aequinoctial points in the arc C u and as much in the alternate arc u s descending to s. But in the arc s u and its alternate rising to C. The cause of the twining is the Earths Annual Motion the same way in the Ecliptique and makes the four quarters of it and makes also their revolution twice as slow as that of the Aequinoctial points And therefore the Motion of it is the same compounded Motion which Copernicus takes for his Supposition and is the cause of the Precession of the Aequinoctial points and consequently of the variation of the Obliquity adding to it or taking from it somewhere more somewhere less so as that one with another the addition is not much more nor the substraction much less than 30 minutes But as
think you must happen to the Sea which resteth on it and is a Fluid Body A. I think it must make the Sea rise and fall And the same happeneth also to the Air from the Motion of the Sun B. Remember also in what manner the Sea is situated in respect of the Dry Land A. Is not there a great Sea that reacheth from the Straight of Magellan Eastward to the Indies and thence to the same Straight again And is not there a great Sea called the Atlantick Sea that runneth Northward to us and does not the great South-Sea run also up into the Northern Seas But I think the Indian and the South-Sea of themselves to be greater than all the rest of the Surface of the Globe B. How lieth the water in those two Seas A. East and West and rises and falls a little as it is forc'd to do by this compounded Motion which is a kind of succussion of the Earth and fills both the Atlantick and Northern Seas B. All this would not make a visible difference between High and Low water because this Motion being so regular the unevenness would not be great enough to be seen For though in a Bason the water would be thrown into the Air yet the Earth cannot throw the Sea into the Air. A. Yes The Bason if gently moved will make the water so move that you shall hardly see it rise B. It may be so But you should never see it rise as it doth if it were not checkt For at the Straight of Magellan the great South-Sea is checkt by the shore of the Continent of Peru and Chily and forced to rise to a great height and made to run up into the Northern Seas on that side by the coast of China and at the return is checkt again and forced through the Atlantick into the British and German Seas And this is done every day For we have supposed that the Earths Motion in the Ecliptique caused by the Sun is Annual and that its Motion in the Aequinoctial is Diurnal It followeth therefore from this compounded Motion of the Earth the Sea must Ebb and Flow twice in the space of Twenty four hours or thereabout A. Has the Moon nothing to do in this business B. Yes For she hath also the like Motion And is though less swift yet much neerer to the Earth And therefore when the Sun and Moon are in Conjunction or Opposition the Earth as from two Agents at once must needs have a greater Succussion And if it chance at the same time the Moon also be in the Ecliptique it will be yet greater because the Moon then worketh on the Earth less obliquely A. But when the Full or New Moon happen to be then when the Earth is in the Aequinoctial points the Tides are greater than ordinary Why is that B. Because then the force by which they move the Sea is at that time to the force by which they move the same at other times as the Aequinoctial Circle to one of its Parallels which is a lesser Circle A. 'T is evident And 't is pleasant to see the Concord of so many and various motions when they proceed from one and the same Hypothesis But what say you to the stupendious Tides which happen on the Coasts of Lincolnshire on the East and in the River of Severn on the West B. The cause of that is their proper Scituation For the Current of the Ocean through the Atlantick Sea and the Current of the South-Sea through the Northern Seas meeting together raise the water in the Irish and British Seas a great deal higher than ordinary Therefore the mouth of the Severn being directly opposite to the Current from the Atlantick Sea and those Sands on the Coast of Lincolnshire directly opposite to the Current of the German Sea those Tides must needs fall furiously into them by this Succussion of the water A. Does when the Tide runs up into a River the water all rise together and fall together when it goes out No One part riseth and another falleth at the same time because the Motion of the Earth rising and falling is that which makes the Tide A. Have you any Experiment that shews it B. Yes You know that in the Thames it is high water at Greenwich before it is high water at London-bridge The water therefore falls at Greenwich whilst it riseth all the way to London But except the top of the water went up and the lower part downward it were impossible A. 'T is certain It is strange that this one Motion should salve so many apparences and so easily But I will produce one Experiment of water not in the Sea but in a Glass If you can shew me that the cause of it is this compounded Motion I shall go neer to think it the Cause of all other Effects of Nature hitherto disputed of The Experiment is common and described by the Lord Chancellour Bacon in the third page of his Natural History Take saith he a Glass of water and draw your finger round about the lip of the Glass pressing it somewhat hard after you have done so a few times it will make the water frisk up into a fine Dew After I had read this I tried the same with all diligence my self and found true not onely the frisking of the water to above an inch high but also the whole Superficies to circulate and withal to make a pleasant sound The Cause of the frisking he attributes to a tumult of the inward parts of the Substance of the Glass striving to free it self from the pressure B. I have tried and found both the Sound and Motion and do not doubt but the pressure of the parts of the Glass was part of the Cause But the Motion of my finger about the Glass was always parallel and when it chanced to be otherwise both Sound and Motion ceased A. I found the same And being satisfied I proceed to other questions How is the water being a heavie Body made to ascend in small particles into the Air and be there for a time sustained in form of a Cloud and then fall down again in Rain B. I have shewn already that this compounded Motion of the Sun in one part of its Circumlation drives the Air one way and in the other part the contrary way and that it cannot draw it back again no more than he that sets a stone a flying can pull it back The Air therefore which is contiguous to the water being thus distracted must either leave a Vacuum or else some part of the water must rise and fill the spaces continually forsaken by the Air. But that there is no Vacuum you have granted Therefore the water riseth into the Air and maketh the Clouds and seeing they are very small and invisible parts of the water are though naturally heavie easily carried up and down with the Wind till meeting with some Mountain or other Clouds they be prest together into greater drops and
fall by their weight So also it is forced up in moist ground and with it many small Atomes of the Earth which are either twisted with the rising water into Plants or are carried up and down in the Air incertainly But the greatest Quantity of Water is forced up from the great South and Indian Seas that lie under the Tropique of Capricorn And this Climate is that which makes the Suns Perigaeum to be always on the Winter-Solstice And that is the part of the Terrestrial Globe which Keplerus says is kinde to the Sun whereas the other part of the Globe which is almost all dry land has an Antipathy to the Sun And so you see where this Magnetical vertue of the Earth lies For the Globe of the Earth having no Natural Appetite to any place may be drawn by this Motion of the Sun a little neerer to it together with the water which it raiseth A. Can you guess what may be the Cause of Wind B. I think it manifest that the unconstant Winds proceed from the uncertain Motion of the Clouds ascending and descending or meeting with one another For the Winds after they are generated in any place by the descent of a Cloud they drive other Clouds this way and that way before them the Air seeking to free it self from being pent up in a straight For when a Cloud descendeth it makes no wind sensible directly under it self But the Air between it and the Earth is prest and forced to move violently outward For it is a certain Experiment of Mariners that if the Sea go high when they are becalmed they say they shall have more Wind than they would and take in their Sails all but what is necessary for steering They know it seems that the Sea is moved by the descent of Clouds at some distance off Which presseth the water and makes it come to them in great Waves For a Horizontal Wind does but curl the Water A. From whence come the Rivers B. From the Rain or from the falling of Snow on the higher ground But when it descendeth under ground the place where it again ariseth is called the Spring A. How then can there be a Spring upon the top of a Hill B. There is no Spring upon the very top of a Hill unless some Natural Pipe bring it thither from a higher Hill A. Julius Scaliger says there is a River and in it a Lake upon the top of Mount Cenis in Savoy and will therefore have the Springs to be ingendred in the Caverns of the Earth by Condensation of the Air. B. I wonder he should say that I have pass'd over that Hill twice since the time I read that in Scaliger and found that River as I pass'd and went by the side of it in plain ground almost two miles Where I saw the water from two great Hills one on one side the other on the other in a thousand small Rillets of melting Snow fall down into it Which has made me never to use any Experiment the which I have not my self seen As for the conversion of Air into Water by Condensation and of Water into Air by Rarefaction though it be the doctrine of the Peripatetiques it is a thing incogitable and the words are insignificant For by Densum is signified onely frequencie and closeness of parts and by Rarum the contrary As when we say a Town is thick with houses or a Wood with trees we mean not that one house or tree is thicker than another but that the spaces between are not so great But since there is no Vacuum the spaces between the parts of Air are no larger than between the parts of Water or of any thing else A. What think you of those things which Mariners that have sailed through the Atlantick Sea called Spouts which pour down water enough at once to drown a great Ship B. 'T is a thing I have not seen And therefore can say nothing to it though I doubt not but when two very large and heavie Clouds shall be driven together by two great and contrary winds the thing is possible A. I think your reason good And now will propound to you another Experiment I have seen an exceeding small Tube of Glass with both ends open set upright in a Vessel of Water and that the Superficies of the Water within the Tube was higher a good deal than of that in the Vessel but I see no reason for it B. Was not part of the Glass under Water Must not then the Water in the Vessel rise Must not the Air that lay upon it rise with it Whither should this rising Air go since there is no place empty to receive it It is therefore no wonder if the Water press'd by the Substance of the Glass which is dipt into it do rather rise into a very small Pipe than come about a longer way into the open Air. A. 'T is very probable I observed also that the top of the inclosed Water was a concave Superficies which I never saw in other Fluids B. The Water hath some degree of tenacity though not so great but that it will yield a little to the Motion of the Air as is manifest in the Bubbles of water where the concavity is always towards the Air. And this I think the cause why the Air and Water meeting in the Tube make the Superficies towards the Air concave which it cannot do to a Fluid of greater tenacity A. If you put into a Bason of Water a long rag of Cloth first drenched in water and let the longer part of it hang out it is known by Experience that the Water will drop out as long as there is any part of the other end under Water B. The cause of it is that water as I told you hath a degree of tenacity And therefore being continued in the rag till it be lower without than within the weight will make it continue dropping though not onely because it is heavie for if the rag lay higher without than within and were made heavier by the breadth it would not descend but 't is because all heavie Bodies Naturally descend with proportion of swiftness duplicate to that of the time whereof I shall say more when we talk of Gravity A. You see how despicable Experiments I trouble you with But I hope you will pardon me B. As for mean and common Experiments I think them a great deal better Witnesses of Nature than those that are forced by fire and known but to very few CAP. VI. Of the Causes and Effects of Heat and Cold. A. 'T Is a fine day and pleasant walking through the Fields but that the Sun is a little too hot B. How know you that the Sun is hot A. I feel it B. That is to say you know that your self but not that the Sun is hot But when you finde your self hot what Body do you feel A. None B. How then can you infer your heat from the Sense of Feeling Your walking
Aequator B. And so did I once But the reason commonly given for it is so improbable that I do not think so now For the Cause they render of it is onely that the Motion of the Earth is swiftest in the Aequinoctial and slowest about the Poles and consequently since Motion is the Cause of Heat and Cold is but as 't was thought a want of the same they inferr'd that the greatest Cold must be about the Poles of the Aequinoctial Wherein they miscounted For not every Motion causeth Heat but this agitation onely which we call compounded Motion though some have alleadged Experience for that opinion as that a Bullet out of a Gun will with its own swiftness melt Which I never shall believe A. 'T is a common thing with many Philosophers to maintain their Fancies with any rash report and sometimes with a Lye But how is it possible that so soft a Substance as water should be turned into so hard a Substance as Ice B. When the Air shaves the Globe of the Earth with such swiftness as that of Sixty miles in a minute of an hour it cannot where it meets with still water but beat it up into small and undistinguishable bubbles and involve it self in them as in so many bladders or skins of Water And Ice is nothing else but the smallest imaginable parts of Air and Water mixt which is made hard by this compounded Motion that keeps the parts so close together as not to be separated in one place without disordering the Motion of them all For when a Body will not easily yield to the impression of an external Movent in one place without yielding in all we call it Hard And when it does we say 't is Soft A. Why is not Ice as well made in a moved as in a still water Are there not great Seas of Ice in the Northern parts of the Earth B. Yes and perhaps also in the Southern parts But I cannot imagine how Ice can be made in such agitation as is always in the open Sea made by the Tides and by the Winds But how it may be made at the Shoar it is not hard to imagine For in a River or Current though swift the water that adhereth to the banks is quiet and easily by the Motion of the Air driven into small insensible bubbles and so may the water that adhereth to those bubbles and so forwards till it come into a stream that breaks it and then it is no wonder though the fragments be driven into the open Sea and freeze together into greater lumps But when in the open Sea or at the Shoar the Tide or a great Wave shall arise this young and tender Ice will presently be washt away And therefore I think it evident that as in the Thames the Ice is first made at the banks where the Tide is weak or none and broken by the stream comes down to London and part goes to the Sea floating till it dissolve and part being too great to pass the Bridge stoppeth there and sustains that which follows till the River be quite frozen over So also the Ice in the Northern Seas begins first at the banks of the Continent and Islands which are scituated in that Climate and then broken off are carried up and down and one against another till they become great Bodies A. But what if there be Islands and narrow Inlets of the Sea or Rivers also about the Pole of the Aequinoctial B. If there be 't is very likely the Sea may also there be covered all over with Ice But for the truth of this we must stay for some further discovery A. When the Ice is once made and hard what dissolves it B. The Principal Cause of it is the weight of the water it self but not without some abatement in the Stream of the Air that hardned it as when the Sun-beams are less oblique to the Earth or some contrary Wind resisteth the stream of the Air. For when the impediment is removed then the nature of the water only worketh and being a heavie Body downward A. I forgot to ask you Why two pieces of Wood rub'd swiftly one against another will at length set on fire B. Not onely at length but quickly if the Wood be dry And the Cause is evident viz. the compounded Motion which dissipates the external small parts of the Wood. And then the inner parts must of necessity to preserve the Plenitude of the Universe come after first the most Fluid and then those also of greater consistence which are first erected and the Motion continued made to flie swiftly out whereby the Air driven to the Eye of the beholder maketh that fancie which is called Light A. Yes I remember you told me before that upon any strong pressure of the Eye the resistance from within would appear a Light But to return to the enquiry of Heat and Cold there be two things that beyond all other put me into admiration One is the swiftness of kindling in Gunpowder The other is the freezing of Water in a Vessel though not far from the fire set about with other water with Ice and Snow in it When Paper or Flax is flaming the flame creeps gently on and if a house full of Paper were to be burnt with putting a Candle to it it will be long in burning whereas a spark of fire would set on flame a mountain of Gunpowder in almost an instant B. Know you not Gunpowder is made of the powder of Charcole Brimstone and Salt-peter Whereof the first will kindle with a spark the second flame as soon as toucht with fire and the third blows it as being composed of many Orbs of Salt fill'd with Air and as it dissolveth in the flame furiously blowing increaseth it And as for making Ice by the fire side It is manifest that whilst the Snow is dissolving in the external vessel the Air must in the like manner break forth and shave the Superficies of the inner vessel and work through the water till it be frozen A. I could easily assent to this if I could conceive how the Air that shaves as you say the outside of the Vessel could work through it I conceive well enough a pail of water with Ice or Snow dissolving in it and how it causeth Wind. But how that Wind should communicate it self through the vessel of wood or metal so as to make it shave the Superficies of the water which is within it I do not so well understand B. I do not say the inner Superficies of the vessel shaves the water within it But 't is manifest that the Wind made in the Pail of water by the melting Snow or Ice presseth the sides of the Vessel that standeth in it and that the pressure worketh clean through how hard soever the Vessel be and that again worketh on the water within by restitution of its parts and so hardeneth the water by degrees A. I understand you now The Ice in the Pail
is that which maketh Fermentation scattering dissimilar parts and congregating similar A. Why do some hard Bodies resist breaking more one way than another B. The Bodies that do so are for the most part Wood and receive that quality from their generation For the heat of the Sun in the Spring-time draweth up the moisture at the Root and together with it the small parts of the Earth and twisteth it into a small twig by its Motion upwards to some length but to very little other dimensions and so leaves it to dry till the Spring following and then does the same to that and to every small part round about it so that upward the strength is doubled and the next year trebled c. And these are called the grain of the Wood and but touch one another like sticks with little or no binding and therefore can hardly be broken across the grain but easily all-along it Also some other hard Bodies have this quality of being more fragile one way than another as we see in quarrels of a Glass-window that are aptest many times to break in some crooked Line The cause of this may be that when the glass hot from the Furnace is poured out upon a Plain any small stones in or under it will break the stream of it into divers lines and not onely weaken it but also cause it falsly to represent the Object you look on through it A. What is the Cause why a Bow of Wood or Steel or other very hard Body being bent but not broken will recover its former degree of straightness B. I have told you already how the smallest parts of a hard Body have every one by the generation of hardness a Circular or other compounded Motion such Motion is that of the smallest parts of the Bow Which Circles in the bending you press into narrower figures as a Circle into an Ellipsis and an Ellipsis into a narrower but longer Ellipsis with violence which turns their Natural Motion against the outward parts of the Bow so bent and is an Endeavour to stretch the Bow into its former posture Therefore if the impediment be removed the Bow must needs recover its former Figure A. 'T is manifest and the cause can be no other but that except the Bow have Sense B. And though the Bow had Sense and Appetite to boot the Cause will be still the same A. Do you think Air and Water to be pure and Homogeneous Bodies B. Yes and many Bodies both Hard and Heavie to be so too and many liquors also besides water A. Why then do men say they finde one Air healthy another infectious B. Not because the nature of the Air varies but because there are in the Air drawn or rather beaten up by the Sun many little Bodies whereof some have such Motion as is healthful others such as is hurtful to the life of man For the Sun as you see in the generation of Plants can fetch up Earth as well as Water and from the driest ground any kind of Body that lieth loose so it be small enough rather than admit any Emptiness By some of these small Bodies it is that we live which being taken in with our breath pass into our blood and cause it by their compounded Motion to circulate through the Veins and Arteries which the blood of it self being a heavie Body without it cannot do What kind of substance these Atomes are I cannot tell Some suppose them to be Nitre As for those infectious creatures in the Air whereof so many die of the Plague I have heard that Monsieur Des Cartes a very ingenious man was of opinion that they were little Flies But what grounds he had for it I know not though there be many Experiments that invite me to believe it For first we know that the Air is never universally infected over a whole Country but onely in or neer to some populous Town And therefore the cause must also be partly ascribed to the multitude thronged together and constrained to carry their Excrements into the fields round about and neer to their habitation Which in time fermenting breed Worms which commonly in a month or little more naturally become Flies and though engendred at one Town may flie to another Secondly in the beginning of a Plague those that dwell in the Suburbs that is to say neerest to this corruption are the poorest of the people that are nourished for the most part with the Roots and Herbs which grow in that corrupted dirt so that the same filth makes both the blood of poor people and the substance of the Fly And 't is said by Aristotle that every thing is nourished by the matter whereof it is generated Thirdly when a Town is infected the Gentlemen and those that live on wholsomest food scarce one of Five hundred die of the Plague It seems therefore whatsoever creatures they be that invade us from the Air they can discern their proper nourishment and do not enter into the mouth and nostrils with the breath of every man alike as they would do if they were inanimate Fourthly a man may carry the infection with him a great way into the Country in his Clothes and infect a Village Shall another man there draw the Infection from the Clothes onely by his breath Or from the Hangings of a Chamber wherein a man hath died It is impossible Therefore whatsoever killing thing is in the Clothes or Hangings it must rise and go into his mouth or nostrils before it can do him hurt It must therefore be a Fly whereof great numbers get into the blood and there feeding and breeding Worms obstruct the Circulation of the blood and kill the man A. I would we knew the palate of those little Animals we might perhaps finde some medicine to fright them from mingling with our breath But what is that which kills men that lie asleep too neer a Charcole-fire Is it another kind of Fly Or is Charcole venimous B. It is neither Fly nor venim but the Effect of a flameless glowing fire which dissipates those Atomes that maintain the circulation of the blood so that for want of it by degrees they faint and being asleep cannot remove but in short time there sleeping die as is evident by this that being brought into the open Air without other help they recover A. 'T is very likely The next thing I would be informed of is the nature of Gravity But for that if you please we will take another day CAP. VIII Of Gravity and Gravitation B. WHat Books are those A. Two Books written by two learned men concerning Gravity I brought them with me because they furnish me with some material Questions about that Doctrine though of the nature of Gravity I finde no more in either of them than this That Gravity is an Intrinsecal Quality by which a Body so qualified descendeth perpendicularly towards the Superficies of the Earth B. Did neither of them consider that descending is local Motion
that they might have called it an intrinsecal Motion rather than an intrinsecal quality A. Yes But not how Motion should be intrinsecal to the special individual Body moved For how should they when you are the first that ever sought the differences of Qualities in local Motion except your authority in Philosophy were greater with them than it is For 't is hard for a man to conceive except he see it how there should be Motion within a Body otherwise than as it is in living creatures B. But it may be they never sought or despaired of finding what natural Motion could make any inanimate thing tend one way rather than another A. So it seems But the first of them enquires no further than Why so much water being a heavie Body as lies perpendicularly on a Fishes back in the bottom of the Sea should not kill it The other whereof the Author is Dr. Wallis treateth universally of Gravity B. Well But what are the Questions which from these Books you intend to ask me A. The Author of the first Book tells me that Water and other Fluids are Bodies continued and act as to Gravity as a piece of Ice would do of the same Figure and quantity Is that true B. That the Universe supposing there is no place empty is one entire Body and also as he saith it is a continual Body is very true And yet the parts thereof may be contiguous without any other cohesion but Touch. And it is also true that a Vessel of Water will descend in a medium less heavie but Fluid as Ice would do A. But he means that water in a Tub would have the same Effect upon a Fish in the bottom of the Tub as so much Ice would have B. That also would be true if the water were frozen to the sides of it Otherwise the Ice if there be enough will crush the Fish to death But how applies he this to prove that the water cannot hurt a Fish in the Sea by its weight A. It plainly appears that Water does not Gravitate on any part of it self beneath it B. It appears by Experience but not by this Argument though instead of Water the Tub were fill'd with Quicksilver A. I thought so But how it comes to pass that the Fish remains uncrush'd I cannot tell B. The Endeavour of the Quicksilver downward is stopt by the resistance of the hard bottom But all Resistance is a contrary Endeavour that is an Endeavour upwards which gives the like Endeavour to the Quicksilver which is also heavie and thereby the Endeavour of the Quicksilver is diverted to the sides round-about where stopt again by the resistance of the sides it receives an Endeavour upwards which carries the Fish to the top lying all the way upon a soft bed of Quicksilver This is the true manner how the Fish is saved harmless But your Author I believe either wanted age or had too much business to study the doctrine of Motion and never considered that Resistance is not an impediment onely or privation but a contrary Motion and that when a man claps two pieces of Wax together their contrary Endeavour will turn both the pieces into one Cake of Wax A. I know not the Author but it seems he has deeplier considered this Question than other men For in the Introduction to his Book he saith That men have pre-engaged themselves to maintain certain Principles of their own invention and are therefore unwilling to receive any thing that may render their labour fruitless and That they have not strictly enough considered the several interventions that abate impede advance or direct the Gravitation of Bodies B. This is true enough and he himself is one of those men in that he considered not that Resistance is one of those interventions which abate impede and direct Gravitation But what are his Suppositions for the Question he handles A. His first is That as in a Pyramide of Brick wherein the Bricks are so joyned that the uppermost lies every where over the joynt or Cement of the two next below it you may break down a part and leave a Cavity and yet the Bricks above will stand firm and sustain one another by their cross posture So also it is in Wheat Hail-shot Sand or Water and so they arch themselves and thereby the Fish is every way secured by an arch of water over it B. That the cause why Fishes are not crusht nor hurt in the bottom of the Sea by the weight of the water is the waters arching it self is very manifest For if the uppermost Orb of the water should descend by its Gravity it would tend toward the Centre of the Earth and place it self all the way in a less and lesser Orb which is impossible For the places of the same Body are always equal But that Wheat Sand Hail-shot or loose Stones should make a firm arch is not credible A. The Author therefore it seems quits it And taketh a second Hypothesis for the true Cause though the former he saith be not useless but contributes its part to it B. I see though he depart from his Hypothesis he looks back upon it with some kindness What is his second Hypothesis A. It is That Air and Water have an Endeavour to Motion upward downward directly obliquely and every way For Air he saith will come down his chimney and in at his door and up his stairs B. Yes and mine too and so would Water if I dwelt under water rather than admit of Vacuum But what of that A. Why then it would follow that those several tendencies or Endeavours would so abate impede and correct one another as none of them should Gravitate Which being granted the Fish can take no harm Wherein I finde one difficulty Which is this The Water having an Endeavour to Motion every way at once methinks it should go no way but lie at rest which he saith was the opinion of Stevinus and rejecteth it saying it would crush the Fish into pieces B. I think the Water in this case would neither rest nor crush For the Endeavour being as he saith intrinsecal and every way must needs drive the water perpetually outward that is to say as to this Question upwards and seeing the same Endeavour in one individual Body cannot be more ways at once than one it will carry it on perpetually without limit beyond the fixed Stars and so we shall never more have rain A. As ridiculous as it is it necessarily follows B. What are Dr. Wallis his Suppositions A. He goes upon Experiments And first he alleadgeth this That Water left to it self without disturbance does naturally settle it self into a Horizontal Plain B. He does not then as your Author and all other men take Gravity for that Quality whereby a Body tendeth to the Centre of the Earth A. Yes he defines Gravity to be a Natural propension towards the Centre of the Earth B. Then he contradicteth himself For if all heavie
Bodies tend naturally to one Centre they shall never settle in a Plain but in a Spherical Superficies But against this That such an Horizontal Plain is found in water by Experience I say it is impossible For the Experiment cannot be made in a Bason but in half a mile at Sea Experience visibly shews the contrary According to this he should think also that a pair of Scales should hang parallel A. He thinks that too B. Let us then leave this Experiment What saies he further concerning Gravity A. He takes for granted not as an Experiment but an Axiome that Nature worketh not by election but ad ultimum virium with all the power it can B. I think he means for 't is a very obscure passage that every inanimate Body by nature worketh all it can without election which may be true But 't is certain that men and beasts work often by election and often without election as when he goes by election and falls without it In this sence I grant him that Nature does all it can But what infers he from it A. That naturally every Body has every way if the ways oppose not one another an Endeavour to Motion And consequently that if a Vessel have two holes one at the side another at the bottom the water will run out at both B. Does he think the Body of water that runs out at the side and that which runs out at the bottom is but one and the same Body of water A. No sure He cannot think but that they are two several parts of the whole Water in the Vessel B. What wonder is it then if two parts of water run two ways at once or a thousand parts a thousand ways Does it follow thence that one Body can go more than one way at once Why is he still medling with things of such difficulty He will finde at last that he has not a Genius either for Natural Philosophy or for Geometry What other Suppositions has he A. My first Author had affirmed that a lighter Body does not Gravitate on a heavier against this Dr. Wallis thus argueth Let there be a Siphon A B C D filled with Quicksilver to the level A D. If then you pour Oyl upon A as high as to E he asketh if the Oyl in A E as being heavie shall not press down the Quicksilver a little at A and make it rise a little at D suppose to F. And answers himself that certainly it will So that it is neither an Experiment nor an Hypothesis but onely his opinion B. Whatsoever it be it is not true though the Doctor may be pardoned because the contrary was never proved A. Can you prove the contrary B. Yes For the Endeavour of the Quicksilver both from A and D downward is stronger than that of the Oyl downward If therefore the Endeavour of the Quicksilver were not resisted by the bottom B C it would fall so by reason of the acceleration of heavie Bodies in their descending as to leave the Oyl so that it should not onely not press but also not touch the Quicksilver It is true in a pair of Scales equally charged with Quicksilver that the addition of a little Oyl to either Scale will make it praeponderate And that was it deceiv'd him A. 'T is evident The last Experiment he cites is the weighing of Air in a pair of Scales where 't is found manifestly that it has some little weight For if you weigh a Bladder and put the weight into one Scale and then blow the Bladder full of Air and put it into the other Scale the full Bladder will outweigh the empty Must not then the Air Gravitate B. It does not follow I have seen the Experiment just as you describe it but it can never be thence demonstrated that Air has any weight For as much Air as is prest downward by the weight of the blown Bladder so much will rise from below and lay it self Spherically at the altitude of the Center of gravity of the Bladder so blown So that all the Air within the Bladder above that Centre is carried thither imprisoned and by violence And the force that carries it up is equal to that which presseth it down There must therefore be allowed some little counterpoise in the other Scale to ballance it Therefore the Experiment proves nothing to his purpose And whereas they say there be small heavie Bodies in the Air which make it Gravitate do they think the force which brought them thither cannot hold them there A. I leave this Question of the Fish as cleerly resolved because the water tending every way to one point which is the Centre of the Earth must of necessity arch it self And now tell me your own opinion concerning the Cause of Gravity and why all Bodies descend or ascend not all alike For there can be no more Matter in one place than another if the places be equal B. I have already shewed you in general that the difference of Motion in the parts of several Bodies makes the difference of their Natures And all the difference of Motions consisteth either in swiftness or in the way or in the duration But to tell you in Special why Gold is heaviest and then Quicksilver and then perhaps Lead is more than I hope to know or mean to enquire for I doubt not but that the Species of heavie hard Opaque and Diaphanous were all made so at their creation and at the same time separated from different Species So that I cannot guess at any particular Motions that should constitute their natures further than I am guided by the Experiments made by fire or mixture A. You hope not then to make Gold by Art B. No unless I could make one and the same thing heavier than it was God hath from the beginning made all the Kindes of Hard and Heavie and Diaphanous Bodies that are and of such Figure and magnitude as he thought fit but how small soever they may by accretion become greater in the Mine or perhaps by generation though we know not how But that Gold by the art of man should be made of not Gold I cannot understand nor can they that pretend to shew how For the heaviest of all Bodies by what mixture soever of other Bodies will be made lighter and not to be received for Gold A. Why when the Cause of Gravity consisteth in Motion should you despair of finding it B. It is certain that when any two Bodies meet as the Earth and any heavie Body will the Motion that brings them to or towards one another must be upon two contrary ways and so also it is when two Bodies press each other in order to make them Hard. So that one contrariety of Motion might cause both Hard and Heavie But it doth not For the hardest Bodies are not always the heaviest Therefore I finde no access that way to compare the Causes of different Endeavours of heavie Bodies to descend A. But shew
ask concerning Gravity If Gravity be as some define it an intrinsecal quality whereby a Body descendeth towards the Center of the Earth how is it possible that a piece of Iron that hath this intrinsecal quality should rise from the Earth to go to a Loadstone Hath it also an intrinsecal quality to go from the Earth It cannot be The Cause therefore must be extrinsecal And because when they are come together in the Air if you leave them to their own nature they will fall down together they must also have some like extrinsecal Cause And so this magnetique vertue will be such another vertue as makes all other heavy Bodies to descend in this our World to the Earth If therefore you can from this your Hypothesis of compounded Motion by which you have so probably salved the Problem of Gravity salve also this of the Loadstone I shall acknowledge both your Hypothesis to be true and your Conclusion to be well deduced B. I think it not impossible But I will proceed no further in it now than for the facilitating of the demonstrations to tell you the several proprieties of the Magnet whereof I am to shew the causes As first That Iron and no other Body at some little distance though heavy will rise to it Secondly That if it be laid upon a still Water in a floating Vessel and left to it self it will turn it self till it lye in a Meridian that is to say with one and the same Line still North and South Thirdly If you take a long slender piece of Iron and apply the Loadstone to it and according to the position of the Poles of the Loadstone draw it over to the end of the Iron the Iron will have the same Poles with the Magnet so it be drawn with some pressure but the Poles will lye in a contrary Position and also this long Iron will draw other Iron to it as the Magnet doth Fourthly This long Iron if it be so small as that poiz'd upon a Pin the weight of it have no visible Effect the Navigators use it for the Needle of their Compass because it points North and South saving that in most places by particular accidents it is diverted which diversion is called the variation of the Horizontal Needle Fifthly The same Needle placed in a Plain perpendicular to the Horizon hath another Motion called the Inclination Which that you may the better conceive draw a fourth Figure wherein let there be a Circle to represent the Terrella that is to say a Spherical Magnet A. Let this be it whose Center is A the North Pole B the South Pole C. B. Join B C and cross it at right Angles with the Diameter D E. A. 'T is done B. Upon the point D set the Needle parallel to B C with the cross for the South Pole and the Barb for the North and describe a Square about the Circle B D C E and divide the arch D B into four equal parts in a b c. A. 'T is done B. Then place the middle of the Needle on the points a b c so that they may freely turn and set the Barb which is at D toward the North and that which is at C towards the South You see plainly by this that the Angles of Inclination through the Arch D C taken all together are double to a Right Angle For when the South point of the Needle looking North as at D comes to look South as at C it must make half a Circle A. That is true And if you draw the Sine of the Arch D a which is d a and the Sine of the Arch B a which is a c and the Sine of the Arch D b which is b f and the Sine of the Arch B c which is c g the Needle will lye upon b f with the North-point downwards so that the Needle will be parallel to A D. Then from a draw the line a h making the Angle e a h equal to the Angle D A a. And then the Needle at a shall lye in the line a h with the South point toward h. Finally draw the line c h which with c g will also make a quarter of a right Angle and therefore if the Needle be plac'd on the point c it will lye in c h with the South point toward h. And thus you see by what degrees the Needle inclines or dips under the Horizon more and more from D till it come to the North Pole at B where it will lye parallel to the Needle in D but with their Barbs looking contrary ways And this is certain by experience and by none contradicted B. You see then why the degrees of the Inclinatory Needle in coming from D to B are double to the degrees of a Quadrant It is found also by experience that Iron both of the Mine and of the Furnace put into a Vessel so as to float will lay it self if some accident in the Earth hinder it not exactly North and South And now I am from this compounded Motion supposed by Copernicus to derive the causes why a Loadstone draws Iron why it makes Iron to do the same why naturally it placeth it self in a parallel to the Axis of the Earth why by passing it over the Needle it changes its Poles and what is the cause that it inclines But it is your part to remember what I told you of Motion at our second meeting and what I told you of this compounded Motion supposed by Copernicus at our fourth meeting CAP. IX Of the Loadstone and its Poles and whether they shew the Longitude of places on the Earth A. I Come now to hear what Natural Causes you can assign of the vertues of the Magnet and first why it draws Iron to it and only Iron B. You know I have no other cause to assign but some local Motion and that I never approved of any argument drawn from Sympathy Influence Substantial Forms or Incorporeal Effluvia For I am not nor am accounted by my Antagonists for a Witch But to answer this Question I should describe the Globe of the Earth greater than it is at B in the first Figure but that the Terrella in the fourth Figure will serve our turn For 't is but calling B and C the Poles of the Earth and D E the Diameter of the Aequinoctial Circle and making D the East and E the West And then you must remember that the Annual Motion of the Earth is from West to East and compounded of a straight and circular Motion so as that every point of it shall describe a small Circle from West to East as is done by the whole Globe And let the Circles about a b c be three of those small Circles A. Before you go any further I pray you shew me how I must distinguish East and West in every part of this Figure For wheresoever I am on Earth suppose at London and see the Sun rise suppose in Cancer is not a
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
Sphere that encompasseth the Earth being a substance that hath not solidity to keep pace with the Earth looseth in its Motion And that may be the Cause of the Motion of the Magnetick Poles from East to West A. This is very fine and unexpected The Magnetick Sphere which I took for a Globe made of a Magnet has not solidity to keep pace with the Earth though it be one of the hardest Stones that are It encompasseth the Earth yet I thought nothing had encompassed the Earth but Air in which I breath and move By this also the whole Earth must be a Loadstone For two Bodies cannot be in one place So that he is yet no further than Dr. Gilbert whom he sleights And if the Sphere be a Magnet then the Earth and Loadstone have the same Poles See the force of Truth which though it could not draw to it his reason hath drawn his words to it B. But perhaps he meant that the Magnetick vertue encompasseth the Earth and not the Magnetick Body A. But that helpeth him not For if the Body of the Magnet be not there the vertue then is the vertue of the Earth and so again the Poles of the Earth are Magnetick Poles B. You see how unsafe it is to boast of Doctrines as of Gods gifts till we are sure that they are true For God giveth and denieth as he pleaseth not as our selves wish as now to him he hath given Confidence enough but hath denied him at least hitherto the finding of the Longitudes In the next place Pag. 8. he seems much pleased that his Doctrine agrees with an opinion of Keplerus That from the Creation to the year of our Lord it is to the year 1657 now 5650 years and with that which he saith some Divines have held in times past That as this World was created in six days so it should continue six thousand years By which account the World will be at an end 350 years hence though the Scripture tell us it shall come as a Thief in the night O what advantage 340 years hence will they have that know this over them that know it not by taking up Money at Interest or selling Lands at 20 years purchase A. But he says he will not meddle with that B. Yes when he had medled with it too much already A. But you have not told me wherein consisteth this Agreement between him and Keplerus B. I forgot it 'T is in the Motion of the Magnetick Poles For precedently Pag. 7. he had said that their Period or Revolution was 600 years their yearly Motion 36 min. and Pag. 8. that their Motion is by sixes Six tenths of a degree in one year six degrees in ten year sixty degrees in a hundred year and six times sixty degrees in 600 year A. But what Natural Cause doth he assign of this revolution of 600 years B. None at all For the Magnet lying upon the Earth can have no Motion at all but what the Earth and the Air give it And because it is always at 8 deg 30 min. distance from the Pole of the Earth the Earth can give it no other Motion than what it gives to its own Poles by the precession of the Aequinoctial points Nor can the Air give it any Motion but by its Stream which must needs vary when the Stream varieth But what a vast difference does he make between the period of the Motion of the Aequinoctial points which are about or near 36000 years according to Copernicus Lib. 3. Cap. 6. which makes the Annual precession to be 36 seconds and the period of the Magnetical Poles Motion which is but 600 years A. Go on B. He comes now Pag. 15. to the Inclinatory Needle upon a Spherical Loadstone Where he shews by Diagram that the Needle and the Instrument together moved toward the Magnetical Pole make the sum of the Inclinations equal to two Quadrants setting the North-point of the Needle Southward Which I confess is true But in the same Page he ascribeth the same Motion to the Earth in these words As the Horizontal Needle hath a double Motion about the Round Loadstone or Terrulla so also the Inclinatory Needle hath a double Motion about the Earth What is this but a confession that the Poles of the Magnet and of the Earth are the same A. 'T is plain enough B. Besides seeing he placeth the Magnetical Pole at M in the Meridian of Vaygates the Needle being touch'd shall Incline to the Pole of the Earth which is P as well there as at London and make the North-Pole of the Earth point South A. 'T is certain because he puts both the Magnetical Pole and the Pole of the Earth in the same Meridian of the Earth Nor see I any Cause why the Needle being the same it should not be as subject to Variation and to Variation of Variation and to all Accidents of the Earth there as in any other part B. He putteth Pag. 16. a Question At what distance from the Earth are the Magnetick Poles and answers to it They are very near the Earth because the nearer the Earth the greater the strength What think you of this A. I think they are in the Superficies of the Magnet as the Pole of the Earth is in the Superficies of the Earth And consequently that then the Earth must be a part of the Magnet and their Poles the same For the Body of the Magnet and the Body of the Earth if they be two cannot be in one place B. His next words are Some things are to be considered concerning those Variations of the Horizontal Needle which are not according to the scituation of the place from the Magnetick Poles but are contrary as all the West-Indies according to the Poles should be Easterly and they are Westerly Which is by some Accidental Cause in the Earth and their Motion as I formerly said is a forced Motion and not Natural A. He has clearly overthrown his main Doctrine For to say the Motion of the Needle is forced and unnatural is a most pityful shift and manifestly false no Motion being more constant or less accidental notwithstanding the Variation to which the Inclinatory Needle is no less subject than the Horizontal Needle B. That which deceived him was that he thought them two sorts of Needles forgetting what he had said of Normans Invention of the Inclinatory Needle by the inclining of the Horizontal Needle Pag. 11. For I will shew you that what he says is Easterly and should be Westerly should be Easterly as it is Consider the fourth Figure in which B is the North-Pole and B c 11 deg 15 min. Easterly which was the Variation at London in 1576 Easterly Suppose A c to be the Needle shall it not incline as well here as at D a and the Variation B c be Easterly Again D a is 11 deg 15 min. and the Needle in D parallel to A B and at a inclining also 11 deg 15 min. Westerly
not declared in what that resistance consisteth B. I suppose it proceedeth from the Hardness A. But from thence it will follow that all Transparent Bodies that equally refract are equally Hard. Which I think is not true because the Refraction of Glass is not greater at least in comparison of their Hardnesses than that of Water B. I confess it Therefore I think we must take in Gravity to a Share in the production of this Refraction For I never considered Refraction but in Glass because my business then was only to find the Causes of the Phaenomena of Telescopes and Microscopes Let therefore A B in Fig. 7. be a hard and consequently a heavy Body And from above as from the Sun let C A be the line of Incidence and produced to D. And draw A E perpendicular to A B. It is manifest that the Hardness in A B shall turn the stream of the Light inwards toward A E suppose in the line A e. It is also evident that the Endeavour in B which is being heavy downward shall turn the stream again inward towards A E as in A b. Thus it is in Refraction from the Sun downwards In like manner if the light come from below as from a Candle in the point D the line of Incidence will be D A and produced will pass to C. And the resistance of the Hardness in A will turn the stream A C inward suppose into B l and make C l equal to D e. For passing into a thinner Medium it will depart from the perpendicular in an Angle equal to the Angle D A e by which it came nearer to it in A e. So also the resistance of the Gravity in the point A shall turn the stream of the Light into the line A i and make the Angle l A i equal to the Angle e A b. And thus you see in what manner though not in what proportion Hardness and Gravity conjoyn their resistance in the Causing of Refraction A. But you proved yesterday that a heavy Body does not Gravitate upon a Body equally heavy Now this A B has upper parts and lower parts and if the upper parts do not Gravitate upon the lower parts how can there be any Endeavour at all downward to contribute to the Refraction B. I told you yesterday that when a heavy Body was set upon another Body heavier or harder than it self the Endeavour of it downward was diverted another way but not that it was extinguished But in this case where it lyeth upon Air the first endeavour of the lowest part worketh downward For neither Motion nor Body can be utterly extinguished by a less than an Omnipotent power All Bodies as long as they are Bodies are in Motion one way or other though the farther it be communicated so much the less A. But since you hold that Motion is propagated through all Bodies how hard or heavy soever they be I see no Cause but that all Bodies should be Transparent B. There are divers Causes that take away Transparency First if the Body be not perfectly Homogeneous that is to say if the smallest parts of it be not all precisely of the same nature or do not so touch one another as to leave no Vacuum within it or though they touch if they be not as hard in the contact as in any other line For then the Refractions will be so changed both in their direction and in their strength as that no Light shall come through it to the Eye as in Wood and ordinary Stone and Metal Secondly The Gravity and hardness may be so great as to make the Angle refracted so great as the second Refraction shall not direct the beam of light to the Eye as if the Angle of Refraction were D A E the Refracted line would be perpendicular to A B and never come to the line A D in which is the Eye A. To know how much of the Refraction is due to the Hardness and how much to the Gravity I believe it is impossible though the Quantity of the whole be easily measured in a Diaphanous Body given And both you and Mr. Warner have demonstrated that as the Sine of the Angle Refracted in one Inclination is to the Sine of the Angle Refracted in another Inclination so is the Sine of one Inclination to the Sine of the Angle of the other Inclination Which Demonstrations are both published by Mersennus in the end of the first Volume of his Cogitata Physico-Mathematica But since there be many Bodies through which though there pass Light enough yet no Object appears through them to the Eye what is the reason of that B. You mean Paper For Paper-Windows will enlighten a Room and yet not show the Image of an Object without the Room But 't is because there are in Paper abundance of pores through which the Air passing moveth the Air within by the Reflections whereof any thing within may be seen And in the same Paper there are again as many parts not Transparent through which the Air cannot pass but must be reflected first to all parts of the Object and from them again to the Paper and at the Paper either reflected again or transmitted according as it falls upon Pores or not Pores so that the Light from the Object can never come together at the Eye A. There belongs yet to this Subject the Causes of the diversity of Colours But I am so well satisfied with that which you have written of it in the 24th Chapter of your Book de Corpore that I need not trouble you further in it And now I have but one Question more to ask you which I thought upon last night I have read in an antient Historian that Living Creatures after a great deluge were produced by the Earth which being then very soft there were bred in it it may be by the rapid Motion of the Sun many Blisters which in time breaking brought forth like so many Eggs all manner of living Creatures great and small which since it is grown hard it cannot do What think you of it B. It is true that the Earth produced the first living Creatures of all sorts but Man For God said Gen. 1. vers 24. Let the Earth produce every living Creature Cattle and creeping thing c. But then again ver 25. it is said that God made the Beast of the Earth c. So that it is evident that God gave unto the Earth that vertue Which vertue must needs consist in Motion because all Generation is Motion But Man though the same day was made afterward A. Why hath not the Earth the same vertue now Is not the Sun the same it was Or is there no Earth now soft enough B. Yes And it may be the Earth may yet produce some very small Living Creatures And perhaps Male and Female For the smallest Creatures which we take notice of do engender though they do not all by conjunction therefore if the Earth produce living Creatures at this day God did not absolutely rest from all his Works on the seventh day but as it is Cap. 2. ver 2. he rested from all the work he had made And therefore it is no harm to think that God worketh still and when and where and what he pleaseth Beside 't is very hard to believe that to produce Male and Female and all that belongs thereto as also the several and curious Organs of Sense and Memory could be the work of any thing that had not understanding From whence I think we may conclude that whatsoever was made after the Creation was a new Creature made by God no therwise than the first Creatures were excepting only Man A. They are then in an Errour that think there are no more different kinds of Animals in the World now than there were in the Ark of Noah B. Yes doubtless For they have no Text of Scripture from which it can be proved A. The Questions of Nature which I could yet propound are innumerable And since I cannot go through them I must give over somewhere and why not here For I have troubled you enough though I hope you will forgive me B. So God forgive us both as we do one another But forget not to take with you the Demonstration of a straight Line equal to an Arc of a Circle FINIS Fig. 1. Fig. 3. Fig. 4.