divide one part into ten and that one into ten parts more and those are tens of tens Let A be nul that is a cyfer and there place sixty the second part sixty one the line joyned to right Angles will be two the third part sixty two the line joyned to it will be five so the twentieth part will be eighty and the line joyned to the Angle fifty six to the extremities of these lines I fasten a pin and I put a brass Cithern-wire upon them and upon it I draw a line and the Parabolical line is exactly described by it for should we draw it without the help of this cord it will be wavering and not perfect Then take a brass Table of convenient thickness and draw the line now found upon it filing away all that that shall be above the line CA. These things being done take an iron rod of an exact length namely twelve foot as the line DC and at the end fasten a plate which shall be for the circumvolution of the axis at the other end fasten a spike that it may be fastned somewhere and be handsomely turned about So being well fixed we turn it about by adding clay mingled with straw that it may excellent well make a hollow place like to the form of a Parabolical Section which being dried we must make another solid one that it may contain the liquid Metal as the maner is CHAP. XVII A Parabolical Section that may burn to infinite distance ZOnaras the Greek writes in the third Tome of his Histories That Anastasius moved sedition against Vitalianus a Thracian and he got those of Mysia and the Scythians to stand with him and in the Country by Constantinople he plundered the people and besieged the City with a Fleet. Marianus the Deputy opposed him and there being a fight at sea by an engine made by Proclus a most excellent man for he then was famous for Philosophy and Mathematicks for he not onely knew all the secrets of the most eminent Artificer Archimedes but he found out some new inventions himself the enemies Navy was vanquished For Proclus is reported to have made Burning-Glasses of brass and to have hanged them on the wall against the enemies Ships and when the Sun beams fell upon them that fire brake forth of them like to lightning and so burnt their Ships and men at sea as Dion reports that Archimedes did formerly to the Romans besieging Syracuse But I will shew you a far more excellent way than the rest and that no man as ever I knew writ of and it exceeds the invention of all the Antients and of our Age also and I think the wit of man cannot go beyond it This Glass doth not burn for ten twenty a hundred or a thousand paces or to a set distance but at infinite distance nor doth it kindle in the Cane where the rays meet but the burning line proceeds from the Centre of the Glass of any Longitude and it burns all it meets with in the way Moreover it burns behind before and of all sides Yet I think it an unworthy act to divulge it to the ignorant common people yet let it go into the light that the immense goodness of our great God may be praised and adored Because a proportional Radius doth proceed from the greater Section from the less is made the greater to avoid this make it of a Cylindrical Section for it is the mean and let it be set for the axis of the small and of the greater dissection which may pass through the middle parallels this held against the Sun doth make refraction of the beams sent into it very far and perpendicularly from the Centre of a Cylindrical Section and in this Art the reason cannot be found that the beams uniting should part again Wherefore it receives them directly which it sends back again obliquely into beams far from the superficies of it For the beams passing through the narrow hole of a window are forthwith dilated nor is their proportion kept by being far removed therefore it may reverberate and burn where the Cane seems clearest which will be neer the Centre nor is it far distant from the point where the rays meet but neer the ray coming forth from that point from the superficies of the Glass called Parabolicall which must remain firm in that place which I said before Let experiment be made of its vertue by threds passing from its Centre or iron wire or hair and it is no matter whether it be Parabolical or Sphaerical or any Section of the same order then let it be excellent well fitted upon the Centre of the said Section If the rays go forth above or a little beneath it is no matter if not much money or much money be laid out to make it The making of it depends meerly on the Artificers hand the quantity is nothing be it small or great The Latitude of the hollow is not necessary onely let it be sent forth from the middle that the rays may meet excellent well in the Centre Let the window be made open aslaunt that it may receive a Parabolical Glass and thus shall you have a Glass if that be well done I spake of He that hath ears to hear let him hear I have not spoken barbarously nor could I speak more briefly or more plainly But if a small one do not answer a great one in proportion know that you will operate nothing let it be large about the basis small at the top equidistant to the first Let it not be a steel Glass because it cannot sustain the heat of the burning and by burning it loseth its brightness Let it be therefore of Glass a finger thick Let the Tin foil be of purged Antimony and Lead such as they make in Germany let the form be of clay put the Glass upon it and melt it in a Glass furnace that it may take its form This is a wonder that that which causeth so much burning in the work is cold or at most but luke-warm If you would have it burn before of the Section which is about the basis make a circle in the middle point whereof fit the Artifice that the ray returning may come forth to the fore part This I have said and I have observed that we may use this Artifice in great and wonderful things and chiefly by inscribing letters in a full Moon For whatsoever we have written by this Glass as I said of a plain Glass we may send letters of it to a very great distance and because I said it sends forth to infinite distance it is sent as far as the Moon especially being helped by its light CHAP. XVIII To make a Burning-Glass of many Sphaerical Sections VItellio describes a certain composition of a Burning-glass made of divers Sphaeral Sections but what he writes he proves not nor doth he understand what he says whilst I was searching for that I found this Propound the distance of combustion let
may be easily assured of this for let iron be balanced equally and let one end of the Loadstone draw it if you turn the other end to it it will fly back and turn to the contrary part these points run in a right line through the middle of the stone Yet observe this that the iron which is drawn by one point of the Loadstone or is within the compass of its vertue for a while obtains presently this vertue that what is drawn by the one end of it will be driven off by the other You shall know these differences of attraction more clearly by the following experiment CHAP. XXIV How iron will be made leap upon a Table no Loadstone being seen BY reason of this consent and discord of the Loadstone I use to make pretty sport to make my friends merry For casting the iron on the Table and not putting any Loadstone neer it that the spectators can see the iron will seem to move it self which is very pleasant to behold I do it thus divide a needle in the middle cast one half of it upon the Table but first rub the head of it with one end of the Loadstone Put your hand with the Loadstone privately under the Table and there where the head of the needle lyeth the Loadstone will stick and the needle will presently stand upright and standing so to the wonder of the beholders will walk over the Table and follow the motion of the hand that guides it when it hath gone thus a while presently turn the stone upside down and put the contrary part of the Loadstone to the needle and which is strange the needle will turn about and if it went on the head before it will now go on the point and draw your hand which way you will the needle will follow it and if you turn the stone three or four times putting sometimes the south point sometimes the north point of the stone to it the needle will turn as often and sometimes stand on the head sometimes on the point upright or walk so as you please and sometime it will go with that part it stood upon sometimes it will stand on the part it went I can present my friends with the same sight in a more strange manner for if you put the two pieces of a needle upon a paper or Table whereof one hath touched the north point the other the south point of the stone I can so place two stones that one of the needles shall go upon the head the other upon the point and sometimes one shall turn then both at once or they shall dance orderly and move when any musick is playd on And this is a pretty sight to shew your friends that cannot but admire it CHAP. XXV That the vertue of the Loadstone is sent through the pieces of Iron THat vertue that is imparted to the iron by the Loadstone doth not stay in the iron but is sent from one to another For if you draw a â—eel needle by the touch of the Loadstone and put another needle to the end of that needle that part will draw the needle and hold it hanging in the air and if you apply another needle to that it will do the same You may do this with as many needles as the force of the Loadstone can reach unto but when it grows faint the needle will let the other needle fall as not having strength enough to bear its weight And thus you may hang a great many needles in a chain in the air Plato knew this vertue for he speaks of it in Ione which stone not onely draws iron rings but infuseth vertue into the rings themselves that they can do the same and attract rings as the one doth whence sometimes you shall see a long concatenation of iron rings and all the vertue of them is attracted from that stone Lucretius knew it also A Stone there is that men admire much That makes rings hang in chains by touch Sometimes five or six links will be Fast joyn'd together and agree All this vertue from the Stone ariseth Such force it hath Pliny speaking of the same vertue saith Onely this matter receives strength from another stone and holds it a long time laying hold of another iron that sometimes you shall see a chain of rings which the ignorant vulgar call Live iron Galen You may see in the Loadstone that when it toucheth iron it will â—â—ick to it without any bands and if that was first touched touch another that will â—â—ick as the first doth and likewise a third to the second Augustine de civitate Dei speaking of this wonder said We know that the Loadstone will wonderfully draw iron which when I first saw I trembled at it exceedingly For I saw an iron-ring drawn by the stone that hung in the air by it that communicated the same force to others for another ring put to the first made that hang also and as the first ring hung by the stone so the second ring hung by the first ring In the same manner was there a third and fourth ring applied and fastned and so their rings hung together by the outsides not fastned inwardly like to a chain of rings Who would not admire at the vertue of this stone that was not onely within it but ran through so many rings that hung by it and held them fast with invisible bands But the greater the vertue of the Loadstone is the more rings it will hang up I have hang'd ten needles with a stone of a pound weight But he that would draw many needles let him rub the heads onely against the Loadstone and they will all hold the heads by their points CHAP. XXVI The Loadstone within the sphere of its vertue sends it forth without touching ANd the Loadstone doth not onely impart its vertue to the iron by touching it but which is wonderful within the compass of its vertue it will impart vertue to the iron if it be but present to draw another iron For if you put your Loadstone so neer to the iron that it may have it onely within the circumference of its vertue and you put another iron neer to that iron it will draw it to it and if another touch that which is drawn it will draw that also that you shall see a long chain of rings or needles hanging in the air But when they hang thus together if you â—emove the Loadstone a little farther off the last ring will fall and if yet you remove â— farther the next will fall until they all fall off whence it is clear that without touching it can impart its vertue to the iron CHAP. XXVII How the Loadstone can hang up iron in the air I Have a long time endeavoured much to make iron hang in the air and not touch the Loadstone nor yet tied beneath and now I think it almost impossible to be done Pliny saith it Dinocrates the Architect began to vault the Temple of Arsinoe with
if you put that part to it from which it received its force it will not endure it but drives it from it and draws to it the contrary and opposite part namely the Southern part the reason whereof I set down before The same falls out if you touch the Needle with the South part of the Loadstone for if you presently put the same to it it will resist it and draw to it the North point Hence the parts that are alike are at enmity and rejected as Adversaries and the parts that are unlike do agree as Friends Whence it is apparent That the Loadstone imparts to the Iron a contrary force from what the end it self is and the Steel receives the force of that point of the Loadstone which it toucheth not And I prove it thus Take two Needles and put them in Boats or hang them by Threeds that being touched with the Loadstone they may move freely they are contrary one to the other and they will joyn in the parts that were touched with contrary ends of the Loadstone and will not endure the ends that are alike CHAP. XLI Two Needles touched by the Loadstone obtain contrary Forces I Will relate a strange thing yet not far from Reason If you touch two Needles with a Loadstone together and set them on the same point of it the other parts that hang on the Loadstone will abhor and flie one from the other and if you force them together with your hands so soon as you let them alone they will presently return to their postures and depart as far as they can from one another The reason is this That if two Needles stick fast to one Northern point of the Loadstone with their points you must imagine that they did receive a Southern vertue and because they are of the same similitude they will not endure one the other and because they are fastened to the Loadstone they cannot get off being compelled by a greater force but the opposite points of the Needle because they are both alike Northerly they must needs abhor one the other and when they are free one will part from the other And when they are so hanging on if you put to them the Southern part of another Loadstone they will presently let go their hold and go as far off as they can that sometimes they are pulled off from the Loadstone being forced by an invisible vapor CHAP. XLII That the force of the Iron that draws will drive off Iron by diversity of Situation THat as I said of the Loadstone alone is true of the Iron that is touched with it for if you put a Needle touched with a Loadstone by a Boat swimming in the Water or hanged by a Threed or turning on a point equally balanced if you put upon this a Needle touched with a Loadstone it will draw it and that part that attracted the Iron above will put underneath drive it away and the part that drives off above will draw to it put underneath where you may observe that the position will work contrary operations CHAP. XLIII The Needle touched by the Loadstone on one part doth not alwayes receive Vertue on both parts IF the Needle be touched at one end by the Loadstone it receives Vertue at that end and at the other end the contrary vertue But that must not be understood absolutely but of that Needle that is of a proportionable length for if it be too long the vertue will not come to the other end But would we know how far the vertue is come we must know how far reached the Circumference of the Vertue as I said Therefore if the Circumference of it be a foot the force will go a foot-long into the Needle If we would try this Touch a long Needle three foot long with a Loadstone at one end if it touch the Iron at the other end the Iron touched will not move from its place but if you touch it a foot or two long namely as far as the Circumference of the Loadstones Vertue will reach and then touch the Needle it will presently move and be drawn by it CHAP. XLIV The Needle touched in the middle by the Loadstone sends forth its Force at both ends IF the Needle be somewhat too long and we rub it with the stone in the middle of it the forces of the stones part are diffused to both ends of it but very obscurely for you shall not know which is the end but if you touch it something farther from the middle the neerer part will receive the forces of the part that touched it be it the Northerly or Southerly part CHAP. XLV An Iron Ring touched by a Loadstone will receive both Vertues BUt if we rub an Iron Ring on the one side with a Loadstone then the part that is touched will receive the vertue of the part of the Loadstone that touched it and the opposite part will receive the contrary and therefore the middle of the Iron Ring will be capable but of half the force of it as if it were straight But if we make a Pin round as a Ring and the part joynted together with a joynt be rubbed with a Loadstone and being rubbed be stretched straight again the ends shall receive the same vertue be it Northern or Southern But by degrees that force will grow feeble and in a short time become Northerly and the other Southerly or will receive more vertue then it first had may be when it was touched farther from the end But if you would that of these a Chain of Iron should hang in the Air so soon as one ring touched on one side with the Loadstone hath received force on the other side by it we may hang a Chain of Rings in the Air as we may of Loadstones so then if the Rings be laid in order upon a Table that they may one touch the other though they do not fasten put the Loadstone to them and not onely the first will be drawn but the next and the third that they will hang like links of Rings and not only will it be so if the Loadstone touch the first that the rest will follow but if the stone be but neer it will do the same without touching them CHAP. XLVI An Iron Plate touched in the middle will diffuse its forces to both ends WHat I said of a long Needle I say also of an Iron Bar for if you touch it in the middle the Beams of it are spread like the Beams of the Sun or light of a Candle from the Centre to the Circumference and extream parts But if we touch an Iron Morter being the force is feeble where it is touched about the superficies some vertue may be be perceived but it is very weak in the extream parts CHAP. XLVII How filings of Iron may receive force IF you wrap up filings of Iron in a paper as Druggists do like a Pyramis and put a Loadstone neer it all the filings together will receive
within the earth that so the herb may not bud forth but all the nourishment may be converted to the head of the herb So may we make Onions to grow bigger as Theophrastus supposeth if we take away all the stalk that the whole force of the nourishment may descend downwards lest if it should be diffused the chief vertue thereof should spend it self upon the seeding Sotion saith that if a man plant Onions he must cut off both the tops and the tails thereof that so they may grow to a greater bigness then ordinary Palladius saith that if we desire to have great-headed Onions we must cut off all the blade that so the juyce may be forced down to the lower parts In like manner if we would have Garlick-heads greater then common we must take all the greenish substance thereof before it be bladed and turn it downward that so it may grow into the earth There is yet another Device whereby to make herbs and roots grow bigger then ordinary but yet I like not so well of it howsoever many ancient Writers have set it down and first How to make Leeks grow greater Columella hath prescribed this course you must take a great many Leek-seeds and binde them together in thin linen clouts and so cast them into the ground and they will yeeld large and great leeks Which thing Palladius also confirms by his authority in the very same words But both of them had it out of Theophrastus who putteth it for a general Rule That if a man sowe many seeds bound up together in a linen cloth it will cause both the root to be larger and the buds to be larger also and therefore in his time they were wont to sow Leeks Parsly and other herbs after the same manner for they are of more force when there be many seeds together all of them concurring into one nature Moreover it makes not a little to the enlarging of fruits to take the seeds which we would sow out of some certain part of the former fruit As for example we shall procure A Gourd of a greater or larger growth if we take the seed out of the middle of a Gourd and set it with the top downward This course Columella prescribes in his Hortulus Look saith he where the Gourd swells most and is of the largest compass thence even out of the middle thereof you must take your seed and that will yeeld you the largest fruit And this is experienced not in Gourds onely but also in all other fruits for the seeds which grow in the bowels or belly as it were of any fruit are commonly most perfect and yeeld most perfect fruit wheras the seeds that grow in the outward parts produce for the most part weak unperfect fruit Likewise the grains that are in the middle of the ear yeeld the best corn whereas both the highest and the lowest are not so perfect but because Gourds yeeld great increase therefore the experience hereof is more evidently in them then in any other Cucumbers will be of a great growth as the Quintiles say if the seeds be set with their heads downward or else if you set a vessel full of water under them in the ground that so the roots may be drenched therein for we have known them grow both sweeter and greater by this Device CHAP. XII How to produce fruit that shall not have any stone or kernel in it IT is a received thing in Philosophy especially amongst those that have set forth unto us the choicest and nicest points of Husbandry that if you take Quicksets or any branches that you would plant and get out the pith of them with some ear-picker or any like instrument made of bone they will yeeld fruit without any stone and without any kernel for it is the pith that both breedeth and nourisheth the substance of the kernel But the Arcadians are of a quite contrary opinion for say they every tree that hath any pith in it at all will live but if all the pith be taken out of it it will be so far from yeelding any stoneless fruit that it cannot chuse but die and be quite dried up The reason is because the pith is the moistest and most lively part of any tree or plant for the nourishment which the ground sends up into any plant is conveyed especially by the pith into all the other parts for Nature hath so ordained it that all the parts draw their nourishment as it were their soul and their breath thorow the marrow or pith of the stock as it were thorow a Squirt or Conduit-pipe Which may appear by experience seeing any bough or stalk so soon as the marrow is gone returns and crooks backward till it be quite dried up as the Ancients have shewed But I for my part must needs hold both against Theophrastus and against others also that have written of Husbandry both that trees may live after their marrow is taken from them and also that they will bring forth fruit having stones or kernels in them though there be no pith in the trees themselves as I have shewed more at large in my books of Husbandry Notwithstanding lest I should omit any thing belonging to this argument I have thought good here to set down the examples which those Ancients have delivered in writing that every man that lists may make trial hereof and haply some amongst the rest using greater diligence in the proof hereof then I did may finde better success herein then I have found There be many means whereby Plants may be deprived of kernels as namely by engraffing by taking out their pith by soiling with dung or by watering and by other Devices We will first begin as our wonted manner is with engraffing and will shew how to produce A Peach-apple without a stone Palladius saith he learned this new kinde of engraffing of a certain Spaniard which he saith also he had experienced in a Peach-tree Take a Willow-bough about the thickness of a mans arm but it must be very sound and two yards long at the least bore it thorow the middle and carry it where a young Peach-tree grows then strip off all the Peach-tree-sprigs all but the very top and draw it thorow the hole of the Willow-bough then stick both ends of the Willow into the ground that it may stand bending like a bowe and fill up the hole that you bored with dirt and moss bind them in with thongs About a year after when the Peach-tree and the Willow are incorporated into each other cut the plant beneath the joyning place and remove it and cover both the Willow-bough and the top of the plant also with earth and by this means you shall procure Peaches without stones But this must be done in moist and waterish places and besides the Willow must be relieved with continual watering that so the nature of the wood may be cherished as it delights in moisture and it may also minister abundant
we shall speak of the rest in other places CHAP. IV. The force of the stone is sent by a right line from North to South through the length of it BUt the two points we speak of are the end of the right line running through the middle of the stone from North to South if any man break the stone and break this line those ends of the division will presently be of another property and vertue and will be enemies one to the other which is a great wonder for these two points when they were joined together had the same force of turning to the pole but now being parted asunder one will turn to the North the other to the South keeping the same posture and position they had in the Mine where they were bred and the same happens in the least bits that are seen in the greatest load-stone For example let the rock of Load-stone be ABCD and let the line from North to South be AB if we shall cut the stone AB out of the rock the very line AB in the stone will represent the polar line from North to South But if we break the stone broad-wayes every little piece will keep its line Cut the stone AB broad-ways as CF there will be two stones ACD and EFB I say the stones cut through the line CD each of them will have its poles of the world In the stone AGD the North-pole will be A the South G. In the stone EFB the North will be H the South B and that is beyond all admiration that the points GH whilst the stone was but one were but one as being agreed together they had the same forces but when the stone is divided each part will hold its vertue and be quite contrary and at enmity for G alwayes turns to the South and H to the North and every bit will have its poles and if you fit the divided stones with boats A and H will turn to the North G and B to the South and the same will fall out if you divide AG and HB into many small pieces and if you afterwards join all these pieces together as they were their mutual discord of nature will be presently reconciled Wherefore Cardanus said false that the Load-stone draws where it hath but a thin cover and more in one part then another for it attracts onely from one certain point as it had its position before in the mines CHAP. V. That the polar line in the Loadstone is not stable but moveable BUt the like wonder of nature cannot but be admired amongst many that God hath made and therefore I would have no man ignorant thereof This polar line spoken of is not alwayes certain in the same place nor doth it stand alwayes firm but changes and takes the contrary positions but this is constant in it that it alwayes runs through the middle of the stone like a King that hath alwayes his Court or fort in the midst of his Country for consisting in the centre from whence the extream parts are as it were the circumference it can easily send its forces to all parts and defend it self But an example shall clear this Let the stone be AECF and let the line AC running through the length of it be the polar line we speak of wherein the force of it resides which runs from the North to the South-pole I say if you divide the stone in two pieces by the line AC that one piece may be AED the other BCF if they be taken asunder that the force of it doth not reside in the extream part of the line AD or BC but being divided in the middle the force is received in the middle of each stone and in the stone AED it will be GH and in BCF it will be IL which cannot be spoken without admiration that in a dead stone there should be a living vertue to move it self who is there unless he try it that will believe these things For as the line that stretcheth from North to South was in the prime so if you divide the stone into a thousand parts that force is sent into all those parts each of them holding its own line in the middle of it so if we shall divide the part AED into other parts and shall part the smallest of them what part soever is parted from its confines it will have that same lively force running long-ways through the middle of it and so it will be if you divide the stone into the smallest sand but the greater wonder is that if you joit all the parts together again as they were at first they will all have the same force united and that will retire into the middle of the stone CHAP. VI. That the force of North and South is vigorous in the points BUt what is more wonderful Though the force retreats to the middle of the stone yet it doth not send it self forth by the middle but by the extream parts of the stone and lies still in the middle as if it were asleep but it is awake in the end and there it comes forth But if a man break the stone he shall see it more perfectly I shall give an example for such that are curious to search out the vertue of the Load-stone Let the Load-stone be AB and A the North pole B the South I say that in AB the end of the stone the force is greater and in the middle of the line ILN it is more weak and drowsie unless there be any vertue unknown in the right and left side CD but the neerer it is to the North or South the more it augments but the farther off it is the more it faints Break the stone in C and G wherein there lay hid a vertue unperceived but it will appear when the stone is broken and shew its properties and one point will shew forth the North the other the South And if these things seem superfluous yet are they necessary as the grounds of what I must say CHAP. VII That by the touching of other stones those points will not change their forces ANd because I said that the Load-stone doth not always hold its forces equal but that one stone is more powerful in operation then another for some are faint and weak I shall put the first question whether by rubbing and touching the weaker stones with the stronger those forces will be changed or stay as they were as if a Load-stone is sluggish in pointing out the pole whether in a stronger stone rubbed with the North point upon the North point of the weaker can help it at all or if we shall rub the South point of the other on the North point of this whether the North point rubbed on will be gone and become the South point or continue in its former vertue Where we have not reason to direct us experience shall prove it For let a Loadstone be of what forces and properties it may be by rubbing it against
go along with the part it agrees with or will go from that part it is contrary to by which Reason you may know that one hinders the other We may also by another Experiment be made more certain of the same thing If you draw one Loadstone with another and let it hang in the Air if to the place where they joyn you apply the contrary force of another Loadstone by this meeting with their Enemy both their forces will fail and faint and if the same be of a great force the stone that drew will let the other go and falls from it And also not without mirth and admiration you shall see a Chain of many pieces of Loadstones hanging together and if you apply the contrary side to the third or fourth stone the Chain is presently broken and the part falls off and will not hang fast but the other parts whither the force of it comes not will yet stick fast together in a Link unless you put the end of the contrary part to them CHAP. XV. How to know the Polar points in the Loadstone VVE may know by another and more certain way then that I set down before which are the vertical points in the Loadstone which turn to the North which to the South and especially that point that sends forth the attractive vertue will be discovered Thus That point that most vehemently draws unto it the South point of another stone and sticks fast to it that is the North point and that point the North part of another stone willingly joyns with is the South point The same also may be known by the driving off That point that drives off from it and refuseth the North part of the stone put against it is the North point and the 〈◊〉 point that drives from it the South point And he that would have the true pole more exactly demonstrated let him do thus Put a little bit of a Loadstone not much greater or lesser then a Millet-Seed to the Loadstone and if it presently draw it at a distance and when it is drawn it sticks fast and is hardly taken from it it is an Argument of the true end whence that force proceeds You may also draw about a little bit about that point to see if it will draw weakly or strongly and whether it will part from that place of it self or unwillingly Briefly That point that draws with most force and will hardly let loose what it hath attracted is the true point of attraction giving you to understand That the Pole sends its force to the Circumference I have known it so as from the Centre to the Circumference And as the light of a Candle is spread every way and enlightens the Chamber and the farther it is off from it the weaker it shines and at too great a distance is lost and the neerer it is the more cleerly it illuminates so the force flies forth at that point and the neerer it is the more forcibly it attracts and the further off the more faintly and if it be set too far off it vanisheth quite and doth nothing Wherefore for that we shall say of it and mark it for we shall call the length of its forces the compass of its vertues CHAP. XVI That the force of drawing and driving off can be hindred by no hindrance BUt this is above all wonder that you can never wonder so much as you should That the force of the stone for attraction and repelling can be included in no bounds can be hindered by nothing or held back but it will penetrate invisibly and will move and stir those stones that are sympathizing with it if they be put to it and will exercise its forces as if there were nothing between but this must be within the compass of its vertue for if you hang some Loadstone fitly upon a Table of wood stone or metal or lying equally balanced and you shall put your Loadstone under the Table and stir it there the vertue of it will pass from this body like a Spirit penetrating the solid Table and move the stone above it and stir it as it self is moved as this moves so moves that and when this rests that doth the same But if the Table be made of Loadstone or Iron the vertue is hindred and can do nothing we shall shew the reasons of it in their proper places Of so many strange miracles in Nature there is none more wonderful then this CHAP. XVII How to make an Army of Sand to fight before you ANd it is as pleasant as wonderful that I shewed to my Friends who beheld on a plain Table an Army of Sand divided into the Right and Left Wings fighting to the wonder of the Spectators and many that were ignorant of the business thought it was done by the help of the Devil I pouned a Loadstone into powder some very small some somthing gross and I made some of little bits that they might better represent Troops of Horse or Companies of Foot and so I set my Army here and there The Wings were on the Right and Left and the main Body was in the middle accompanied with Troops of Horse under a smooth Table I put a very principal Loadstone with my Hand When this was put there the Left Wing marched and on the Right Hand with another stone the Right Wing marched when they drew neer together and were more neer the Loadstone the Sands trembled and by degrees they seemed like those that take up their Spears and when the Loadstone was laid down they laid down their Spears as if they were ready to fight and did threaten to kill and slay and the better the Loadstone was the higher would these hairs stretch forth themselves and as I moved my Hands by little and little so the Army marched on and when the stones came neer to one the other they seemed to fight and run one within the other so the other Wings and Troops came on and shewed the form of a Battle and you might see them sometimes retreat sometimes march forward sometimes to conquer and sometimes to be conquered sometimes to lift up their Spears and lay them down again as the Loadstone was put neer to them or farther off and the more force there was to send forth every way But this is the greater wonder because what is done on a plain Board may be done hanging in the Air that you may see them like the Antipodes in Battel for stretching out a Paper or setting a Table aloft the Loadstones moved above the Table will do the same thing we speak of and shew it to the Spectator But if one that is ingenious do the business he will do more and greater Feats then we can write of CHAP. XVIII The Situation makes the Vertues of the Stone contrary IT cannot want wonder as it doth reason That the position should shew the Vertues contrary to all that we have said for the stone put above the Table will do
one thing and another thing if it be put under the Table for if you fit the stone by equally poising it to make it move freely or put it into a Boat and put a stone above it it will attract it or reject it as we said before but if you put it under the stone it will work contrarily for that part that drew above will drive off beneath and that will draw beneath that drove off above that is if you place the stone above and beneath in a perpendicular By which Experiments one may see cleerly That the situation will work contrary operations and change the forces of it by turns Wherefore in the operations of it you must chiefly mark the position if you put the Loastone above or beneath CHAP. XIX How the attractive force of the Loadstone may be weighed WE can also measure that attracting or expelling vertue of the Loadstone or poise it in a balance which will be of no small consequence in the following considerations and especially for a perpetual motion and to make Iron hang pendulous in the Air when the true and certain attractive Vertue is found our from the Circumference to the Centre The Art is this Put a piece of a Loadstone into a balance and in the other scale as much weight of some other matter that the scale may hang equal then we apply a piece of Iron lying on a Table that it may stick to the Loadstone that is in the scale and that they may stick fast by their friendly points you shall by degrees cast some sand into the other scale and that so long till the scale and iron part so by weighing the weight of the sand we have the Vertue of the Loadstone we sought to finde We may also put the iron into the scale and lay the Loadstone on the Table CHAP. XX. Of the mutual attraction and driving off of the Loadstone and of Iron NOw are we come to the other part of our Treaty wherein we discourse of the mutual union of Loadstones and of their differences one with the other the effects whereof are so known that they are in the mouths of all men nor will any man almost say that he knows them not The operation is this Because there is such a Natural concord and sympathy between the iron and the Loadstone as if they had made a League that when the Loadstone comes neer the iron the iron presently stirs and runs to meet it to be embraced by the Loadstone And that embraceth it so fast that with tossing of it up and down you can scarce part them And the Loadstone runs as fast to the iron and is as much in love with that and unity with it for neither of them will refuse to be drawn But the weaker still runs willingly to meet the other That you may believe this you shall try it thus Either hang them both by a thread or put them in boats or balance them on the needle Pliny speaking of this saith For what is more wonderful or wherein is Nature more wanton what is more sluggish than a cold stone yet Nature hath given this both sense and hands What is more powerful than hard iron yet it yields and submits for the Loadstone draws it and that matter that conquers all things runs after I know not what and as it comes neer it stops and lays fast hold and stays constantly to be embraced Lucretius seeking the cause of this effect How it should be that Loadstone Iron draws And Orpheus in his Verses relates that iron is drawn by the Loadstone as a Bride after the Bridegroom to be embraced and the iron is so desirous to joyn with it as her husband and is so sollicitous to meet the Loadstone when it is hindred by its weight yet it will stand an end as if it held up its hands to beg of the stone and flattering of it as if it were impatient that it cannot come at it by reason of its ponderosity and shews that it is not content with its condition but if it once kist the Loadstone as if the desire were satisfied it then is at rest and they are so mutually in love that if one cannot come at the other it will hang pendulous in the air Wherefore Albertus very ignorantly told Frederick the Emperour that a friend of his shew'd a Loadstone that did not attract iron but was attracted by it since the lighter of these two will stir when the heavier approaches neer it CHAP. XXI The Iron and Loadstone are in greater amity then the Loadstone is with the Loadstone THe exceeding love of the Iron with the Loadstone is greater and more effectual and far stronger then that of the Loadstone with the Loadstone and this is easily proved For lay on a Table pieces of iron and Loadstone of the same weight and let another Loadstone be brought neer when it comes to a fit distance the iron will presently stir and runs toward the Loadstone and embraceth it And it is proved better thus Let a Loadstone embrace a Loadstone and be set softly neer the iron when the force of its circumference comes to the iron the Loadstone will presently let fall the Loadstone and lay hold on the iron but let iron and that be joyned no Loadstone can ever take them asunder to stick there CHAP. XXII The Loadstone doth not draw on all parts but at certain points YEt we must not think that the Loadstone draws the iron with every part but at a set and certain point which is to be searched out with great reason care and diligence You shall find it thus either hang up the iron or balance it on a Table that it may presently leap to be embraced from them then carry your Loadstone round about it and when you see the iron tremble and run toward the Loadstone touching it that is the very point of attraction and the beams of its vertue are sent round about from that point wherefore the farther from that point the iron is the more faintly and weakly will it move for the more forcible vertue nests in the Centre as in its Throne CHAP. XXIII That the same Loadstone that draws doth on the contrary point drive off the iron THat no man might be deceived thinking the Loadstone that draws iron to be different from that stone that drives it off I tell him of it beforehand and I shall by experiments dissipate this cloud Pliny saith the Loadstone that draws iron to it is not the same with that which drives iron from it And again In the same Ethiopia there is a mountain that produceth the stone Theamedes that drives off iron and rejecteth it Pliny not knowing this erred exceedingly thinking that they were two stones that had these contrary operations whereas it is but one and the same stone that by sympathy and similitude draws the willing iron to it but with the opposite part by antipathy of Natures it drives it off And you