yet as truely as that That end which cooled toward the South will draw the true North end of the needle and that end which cooled toward the North will draw the true South end of the needle If so be as yet you will haue another infallible argument doe thus Marke what end draweth the North end of the needle afterward put the new made Magnet into the fire againe and when it hath been glowing for the space of halfe a quarter of an houre take it out and coole it being placed with that marked end toward the North most assuredly that end now will draw the South end of the needle the North end of the needle will shun it which before approached vnto it The reason here of is because the fire hauing abolished all the former Magneticall qualitie of that masse wherewith it was in a contrary position affected in the former cooling now leaueth it apt and fit to receiue any other new impression which presently it taketh againe 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 Magneticall force and vertue 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 sort certaine it is that this lumpe of earth or bricke-bat hath some magneticall vertue therein yet so feeble and weake that our sence cannot discerne it because of the vnfitnesse of the forme and the confused dispersion of that weake force through the whole body thereof Then suppose you will bring either of these into an extended ovall forme which is most apt as before I said for any body magneticall to shew his force yet this will helpe it nothing at all of it selfe as you may easily make experience in euery Loadstone For if you take a loadstone of a confused forme it is not inough to bring it into a conuenient ovall except with diligence you reserue the points of the North and South in the two ends thereof for if you leaue the points in the sides you marre it with this ovall forme For the stone will not lightly be of one quarter of the force it was ofbefore For the ovall forme giueth it no vertue but is the fittest for it to shew the vttermost of that strength which of it selfe it had before if you obserue the due points and not otherwise But in this earth and bricke it is not possible to finde the due points in such sort as you may in a Loadstone because of the weaknesse of the magneticall force therein contained And therefore you cannot bring that into a regular ovall forme to haue the due points in the very ends But if you first make it into an ovall forme and by the fire take away the confused magneticall force and all other peruerse qualities thereof that being by nature a magneticall body in his cooling before specified receiueth presently by that vnresistable power of the earth his magneticall vertue according vnto that forme and will regularly haue his due points precisely in the ends without any confusion Iohannes Baptista-Porta Neapolitanus writeth that hee did make triall of the way that Paracelsus hath set downe for to increase the vertue of a magnet namely to heate him red hot in the fire and to quench him in the oyle of Crocus Martis And Baptista Porta saith that hee found it a detestable falshood For saith hee he is so farre from increasing his vertue as that being once red hot he looseth all his own past all recouery But for all this that hee saith I doubt whether Paracelsus be iustly reprooued or not for by mine owne experience I know that the heating of a Loadstone vntill he be red hotte doth weaken a loadstone but taketh not away all his force and in my triall here of I found a very manifest proofe of the magnetisme of the earth which I thought necessary for to insert in this place I haue made this triall of Fragments of magnets of diuers kindes and also of diuers kindes of Iron Mines which are next in degree vnto magnets namely after this sort Heate him in the fire by little and little for feare of breaking vntill he be red hotte then take him out and let him coole then marke with chalke or what you please those parts that respect the North and South and you shall finde those marked places the North and South Poles of the Magnet put him into the fire againe vntill he be red hotte and coole him contrarily and you shall haue the contrary effect Therefore if Baptista Porta did make his triall with a Loadstone very long in forme and chaunced for Master D. Gilberts mistery of the Earths magnetisme was not then reuealed for to coole him in his oyle of Crocus Martis with his ends East and West the axis of the stone being then ouerth wart in the middle it were no maruell if he found no force in the ends And I do not thinke it improbable but that Paracelsus way may doe some good rightly vsed Doctour Gilbert writech that some Iron mine will affect a magneticall needle as it is of it selfe being vnprepared by fire but as yet I neuer could finde any such but this I haue often tried that it being of no manner of magneticall vertue of it selfe no more then a flintstone vnprepared by fire being made red hott and cooled is presently impregnated with very apparant magneticall vertue according to the scituation that hee is cooled in and although you heate and coole him often and diuers waies he will still keepe his vertue according to the scituations of his cooling And some Iron Mines I haue found which being but in this sort prepared haue had as strong force as some naturall magnets haue had It is the goodnesse of the Loadstone ioyned with a fit forme that will shew great force For as a very good forme with base substance can doe but very litle so the substance of the Loadstone bee it neuer so excellent except it haue some conuenient forme is not auaileable For example an excellent loadstone of a pound waight and of a good fashion being vsed artificially may take vp foure pounds of Iron beate it into small pouder and it shall bee of no force to take vp one ounce of Iron yea I am very well assured that halfe an ounce of a Loadstone of good fashion and of like vertue will take vp more then that pound will doe being beaten into powder Whence to adde this by the way it appeareth manifestly that it is a great error of those Phisitions and Surgeons which to remedy ruptures doe prescribe vnto their Patients to take the pouder of a Loadstone inwardly and the small filing of iron mingled in some plaister outwardly supposing that herein the magneticall drawing should doe great wonders Whereas they consider not that the stone being dissolued into powder euery little particle of the dust hath
two points contrarie the one drawing to the other repelling and putting from and so being thus confounded by a contrarie working doth much more harme then good with his magneticall quality As for the astringent and drying properties of the Loadstone I leaue them to the diligent obseruation and iudgment of the skilfull in phisicke But to returne to our purpose and to alledge this also besides the former manifest proofe if the earth were not by nature a magneticall body the afore mentioned peice of earth could not receiue from a Loadstone any magneticall power But most certaine it is and by many vndoubted experiments confirmed that it will euidently receiue magneticall power from a Loadstone therefore it is manifest that the earth is by nature a magneticall body Furthermore as among all the mettals iron doth incomparably more resemble the earth in substance then any other doth it likewise doth more participate with the earth in quality and principally in the magneticall peculiar property hereof as notorious experience declareth yea euery peice of iron Oare being naturally as D. Gilbert sheweth a magnet although of feeble force and all magnets being a kinde of iron Oare is the very cause that onely iron or steele and no other mettall is capable of that vertue namely to haue that reuiued and multiplied by the vicinity of a magnet which at the first in some measure was originall in it selfe as it is aforesaid It is also well knowne that the magnet is a Stone most commonly of inuincible hardnesse nothing inferiour to any iron or steele of the excellentest sort notwithstanding sometimes wee see of them that are nothing but a dry lumpe of earth and yet of those also some stronger in vertue then diuers of the hard stony ones are Which earthly magnets if a man assay to bring it into a fashion by grinding on a grinding stone according to the common vse they will consume into very mudde in the water Now to drawe towards an end of this matter albeit the magneticall vertue be most eminent in the magnet as in the precise and perfect subiect thereof yet is the selfe same quality in a meaner degree euidently to be discerned in euery peice of earth prepared and ordered as is aforesaid yea although it be not cooled with his ends North and South that it may take his magneticall force from the vertue of the earth for if you coole it with his ends but East and West and set two Loadstones in the cooling the one at one end and the other at the other end it will receiue a sensible and apparant magneticall vertue according to those points of the Loadstone that were applied vnto it namely that end which was next the South point of the Loadstone will haue a North properly and that end that was next the North point will haue a South property yea if you set the North part of two loadstones vnto each end both ends of this new made magnet will haue a South property And contrariwise if you apply the South ends of two magnets both his ends will haue a North property And those properties before mentioned will shew themselues to be magneticall because whether end of this new magnet draweth any one end of a magneticall needle the same will chase away the other which is proper only vnto magnets and magnetical bodies After the like sort only by application of two strong loadstones by the space of 24. houres you may alter the points of any base loadstone which you would and make them both North or South as you please so that the loadstone which you would alter be but base in qualitie and not great in substance and that the other be of a reasonable bignes and good strength And this vertue by such application of two loadstones I haue often found effectuall in new bricke lately taken from the kill without any farther putting into the fire at all And although it be against the nature of a loadstone to haue both his ends naturally of one vertue that is to say both of them of a North property or both of them of a South property yet here it is to be vnderstood that it is the forcible violence of the strong ones being applied iointly vnto each end of the weake that doe chase the contrarie property of the weake one into the middle thereof And therefore if you diuide this weak one in the middle then both those ends which being ioyned together were the middle where no loadstone can shew any vertue being now disioyned and become ends will presently shew a contrary property according vnto magneticall nature vnto the other two ends CHAP. II. The ambiguity of the North and South ends of Magnets and Magneticall bodies explained and Doctor Gilbert therein defended THere is not any one errour that breedeth a greater confusion in magneticall knowledge then the mistaking of the right vnderstanding of the true North and South ends aswell in magnets themselues as also in magneticall bodies who soeuer therefore that will take a little paines in the beginning for to vnderstand this well shall free himselfe from many intricate difficulties in this argument which otherwise must needes befall him wherein some hauing limed themselues haue fallen into many errors euery one still begetting another worse then himselfe All those which did write before Doctor Gilbert did name that end of a magnet which being placed in a wooden dish and set to swimme in water would turne and settle it selfe towards the North the North end of the magnet and the other the South end And euen so did they of all Dial-needles Compasses and magneticall bodies But Doctour Gilbert not for any new-fangled innouation or selfe-conceit but vpon good reason and firme demonstration auoucheth and prooueth the contrarie and clearely sheweth that the former vulgar assertion seriously defended tendeth vnto the ouerthrow of all magneticall Philosophie by vndermining as it were the whole frame thereof and yet in common speech the old rule may hold Loquendum cum vulgo sentiendum cum sapientibus For it would seeme a strange speech vnto a Marriner to tell him that his Flower de luce were become the South point of his compasse and yet this assertion is most true and certaine that it is the North end of euery magnet and magneticall body that being placed in a thinne wodden dish in water or any magneticall needle vpon his pinne which setteth it selfe and pointeth vnto the South and it is the South end which pointeth vnto the North. For proofe hereof take these wordes of North and South in whether of the two former significations you please and make triall thereof in any two magnets or any two magneticall bodies so placed that they may freely turne according vnto their natures and you shall alwaies see a naturall inclination of the contrary ends of the one vnto the contrary ends of the other as of the North end of the one vnto the South end of the other and reciprocated
MAGNETICALL Aduertisements OR DIVERS PERTINENT obseruations and approued experiments concerning the natures and properties of the Load-stone Uery pleasant for knowledge and most needfull for practise of trauelling or framing of Instruments fit for Trauellers both by Sea and Land Whereunto is annexed a breife Discouerie of the idle Animaduersions of MARK RIDLEY Dr. in Physicke vpon this Treatise entituled Magneticall Aduertisements ACTS 17. 26. He hath made of one bloud all nations of men for to dwell on the face of the earth and hath determined the times before appointed and the bounds of their habitation that they should seeke the Lord c. The second Edition LONDON Printed by Edward Griffin for Timothy Barlow and are to be sold at his shop in Pauls Church-yard at the signe of Time 1618. TO THE RIGHT WORSHIPFVLL DIScreet and learned Gentleman S ir DVDLEY DIGGES Knight SIR the nature powerfulnesse and strange properties of the loadstone are such that the more they are known the more they are iustly admired in their most liuely expressing that infinite power and goodnes of our God who hath created so precious a Iewell for the profitable vse of man and for the enlarging and setting forth of his owne glory Into the search of which admirable and secret vertues my selfe by the space of these forty yeeres haue somewhat entred as my leasure and occasions would serue and at by times partly by reading other mens writings and partly by my owne industrie and practize Whereby what I haue collected and found this little Treatise will shew Which whether it be any thing or nothing I do referre vnto the iudicious Readers consideration but in special to your fauorable construction and good acceptance Many yeeres since diuers of my good friends and among them some honourable persons were very desirous that I should publish such obseruations as I had collected both before and also after the setting forth of D. Gilberts booke And none more earnest herein then D. Gilbert himselfe vnto whom I communicated what I had obserued of my selfe and what I had built vpon his foundation of the Magnetisme of the earth Both which hee liked well and wished me to publish them as I remember at the time of our priuate conference as may further appeare by letters that I receiued from him which I haue to shew vnder his owne hand But aboue all others the perswasions of that learned honourable Gentleman Sir Thomas Challenor late Chamberlaine vnto the Mirrour of honour Prince Henry preuailed most with me Vnto whom I was all the time that I attended that Prince his highnesse for his loue and curtesie much beholding Whereupon about seauen yeeres since I deliuered vnto him this Treatise finished almost as now it is sauing some few additions vpon necessary occasions But that Copie was either mislaied or embeseled that he lost it About three yeeres since he sent earnestly vnto mee for an other Copie which also he receiued promising me by his letters that within three months hee would put that to the presse and that it should be carefully and correctly performed But what is become euen of that also I know not Only this I am sure of that I haue met with many portraitures of my Magneticall implements and diuers of my propositions set abroad in print in another mans name and yet some of them not rightly vnderstood by the partie vsurping them Now that it hath pleased God to take Sir Thomas Challenor and that vpon enquirie I can heare no tidings of those my lost labours and knowing that diuers are very desirous to see them I haue once againe reuiued my scattered papers collected them together made choice of your selfe to whom to entitle according vnto our vsuall curtesies these magneticals your worthy selfe I say in many respects First because your rare learning ioin'd with so great pietie accompanied with so pleasing a carriage of your selfe towards euerie man is such as causeth all good men which know you to loue you by force of a naturall sympathy not vnlike the appetite of concourse coniunction whereby our very Magnets doe affect their proper obiects And this was verie conspicuous in our renowned iudicious Prince Henry who loued you singularlie well for your vertues and delighted no lesse to conferre with you for your knowledge in matters appertaining vnto Discoueries and Cosmographicall learnings in the which his highnes was more then vulgarly skilfull Another is the glorious fauour which I see reflected vpon you from that most reuerend and singular ornament of our Church and State reioycing in Gods blessing of his labors in your education like as God hath hitherto blessed him in all things and not onely my prayers and such as I am who are so much bounden vnto him but the praiers of many thousands that neuer saw him will not cease to beseech the Almightie long to preserue him and alwaies to prosper him in his godly proceedings Wherefore this extraordinary respect which he hath vnto you both is and must be a commanding motiue vnto mee to shew my good will by the best poore meanes that I can toward you Yet one more I haue which is this That whereas a worthy societie of Gentlemen and Marchants is very highly and iustly commended and honoured of all men for their great charges in their constant and indefatigable proceedings for discoueries of vnknown passages to new Countries and Nations for the further aduancement of Gods glorie the honour of our King and principall benefit of the whole Kingdome In remembring of those honourable attempts you must in no wise be forgotten and especially in a Treatise mentioning the vertues and properties of the Loadstone being the leader and guide to these admirable exploits who besides your souud knowledge herein doe with great constancie ioine both your purse and counsaile for the atcheiuing of them yea and that without expectation or hope of priuate gaine but onely of your noble genorositie knowing full well that the aduancement of Gods glorie is absolutely of it selfe the greatest gaine with a contented minde Wherewith he that onely is all-and selfe-sufficient enrich you more and more in this world and to your eternall happinesse most abundantly and perfectly satisfie you by making you drinke of the riuer of his pleasures in the world to come Amen Yours with all hearty affection WILLIAM BARLOWE THE PREFACE to the Reader THat wonderfull propertie of the body of the whole earth called the Magneticall vertue most admirably found out as learnedly demonstrated by Doctor Gilbert Phisitian vnto our late renowned Soueraigne Queene Elizabeth of happy memory is the very true fountaine of all Magneticall knowledge So that although certaine properties of the Loadstone were knowne before yet all the reasons of those properties were vtterly vnknowne and neuer before reuealed as I take it vnto the sonnes of men And although as yet many doe doubt and mistrust that the earth it selfe hath no such vertue I doe nothing wonder at it because
of a Loadstone B. a long square peece the ends iron the middle copper C. hath a lesse space of copper and D. least of all If you apply the Loadstone vnto A he will hold A very strongly but if you put any of the other three peeces vnder A that it may touch any of them hee will not by any meanes lift it vp If you apply the Loadstone vnto B he will take it vp very weakly and C somewhat more strongly but D strongest of all these three yet not comparable to the strength wherewith hee taketh vp A. Againe although the Loadstone taketh vp B but weakly yet if you place B vpon A he will take them both very strongly yea more place B vpon C these two vpon D all three vpon A apply the Loadstone vnto B being the vppermost and he will lift them all vp very easily The cause hereof is when a Loadstone with his double cappe is placed vpon A the force of both ends striuing in that peece of iron paralel-wise vnto the Axis of the stone the North and South forces are driuen more closely vnto their proper ends But in B because of the intermediate copper there can be no such close driuing of his forces into their proper ends as was in A and therefore the Loadstone lifteth vp B but only as if his two ends were two little loose peeces of iron hanging in the aire and the intermediate copper a burthen vpon them But placing B vpon A A in the manner as it were of a bridge ioyneth the two ends together into their former combats and the two ends of B forasmuch as they are but as it were two loose peeces of iron hanging in the aire the two forces of the Loadstone North and South distinctly and seuerally passe thorow them downwards into A which it could not doe if it had beene one entire peece of iron and so all those foure peeces being placed one vpon another so that A be vndermost whether directly or sidewise the Loadstone will easily lift them all vp and not otherwise When a Loadstone lifteth vp iron at one end onely the vertue of the stone is infused into the whole body downward of that iron if it be not very long But when by the meanes of the double cappes both ends doe lift iron ioyntly together he infuseth very small force downeward into the body of the iron that it lifteth vp for the forces of the both ends are so striuing in a collaterall line of the iron paralell vnto the Axis of the stone that whereas a good Magnet lifting vp at one end will extend his vertue downewards twelue or fourteene inches in applying both ends vnto the iron by the meanes of the double caps hee will not extend his force downeward the distance of one inch nor with any strength the distance of halfe an inch as in this former example Pliny in his naturall historie writeth that Dinocrates that famous Architect builder of Alexandria at Ptolemies commandement began to vault a Temple with Magnets that there might seeme to hang in the aire the image of his sister Arsinoe made of iron for that purpose but both Dinocrates and Ptolemie dying in the meane space that enterprise ceased Neither indeed if they both had liued could it euer haue come to passe by that means by reason of two impossibilities The one is that by the force of the Loadstones nothing can so hang in the aire but that it either must touch the stone it selfe or some other intermediate substance betweene it and the stone that barreth it from comming to the stone it selfe For example lay two or three needles vpon a smooth table put a siluer or pewter plate vpon them and vpon the plate a Loadstone then lift vp the plate aloft with the Loadstone lying still vpon it and you shall see the needles hanging indeed in the aire endlong and if you moue the stone about the plate following still vnderneath but euermore touching the plate which is the intermediate body that keepeth them from comming to touch the stone which otherwise by their naturall inclination very speedily they would doe But as for that image of Arsinoe how had it beene possible for it to haue touched at once mediately or immediately so great a number of Magnets whereof the pretended vault must needs haue 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 solitarie and seuered from his company might shew more force then al that insociable societie could doe each one hindering the efficacie of the other Much like a teeme of many horses where euery one drawing his sundry way might soone with disordered stretching tire himselfe and his fellowes but neuer moue the loade one iot from the place Insomuch as one and possibly the worst would doe more good alone where hee might orderly and freely vse his owne strength then hee and all the many of them could doe being ioyned together in vicinitie of bodies but extremely distracted through contrarietie of courses The only way to performe such a matter if it were worth a doing would be to prepare one mightie great Loadstone of excellent goodnesse which hauing his due proportion after an extended ouall forme should be sitted with double cappes and so placed in the roofe of a building that his Axis be paralell to the Horizon in this sort out of all doubt a faire large image might bee held vp very strongly by such a Magnet let the stuffe or substance thereof be whatsoeuer howbeit the lighter the better so that there be fastened vnto the vppermost part of the Image a small peece of iron accordingly prepared and placed for the two prominent ends of the double cappes of the stone to lay hold thereon But enough hereof In the capping of Magnets this generall rule is to be obserued that they ought to be made of the finest and softest iron and not of steele the waight also which the Magnet taketh vp should be of the like iron and not of steele as aforesaid For although steele retaineth at the least ten times as much vertue as iron when it is once separated from the stone can doe yet as long as there is any contiguitie betweene the stone and them hee holdeth iron more strongly then steele Both which differences in either of them by manifest experience are certaine and seeme to proceede of notable fastnesse or closenesse in the steele aboue the iron by meanes whereof the magneticall vertue doth longer and more forcibly continue in that then in this euen as fire more mightily possesseth and for a greater space abideth in stone or any such firme or solid matter then in wood or straw or the like thinne and hollow substances and therefore those compasse-makers that make the wiers of their flies for sailing compasses of meere iron ought not by any meanes to be suffered for to gaine two pence in a compasse and
from the stone with a sticke and lay it vpon the end of a needle not touched and they shall finde in it no force at all nay it is a hurt vnto the needle For it giueth a superfluous burthen for a small time and cannot but incumber his action by reason that euery one of those little parcels of dust though beaten out at one end hath also for his small quantity both a North and South vertue And therefore marreth as much as it maketh at either end of the needle The proofe heereof is manifest if you put off that dust or beard vpon a paper and hold a Magnet therunder for as you turne towards the paper the North or South of the stone so will euery one of those particles in like sort turne it selfe shewing thereby a double nature CHAP. X. Of the fashioning of the compasse needle THe Compasse needle being the most admirable and vsefull instrument of the whole world is both amongst ours and other nations for the most part so bungerly and absurdly contriued as nothing more And therefore entreating now of the nature and vse of the Magnet I haue thought good also to employ my best endeauour to aduance this noblle instrument towards his highest perfection being the principall thing by which the worthy effect of the Magnet is made most profitable vnto mankinde Heerein fiue things are to be considered the substance that it is made of the forme the waight the capitell and the pin it standeth vpon The substance in any wise ought to bee pure steele and not iron For most assuredly steele will take at the least tenne times more vertue then iron can doe but especially if it hath his right temper And that is this Heat it in the fire vntill it be past red hot that it be whitish hot and qnench it in cold water suddenly So is it brickle in a manner as glasse it selfe and is at that time incapable of the vertue of the Loadstone Then must you laying it vpon a plaine table warily rubbe with fine sand all the blacke cullour from it if before you put it into the fire you annoynt it with soape it will scale white of it selfe then heat a barre of iron well neere red hot and holding one end of the needle with a small paire of tongs lay the other end vpon the hot barre and presently you shall see that end turne from white to a yellowish and after to a blewish cullour then take that end with your tongs and doe thlike vnto the other thrusting it forward vpon the barre vntill the cullour of the whole needle become blewish then throw it on a table and let coole of it selfe and so is he of the excellentest temper and most capable to receiue the greatest power from the Magnet If this seeme too curious especially for some fashions of needles then vse but the hammer hardening as workmen call it which is well neere as good As concerning the forme diuers men are of diuers mindes some vse a kind of square one others a loop I meane an extended ouall forme and this is most common But now a dayes a narrow straight place being somewhat broader in the middle is in great request Of these three I holde the loope or ouall forme if it bee well made to bee the best which is that if it be of steele his ends be welded together hauing a lattin narrow plate issuing from the capitell vnto the middle of the two sides of the Loope and there riuetted and riuetting if it bee handsomely shouldered in by the workman is better then soadering because hauing fitted the lattin plate bearing the capitell vnto the Loope you may first put your Loope into his temper and then riuet this vnto him afterwards which otherwise would bee marred in the fire and the wide Loope is better then the narrow or the straight plate and that for two reasons The one is hecause as in a Magnet it selfe the force that is in the whole body sheweth it selfe most strongly in his two poles euen so this being a Magneticall body doth the like in his ends which are his poles and the sides of a wide compassed Loope being longer then of a narrower of the same length in the Axis must needes containe 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 inconueniences a true circle were best of all which is that except you marke the two places that you would haue for the North and Souch very curiously you shall neuer giue him the right touch yea very exceeding hardly although you doe marke them and also the lattin stay that holdeth the capitell would bee exceding long and a superfluous burden but the very best forme of all as I take it in all respects is this a true circle hauing his Axis going out beyond the circle at each end narrow and narrower vnto a reasonable sharpe point and being pure steele as the circle it selfe is haning in the middest a conuenient receptacle to place the capitell in This circle must haue foure very small holes drilled through it equally distant each from other for the foure cardinall points and in both the two poynts that issue without the circle being for North and South of equall distance betweene the circle and the end of the poynt two moe if it be a large one otherwise one is enough according vnto this picture following And this needle is most fit to be vsed for the obseruation of the variation alone without any flie as I will shew at the latter end of this Treatise Whensoeuer you wil set this needle vnto the fly you must put the capitell through the center of the flie very precisely and placing the points of the Diameter where you will haue them thrust little small pins through the vpper face of the flie and those small holes in the needle the heads of the pinnes will shew you if the flie bee larger then your needle at what poynt your needle standeth and bowing the body of your pinnes being thrust through those little holes close to the card below will keep it steddy at that place and from warping also And so foure pins at the foure cardinall points will serue the turne Againe if you please for to place this needle vpon the vpper face of the Card according vnto Steuinius it is no more but to haue the capitell loose thrust thorough the center in the bottome of the flie and the needle placed and fastened on the top or vpper face of the carde But if you will haue a Magneticall needle to serue onely for one size of a flie the best way is insteed of the two pinnes in the ends of the Axis to haue a couple of little halfe staples and a Flower de luce on one of them as you see in the Loope riuetted there That in turning about the needle they may
before I read his learned workes and had tried many of his experiments with mine owne hands and had conferred with great Trauellers and pervsed the obseruations of our chiefest Nauigators both for their variations and declinations I neuer beleeued it my selfe But this I may truely affirme that searching with diligence his first fiue bookes and making triall of all those propositions which I iudged to be of importance I alwaies found the maine drift touching this point certaine constant and agreeable to the diligent obsernations of diuers men of experience although in some other matters of the Loadstone his experiments and mine did sometimes disagree as I signified to himselfe in his life time which he did take in very good part as I haue yet his owne letters to shew But concerning his sixth Booke entreating of the motion of the earth I thinke there is no man liuing farther from beleeuing it than my selfe being nothing at all perswaded there vnto by the reasons of other men which he alledgeth and as little or lesse if it were possible by those his inventions endeuouring to proue the motion of the earth by the earthes Magneticall force and vertue Amicus Socrates Amicus Plato sed magis amica veritas is the onely cause why I doe embrace his iudgment in the one and refuse it in the other in matters of this nature following this Rule Nullius addictus iurare in verba Magistri But to returne to the Magnetisme of the whole earth I doe hold it to be one of the rarest and excellent est inventions and the best followed by him with euident proofes and of the greatest consequence for the admirable art of Nauigation that euer was found out since the Creation of the world so that it may well be said of him touching that point Exegit monumentum aere perennius Regalique situ pyramidū altius in respect of the manifold vse and commoditie thereof in the doings of this life The properties of the Magnet seruing not onely for Sea-affaires but also for trauelling by Land in vaste and solitarie deserts for moueable Sun-dyalls in all places of the world for the more ready and exact Chorographie of any Countrey or the true plotting of any ground and for the following of any Minerall veyne that is voide of Iron vnder the earth for Pioners and diggers in Mines And in all this appeareth the wonderfull power and goodnes of God who hath vouchsafed to reueale vnto the weake knowledge of man now towards the end of the world his admirable treasure before vnknowne of his powerfull Creation by effect so plaine vnto the mean est capacitie And that out of a base contemptible and dead creature as it seemeth to be and yet filled with such excellent and wonderfull vertue that all the Gemms of the world haue not the like neither if it were wanting could supply the want thereof or counter vaile the benefit that it bringeth to the life of man Claudianus a famous Poet well nere twelue hundred yeares since saith as much in commendation of the Magnete when as yet the Serediticall or Iron-drawing property thereof was onely knowne Lapis est cognomine Magnes Decolor obscurus vilis c. And againe Sed noua si nigri videas miracula saxi Tunc superat pulchros cultus quicquid Eoïs Indus littoribus rubra scrutatur in algâ But what would he not haue said had hee seene the true closset indeed of all Magneticall miracles vnlocked and in glorious manner set wide open as now it is at this day Many of our Nation both Gentlemen and others of excellent witts and louers of these knowledges not able to read Doctor Gilberts Booke in Latin haue bin euer since the first publishing thereof exceeding desirous to haue it translated into English but hitherto no man hath done it neither to my knowledge as yet goeth about any such matter whereof one principall cause is that there are very few that vnderstand his Booke because they haue not Loadstones of diuers formes but especially round ones Also such versory needles fitly framed and artificially placed vpon their pins and other such implements as he doth there prescribe wherewith being furnished as they read his propositions in words they might still see the truth of them in the things themselues according as himselfe forewarneth that these skills must be learned Ex rebus ipsis non solum ex libris out of the things themselues and not onely out of Bookes A second cause may be for that there are diuers words of Art in the whole course of this booke proper to this subiect and fit to the explanation of his figures and diagrammes which cannot be vnderstood but by the helpe of the Mathematicks and good trauelling in the Magneticall practise Moreouer his alleadging of other mens erroneous opinions concerning this Argument and his confutations thereof may seeme at the first to a yong beginner somewhat harsh and tedious Both which I suppose in the English translation if any were might well be omitted like as in this my Treatise I thinke it not altogether so pertinent to handle them all And a sport it is to behold diuers of smart witts and such as weene themselues to be so great Clerkes that they will aduenture boldly to dispute de omni scibili how miserably they runne their witts on ground when onely by a slender reading ouer of his booke or most commonly some part thereof they will take vpon them to define controule and discourse of those matters fearing nothing more than that of the Poet mihi turpe relinqui est Et quod non didici sane nescire fateri For being vrged by diuers of our Gentlemen among whom these knowledges are had now a daies in some request somewhat they must speake which must be either superciliously to scorne such things as vanities because themselues vnderstand them not or else with slender ostentation to blunder out their masked ignorance supposing it to be inough for them to say that they haue read Dr. Gilberts Booke and so to vse that for a Supersedeas to acquite them of any farther inquirie But many being now at length weary to take such counterfeit shewes for good payment doe seriously seeke to haue some sound knowledge of the things themselues and not to depend vpon other mens extravagant disputes but to be their owne iudges in matters that concerne themselues and are subiect to their owne senses and reasons and especially because some of them must aduenture their whole estates yea and also their liues vpon the right vnderstanding of some Magneticall conclusions Wherefore vpon the earnest longing of certaine mine Honorable and Worshipfull freinds and for the singular loue that I beare to the louers and practizers of the worthy Art of Nauigation and to satisfie the commendable desires of such as like to haue some insight though themselues be not praectizers in these matters of admirable knowledge and great vtilitie I haue vndertaken to contriue all the
cheifest points of this most necessary skill and the vse of them in this short Treatise Not meaning to translate Doctor Gilberts booke but to take those thing out of it which I shall thinke fit for this purpose which are onely the Magnetisme of the whole earth and some of the consequents thereof and to adde the rest of mine own industry Wherin I may be bold after asort to challenge a right as hauing endeuoured to get some insight in this argument a matter well knowne to diuers aboue the space of twenty yeares ere Doctor Gilberts book saw light And in very deed I communicated many of my obseruations with him aboue one whole yeare before he put it out in print To be short of all that I shall set downe in this Treatise my request is that the Reader will admit nothing but that which shall be confirmed by good reason or vndoubted experiments And I purpose God willing to tye my selfe as strictly vnto this rule as euer any man did that hath written of the like argument making it euen a matter of conscienae to deliuer any thing herein for certaintie that my selfe shall not know to be sound And so by this meanes shall I neither abuse the Reader with any vntrue assertion nor iniurie so certaine and so excellent a knowledge with any doubtfull or vnapproueable conclusions Contents of this Treatise CHAP. I. OF the Magneticall power of the whole Globe of the Earth CHAP. II. Of the ambiguitie of the North and Sooth ends of Magnets and Magneticall bodies explained and Doctor Gilbert therein defended CHAP. III. Certaine generall obseruations of the nature and properties of the Loadstone CHAP. IIII. By what meanes the chiefest points of any Magnet of what forme soeuer may easily be found out CHAP. V. The manner of Capping both with single and double Capps and the nature of them CHAP. VI. Of cementing and peicing of Loadstones CHAP. VII Of the variation of the Magneticall Needle with the Appurtenances therto belonging CHAP. VIII A discouery of Errors committed in the making and touching Magneticall Needes and Wiars of sayling Compasses with an aduise for the true and right making and touching of them CHAP. IX Of the touching with a Loadstone capped and without the Cappe CHAP. X. Of the fashioning of the Compasse Needle CHAP. XI A Sayling Compasse fitted for obseruing at Sea the variation amplitude of either Sunne or Starres Capes or trendings c. CHAP. XII A comparison of the seuerall vses of the Horizontall and Inclinatory Magneticall Needles A true copie of one of D. Gilberts letters written to the Author concerning his Magneticall Experiments MAGNETICALL Aduertisements CHAP. I. Of the magneticall power and force of the whole Globe of the Earth COncerning the Magneticall force of the whole body of the Earth I haue selected these experiments to proue it Take any peece of solid earth that hath some toughnesse to hold together and will abide the fire as any sort of clay or bricke which somtimes was clay fashion it in such manner that it bee vniformely extended towards both ends the Ouall or long figure is fittest for our purpose put it into a fire of charcoles increasing the heat by little and little and at the length with often blowing make it throughly as red hot as you can let it remaine so for the space of halfe an houre or more that thereby all superfluous moisture may be consumed and aduerse qualities separated from it then take it forth and let it coole of it selfe being first set North and South with either end answerable to the variation of the place not paralell vnto the Horizon but eleuated answerable to the Latitude as nere as you can Certaine it is that this peece of earth thus ordered will sensibly shew you that it hath true Magneticall vertue But here before I proceed any farther I must deliuer vnto you a necessary obseruation There are two kindes of Attractions as they are commonly called the one Magneticall the other Electricall The Magneticall hath alwaies speciall respect vnto the North South points of the Magnete or Magneticall body The Electricall body hath no manner of respect vnto any one point of the Electricall body more than another And by this difference these two kinds of Attractions are easily discerned As also by this looke what end of the Magneticall needle the one end of the Magnet doth draw the other will chase away but the Electricall body draweth alike at all ends And thirdly after this sort lapp this Electricall body in a paper and it will draw nothing at all but interposition of brasse or of a stone wall within the orbe of the Magnets vertue doth nothing weaken the same or hinder his effect towards his peculiar obiect Notwithstanding to speake properly Attraction pertaineth onely to Electricall bodies because the whole attractiue vertue is onely in the Electricall body it selfe and nothing at all in the thing that is attracted The Attraction commonly so called of the Loadstone is rightly to be termed Concursion Confluence or Coition because it is the running or vigorous meeting together of two Magneticall bodies hauing a mutuall inclination the one to ioyne with the other or by any other name bearing like sense For the true knowledge thereof being but lately as a stranger arriued amongst vs common vse Quempenes arbitrium est ius normal loquendi hath as yet scant suted it with a conuenient name to expresse this property So that Magneticall Concursion is neuer but betweene two bodies such as both of them are Magneticall As of one Loadstone with another or of a Loadstone with yron or steele or yron oare if it be prepared or betweene two peeces of yron or steele that are reuiued with a Loadstone for indeed the Loadstone can but reuiue and multiply Magneticall force in a body that naturally hath it in some measure before but cannot infuse it into any thing that before is vtterly voide of it as of mettals in yron or steele and not in gold siluer brasse c. Electrum in this argument is named that which is either Amber in substance or at the least of the quality and that Amber being rubbed hath to take vp moats feathers strawes sticks and other small things The which property is also in ieate brimstome hard waxe if it be smooth and in infinite other things both naturall and compound all which because of that qualitie in this argument are termed Electricall bodies and their taking vp of things is called Electricall attraction hauing onely a slender resemblance and no truth of the Magneticall qualitie But that aboue-mentioned peece of earth prepared in such sort as is before prescribed will by Magneticall concursion shew it selfe to be a true Magneticall body For the one end of the Magneticall needle will couet towards the one of the prepared masle and flie from the other And contrariwise also though it will do both but weakely not with power comparable to a naturall Loadstone
to a Masons trade they will haue 40 points twenty North and as many South and will worke the like effect in drawing yron as to vse the former grosse similitude if a teeme of horses were set in their traces contrary the one to the other the one to pull one way the other another As for the Turkes Mahomet hanging in the ayer with his yron chest it is a most grosse vntruth and vtterly impossible is it for any thing so to hange in the ayer by any Magneticall power but that either it must touch the stone it selfe or else some intermediate body that hindreth it from comming to the stone like as before I haue shewed or else some stay below to keepe it from ascending as some small wier that may scantly bee seene or perceiued CHAP. VII Of the variation of the Magneticall Needle with the Appurtenances therevnto belonging THE variation of the Magneticall Needle being aptly fitted and placed vpon his pinne is nothing else but the swaruing of the pointing thereof in the Horizon from the meridian line there the portion of the Horizon intercepted betweene the true Meridian line and this pointing sheweth of what quantitie the variation is and giueth it his name to wit which way it lyeth either Easterly or Westerly and it is obserued by either end of the needle as you please In times past men obserued onely by the North end of the needle because they vnderstood not that the Loadstone hath a South vertue as well as a North And therefore did touch their needles and wyars of their compasses alwaies for the North onely leauing those ends of the wyars bare that they might be refreshed with a new touch at any time afterwards but the other ends they couered not knowing that they were also apt to receiue as forcible a vertue from the Loadstone for the South as the other for the North. For the right vnderstanding of the variation with his necessary dependants wee must vse the meanes of two circles The one of them I will call the Magneticall Almicanter The other is already knowne by the name of the Magneticall Meridian This Magneticall Almicanter is a circle paralell vnto the Horizon whose center is the verticall point and is described by the distance betweene the verticall point and the neerer Pole of the earth The true Magneticall Pole is the pole of the earth The magneticall respectiue Pole or which is all one the Pole of the Magneticall Meridian is a point in the Magneticall almicanter distant Easterly or Westerly from the true pole as many degrees in that almicanter as the variation of that place containeth in the Horizon but alwaies it is in the contrary part of the true Meridian that is if the variation of the South point of the needle be Easterly the respectiue pole is Westerly but if you obserue with the North end of the needle the respectiue pole and the variation are both one way in all our Northerne Climates If the variation of the South point of the needle bee Westerly then is the respectiue pole so many degrees in the said almicanter Easterly and therefore alwaies of the same height with the true pole aboue the Horizon For since all great Circles of the globe doe necessarily cut one another in two points into two equall parts these two therefore must needes doe euen so in the Zenith and Nadir by their very definitions So that these two points the Zenith and Nadir are alwaies alike common vnto them both aswell vnto the true as vnto the Magneticall Meridian Where-hence it followeth necessarily that alwaies the one halfe of the magneticall meridian is on the East-side and the other on the West side of the true meridian the common Zenith and Nadir euermore keeping their equall distances from the Poles of the one of them as they doe from the other For example Suppose the common Zenith to be in the Aequator you sayling East or West as long as there is no variation there is no magneticall meridian there are no magneticall Poles but those of the world But as soone as sayling still vnder the line you doe finde a variation it is the magneticall meridian that by his swaruing from the true meridian of the world in the Horizon sheweth the quantity of the variation and giueth it also the denomination of Easterly or Westerly and his axis is the line of variation But supposing the common Zenith to be in any paralel betweene the Aequator and the Pole then is it not the axis but some other Diameter of the magneticall meridian which sheweth the variation in the Horizon And the magneticall meridian euermore cutteth iust so many degrees of the magneticall almicanter on the one side of the true meridian as the same Magneticall Pole is distant in the same almicanter on the other side of the true Meridian from the Pole of the World And this is to be vnderstood in correspondent manner as well of the South Hemisphere as of the North. The respectiue Magneticall meridian where any variation is is a circle that passeth by the verticall point and the Nadir and both the respectiue Poles crossing the Horizon at right angles in the points of variation of which circle the line of variation is a Diameter but where there is no variation the true and Magneticall meridian are both one the selfe same and so in like manner are their Diameters Those circles and poles are tearmed respectiue because that in euery place where any variation is the Magneticall needle doth respect them as well in the property of direction as in that of declination or inclination For thus also very well it may bee tearmed By the property of direction I doe meane with Doctour Gilbert the Horizontall motion of the Magneticall needle By the declination or inclination I meane the descending and as it were the sinking motion of the neede vnder the Horizon in his proper Azimath or Magneticall meridian But if there be no variation the needle alwaies pointeth vnto the true Meridian of the earth and towards the Poles therof in both those properties The true Poles of the earth which are those two points equally distant from each part of the Aequinoctiall of the earth are alwaies the selfe same The respectiue Poles alter with euery Horizon where there is any variation but neuer out of the aforenamed almicanter of that place The causes of the differences of the respectiue Poles and Meridians from the true Poles and meridians and so of all variations are onely two The chiefe and most generall is the vastenesse of the Ocean sea by moistnesse whereof the Magneticall collaterall force of so much earth as it couereth is much hindered and dulled And by that meanes the next great Continent hath more power ouer the correspondent end of the Magneticall needle then otherwise it could haue if all were alike one entire Continent and therefore causeth the directiue property of the needle somewhat to swarue towards that way
which is that which we call variation but yet the vastenesse of the Ocean doth not hinder the declination of the Magneticall needle Because his hangings consisteth but in length and breadth and not in depth For although in comparison of a pond or riuer the sea is said to be of a wonderfull depth yet if this depth be compared with a Semidiameter of the earth it beareth a very exceeding small proportion nothing at all to hinder the mightie magneticall declinatory force of the whole earth For the greatest depth that euer any man of skill esteemed it at was not aboue two English mile at the vttermost when as daily experience maketh it manifest that a great Continent wil shew his Magneticall collaterall force by causing a variation aboue two hundred miles of from the place and therefore Doctor Gilberts feare in that point I take to be needlesse supposing a variation of declination The second cause of variation is any great mountainous region not farre of when a man is in some great Latitude towards either of the Poles if that mountainous region lie Easterly or Westerly from you it will cause the needle somewhat to swarue that way But variations of this sort are of small continuance and in sayling subiect vnto sudaine alterations yea many times quite contrary from Westerly to Easterly afterwards backe againe within short space as our first famous Pilote Steuen Burrough found by his experience in the discouery of the Scythian sea-coast between the north Cape of Finmarke and Vaygates The reason whereof ought heedfully to be regarded which is that the Magneticall force of the whole earth doth as in all Magnets shew it selfe most strongely in the two Poles thereof and in those places which are neere vnto them but alwayes it must be remembred that all the force they haue doth issue out of the whole terrestriall body as it doth likewise in all Magnets out of the body of the Magnet and therefore in any part of the superficies of the whole terrestriall body it is impossible that any variation be aboue 90. degrees because the vertue of the whole can neuer bee ouerswaied by the imperfection of a part and especially of so small a part as any one portion of the Ocean is in his very superficies in respect of the body of the whole earth yea I am thorowly perswaded that there neuer was nor euer will bee any variation by any good obseruation found for to bee so much as ninety neither any shew of so great variation any where except it bee very neere vnto either of the Poles where there is small credit to be giuen to the obseruing of any variation for the variation being as aforesaid the difference of the pointing of the magneticall Needle in the Horizon from the true Meridian for asmuch as in places neere the Pole there is no manner of certaintie of either of these it is not possible to finde the variation if there be any The reason whereof is this no man may trauell those Seas but whiles the Sunne abideth on that side of the Aequator whereby they haue continuall day and by that meanes are secluded from any helpe of the starres neither if they might bee seene would they bring any great helpe For the difference of heighth in many houres is so small that by a very large instrument a diligent obseruer with great paines will hardly finde the Meridian Line all the Meridians themselues comming so neere one to another and meeting in the Pole and their Horizon being in a manner paralell vnto the Aequinoctiall And as for the horizontall magneticall Needles to shew their pointing in the Horizon as they were wont to doe they comming into this climate may say Fuimus Troes Their direction is as it were giddy and vncertaine and when their center commeth vnto the Pole it selfe it is quite vanished away for from thence all the points of the Horizon are onely South if it be at the North Pole and North from the South Pole and therefore in that place the instrument of declination is farre more sure then the Horizontall Compasse And as in the Poles themselues there is no direction at all so of necessitie neere vnto them it must bee a very confused direction Those two places that are called the Poles haue no strength of themselues as aforesaid but as it is contributed vnto them of the whole As in a Magnet if you breake off a peece of the contrary end the end that is left will bee according vnto that proportion diminished in his strength and the polar peece that was broken off be it neuer so little will haue two poles as well as the great so that the two parts will haue foure Poles two of them North and two South Put this little peece that was broken off in his place againe and then each peece will lose one of his Poles in the same very instant and the whole will haue but two Poles the one North the other South as at the first Againe if you cut off a peece of one side of a Loadstone that is brought into a round or an ovall forme hauing his Poles marked in their due places at each end presently both end will be abridged of part of the force they had and the Poles themselues will be remoued vnto the other side from the places that were marked and those markes will stand but for idle ciphers in comparison of that they were before Againe take a Magnet of a round or an extended ovall forme I doe still exemplifie in these because they are of all others as I haue often admonished for all magneticall proofes the most excellent formes and set markes on the two Poles take a fine needle or any straight small wier and set it on the aequinoctiall I meane thereby the middle betweene the two ends of the stone then will it point directly towards each Pole if the stone bee sound without any flawes or any other grosse substance as may bee intermingled with it and if you thrust this needle towards either end according vnto his owne direction he will trace you a circle right ouer both of these marked Poles which is the true Meridian of the stone But if this stone hath in either of the sides any imperfection when the needle commeth vnto the edge or brinke thereof it will swarue somewhat towards the sounder side and will point to neither of the true Poles And if a circle bee drawne according to his pointing as hee standeth still in that place this shall be a respectiue Meridian of that stone proper vnto that place and the Poles the respectiue Poles differing from the true Meridian of the stone and his Poles Now if you thrust the needle further towards the end vpon the brinke of this imperfection it will not point as before but either further off or neerer towards the true Poles and will giue his direction for a new respectiue Meridian and new respectiue Poles And in such
and finding diuers good secrets I pray proceede with double capping your Loadstone you speake of I shall bee glad to see you as you write as any man I will haue any leisure if it were a moneth to conferre with you you haue shewed mee more and brought more light than any man hath done Sir I will commend you to my L. of Effingham there is heere a wise learned man a Secretary of Venice he came sent by that State and was honourably receiued by her Maiesty he brought me a lattin letter from a Gentle-man of Venice that is very well learned whose name is Iohannes Franciscus Sagredus he is a great Magneticall man and writeth that hee hath conserred with diuers learned men of Venice and with the Readers of Padua and reporteth wonderfull liking of my booke you shall haue a coppy of he letter Sir I purpose to adioyne an appeudix of tx or eight sheets of paper tu my booke after a while I am in hand with it of some new inuentions and I would haue some of your experiments in your name and inuention put into it if you please that you may be knowen for an augmenter of that act So for this time in haste I take my leaue the xiiijth of February Your very louing friend W. Cilbert Faults escaped IN the Preface speaking of Claudianus serediticall for sideriticall fol. 12. lin 22. reciprocated for riciprocally fol. 50. lin 21. hangings for hugenes fol. 53. lin 16. as may be for as many be fol. 57. lin 10. but this is not for this is not fol. 68. lin 19. supposeth the fly for supporteth the fly fol 79. lin 11. set the same for set the Sunne item lin 27. the difference is then for the difference is ten fol. 82. lin 8. higher for heuier fol. 84. lin 26. three in Diameter for three inches in Diameter fol. 85. lin 10. littles circles for little circles The last line saue one of D. Gilberts letter act for arte A BREIFE DISCOVERY OF THE IDLE ANIMADVERSIONS OF MARKE RIDLEY Doctor in PHISICKE vpon a Treatise entituled Magneticall Aduertisements moueat Cornicula risum Furtiuis nudata coloribus LONDON Printed by Edward Griffin for Timothy Barlow at the signe of Time in Paules Church-yard 1618. TO THE RIGHT NOBLE AND WORthy minded industrious Gentlemen and others who are any way addicted vnto MAGNETICALL Knowledge SO it is that for a long time I haue bin greatly delighted in the contemplation of the properties and vertues of this admirable creature of God which we call the Magnet or Loadstone And as my leisure and occasions haue serued by conference from time to time with the skilfullest Nauigators of our age by reading all the Treatises as came vnto my knowledge of such as had written thereof and therewithall trying by practise the truth of those things which I doubted of and lastly finding some things by my owne experience of good importance by others not at all mentioned The chiefe of these which I iudged profitable for common vse I did set forth in a small Treatise intituled Magneticall Aduertisements And although of mine owne louing affection towards such as yee are I haue bin alwaies ready to further you in these knowledges the best I could yet I doe assure you faithfully that diuers of good iudgment learning and eminent place vnto whom I communicated my experiments very vehemently vrged my publishing of them A copie of this Treatise being by stealth written out of my Manuscript by one that vnderstood it not and by that meanes committed diuers errors this Doctor Ridley deuoured some of them and by his endeuouring to square my propositions according to his owne conceipts and so superciliously to controll and censure the things which he vnderstood not he hath missed of the truth very farre and wide and hath herein wronged both himselfe and mee and his readers but most of all his beleeuers and yet such is his kinde disposition that he hath purloyned out of the scambled copie of my Treatise for to adorne his owne Treatise of Magneticall bodies and Motions all these that follow as in his Treatise Fol. 7. The hilly knobbes and angulous parts c. for 17 lines Fol. 8. The greater stones c. 5 lines Fol. 9. Steele and yron c. 4 lines Fol. 10. The 14. 17. 18. 19. figures are mine Fol. 18. 19. The 1. 2. 3. 7. waies are mine the 4. Doctor Gilberts Fol. 22. Euery part and peece of a Loadstone c. 7 lines Fol. 27. If a wyer be touched c. 5 lines Fol. 30. 31. It is to be obserued in the fashion of a Magnet c. 16 lines Fol. 36. For although that naturally c. 9 lines Fol. 51. 52. Also if a Magnet be fastened c. 4 lines This practise is profitable for Trauellers c. 14 lines moe Fol. 63. 64. The best way to touch c. 11 lines And some haue thought it better c. 14 lines Fol. 66. Set two Loadstones c. 3 lines Fol. 71. An Adamant doth loose much of his vertue c. 3 lines Fol. 72. That 20. Chapter onely a few words chopped and changed is whole mine Fol. 83. And for this cause the Adamant c. 3 lines Fol. 89. A peece of Steele well tempered c. 2 lines The two next are his owne and very absurd Fol. 90. Now it is to be obserued c. 10 lines Fol. 95. The needles and compasses c. 14. lines So that it cannot but seeme to any indifferent person very strange that Doctor Ridley would publikely so traduce mee and that by name and so contemptuously in his friuolous Animaduersions and could neuer hit vpon my name no not so much as once to acknowledge it in all these things which he hath by stealth learned of mee and inserted into his Magneticall Motions for his owne the which with their consequents if you withdraw from his Treatise you will leaue his motions very dull For except this Ridley had ploughed with my Heifor hee had not knowne my Riddle Sic vos non vobis In my aduertisements indeed I made mention that some body had in this manner dealt euilly with mee and I reproued certaine faults that some body had committed especially in the fundamentall Magneticall heare-sayes of misnaming of the true North and South in Magnets and Magneticall bodies and in making the Inclinatory needle with the one end heauier than the other and some others But these two especially for because they doe draw on many others as they doe both in his Booke and wheresoeuer they shall be admitted they will increase like a snow-ball waxing still greater as they goe and all his dawbing of them with his vntempered morter in his silly Animaduersions do amend the matter nothing at all but make it farre worse than before For the common good I might not let them passe vnreproued and yet I would not publikely name him but vsed this word somebody The like himselfe hath viz. Some say some