or file somewhat from that end that hangeth down or else add a piece of Wax or some other thing to the other end of the Needle to counterpose it and make it stand equidistant as it did at the first setting on and this is a thing very certain that is the Northerly descent of the Needle will be more or less in all places of Northerly Latitude in the greater Latitude the more and in the lesser Latitude the lesser But if any Traveller carry this Needle beyond the Aequatour in the like Latitude Southerly that end which is downwards in the Northerly will rise Southerly and the other sink down even as much and the nearer you Travel towards either pole the more that end which pointeth towards the pole will tend downwards this is most certain in every Dyal Needle but a great deal more appeareth in a long one then in a short one we cannot find that the property of direction by the Magnetical Needle hath been unlargly practiced for Sailing above 300 years And as for the property of declination under the Horizon thereby to shew the Latitude by the Instrument thereunto belonging it is as yet a very new come Guest into the World born and bred with us in England and except it had been in exceeding few mens hands yet much used much less come unto his perfection But this is not to be marvailed at because it is not above 60 years old neither is it to be wondered at if any Critical Fellows do contemn and deride it forasmuch at either their want of knowledge or of patience will not give them leave truly to consider of it But what Navigatour or rather Nugatour whatsoever contemneth it shall be sure to repent if ever he comes to his right wits to consider what it is that he hath contemned And although the Needles for direction and declination do differ much in their shapes each from the other yet the properties are both one and the same For the Needles for direction do decline as aforesaid as far as the unfitness of their form and place will permit them and the declining Needle will not work but only in his Magnetical Meridian which himself will find out if you turn the Instrument about untill the Needle shew his least declination under the Horizon and there do play up and down and stop in the end of the same place again But if you would have a Needle fitted to shew both his properties do thus cause a Needle to be made about six Inches long even and smooth saving that he must be a little bigger in the middle then instead of an Axis which declinatory Needles have let him have a small hole drilled precisely in the middest and this hole being very small let it be somewhat wider outwards on each side then in the middest which our Workmen call Sinkboared where it must be left very sharp even almost as the edge of a Knife put through this hole a small Virginal Lattin Wyer and fit the Needle so that it hang precisely even upon this Wyer instead of an Axletree then touch him with the Loadstone and you shall presently see the end that should point towards the North decline or bend down to his due point of declination if it be placed in the Magnetical Meridian and set a little piece of Wax or any other thing upon the contrary part for a counterpoise in that the Needle may stand parallel with the Horizon then if you stand at right angles with that Virginal Wyer it is certainly in the Magnetical Meridian so that hanging in this counterpose if you turn about the Wyer untill the Needle do make right Angles with it then doth the Needle by his directive virtue point unto the Magnetical Meridian Line Take off the counterpoise then it sheweth the declination so that one and the self same Needle in the same place only by taking off and putting on a little piece of Wax sheweth plainly both those properties of directions and declinations and in like manner every inclinatory Needle will do if the points of his Axis be sharp and held in his box parallel to the Horizon he will shew both those properties of direction and declination a fine piece of Cork or Leather or any Tough substance may serve this Needle for a counterpoise in all Latitudes by thrusting it towards the center in the less Latitudes and towards the end in the greater and I think it not impossible but that a skilful Geometrician may so graduate the one half of such a Needle that it alone with its counterpoise may be a means to give a probable conjecture for the Latitude of any place whatsoever It will be very convenient in the next place to make a discovery of the Errours committed in making and touching Magnetical Needles and Wyers of Sayling Compasses and to give advise for the true and right making and touching of them First The Wyers that are commonly made both with us and in forrain Countries are of so base and drossie Iron not apt or sufficient to receive the tenth part of the virtue that fine steel Wyer could do Secondly The ends of the Wyers are for the most part not filed smooth nor â—itted even together upon the Axis of the file by means whereof the touch of the stone is more dully received and the standing of the file more uncertain the Magnetical force not being in the true Axis thereof Some who would seem to be of great skill have imagined that the best way to add strength to a Needle is with a Hammer to give some strokes to the point of the stone thereby causing Litrages as it were or Beard to hang down from it and that the Needle in his touching taking some part of that with him should have the stronger touch But they that so suppose deceive themselves therein for a Beard is nothing else but â—he fine dust of the stone hanging together by virtue â—hereof which being seperated from the stone alâ—hough it were a right good one is not able any whit â—t all to turn a Needle of it self The tryal is soon made by this means let them take off that beard from the stone with a stick and lay it upon the end of a Neeâ—le not touched and they shall find in it no force at all â—ay it is hurtful to the Needle for it giveth a superfluâ—us burthen for a small time and cannot but incumber â—is action by reason that every one of those little parâ—els of dust though beaten out at one end hath also â—or its small quantity both a North and a South virtue And therefore marreth as much as it maketh at either â—nd of the Needle The proof hereof is manifest if â—ou put off that dust or beard upon a paper and hold a â—oad-stone under it for as you turn towards the paper â—he North or South of the Stone so will every one of these particles in like manner turn it self shewing â—hereby a double nature
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
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
time with a piece of Cork or a dry Stick in the Water the Magnetical Meridian may be seen a matter though mean and trivial in shew yet between whiles of so great importance that it may serve to save many mens lives A sixt way is also if you prepare a little round Load-stone of a quarter of an Inch Diameter or thereabouts but it must be a very good one having his Poles marked and sitted in such manner that it easily turn about in a little Frame according to the following Picture The like also in his manner will come to pass if you have a small declinatory Needle in a frame in this manner Then by moving it in his Frame all over the stone the North Pole of this will find the South of the other and likewise will the South the North of the great one for it is not in outward shew one Magnet and another as is between a Magnet and a Magnetical Needle the contrary ends of the Magnet will covet in their motion to meet together but the end of the Needle which turneth North will come unto the North of the stone For in very truth it is the South point of the Needle even as the Magnet it self being placed in a Wooden Dish in Water will turn with his North end to the South and with his South end Dish and all towards the North. The like effect will also follow if you hang as aforesaid a small Load-stone in the middle of a small Silk Thread and that it may freely turn without impediment according to its nature but this property it will shew quicker or flower according unto the goodness of the substance and fitness of the form The best form for this purpose is the extended â—â—all having his Poles precisely in the ends If his Poles be some pretty distance the one end towards the East of the stone and the other as much towards the West this stone in his length will not point to the Magnetical North and South as otherwise he would but unto some other point of the Horizon yea following this experiment in this manner you may make him stand in any one Point of the Compass only you ought to abridge the stone in his length that he may â—ome somewhat nearer to a circular form so that is diameter of North and South being through the Magnetisme of the Earth the cause of this motion â—ay be so much the longer in comparison of the Mass of â—he stone and consequently more effectual After the â—ke manner you may so touch the Wyars of a Comâ—ass that the Flower de Luce of the flie stand unto what point of the Horizon you please although the â—iameter of the Wyars do still remain fixed under the Flower de Luce and the South point of the Card. Finally to conclude this point with some Magnetical Delights if you touch two Sowing Needles in a contraâ—y manner that is the point of the one Northrely and â—he other Southerly and set them with their Corks the one at the one side of a Bason of Water and the other at the other you shall see them as quickned with Vital Spirit even so to move the one end towards the other at the first fair and softly but when they draw near they will rush together as it were with a kind Violence the point of the one striking precisely at the point of the other you must place the Needle whose point is â—ouched for the North on the South fide of the Bason otherwise the heads and not the points will run together a thing far more worthy of admiration then all the self movers of any Dadalus or Architaâ— Tarentinus and more strange to behold then the Connexion of â—ron Rings combined by Virtue Magnetical whereat St. Augustine so much and that justly did wonder Another excellent and secret conclusion upon this stone pretended to be found out in these latter times â—s that by touching two Needles with the same stone they being severally set so as they may turn upon two round Tables hanging on their Borders the Alphabet written Circuler wise if two Friends agreeing upon the time the one at Paris the other at London having each of them their Table thus equally fitted be disposed upon certain days and at certain hours to confer it is to be done by turning the Needle in one of the Tables to the Alphabet and the other by Sympathy will turn it self in the self same manner in the other Table though never so far distant Which conclusion if infallibly true may likewise prove of good and great consequence howsoever I will set it down as I find it described by Faminanus Arada Lib 2. Prolus 6. in imitatton of the Stile and Vain of Lucretius Magnesi genus est Lapidis mirabile cuâ—si Corpora ferrisue plura stilo admoveris inde Non modo nim notumque tratiant que semper ad Vrsam Quis lucet nicina polo se vertere tentent Verum etiam mira inter se ratione modoque Quotquot eum Lapidem tetigere stiti simul omnes Conspirare situm motumque vide bis in unum Vt si forte ex tiâ— aliquis Romae moveatur Alter ad hunc motum quamvis sit disitus longe Arcano se naturai foedere vertat Ergo age quid si scire notes qui distat amicum Ad quem nulla accedere possit Epistola sume Plunum Orbem patulumque notas Elementaque primo Ordine quo discunt pueri describe per oras Extremas Orbis medioque repone jacentem Qui tetigit Magneta stylum ut versatilis inde Litterulam quumcunque velis coâ—ingere possit Hujus ad exemplum simuli fabricaveris Orbem Margine descriptum munitumque indice ferri Ferri quod motum Magnete accipit ab illo Hunc Orbem dissessurus sibi portet Amicus Conveniatque prius quo tempere quiesue diebus Exploret stylus an trepides quid ve indice signes His ita compositi si clam cupis alloqui amicum Quem procui a Te Te terrai distinet ora Orbi adjunge manum ferrum versatile tracta Hic disposta vides Elementa in Margine toto Queis opus est ad verba notis hunc dirige ferrum Litterulesque modo hanc modo et illam euspride tange Dum ferrum per eas iterumque sterâ—mque rotando Componas singulatim sensa omnia mentis Mira fides longe qui distat cerâ—it amious Nullius impulsu trepidare volubile ferrum Nunc huc nunc illuc discuere conscius tuaret Observatque stoti ductum sequiturque legendo Hinc atq hinc Elementa quibus in verba coactis Quid sit opus sentit ferroque interprete discit Quin etiam cum stare stylum videâ— ipse vicissim Si quae respondenda putat simili ratione Litterulis verie tactis rescribit amico O Vtinam haec ratio scribendi prodeâ—t asu Cautior et citior properat Epistola nullas Latronum veritae insidias fluviosque Morantes Ipse
denomination Now for a further consideration of these properties suppose that you will cut a piece of this Magnet Meridionally viz. C D. manifest experience will shew that C. which did in nature participate with A. in the intire Magnet E. as being both of the true North part thereof now being seperate will not abide it In like manner D. of the other end of the little one will not abide B. of the great one with whom being intire in nature he did participate as being both the Southerly parts of thr entire Magnet E and that because the ends of like denomination of any two Magnets do naturrlly fly the one from the other The stone being brought to his perfect form you must have a mould made of Iron of the same proportion in every respect and equal in all his dimensions then setting your stone aside let your Work-man frame and fassion his caps and sit them upon his mould as if it were the stone thus shall you be sure to preserve your Magnets from many dangers very incident to rude handling and having so done you may set them on the stone it self amending any small faults without indangering the stone either with bruisings or knocks for the thickness and largness of the caps there can be no general rule prescribed but it must be left to the tryal and ingenious discretion and dexterity of the Workman as also for the handsome fastening either by Soadering or Reveting of them with Latin plates to the caps to keep them in their places fast and firm and steady according as you see in the Ticture of a stone armed with single caps Now therefore in this position both ends of the Magnet being applyed unto the two ends of the Iron these two contrary forces strive in this piece of Iron the North to repell the South and the South the North so that each force is driven nearer his own end and becometh there so much the stronger then otherwise it would be For proof whereof take a little narrow square piece of Iron of the length of the capped stone and joyn it in the midst with Copper after this manner A. iâ— supposed to be a â—â—ng square on a square like piece of Iron in length fitting the two double caps of a Load-stone B. a long square piece the ends Iron the middle Copper and D. least of all If you apply the Load-stone unto A he will hold A. very strongly but if you put any of the other three pieces under A that it may touch any of them he will not by any means lift it up If you apply the Load-stone unto B he will take it up very weakly and C. somewhat more strongly but D. strongest of all these three yet not comparable to the strength wherewith he taketh up A. Aagain although the Load-stone take up B. but weakly yet if you place B. upon A he will take them up both very strongly yea more place B. upon C the two upon D all three upon A apply the Load-stone upon B being the uppermost and he will lift them all up very easily The cause thereof is when a Load-stone with his double cap is placed upon A the force of both ends striving in that piece of Iron paralellwise unto the Axis of the stone the North and South forces are driven more closely unto their proper ends But B. because of the immediate Copper there cannot be no such close driving of his forces unto their proper ends as was in A and therefore the Load-stone lifteth up B. but only as if his two ends were two little loose pieces of Iron hanging in the Air and the intermediate Copper a burthen upon them But by placing B. upon A A. in the manner as it were of a Bridge joyneth the two ends together in their former combats and the two ends of B. forasmuch as they are but as it were two loose pieces of Iron hanging in the Air the two forces of the Load-stone North and South distinctly and severally pass thorough them downwards into A which iâ— could not do if it had been one intire piece of Iron and so all those four pieces being placed one upon another so that A. be undermost whether directly or side-ways the Load-stone will easily lift them all up and not otherwise When a Load-stone lifteth up Iron at one end only the virtue of a stone is infused into the whole body downward of that Iron if it be not very long But when by means of the double caps both ends do lift Iron joyntly together he infuseth very small force downwards into the body of the Iron that it lifteth up for the forces of both ends are so striving in the Collateral Line of the Iron paralell to the Axis of the stone that whereas a good Magnet lifting up at one end will entend his virtue downwards twelve or fourteen Inches in applying both ends unto the Iron by the means of the double caps he will not extend his force downwards the distance of one Inch nor with any strength the distance of half an Inch as in this former Example Pliny in his natural History writeth that Dinocrates that Famous Architect Builder of Alexandria at Ptolomies command began to vault a Temple with Magnets that there might seem to hang in the Air the Image of his Sister Arsinoe made of Iron for that purpose but both Dinocrates and Ptolomie dying in the mean space that enterprise ceased Neither indeed if the both had lived could it ever have come to pass by that means by reason of two impossibilities the one is that by the force of the Load-stones nothing can so hang in the Air but that it either must touch the stone it self or some other intermediate substance between it and the stone that bareth it from coming to the stone it self For Example lay two or three Needles upon a smooth Table put a Silver or Pewter Plate upon them and upon that Plate a Load-stone then lift up the Plate aloft with the Load-stone lying still upon it and you shall see the Needles hanging indeed in the Air endlong and if you move the stone about the Plate following still underneath but evermore touching the Plate which is the intermediate body which keepeth them from coming to touch the stone which otherwise by their natural inclination very speedily they would do But as for the Image of Arsinoe how had it been possible for it to have toucht at once mediately or immediately so great a number of Load-stones whereof the pretended Vault must needs have consisted the other is that such a multitude of Magnets would nothing but confound the one the others forces so that one of them alone being solitary and severed from his company might shew more force than all the insociable society could do each one hindering the efficacie of the other Much like a Team of many Horses where every one drawing his several way might soon with disordered stretching tire himself and his fellows but never
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
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