of the Load-stone are such that the more they â—re known the more they are justly admired in their most Lively expressing that infinite power and goodness of God who Created so pretious a Jewel for the profiâ—able use of Man and for the inlarging and setting forth of his lory Into the search of which admirable and secret Virtues my self for the space of some years â—ave made a strict Inquiry partly by Reading of other mens Writings and partly by my own Industry and â—ractice whereby what I have collected and found his little Treatise will shew I doe acknowledge that the wonderful property of â—he body of the whole Earth called the Magnetical Virâ—ue is most admirably found out and Learnedly discoursed by Doctor Gilbert Physitian to the renowned Queen Elizabeth of happy Memory Is the â—ery true Fountain of all Magnetical Knowledge for â—ll our later Authors have but borrowed from this Country-man of ours And though certain properties â—f the Load-stone were known before his time yet all â—he reasons of those properties were altogether unknow and never before revealed as I take it to the â—ons of men And although as yet many doe doubt and mistrust the Earth it self hath no such Virtue I doe nothing wonder at it because before I read his Learned Works and had tryed many of his Experiments with my own hands and had confered with great Travellers and perused the observations of our chiefest Navigators both for the Variations and Declinations I never beâ—ieved it my self But this I may truly affirm that searching with diligence his first fine Books and makâ—ng Tryal of those Propositions which I judged to be of Importance I always found the main drift touching this point constant and agreeable to the diligent Observations of many men of Experience although in some other matters of the Load-stone his Experiments and mine did sometimes disagree But concerning his sixt Book Entreating of the motion of the Earth I think there is no Man living further from believing it then my self being nothing at all perswaded thereunto by reasons of other men which he alledgeth and as little or less if it were possible by those his Inventions endeavouring to prove the motion of the Earth by the Earths Magnetical Force and Virtue Amicus Socrates Amicus Plaâ—o sed Magis amica veritas is the only cause why I do embrace his judgment in the one and refuse it in the other in matters of this nature following this Rule Nullius addictus inrare in Verba Magistri Reader be pleased to pass by this digressiion we are to return hearty thanks to God who hath revealed unto the weak Knowledge of Man now towards the end of the World this admirable Treasure before unknown of his powerful Creation by effect so plain unto the meanest Capacity and that out of a base contemptible and dead a Creature as it seemeth to be and yet filled with such excellent wonderful Virtue that all the Gems of the World have not the like neither if it were wanting could they supply the want thereof or countervaile the Benifit that it brings to the Life of Man Clandian a Famous Poet well near Twelve-hundred years since saith as much commendations of the Magnet when as yet the Sereditical or Iron drawing Properties was only known Lapis est cognomine Mâ—gnes Decolor Obscurus nilis c. And again Sed Novasi nigri videas miracula suxi Tuno superat pulchros cultus et quicquid Eâ—iâ— Indus Littoribus rubra scrutatur in alga But what would he not have said had he seen the Closset indeed of all Magnetical Miracles Unlocked and in so glorious a manner set wide open as now it is at this day had he had Load-stones of divers forms but especially round ones also such Versory Needles fitly framed and Artificially placed upon their Pins and other Implements as are prescribed wherewith being furnished he might still see the Truth of them in things themselves for these skills must be Learned ex rebus ipsis non solum ex Libris and withall there are several Figures and Diagrams which cannot be understood but by the help of the Mathematicks and good Travelling in the Magnetical Practice To be short of all that I have set down in this Treatise my request is that the Reader will admit nothing but that which shall be confirmed by good Reason or undoubted Experience And I purpose God willing to tye my self as strictly unto this Rule as ever any Man did that hath Written of the like Argument making it even a matter of Conscience to deliver any thing herein for certainty that my self shall not know to be sound And so by this means I shall neither abuse the Reader with any untrue assertion nor injure so certain and so excellent a Knowledge with any doubtful or reproveable Conclusions It is a common Proverb that in Stones Woods and Herbs consisteth great Virtue which saying is doubtless most manifest by the daily experience of the Load-stone found in sundry parts of India some will have it to be found in Spain by one Named Heraeleon as Hicander saith where in the time of his keeping of Cattle the Iron Nailes of his Shoos and Pike of his Staff cleft fast to the Stone Of these Magnets are five sorts or kinds as Soracus writeth One of Aetheopiâ— another of Macedonia a third in Echio of Boecia the fourth at Troades of Alexandria the fifth of Magnesiâ— Asiae The difference of the stone is whether it be Male or Female The next difference is in Colour for that which is found in Macedonia and Magnesiae iâ— ruddish and black and of Female kind and therefore without Virtue The worst of Magnesia Asiae is white and attracteth not Iron it is like unto a Pumice stone Some approve those for the best which are Blew of a Heavenly colour That of Aethiope is most praised and as Pliny saith is sold for the weight in Silver This is found in Zimri a sandy Region of Aethiopâ— where is also found Haematites Magnes of Bloody colour appearing like Blood if it be ground and also like Saffron which in drawing of Iron is not of the like virtue to the Haematites Magnes All these are reputed good Medicines for the Eyes each of them according to their Portion and doe especially stay the Epiphorus that is the dropping and watering of the Eyes and also being burnt and made in powder they heal Burnings Not far from the same place in Aethiopia is a Mountain which produceth the stone called Theamedes which putteth from it and refuseth Iron I have often proved the virtue and power of the Load-stone by the Needle which is in some Dyals by the attraction there of moving it self from side to side and round about And as we shall hereafter more fully shew although the stone were under a Table yet doth the Needle being above the Table naturally follow the moving oâ— the stone It is therefore for this we only insert by the bye
if there be great virtue in Stones Woods and Herbs It hath also been proved that the Ships Compact with Iron Nailes Sayling by the Sea of Aethiope and by a Tempest driven to Land to certain Capes or Lands ends have by these stonas either been drawn to the bottom of the Sea or else the Nailes being drawn out by the Virtue of the stone the Ship hath falen in a thousand pieces And therefore the discreet and wary Cantabrians expert Mariners Sayling by the Aethiopian Sea frame their Ships with Pins and Hoops of wood to prevent the danger that might chance on the same occasion This stone is known by colour virtue weight and equality the best colour is said to be like pure Iron shining mixed with Indian or Heavenly colour and is in a manner like Iron Polished This stone is also often times found in Norway and Elua and in certain Regions of the North and is brought from thence to certain Regions in Normandy and Flanders The experience of the virtue of the stone is easie for it attracteth to it a great weight of Iron It is judged to be strong and the heavier also the better By equality it is judged if it be alike in one substance and colour but if it be unequal with chapes as we shall hereafter express together with hollow places indented having red spots here and there it is unapt not so fit for the Art of Navigation or of continual Motion It representeth the similitude of Heaven for like as in Heaven there are two points immoveable ending in the Axle-tree of the Sphere upon which the whole Frame of Heaven is turned as may be experienced by the Art that Christal and other stones are Polished even so the Load-stone reduced into a Globious or round Form laying thereon a Needle or any other like Iron then which way soever the Needle turneth and resteth thereby is shewed the place of the Poles and that this may be done more certainly it must be often times attempted and the Line shewed by the Needle must be observed for such Lines shall cut the one the other in two Points as the Meridian Circles joyn together the Poles of the World but of this also more shall hereafter he said This shall for the present be only instanced That if the round stone as is said be found in the place which often times draws Iron if then the point doe exactly appear part of the broken Needle must be laid upon the sinne and be so often by little and little transposed untill the Style or â—in be Perpendicler or Plummet do directly fall upon the stone for there on the contrary part by like manner shall be found the other Pole A. shall be the true point and B. the false Load-stones let them be of what parts soever of the World have the self same general directive property I mean of shewing the North and South and also the self same Points respective declining or dipping under the Horizon They do likewise agree in their variations and each one will draw Iron and likewise one another Every Load-stone of what form soever it be hath either actually or potentially two points the one Northern the other Southern Actually if either by casualty if it so fall out or by â—ndustry the stone be fashioned that those two oppoâ—â—e points be eminent or perspicious therein Potentiâ—lly if that either the stone be flat and but thin in the dimension of the North and South though broad otherwise for so shall the virtue of the stone be dispersed to the extream parts thereof in the Edges round about or if fit have two opposite points in any concavity then will the stone shew in the eminent Border or Edge of that concavity only a confused dull force and in the concavity very little or nothing at all That stone is also well proportioned for touching which resembleth an Oval form and hath his due points in his ends and is void of any bunch or concavity for the general form of a stone being good every concavity is a diminishing of his force and every bunch is a superfluous Burthen Insomuch that my self have had experience of a stone that of substance was very good and of weight was three and twenty ounces but of disordered form it therefore took away twelve ounces from him and yet diminished not one jote of his force And this I did in a stone that was all of like force but if it be one that is intermixed of divers substances as many such there are and those easily discovered by their colour you may sometimes take away three quarters or more of his substance without diminishing any thing at all of his virtue we have already said the Iron colour is best very black or white seldom proves good gray indifferent the moâ—â— white is in any stone so much the â—â—rse Thâ—â—e are certain that are of an Iron colour mâ—â—glâ—◠〈…〉 of which 〈◊〉 are good and some bu◠〈…〉 〈◊〉 wâ—y you may prove whether a Magnet be goâ—â—◠〈◊〉 the 〈◊〉 is by 〈◊〉 aâ— Iron with the bare stâ—â—e that other by giving more or less virtue to a Knife on any thing to lift Iron the third is if it will with good strength move a Magnetical Needle a pretty good distance off and readily alter the ends of the Needle without touching them making the North South and the South North the two latter do never fail but the first doth divers times And very certain it is that whatsoever stone doth most stronly impart his force to a Knife or move a Needle with quickness the power and lifting up of Iron is such a one will mightily be increased with a Cap. For this is generally the nature of all Magnets that if there be two of different quantities and of equal strength in lifting up Iron the greater will give the stronger touch and move a Magnetical Needle farther off although the lesser will take as much Iron or somthing more than the greater And again suppose there be a Load-stone of a pound weight that being fitly armed will take up four pounds of Iron and not above if you divide him into very small pieces you shall find of them being orderly used that will lift up twenty times his own weight and a great deale more if they be very small as of three or four Grains weight and yet where the great one will give a touch unto a Knife for to take up four ounces of Iron and will move a Magnetical Needle three Foot off this little one will not give a touch to a Knife to take up a Needle nor move a Magnetical Needle four Inches off that as a Magnet is diminished in substance I mean a Magnet of a regular for it so doth he loose in his virtue and touching and increaseth in his small 〈◊〉 for lifting â—p Iron â—hereby it is manifest that these two properties 〈…〉 joyntly together in the 〈…〉 â—nd here hence it is that many 〈…〉 ally set in
â—ings 〈…〉 a great piece 〈…〉 â—he great one whose parâ—icieâ—â— they are 〈…〉 great one should do the 〈◊〉 namely to take in so many times their own weights Also very often it is seen that Magnets being of like form and weight but of divers kinds the one will take up more Iron of himâ—elf without the Cap and yet the other give a far stronger touch but then if you do fit both of them accordâ—ngly with Caps he which gave the stronger touch will take up more Iron then the other The principal â—orce of the Load-stone well proportioned passeth in 〈◊〉 direct Line from the middle of his substance being as it were a center through his two ends or points which are the imaginary likes of his chiefest force from which center there isse infinite others also through all parts of the superficies of the stone on either side between the two extream points of the middle all which on either side of the middle being of one nature and property in respect of their touch are exceedingly different in strength for that still waxeth less and less as it approacheth continually nearer and nearer the middle where at length in the middle between the two ends it utterly fainteth and cometh to nothing The Load-stone communicateth his property to the Iron or Steel that is touched with it so far forth as the Iron or Steel which is touched hath the ability to receive and so that good skill in the touching be observed Steel is far better then Iron and receiveth a far strongen touch and much more effectual The purer Steel so much the better and if it be Iron the purer likewise the better always regarding that both of them be very smooth and clean and have their due temper The principal property in common use is the shewing of North and South in the Horizon with the appendants thereunto belonging which is more apparant more strong and more commodious in the Iron and Steel that is touched then it is in the stone it self because the substance of them may be filled and cut away and drawn into any form that we like or approve of our selves which the substance of the stone will not permit The Lood-stone is of such a nature that every piece broken off and seperated from the whole hath all the properties of the whole the same several points North and South and ability also for the touch like in kind though not of equal power according to the quantity and proportion of the Piece and the part of the Stone that it is taken from and this property in a meaner sort hath touched the Needle and the Wyar of a compass also That one stone may draw another lay the one upon a board or box in the Water that it may freely float and hold another in your hand If then the North part of the stone which you hold in your hand you turn towards the South part of that which floateth in the box or otherwise the South part to the North the floating stone shall turn towards your hand and if contrarywise you turn the like part to his like that is to say the South part to the south c. the floating Stone shall fly from you By this experiment certain Phisitians are confuted who dispute on this manner If Scemmonea draw unto it choler by Similitude or Likeness of Nature Ergo much more should one Magnet draw another rather then Iron So that what they assume falsely we have now taught to be true The like judgment is of the long slender Iron which is rubbed with the Stone For if in the Water it be laid on a light piece of Wood or a straw or such like so that it may freely float upon the Water the one end of it shall turn to the North and the other to the South And if holding the Stone in your hand you turn his North point to the South extremity or end or contrarywise the Stone shall then draw Iron but contrarily if you turn the like part to the like as is aforesaid it shall fly from the Iron and drive it away Impossible Impossible Natural The reason is that the agent doth not onely indeavour to make the patient like it self but also in such a manner to unite it with himself that of them two be made one as may appear by this reason Take the same Magnes A D. of which A. signifieth the North point and D. the South Divide the Stone into two parts A B. and C. D put A B. to the Water as is said and by this means you shall see A. turn to the North and B. to the South For the breaking or dividing of the Stone as we said diminisheth not the Virtue thereof so that it be Homogenie that is all parts alike Take therefore A B. for the patient and C D. for the agent then whereas the agent in the best manner it may worketh to conserve the order of Nature â—t is manifest that D. cannot draw C the South For although they could by that means be joyned yet should not so be made one of them two the parts remaining in their Vertue For if A. should remain North then D. should be South which is certain to have the powers of the North. Neither contrariwise shall C. draw A. for both are Northly and so should B. be the North which first was South and D. in like manner For so should the order of Nature be inverted It remaineth therefore that A. shall naturally draw D. and B. shall draw C. for so every way shall remain of equall strength Some ignorant Men were of opinion that the Vertue of the Load-stone was not derived from Heaven but rather of the nature of the place where it is engendred saying that the Mines thereof are found in the North and that therefore ever one part of the stone extendeth towards the North. But they surely are ignorant that this stone is found in other places whereof it should as well follow that it should extend it self to other and divers parts as to the North which thing is false as is well known by common experience For it ever Moveth to the North in whatsoever place â—it be Neither is it to be believed that the North-Star of the Marriners is the Pole For as much as that Star is without the Meridian Line and but twice within one revolution of the Firmament But whereas the Marvelous Vertue of this Stone dependeth of Heaven who would believe that only two points thereof should so turn themselves and that rather every part of it should not incline to some like part in Heaven as may thus be proved Let the Stone be brought into a Spherical round forme as is said and the Poles being found let it be turned upon two pins or Turners instruments and there be pullyshed untill it be on every part of equall heaviness which you may well find by often proving For that part that falleth down is heaviest which done frame in
a Teeme of Horses were set in their Traces contrary the one to the other the one to pull one way and the other anorher As for the Turks Mahomet hanging in the Air with his Iron Chest it is a most gross untruth and utterly impossible it is for any thing to hang so in the Air by any Magnetical power but that either it must touch the stone it self or else as we have said some intermediate hoby that hindereth it from coming to the stone or else some stay below to keep it from ascending as some small Wyer that can scarcely be seen or perceived Concerning the Magnetical force of the whole body of the Earth I have selected these experiments to prove it Take any piece of solid Earth that hath some toughness â—o hold together and will abide the fire as any sort of Clay or Brick which sometimes was Clay fashion it in such manner that it be uniformly extended towards both ends the Orall or Long Figure is fittest for our purpose put it into a Fire of Charcoales increasing the heat by little and little and at the length with often blowing make it as throughly red hot as you can let it remain so for the space of half an hour or more that thereby all the superfluous moisture may be consumed and adverse qualities seperated from it then take it forth and let it coole it self being first set North and South with either end answerable to the variation of the place not paralell to the Horizon but elevated answerable to the Latitude as near as you can Certain it is that this piece of Earth thus ordered will sensibly shew you that it hath true Magnetical Virtue But here before I proceed any farther I must deliver unto you a necessary observation There are two sorts of Attractions as they are commonly called the one Magnetical the other Electrical The Magnetical hath always a special respect to the North and South points as we have often said of the Magnet or Magnetical Body The Electrical Body hath no manner of respect to any one point of the Electrical Body more than another and by this difference these two kinds of Attractions are easily discerned as also by this look what end of the Magnetical Needle the one end of the Magnet doth draw the other will chase away but the Electrical Body draweth alike at all ends And Thirdly after this manner lap this Electrical Body in a Paper and it will draw nothing to it at all but interposition of Brass or a stone Wall within the Orbe of the Magnets virtue doth nothing weaken the same or hinder his effect towards his peculiar object Notwithstanding to speak properly Attraction appertaineth only to Electrical Bodies because the whole Attractive virtue is only in the Electrical Body it self and nothing as in the thing that is attracted The Attraction commonly so called of the Load-stone is rightly to be termed Concursion Confluence or Coition because it is the running or vigorous meeting together of two Magnetical Bodies having a mutual Inclination the one with the other or by any other name bearing the like sense For the true knowledge thereof being but lately as a stranger arrived amongst us for common use Quem penes arbitrium est et jus et Norma Loquendi hath as yet scant suited it with a convenient Name to express this property so that Magnetical conclusion is never but between two Bodies such as both of them are Magnetical as of one Load-stone with another or of a Load-stone with Iron or Steel or Iron Oare if it be prepared or between two pieces of Iron or Steel thac are Revived with a Load-stone for indeed the Load-stone can but revive and multiply Magnetical force in a Body that naturally hath it in some measure before but cannot infuse it into any thing that before is utterly void of it as of Mettalls in Iron and Steel and not in Gold Silver Brass c. Electrum in this Argument is named that which is either Amber in substance or at least of the quality and that Amber being â—ubed hath an attraction to take up Moats Feathers Straws and other small things the which property is also in â—eate Brimstone Hard-wax if it be smooth and in infinite other things both natural and compound all which because of that quality in this Argument are termed Electrical Bodies and their taking up of things is called Electrical Attraction having only a slender resemblance â—ut no truth of the Magnetical Quality But that above mentioned piece of Earth prepared in such a manner as is before prescribed will by Magnetical Concursion shew it self to be a true Magnetical Body For the one end of the Magnetical Needle will covet towards the one of the prepared Mass and flye from the other And contrarywise also though it will do both but weakly not with power comparable to a natural Load-stone yet as truly as that That end which cooled towards the South will draw the true North end of the Needle and that end which cooled towards the North will draw the true South end of the Needle If so be that as yet you will have another in fallible Argument do thus mark what end draweth the North end of the Needle afterwards put the new made Magnet into the fire again and when it hath been glowing for the space of half a quarter of an hour take it out and cool it being placed with that marked towards the North most assuredly that end now will draw the South end of the Needle and the North end of the Needle will shun it which before approached unto it the reason hereof is because the first having abolished all the former Magnetical quality of that Mass wherewith it was in a contrary position affected in the former cooling now leaving it apt and fit to receive any new Impression which presently it taketh again either regularly if in the cooling it be placed with the ends to the North and South or if it be placed otherwise confusedly by the Magnetical force and virtue of the whole body of the Earth by regular and confused this is the meaning Take any lump of Earth or any Brick-bat ordered in this manner certain it is that this â—ump of Earth or Brick-bat hath some Magnetical virtue therein yet so feeble and weak that our sence cannot discern it because of the unfitness of the form and the confused dispersion of that weak force through the whole body thereof Then suppose you will bring either of these into an extended Ovall form which is apt as before I have said for any body Magnetical to shew his force yet this will help it nothing at all of it self as you may easily make experience in every Load-stone For if you take a Load-stone of a confused form it is not enough to bring it into a convenient Ovall except with diligence you reserve the points of the North and South in the two ends thereof for if you leave the points
in the sides you spoile it with this Ovall form For the stone will not lightly be of one quarter of the force as it was before for the Ovall form giveth it no virtue but it is the fittest for it to shew the uttermost of that strength which of it self it had before if you observe the due points and not otherwise But in this Earth and Brick it is not possible to find the due points in such a manner as you may in a Load-stone because of the weakness of the Magnetical force therein contained And therefore you cannot bring that into a regular Ovall form and by the Fire take away the confused Magnetical force and all other perverse qualities thereof that being by nature a Magnetical body in his cooling before specified receiving presently by that unresistable power of the Earth his Magnetical virtue according unto that form and will regularly have his due points precisely in the ends without any confusion Johannes Babtista Porta writes that he did make tryal of the way that Paracelsus hath set down for to increase the virtue of a Magnet Namely to heat him red hot in the Fire and to quench him in the Oyl of Crocus Martis and Babtista Porta saith that he found it a detestable falsehood But saith he he is so far from increasing his virtue as that being once red hot he looseth all his own past all recovery But for all this that he saith I doubt whether Paracelsus be justly reproved or not for by my own experience I know that the heating of a Load-stone untill it be red hot doth weaken a Load-stone but taketh not away all its force and in my tryal hereof I found a very manifest proof of the Magnetisme of the Earth which I thought necessary to insert in this place I have made this tryal of fragments of Magnets in divers kinds and likewise of divers kinds of Iron Mines which are next in degree to the Magnets Namely after this manner Heat him in the Fire by little and little for fear of breaking untill he be red hot then take him out and let him cool then mark with Chalk or what you please those parts that respect the North and South and you shall find those markt places the North and the South Poles of the Magnet Put him into the fire again untill he be red hot and cool him contrarily and you shall have the contrary effect Therefore if Babtsta Porta did make his tryal with a Load-stone very long in form and chanced for Doctor Gilberts mistery of the Magnetisme was not then revealed for to cool him in his Oyl of Crocus Martis with his ends East and West the Axis of the stone being then overthwart in the middle it were no marvel though it found no force in the ends And I doe not think it impossible but that Paracelsus way may doe some good rightly used Doctor Gilbert writeth that some Iron Mine will affect a Magnetical Needle as it is of it self being unprepared by fire but as yet I never could find any such but this I have often tryed that it being of no manner of Magnetical virtue of it self no more then a Flint stone unprepared by fire being made red hot and cooled is presently impregnated with very apparent Magnetical virtue according to the scituation that he is cooled in and although you heat and cool him often and divers ways he will still keep his virtues according to the situation of his cooling And some Iron Mines I have found which being but in this sort prepared have had as strong force as some natural Magnets have had it is the goodness of the Load-stone joyned with a fit form that will shew great force For as a very good form with a base substance can doe but very little so the substance of the Load-stone be it never so excellent except it have some convenient form is not availeable For example an excellent Load-stone of a pound weight and of a good fashion being used artificially may take up four pounds of Iron beat it into small powder and it shall be of no force to take up one ounce of Iron yea I am very well assured that half an ounce of a Load-stone of good fashion anâ— of like virtue will take up more then a pound will doe being beaten in powder Whence to add to this by the way it appeareth manifestly that it is a great errour of those Physitians and Chirurgeons which to remedy Ruptures doe prescribe unto their Patients to take the powder of Load-stone inwardly and the small filling of Iron inwardly suppose here that the Magnetical drawing should do great wonders whereas they consider not that the stone being dissolved into powder every little particle of the dust hath two points contrary the one drawing to the other repelling and putting from and so being thus confounded by a contrary working doth much more harm then good with his Magnetical quality As for the astringent and drying property of the Load-stone I leave them to the diligent observation of those that are skilful in Physick but to return to our purpose and to alledge this also besides the manifest proof if the Earth were not by Nature a Magnetical body the aforesaid mentioned piece of Earth were not by Nature a Magnetical body the afore mentioned piece of Earth could not receive from a Load-stone any Magnetical power but most certain it is and by many undoubted experiments confired that it will evidently receive a Magnetical power from a Load-stone therefore it is manifest that the Earth is by nature a Magnetical power but most certain it is and by many undoubted experiments confirmed that it will evidently receive Magnetical power from a Load-stone therefore it is manifest that the Earth is by nature a Magnetical body Farthermore as amongst all the Mettalls Iron doth imcomparably more resemble the Earth in substance then any other doth it likewise doth participate more with the Earth in quality and principally in the Magnetical peculiar property hereof as notorious experience declareth yea every piece of Iron Oare being naturally as Doctor Gilbert sheweth a Magnet although of feeble force and all Magnets being a kind of an Iron Oare is the very cause that only Iron or Steel and no other Mettall is capable of that virtue Namely to have that revived and multiplyed by the vicinity of a Magnet which at the first in some measure was originally in it self as it is aforesaid it is also well known that the Magnet is a stone most commonly of invincible hardness nothing inferiour to any Iron or Steel of the excellentest sort notwithstanding sometimes we see of them that are nothing but a dry lump of Earth and yet of those also some are stronger in virtue than divers of the hard stones are which Earthly Magnets if a man assay to bring them into fashion by grinding on a Grinding-stone according to the common use they will consume into very Mud in the Water Now
to draw towards an end of this matter albeit that the Magnetical virtue be most eminent in the Magnet as in the precise and perfect subject thereof yet it is the self same quality in a meaner degree evidently to be perceived in every piece of Earth prepared and ordered as is aforesaid yea although it be not cooled with his ends North and South that it may take its Magnetical force from the virtue of the Earth for if you cool it with his ends but East and West and set two Load-stones in the cooling the one at one end and the other at the other end it will receive a sensible and apparant Magnetical Virtue according to those points of the Load-stone that were applyed unto it namely that end which was next to the South point of the Load-stone will have a North property and that end that was next the North point will have a South property yea if you set the North part of two Load-stones to each end both ends of this new made Magnets will have a South property and contrariwise if you apply the South ends of two Magnets both his ends will have a North property and those properties before mentioned will shew themselves Magnetical because whether end of this new Magnet draweth any one end of a Magnetical Needle the same will cause away the other which is proper only to Magnets and Magnetical Bodies After the like sort only by application of two strong Load-stones by the force of twenty four hours you may alter the points of any base Load-stone which you would and make them both North and South as you please so that the Load-stone that you would alter be but base in quality and not great in substance and that the other be of a reasonable bigness and good strength And this virtue by such an application of two Load-stones I have often found effectual in new Brick lately taken from the Kill without any farther putting into the fire at all and although it be against the nature of the Load-stone to have both his ends naturally of one virtue that is to say both of them of a North property or both of them of a South property yet here is to be understood that it is the forcible violence of the strong ones being applyed joyntly to each end of the weak that do chase the contrary property of the weak one into the middle thereof and therefore if you divide this weak one in the middle then both those ends which being joyned together in the middle where no Load-stone can shew any virtue being now disjoynted and become both ends will presently shew a contrary property according to the Magnetical Nature unto the other two ends The form of the stone is Represented in this following Figure The Form of the Stone I must have on the inner side certain little Nailes and Denticles and small Teeth of Iron of one equal weight to be fastened on the Border or Magnet so that the one be no farther distant from the other then is the thickness of a Bean. The said Wheel also must be in all parts of equal weight then fasten the Axletree in the middle upon the which the Wheel may turn the Axletree remaining altogether immoveable To the which Axletree again shall be joyned a Pin of Silver fastened to the same and placed between the two cases in the highest part whereon place the Load-stone Being thus prepared let it be first brought to a round form then as is said let the Poles be found then the Poles untouched the two contrary sides being between the two Poles must be fyled and polished and the stone brought in a manner to the form of an Egg and somewhat narrower on those two sides least the lower part thereof should possess the inferiour place that it may touch the Walls of the case like a little Wheel The Sea-mans Director as well in distress of Weather as also at his leasure times of Recreation how to make a right use of the Magnetical Needle how to manage the Sayling Compass and the rest of the Instruments of chiefest concernment in the Art of Navigation HAving already discoursed of the virtues of the Load-stone as we are very unwilling for to divide such dear friends we next shall Treat of the Magnetical Needle The variation of the Magnetical Needle being aptly fitted and placed upon his pin is nothing else but the swarving of the pointing of the same in the Horizon from the Meridian line there the portion of the Horizon intercepted between the true Meridian line and this pointing sheweth of what quantity the variation is and giveth it his name to wit which way it lyeth either Easterly or Westerly and it is observed by either end of the Needle as you please In times past men observed only by the North end of the Needle because they understood not that the Load-stone hath a South virtue as well as a North and therefore did touch their Needles and Wyars of their Compasses always for the North only leaving those ends of the Wyars bare that they might be refreshed with a new touch at any time afterwards but the other ends they covered not knowing that they were also apt to receive as forcible a virtue from the Load-stone for the South as the other for the North. For the right understanding of the variation which is necessary dependants we must use the means of two circles the one of them I will call the Magnetical Almicanter the other is already known by the name of the Magnetical Meridian This Magnetical Almicanter is a circle parallel unto the Horizon whose center is the Vertical point and is described by the distance between the Vertical point and the nearer Pole of the Earth the Magnetical respective pole or which is all one the Pole of the Magnetical Meridian is a point in the Magnetical Almicanter as the variation of that place containeth in the Horizon but always it is the contrary part of the true Meridian that is if the variation of the South part of the Needle be Easterly the respective Pole is Westerly but if you observe with the North end of the Needle the respective Pole and the variation are both one way in all our Northern Climates If the variation of the South point of the Needle be Westerly then is the respective pole so many degrees in the said Almicanter Easterly and therefore always of the same height with the true Pole above the Horizon For since all great circles of the Globe do necessarily cut one another in two points into two equal parts these two therefore must even do so in the Zenith and Nadir by the very definition so that these two points the Zenith and Nadir are always alike common to them both as well unto the true as unto the Magnetical Meridian Where-hence it followeth necessarily that always the one half of the Magnetical Meridian is on the East side and the other on the West side of the true
The Compass Needle being the most admirable and useful Instrument in the World is both amongst â—urs and other Nations for the most part so bungerly â—nd absurdly contrived as nothing more And therefore as I have treated of the nature and use of the Magnet I have thought good also to employ my best endeaâ—our to advance this noble Instrument towards its highest perfection being the principal thing by which the worthy effect of the Magnet is made most profitable unto Mankind herein five things are to be consideâ—ed the substance that it is made of the form the weight the capitell the pin it standeth upon the substance in any wise ought to be pure Steel and not â—ron for most assuredly Steel will take at the least ten times more virtue than Iron can do but especially if it hath its right temper And that is this heat it in the fire untill it be past red hot that it be whitish hot and quench it in cold Water suddenly so is it Brick in a manner or Glass it self and is at that time incapable of the virtue of the Load-stone Then must you laying it upon a plain Table warily rub with fine Sand all the black colour from it if before you put into the fire you anoint it with black Soap it will scale white it self theâ— heat a Bar of Iron well near red hot and holding one end of the Needle with a small pair of Tongues lay the other end upon the hot Bar and presently you shall see that end turn from a white to a yellowish and afterwards to a blewish colour then take that end with your Tongues and do the like to the other thrusting it forwards upon the Bar untill the colour of the whole Needle become blewish then throw it on a Table and let it cool it self and so is he of the excellent temper and most capable to receive the greatest power from the Load-stone If this seem too curious especially for some fashions of Needles then use but the Hammer hardening as Workmen call it which is well near as good As concerning the form divers men are of divers minds some use a kind of a square one others a Loop I mean an extended Ovall form and this is most common but now a days a narrow streight plate being somewhat broader in the middle is in great request of these I hold the Loop or Ovall form if it be well made to be the best which is that if it be Steel his ends be welded together having a Lattin narrow plate issuing from the capitell unto the middle of the two sides of the Loop and there rivited and riviting if it be handsomely shoulered in by the Workman is better than soadering because having fitted the Lattin plate bearing the capitell unto the Loop you may first put your Loop into his temper and then rivet this unto him afterwards which otherwise would be spoiled in the fire and the wide Loop is better then the narrow or the streight plate and that for two reasons The one is because as in a Magnet it self the force that is in the whole body sheweth it self most strongly in his two Poles even so this being a Magnetical Body doth the like in his ends which are his Poles and the end of a wide compassed Loop being longer than of a narrower of the same length in the Axis must needs contain so much the more Vertue The other reason is because it supposeth the Flie in his Circular Motion more equally ballanced then the other and therefore were it not for some other Inconveniences a true Circle were best of all which that except you mark the two places that you would have for the North and South very curiously you shall never give him the right touch yea very exceeding hardly although that you do mark them and also the Lattine Stay that holdeth the Capital would be exceeding long and a superfluous burden but the best form of all as I take it in all respects is this A true Circle having his Axis going out beyond the Circle at each end narrow and narrower unto a reasonable sharp point and being pure Steel as the Circle it self having in the midst a convenient Receptacle to place the Capital fitly in This Circle must have four very small holes drilled through it equally distant each from the other for the four Cardinal Points and in both the two Points that issue without the Circle being for North and South of equal distance between the Circle and the end of the Point two more if it be a large one otherwise one is enough according to the following Figure And this Needle is most fit to be used for the Observation of the Variation without any Flie as I will hereafter shew Whensoever you will set this Needle unto the Flie you must put the Capital through the Center of the Flie very precisely and placing the Points of the Diameter where you will have them thrust little small pins through the upper place of the Flie and those smalâ— holes in the Needle the heads of the pins will shew you if the Flie be larger then your Needle at whaâ— Point your Needle standeth and bowing the body oâ— your pins being thrust through those little holes close to the Card below will keep it steady at that place and from warping also And so four pins at the four Cardinal Points will serve the turn Again If you please to place this Needle upon the upper end of the Card according to Stevinius thorough the Center in the bottom of the Flie and the Needle placed and fastened on the top or upper face of the Card. But if you will have a Magnetical Needle to serve only for one size of a Flie the best way is instead of the two pins in the end of the Axis to have a couple of little half Staples and a Flower-de-Luce on one of them as you see in the Loop revitted there That â—in turning about the Needle they may still keep the Flie close unto it and so fasten it upon a Skrew upon the Capital wheresoever you please As for his weight it must be according to his largeness and the weight is one principal cause the very large Compasses are unprofitable For the weight of the weight of the large Card and the heavy Needle pressing upon the pin will cause the Motion of the Flie to be dull and uncertain and therefore let the Pasteboard be no heavier then you must needs and for the size of six Inches Diameter of your Paste-board and a Needle of that length I know that a Needle of half an Ounce weight and half a quartern at the uttermost if a good Workman have it in hand will be fully sufficient of what Form soever The Capital ought to be Lattin and Hammer-hardned well and truly boared not too shallow but of a good convenient depth and wideness at the bottom fitâ—ing the pin it standeth upon at the top The Pin ought to be either
move the Load one jote from the place Insomuch as one and possibly the worst would do more good alone where he might orderly and freely use his own strength then he and all the many of them could do being joyned together in vicinitie of bodies but extreamly distracted through contrarity of courses The only way to perform such a design if it were worth â—he doing would be to prepare one mighty great Load-stone of excellent goodness which having his due proportion after an extended Ovall form should be fitted with double caps and so placed in the Roof of a Building that his Axis be paralell to the Horizon in this manner out of all doubt a fair large Image might be held up very strongly by such a Magnet let the stuff or substance thereof be whatsoever howbeit the lighter the better so that there be fastened to the uppermost part of the Image a small piece of Iron according prepared and placed for the two prominent ends of the double caps of the stone to lay hold thereon But enough hereof In the caping of the Magnets this general rule is to be observed that they ought to be made of the finest and softest Iron and not of Steel the weight also which the Magnet taketh up should be of the like Iron and not of Steel as aforesaid for although Steel at the least retaineth Ten times as much virtue as Iron when it is once seperated from the stone can doe yet as long as there is any contignity between the stone and them he holdeth Iron more stronger than Steel Both which differences in either of them by manifest experience are certain and seem to proceed from notable fastness and closeness in the Steel above the Iron by means whereof the Magnetical Virtue doth longer and more forcibly continue in that than this even as fire more mightily possesseth and for a greater space abideth in stone or any such firm or solid matter then in Wood or Straw or the like thin and hollow substance and therefore those Compass makers that make the Wiers of their Flies for Sailing Compasses of meer Iron ought not by any means to be suffered for to gain Two-pence in a Compas and scarcely that they intollerably abuse those that Travel by Sea to their great danger and mischief To cement and piece Load-stones for your Simmon doe thus take the fine powder of Load-stone half so much powder of New-brick made very small and subtill one part of Burgundy-pitch half so much of Rossen a small portion of unwrought Wax mingle all these together very well upon a soft Fire and make the whole Mass in little Roules Now when you will cement a stone do thus heat the two pieces of the stone very hot and likewise the Simmon then strake the places as you will soder over with the Simmon very thinly and joyn them somewhat hard together letting them so stand untill they be cold and you shall have it fully as strong as if it were an intire stone it self and not to be severed by great heat of Fire In piecing of the Load-stones there must be great care taken to the nature of the Load-stone in general and also to those particular pieces which you would joyn together The Load-stone in general as it is shewed before that his force issueth as it were from a center in the middle of the stone to all the superficies whereof universally but most strongly unto the Poles from the middle one way the stone is all of a Northly nature and all of it Southly the other way For Example In Load-stones there is a part truly said to be divided from the whole when the points of that part or ends or Poles and so by necessary consequence the Axis and Aequator in which the universal frame of Magnetical power consisteth have a position diverse from the Poles or points of the World For this cause in the last example the one half A B. being supposed to swarve from the other half B A. at either end must needs presently be divided from it and now cannot be pars integri but is of necessity totum integrali a several and absolute Magnet of it self and so by an essential property common to all Magnets coveteth with his point A. the contrary B. of that which is under it Wherefore like as exact agreement is between two Mathematical Figures when being applyed together the extreams of the one do precisely fall upon the extreams of the other each upon his correspondent extream and it is made one therewith even such is the perfect composition or setting together the parts of a Magnetical Body and namely of those two equal parts before exemplifyed you must so joyn one upon another that the two extreams or ends be always of the same nature Northly or Southly in both parts and that by the due application of the parts the two Northly ends being united and become one as also the two Southly after the same manner But if these parts being of equal length be joyned longwise the North of the one unto the South of the other those two ends that were being now no ends but the just middle of one Magnet have lost their properties which they had when they were ends For those properties by this Union are abolished but their other ends still reserve their former and stronger virtues of North and South and so according to Magnetical nature one Magnet shall have but two Poles the North and the South Again if you will piece two Load-stones together in thickness the one of them being longer than the other then you must either cut the longer that it may be fit in length unto the shorter or else piece the shorter in such a manner as is before described that he be equal in length to the longer and whatsoever disorderly parts perhaps shall be in any of them they may even after they are cemented very well be ground away Also if there be holes or dents with little pieces of Load-stones cemented their points being observed they may be filled up without any manner of damage or deformity no more then if there had not been any such at all And after this Method you may with labour and industry of many Magnets make one huge and of what form you please And although the Magnets of this body Magnetically compact as I have here shewed were never so many in number yet the whole will have but two principal points the one the North the other the South even as if it were one natural Load-stone and all of them will contribute their forces unto these two points so that if there were twenty of them being after this order cemented together into one body the whole would have but two points but if you will place them in a Vault according to a Masons Trade they will have 40 points twenty North and as many South and will work the like effect in drawing Iron as to use the former gross similitude if