of the Ruler And toward eache end of equall distance therefrom fitte two Sights of three ynches or longer as your Compasis and about a quarter of an ynche broade at the toppe waxing broader toward the foote where they are to be ioynted in such sort that they may for handsomenesse sake be folded the one close vpon the other and stand erected at right angles In the one of these along the middle thereof cut out the mettall beginning a little beneath the top downe to the foote of conuenient breadth that a Lute string hauing a small pearle or bugle on it to slide vp and downe may be fastened precisely in the middle throughout from the toppe to the foote The other Sight being made after the same proportion and forme that the former was hath onely a fine small slit pearced from within very little off the toppe downe to the foote and must in his thickenesse be abated that he weigh no more then the other The Ruler thus furnished with his Sights in the space betweene the sights and the brimme of the Boxe ought to haue two loopes cut out in decent maner to looke downe through them vpon the Flie. And this Ruler must be diuided into many equall small partes as 20 to an ynche or such like the numbers beginning from the Lute string sight vnto the other and from the foote of that other to the toppe When the Ruler is finished as before I haue specified it must a little be let into the brimme of the Boxe that it may stand fast hauing the middle of it right ouer the line of North and South in the Boxe and the Sight with the Lute string ouer the South But let it in such sort be fastened that you may conueniently either take it off or set it on as occasion shall serue So that the Ruler being taken off it is a Sayling Compasse being set on it serueth for the Variation in maner following The Flie of the Compas hauing at opposite partes directly ouer the points of the wyers some markes on the vpper side easie to be discerned if it be a Meridionall Flie it needeth not in as much as the Flower de luce and the South point serue the purpose turne the Boxe toward the East in the foorenoone with the Ruler on it till the Lute string doe cast his shadowe right vpon the middle line of the Ruler or on the slit of the other Sight Then marke immediatly where the shadowe of the pearle doth light vpon what diuision if the lines be diuided otherwise marke it with a penne And also what part the Southend of the wyers or which is all one the Northend doth point vnto in the side of the Boxe In the afternoone doe the like toward the West with the pearle still vnremooued turning the Boxe till the shadowe of the pearle falleth full vpon the place that it did in the forenoone And note then also what part the endes of the wyers doe point vnto Then if the number of partes obserued in the forenoone be alone with those in the afternoone there is no Variation at all for the ends of the wyers doe shewe the true Meridian But if the one exceede the other subtrahe the lesser from the greater And halfe the remainder is the Variation of the Compasse toward that side which had the greater number in his obseruation This Compasse serueth farre better to set the land withall and to describe any Harbour Coaste Hauen Towne or Countrey then any before in common vse by looking through the slitte and bringing the thing that you would note and the Lute string both in one withall marking what partes the wyers doe shewe at that instant Likewise for taking of distances All this may also bee performed with a Circle of Latten about one quarter of an ynche broade hauing a stay going athwart perced through with loope holes that it be no hindrance to viewe the Flie and a Ruler mouing vpon it in forme like to the former Which Circle must be diuided as that within the Boxe was frō the Flower de luce which is to be placed a quarter of a Circle distant frō the line passing along the middle of the stay haue his numbers reckoned towards the endes of the same line And so must the other halfe of the Circle be diuided from the South point Being thus diuided it must be placed euen fast and very fitte close aboue the Glasse And when you will vse it turne the Boxe about till the flower de luce of the Circle stand right ouer the Northerly endes of the wyers And the Boxe so standing set the Ruler according to the forenoone and afternoones obseruation doing all things els as before And you shall finde the selfe same effect I haue tryed at land the Crosse-needle in steade of the Flie and do like it exceeding well Whether is the better at Sea I doe referre it vnto their iudgements that shall make due triall of both The Crosse-needle I call two needles the one of Steele and the other of Latten ioyned together in the Capitell where they crosse each other at right angles and so made that they be of one length very straight and equally standing vpon the pinne no end ouerweyghing the other This Needle well made and fitted as it ought to bee will besides his proper vse supply the vse also of a Perpendicle a matter of great importance to shewe the vpright standing of your Instrument which the single Needle cannot doe neither yet the Flie any whit comparable vnto this But you are diligently to note that in continuance of time as the force of the Touch of the Stone doeth decay so will the North ende of either Needle or Flie rise somewhat higher and the South end sincke lower For this is one of the wonderful properties that the touch of the Magnete hath that a needle as yet not touched standing equally vpō his pinne being once touched with whether ende of the Stone you list the one end thereof shalbe reared higher and the other fall lower The difference whereof as the goodnes of the Stone is greater will accordingly the more appeare And in processe of time as his force stil decaieth so returneth hee more and more to his euen standing againe By reason of which propertie the Artificer is constrained that he may make the Needle lie euen to abate somewhat of the falling end that the other by vertue of the touch raised vp may through this abatement be brought downe to an equalitie of situation with his fellowe When therefore you perceaue the rising of the North end as aforesaid assure your selfe the Flie or Needle is weakened in strength and hath neede to be refreshed with the Stone Otherwise if it were at the first well touched be not too busie with it but let it alone except you bee well assured of the goodnesse of the Stone and of the right maner of touching If the Northend riseth not any thing at all and
or Degree the Needle is at And then working in all respects as before I declared the Variation is made knowen vnto you If you haue a Crosse-needle well made it will serue in steade of the Perpendicle better then the Perpendicle it selfe In as much as it is not subiect to the whirling of the winde but is quiet therefrom being defended by the Glasse close symmond round about The taking of the height of the Sunne at Sea PLace the Verticall vpon his handle the limbe towards you and his perpendicular side ouer against you and turning your backe towards the Sunne keepe the two sights of the Directory euen with the parting of the water and the Element ouer right against you Moue also the sight Ruler of the Verticall vp or downe till at one instant you may see both the Sunne-beame through the vpper sight to fall vpon his due place in the neather and ioyntly therewithall the parting of the water and Element Then haue you the degrees minutes of the sunnes height by meanes of the Proportionall Quadrant as heretofore is specified This may in like maner be performed by looking toward the Horizon directly vnder the Sunne placing the Perpendicular side towardes you and the limbe from you and thrusting the Directory with his long sights from you or else drawing it towards you as you may most conueniently discerne the sunne-beame of the vpper sight to be vpon his iust place in the neather For the better effecting whereof it is requisite to haue a third square sight forked on the neather side with a couple of small peakes to be placed the one on the one side and the other on the other side of the Center of the sight Ruler ready to be taken off or on and hauing a little marke with two crosse-Crosse-lines of equall distance to the holes of the other two sights and the Fiduciall line To the end that this third sight being fastened right ouer the Center of the sight Ruler with his lower edge somewhat aslope and not at right angles with the Fiducial line you may the more easily discerne by meanes of the said marke when the sunne-beame hath perced the other two sights aboue And then haue you all things as before Wherefore if two obseruations be made together the one from the Sunne and the other towards it and both these agree in one The whole Operation must needes bee exact and without any doubt of error The ordinary staues so that they be well made and good regard had to the Eccentricitie of the eye be very commodious for so much as they can performe which cannot be much aboue 45. degrees because the eye at one viewe is scarce capable of a larger Angle And therefore in great Altitudes of the Sunne they are vnseruiceable the Astrolabe or searing as some terme it comming in place of them And yet the vse of this also in a hie Sea is very vncertaine But with the Instrument that nowe is described vnto you you may take the height of the Sunne at what angle so euer yea although he be verticall Herein this and the staffe agree that both of them haue a speciall respect to the Horizon but they differ in the danger of the Eccentricitie of the eye whereunto the staffe is subiect but this is not so and neuer requireth any Angle in the eye of the Obseruer that shall exceede the capacitie of 20. degrees Somewhat also might here haue beene added of the diuerse placing of the sights vpon the Directorie but for breuitie sake I referre it to the consideration and choise of the Practiser vpon diligent triall thereof The Hemisphere The Scope of this Treatise TWo things there are in euery Instrument of speciall and most necessarie consideration the one the body as it were and substance of it the other the ende or purpose whereunto it serues The body or substāce of euery Instrument and namely of this whereof nowe wee treate I call the Materiall partes of which it consists together with their peculiar formes such as whereby that end may be best atteyned best I meane with the greatest both certeintie and facilitie possible The purpose or end I terme the manifold commodities to be reaped thereby and especially in this Instrument the singuler most pleasant and profitable vses whereunto it is and may be applied All which fully to discourse of would require farre more leysure then either my vocation or other many affaires of importance may permit me I shall therefore sufficiently content my selfe in this behalfe if first I deliuer to the skilfuller and more industrious sort a briefe and perfect viewe of the Instrument by a particular and euident description to the eye of all the Members thereof which once conceaued the thing of it selfe without any further words of mine wil most easily and readily vnto them declare his owne vse from point to point in Astronomie Geographie Nauigation and such like excellent faculties But because that the Nauigatour is the man for whose sake chiefely I haue taken these paines And among those of that trade the most part are though commendably perhaps furnished with experience yet but weakely assisted with fitte Instruments and of themselues for want of some contemplatiue knowledge Mathematicall not able either to inuent fitter or to reforme and better those that presently they vse I thought it requisite for them together with the description and frame of the Instrument to adde in the second place some fewe principall admonitions concerning the seuerall most necessarie vses thereof vpon sea or land And in so doing I wil leaue many things to the Readers owne ingenious practise Many also will I omit or rather presuppose as already knowen namely what a Pole is an Equinoctiall a Meridian c. being such as are the first Principles of this Arte wherewith euery man is commonly acquainted and by diuerse in our owne vulgar speache haue in the largest maner oftentimes be handled The names of all the partes of the Hemisphere NOwe if any desire to knowe what this Hemisphere is by it selfe and so must he first if hee will orderly proceede to the getting of perfect knowledge in the vse for no man can well handle an Instrument that he knoweth not a generall declaration of the partes accompanied with their Mechanicall description and a briefe comparing of them with the Globe may so throughly suffice as more herein is not to be required There are therefore in this Instrument two sides to be considered the one more principall which I terme the Face the other lesse which I cal the Backe The Face consisteth of whole Circles and halfe Circles The whole Circles are two in nūber whereof the one being the Base as it were of all the Instrument and immoueable is the fixed Meridian because that turne most commonly it serueth the other moueable I call the Deferent for that it carieth vp downe vpon and in it selfe according to any greater or lesser Eleuation or Latitude
the Horizon of the World and on what side of the Meridian it is whether East or West Set then the Equator in the Hemisphere according to the Latitude giuen And hauing marked in the Moueable Meridian the Declination of the starre whose height you found moue that Semicircle with the point of the stars Declination till in a correspondent Quarter of the Hemisphere to that which it possesseth in the Heauens the starre obteine his precise equall height from the Horizon which is soone measured as before we declared by turning the Moueable Meridian and the Semicircle of Altitudes to and fro til both cut eache other in the point of Declination That portion of the Semicircle of Altitudes comprehended betweene their Intersection and the Horizon is the starres height And immediatly therewithal appeares vpon what point of the Compasse the starre is Also in the Semi-equator the moueable Meridian shewes you the starres houre Howbeit because all distinction of time proceedeth originally from the Sunne that is not the true houre of the Night sought for but an other must be found by the distance of the starre from the Sunne And for this purpose serueth the Zodiake or Circle of right Ascensions described in the Deferent Seeke therefore therein the place of your starre if it be of the number of those that are there set downe otherwise the degree of your starres Coeli-mediation which by the helpe of the Ruler make perfectly to agree with the houre of the starre now to be reckoned in the Circle of houres in the fixed Meridian Finally keeping the said Circle of right Ascensions in this sort immoueable looke therein for the place or degree of the Sunne for that Day and thither mooue the Ruler till it lie directly thereon Then shall the end of the Ruler in the Circle of houres vpon the fixed Meridian shewe you the true houre of the Night required The Latitude being giuen and the Declination of eyther Sunne or Starre to finde howe long they appeare aboue the Horizon and at what Point they rise or set also the Amplitude Orientall SEt the Equator of the Hemisphere according to the Latitude giuen and apply the degree of Declination to the Horizon Afterwards the Instrument thus standing note vpon what houre or part of time the Moueable Meridian falleth in the Equinoctiall For that shalbe the precise time of rising to be nūbred in the houres aboue or of setting in those vnderneath And the Arke of the Equator conteyned betweene the Moueable and fixed Meridian being doubled declareth howe long either sunne or starre continueth aboue the Horizon Now touching the Point of the Compasse it doth presently offer it selfe to be seene in the vtter margen of the Horizon ouer-right against the point of Rising or setting aforesaid From which point to the Pinne being in steade of the true East or West the degrees conteyned in the Horizon represent vnto you the Amplitude Orientall or Occidentall By the Sunne-beame to drawe redily the Meridian line and to finde the Variation of the Compasse FOr more speedie and certaine operation herein if the Sunne be in the East halfe of the world turne the face of the Hemisphere Eastward if in the West halfe then Westward altering a little the situation of the Pole and consequently of the Equinoctiall that the Pole and semicircles of the Instrument may agree and be equidistant vnto those of like denomination in the Heauens Then hold it perpendicularly vpon or ouer any flatte and smooth superficies lying parallele or euen with the Horizon of the world and that directly toward the Sunne that the beame thereof passing through both the sights may shewe the exact minute of time Nowe sith the fixed Meridian of the Hemisphere is in the Meridian of the world the foote of the Hemispheres said Meridian must needes be so likewise Drawe therefore either by direction of the foote it selfe or of the shadowe of it a straight line and produce it in length as you thinke expedient This shall be the Meridian line required with his two extreames pointing out the true South and North whereunto if you drawe a perpendicular crossing it that shall be the Line of the true East and West The variation is thus knowen when the houre is found as immediatly before you haue heard at that instant turne your eye aside toward the Backe of the Instrument and marke what Angle the Needle of the Compas maketh with the line of North South vnderneath it For this Line being by the structure of the Instrument equidistant to the fixed Meridian of it is vnderstood to be in the great Meridian of the world as the fixed Meridian is And therefore looke howe much the Needle swarueth from the same Line so much it declineth from the true Meridian The quantitie of which declining being nothing else but the Variation is foorthwith made manifest by the degrees of the Circles circumference vnderneath conteyned betweene that Line and the end of the Needle To finde when the Twylight begin neth and howe long it continueth THE Sunnes depression vnder the Horizon may soone be knowen by the manner of finding the height thereof aboue And thereunto belongeth this obseruation of the Twylight The beginning whereof in the Morning and ende in the Euening is commonly supposed to be when the Sunne in a Verticall Circle is by the space of 〈◊〉 vnder our Horizon Moue therefore the Moueable Meridian and the Semicircle of Altitudes both together towarde the North part of the Horizon the Pole before being raysed accordingly till the point of the Sunnes declination and the end of 18. degrees being reckoned from the Horison downeward in the Semicircle of Altitudes doe meete ioyntly in one And straightway note what houre the Moueable Meridian lighteth on in the Equator for that is the time when the Twylight beginneth in the Morning if you looke on the vpper side of the Equator and endeth at night if on the nether side Againe turne the Moueable Meridian with the declination or place of the Sunne in it till it be iust in the Horizon and foorthwith see what houre it sheweth in the Equator That segment of the Equator which is comprehended betweene this point of time and the former declares the quantitie or continuance of the Twylight The true measuring of any distance vpon the Globe of the Earth THe Geographicall measuring of mightie Distances vpon the Globe of the Earth is a thing not onely of marueilous pleasure for knowledge but of singuler commoditie for practise seruing to many excellent purposes both bysea and land And although the Computation Arithmeticall vsed herein by the learned grounded vpon the doctrine of Sphericall Triangles is absolute and exquisite yet is the deducing thereof especially when Places differ in Longitude and Latitude not voide of great obscuritie and the operation both by reason of so many multiplications diuisions yea and extractions of rootes exceeding tedious and for the slipperie mistaking or
A B. from whence the degrees of the Quadrant beginne a line precisely equall vnto a namely D F. And from the points D and F. to the Semidiameter A C. raise two Paralleles D E. and F G. Againe from F. toward B. at a distance conuenient take the second line K H. equall vnto a. And from the points H K. rayse other Paralleles H I. and K L. equidistant to the former Afterwards applying the one ende of your Ruler to the Center A. and the other to euery the degrees of the Quadrant B C. drawe lines athwart betweene the Paralleles aforesaid so shall all the lines thus drawen cōteyned betweene the Paralleles be the degrees of the Meridian sought for taking their several Denominations of their correspondent degrees in the Quadrant as by the figure here ensuing is manifest Of what sort soeuer your Cardes be you must alwayes remember that the knowledge of the vse of the Globe must be a moderator vnto them and that thereby you shall still become master ouer your Card to espie and amend his faults whereas otherwise you shall be mastered by your Cards blindly embracing their errors By meanes hereof it was that the famous Nauigators of the World performed their discoueries renowmed voyages hauing no maner of Cardes to sayle by And an easie matter it is for a man that already hath ordinary skill and practise in sayling by vsuall Cardes to learne in one fourthnight so much of the vse of the Globe that vpon his obseruations he may either keepe or change his Points for his best aduantage And of any places whose Longitudes or Latitudes are knowen may tell without any Carde vpon what point they lie and howe farre they are distant from you Also vpon what Point they lie each from other the distance betweene them with diuerse other things that are necessarie and helde for rareties in that facultie For in very many of them Enuie doth so reigne that almost euery one keepeth his owne knowledge to himselfe without imparting it vnto others whereas they should all profite a great deale more if they would communicate their knowledges one with an other for the publique benefite But in so much as eache one affecteth to be singular disdayning the knowledge of others they haue farre lesse knowledge amōg them all then otherwise they might haue for of necessitie many mens practises must cōcurre to make experimental knowledge exact It were greatly to be wished that many of them might be founde so well minded towardes their owne trade as was that notable Pilot Steuen Burrowes who for his skill industrie and performance may iustly be reckoned among the chiefe of our Nation and of the world also if we respect that only in stead of al which he worthily atchieued in the first Moscouian discouerie by the Scythian Sea who if he had bin employed one Sommer more againe towardes the Riuer of Obbe I doubt not but proceeding with his former successe he would haue performed more in that Sommer for trial of a Passage any or none that way vnto Catthay then for the space of these 40. yeeres all Christendome hath done besides not hauing asitseemeth added vnto his 40. leagues of good discouerie euer since The good mind he bare towards his profession he testified herein that by his very earnest meanes he procured that learned and easie Treatise of Martine Curteise concerning the Arte of Nauigation to be translated into our English tongue The which doubtles hath giuen great light vnto all of skil in that faculty that euer were since of our Nation And is more almost then all our Nauigators haue holpen the Arte of Nauigation withall besides A great helpe also would it be for the furtherance of skill if those that are practisers in that Arte and such as are Students of the Mathematikes might often conferre together For except there be a vniting of knowledge with practise there can be nothing excellent Idle knowledge without practise ignorant practise without knowledge serue vnto small purpose But certaine it is that all the good partes which may be wished for or aymed at shall neuer absolutely concurre in one man And therefore if there be but some conuenient mixture of them in any that party is to be esteemed For although many things appertayning to Nauigatiō may be learned taught by rules of Arte yet some necessarie points without which all the rest is nothing are beyond the compasse of Arte As for a man to be of a ready and valiant mind to handle and order those things that are within the reache of his knowledge with dexteritie vpon euery present occasion These and such like are iustly termed the giftes of God For although all things tearmed by Arte are the giftes of God sith euen Arte it selfe is giuen by God who is the Authour and fountaine of all knowledge yet these are tearmed his giftes more peculiarly because the other are giuen by meanes and these without meanes Suppose that a man haue all the knowledge that may be wished for be notwithstanding faint hearted his wits as they say to seeke whē he hath most neede of them his knowledge will ayde him very little Againe if he be of neuer so bolda courage want discretion knowledge iudgement he is very vnfit for the gouernement of a Ship But if such a one be also as most cōmonly they are wilfull taking it for a glorie to be foolehardie this is as great a mischiefe as all other dangers of the Sea if they were all set together Where therefore boldnes of courage directed moderated by discretion iudgement also a body enhabled to brooke the Seas are matched with a willing mind vnto Marine affaires endued with the feare of God wheresoeuer I say these speciall giftes of God are to be found there the ornaments of Arte as necessary additaments will alwayes most effectually take place are most easily attained vnto But where those former at the least in some comperent measure are not al the rest is vanitie It is euen a most irkesome and wofull sight to behold a company of courageous yong Gentlemen to be led on blindfolded as it were in marine actions by such as haue no feare of God before their eyes and many times by those that are very ignorant of almost any thing that good is if any thing might be accompted good where the feare of God is not but onely can tell of their owne experience howe they haue dissimboched from Terra Stolida making their voyage toward the Isle of Pickery gracing themselues as they suppose with swearing and staring and wishly lookes A few such monsters hauing the chiefe gouernement in Ships and voyages are a great deale more dangerous then all the monsters in the Sea And for euery one that is bereft of life by these a hundred at the least are destroyed by the other The serious consideration of these things haue occasioned me of a friendly mind and entire good will wherein toward your profession I wil giue place vnto no man liuing to admonish you of these points which I haue thought necessary Beseeching Almighty God who is the Lord both of Sea dry Land by his holy Spirit of true wisedome to gouerne direct you in all your actions that employing your diligent endeuour in your Arte in his feare and calling vpon him in the time of trouble he may heare and deliuer you from all your distresses And that being deliuered you may accordingly glorifie him yeelding praise and thankes for his mercies before the sonnes of men Let Staffe Carde Compasse Ship and Skill Depend vpon Gods blessed will * * * Cap. 1. Cap. ◠Cap. 3. Cap. 4. Cap. 5. Cap. 6. Cap. 7. Cap. 8. Cap. 1. Cap. 2. Cap. 3. Cap. 4. Cap. 5. Cap. 6. Cap. 7. Cap. 8. Cap. 9. Cap. 10. Cap. 11. Cap. 12. Cap. 13. Cap. 14. Cap. 15. Cap. 16. Cap. 17. Cap. 1. Cap. 2 Cap. 3. Cap. 4. Cap. 5. Cap. 6. Cap. 7.
dispersed and not ioyntly directed to his due points The wyers before they bee touched ought to bee polished and made very cleane and fitted vnto the Flie and then touched after this maner With the North end of the Stone presse each wyer beginning at the middle and so along vnto that ende that you would haue turne Southerly And with the South end of the Stone doe the like from the middle of eache wyer vnto the ende that you would haue turne Northerly Then glewe them in such sort that the Flie may stand equally vpon his pinne hauing both the North and South endes of the wyers vncouered that their Touche may be refreshed as occasion shall require After all this is accomplished that the Instrument thus furnished may truely performe his office there must iust regard be had of the Variation as also of the diuerse Set of the Compasse And likewise that it be not placed neare any Loade-stone yron or steele By the Variation is vnderstood the difference in the Horizon betweene the true and the magneticall Meridian By the Set is meant the setting or placing of the wyers in the bottome of the Flie which sometimes you shal finde standing right vnder the Flower de luce representing the North point sometimes ½ ⅓ c. toward the East of the Flower de luce The Compasse being artificially made and fitted as he ought to be with al his iust regards we must cōceaue euery line drawen from the Center vnto each diuision to represent alwayes the semidiameter of an Azimuth bearing the same name with the diuision of the instrument The line of North South is euery where the intersection of the Meridian with the Horizon and the line that crosseth him at right angles is euery where the intersectiō of the East West Azimuth with the Horizon The like is to be vnderstood of euery one of the other according to their natures so that euery point of the Cōpas when the line thereof is by imagination produced in the Horizon vnto the Heauens is vnderstood to be the base of a Quadrant of some one Azimuth or other and the line falling from the Zenith to the Center of the Compas is as the Perpendicular cōmon to them all Wherefore which way soeuer in any situation a ship doth saile vpon any point of the Compas it must needes be that shee sayleth within the plaine of one Azimuth or other in as much as euery point is the Base of an Azimuth and so performeth alwayes her course vpon the Conuexe of the Sea in a portion or portions of one great Circle or other because all Azimuthes are great Circles Albeit therfore a voyage were to be made from any place in any Latitude more or lesse it skilleth not vnto any other of the same Latitude and that according to the common trade which should not be if great Circle-sayling were knowen brought to perfectiō keeping as neere as may be vnder one Parallele from the beginning to the ende of the voyage yet because in all this Ships motion the Compas is considered as equidistant alwayes vnto the Horizon it must needes followe that all the points of the Compasse his Variation remembred continue their mutuall respect to those of euery Horizon the line of South and North being still the Intersection of the Meridian with the Horizon the line of East and West being still the Intersection of the East and West Azimuth with the Horizon crossing one an other alwayes at right angles so that the situation of the shippe continually altering doeth neuer alter the properties of the Compas whose nature is to deriue those his diuisions vnto euery newe Horizon that hee approcheth vnto all the lines of his points euer remaining Semidiameters of Azimuthes and Bases of their quadrants the line falling from the Zenith through his Center being still the perpendicular common to them all Whereby it is manifest that in as much as the direction of the sayling Compasse is alwayes some one Semidiameter of an Azimuth and the shippe being the body mooued euer stemmeth in the plaine of the selfe same Azimuth also the winde being the efficient that moueth of his mutable propertie driueth foreright diametrally vpon the plaine of the Horizon which cannot be but according to the intersection of the foresaid Azimuth it is therefore impossible if the shippe be moued that is transferred or changed from place to place that the line or tracing of her course comprehended betweene those places should be any other but onely such as is composed of great Circular portions of which the length of the shippe it selfe is alwayes a segment And so describeth she by that meanes in her course before mentioned not a Parallele properly so called as common opinion doth wrongfully imagine consisting of one continual lesser Circular line or otherwise a Spirall line truely so named consisting of a continuall vniforme winding answerable to the nature of the said line but a course quibusdam diuerticulis as learned Nonius termeth it with certaine turnings in and out consisting of small segments of great Circles keeping alwayes as neere the precise parallele or Spirall line as arte can ayde them Wherefore it is confessed that those seuerall courses haue some shew or resemblance of the two sorts of lines aforesaide but by no meanes are they the very lines themselues in deede Who was the first inuenter of this Instrument miraculous and endued as it were with life can hardly be found The lame tale of one Flauius at Amelphis in the kingdome of Naples for to haue deuised it is of very slender probabilitie Pandulphus Collenutius writing the Neapolitane historie telleth vs that they of Amelphis say it is a common opinion there that it was first found out among them But Polidore Virgil who searched most diligently for the Inuentors of things could neuer heare of this opinion yet himselfe being an Italian and as he confesseth in the later ende of his third booke de inuentoribus rerum could neuer vnderstand any thing concerning the first inuention of this instrument Most men suppose the finding thereof to bee very newe and hardly to be proued that it hath beene in any vse in these partes of the Worlde full 200. yeeres agone But whether this propertie of the Loadstone was first knowen in the West or East partes of the world it is very doubtfull The East Indian histories are pestered with such monstrous reports and Legendarie tales that as yet they are but of very small credite Their fabulous genealogies and Frierly discourses doe breede a lingering expectation of some halting Poste that making not so much haste as good speede may with more sinceritie enforme vs of the state of those Countreis and matters vnto them belonging Some fewe yeeres since it so fell out that I had seuerall conference with two East Indians which were brought into England by master Candish and had learned our language The one of them was of Mamillia in the Isle of Luzon the other
of Miaco in Iapan I questioned with them concerning their shipping and maner of sayling They described all things farre different from ours and shewed that in steade of our Compas they vse a Magneticall Needle of sixe ynches long and longer vpon a pinne in a dish of white China earth filled with water In the bottome whereof they haue two crosse lines for the foure principall windes the rest of the diuisions being reserued to the skill of their Pilots Vpon which report of theirs I made present triall howe a Magneticall Needle would stand in water and found it to proue excellently well not doubting but that many conclusions of importance in Marine affaires will thereby more readily be performed I finde that as the Portugals traueiled in their very first discoueries for the East Indies they got a Pilote of Melinde that brought them from thence in 33. dayes within the sight of Calecute and had euen then in vse the Compas the Carde and the sownding line Ludouicus Vartomannus testifieth that in his voyage from Bornco vnto Giaua the Pilots of those Countreys had the vse of both Compas and Carde and had skill to take direction from the South Pole as ours doe from the North euen in those dayes when it was a very daintie matter for any of our Pilots to haue performed the like being as then possessed with an opinion that the Compas would turne round assoone as euer they came vnder the Equator as some doe yet surmise it would doe vnder the Pole or neere the fantasticall Rocke of the purest Magnes Philander in his annotations vpon Vitruuius sheweth that some men deemed it not a newe but an olde inuention and tooke it to be that Nauticall instrument which is called by Plautus in Trinummo and Mercatore by the name of Vorsoria But this Adrianus Turnebus in no case will allowe affirming it rather to bee a kinde of tackle wherewith they turned their Sayle If of olde time they had not this Instrument it seemeth impossible that euer they could haue performed such voyages as they did And if euer they had it then were it as strange that all memorie thereof should be vtterly suppressed and that Ptolomey had not found some mention thereof made in Marinus Tyrius or other Cosmographers whose workes were extant in his time Experience testifieth that this began to be in common vse about the time that Printing was inuented and the making of Gunnes Both which although they are of very excellent vse and great wonderments to the world yet doeth this farre excell and exceede For all things performed by them are marshalled within the limittes and bounds of humane reason and therefore their causes being knowen their wonder ceaseth But this being incomprehensible vnto humane reason carieth it away captiue vnto the astonishment thereof and leadeth it to the admiration of him whose wisedome comprehendeth all things and distributeth knowledge and vnderstanding among men according to such measure times and meanes as seemeth best vnto himselfe opening the eyes of the blind and giuing vnderstanding to the simple destroying the wisedome of the wise and making the vnderstanding of the prudent for to hide it selfe Considering the fowle abuses and errors that dayly are committed in the making and framing of this worthie Instrument I haue thought good heere briefely to note the faults and therewithall to shew the way how they may bee amended Let no man mistake me I speake not saue onely of ordinarie Compasses being the most that euer I sawe such as are in common vse and are sale-ware for Masters and Pilots What some discreete skilfull men carefully doe prouide for themselues I speake not of First therefore for the most part the Carde of the Flie is negligently diuided not only in the Compas which they ordinarily saile by hauing the 32. common partes but as great negligence may be found in the double Flie for their Compasse of Variation where the vttermost Ring which they make moueable about the ordinary Flie is diuided into degrees and there a degree or two oddes breaketh no square with them The wyers of the Flie are as rudely set together hauing their ends not sitted euen and close as were meete but starting a side eache from other not somuch as filed smoothe but rough euen as they were broken whereby they are also disabled from taking so strong a touch as they would if they were made smoothe For remedie hereof it were good to drawe the ouale lines vpon the Carde of the Flie in such sort that the endes being euen with the circumference of the Flie both the middles and the endes may haue an equall distance from the Center Then according to those lines bow and cut the wyers fitting their endes smoothe and so closely ioyning them that they may both seeme to be but one After that holding them together dippe the endes in a little moulten Tinne or if at the first they be welded together it is the better and with the edge of a dull knife scrape off the Tinne againe asmuch as you can come by which will be all in a maner sauing onely a very little that keepeth the endes together and that will hold them so fast that you may conueniently handle them at your pleasure and fasten them on their place according to your desire But before they be set on let them be touched as abouesaid and being set on their touchings at the ends must be refreshed Thus shall your Flie stand and turne equally vpon his pinne if not in stead of the ordinary dawhing with waxe two or three drops at the most will counterpoyse any swaruing and many times you shall not neede any at all which is most commendable The Capitall is commonly wide from the Center of the Flie and likewise the pinne whereon the Flie standeth from the Center in the bottome of the Boxe both grosse and absurd faultes and yet easie to bee auoyded The glasse that couereth the Boxe is commonly crackeled and snarled by the sides and diuerse times also too little These faults they couer with their thicke border of Rosen but better were it to amend them with a little heede taking The Glasse ought therefore to be somewhat thinne smoothe and of euen thickenesse hauing the edges smoothed on a grinding stone or by some other meanes and made very fitte to the Boxe So shall you neede but little quantitie of Simmond onely to keepe out the ayre which is the better both for the clearer view of the Flie and that your Boxe may hang the steaddier and that will it not doe if your Glasse be much thicker on the one side then on the other or els being too little bee thrust neerer the one side then the other and the voide place filled vp with Rosen according to ordinary custome The Boxe is hanged in two Circles the one within the other hauing the pinnes that they turne on a quarter of a Circle in the one distant from the other But these Circles
yet the Flie playeth not then is it to be remedied with sharpening of the pinne The commoditie of the vse of this Needle for a Perpendicle is that because it is within the Boxe the winde cannot hinder it as it will any other Perpendicle especially being small that is in the open ayre The Traueylors lewell THIS Instrument is a Circle about a quarter of an ynch broade hauing his diametrall staye Ruler Sights and all things else as is last before described sauing these additaments The Compasse Boxe of this Instrument must be of Latten of what depth or shallownes you please Only so prepare it that the Needle or Flie want not in any wise space ynough at libertie to play in Let the Circle haue a Quadrant firmely sowdered to his vttermost circumference making right angles with the superficies of the Circle whose semidiameter let be about the length of the semidiameter of the innermost circumference of the Circle or somewhat shorter Diuide the Quadrant into 90. degrees and the numbers of those parts placed in two seueral borders must be reckoned contrary wayes the one beginning where the other endeth Vpon the edge of the vtter Circumference of the Circle where it and the Quadrant meete there must be a strong and firme ioynt fastening the Circle and Quadrant in that place vnto the Boxe in such sort that as the Circle continually riseth so the Quadrant may still sinke in the Ioynt For this Ioynt must issue from the Boxe with a necke somewhat longer then the semidiameter of the Quadrant standing at right angles vpon the Boxe and Circle both hauing in the middle a slit of capacitie sufficient to receaue the Quadrant moued therein vp and downe according to the motion of the Circle itselfe with a little screwe pinne on the one side to stay the Quadrant therewith and so consequently the Circle wheresoeuer you will haue it And on the other side an Inlet must bee handsomely filed that the lower part thereof being of a conuenient quantitie to conteine within it both the borders of the Quadrant may precisely make one right line with the middle of the Axis of the Ioynt and the neither semidiameter of the Quadrant erected So shall it alwayes supply the vse of a fiduciall line and distinctly shewe the numbers that are cut in the borders aforesaid Thus much concerning the description The vse is briefely this When the Circle is not eleuated it is the aboue mentioned Compas of Variation The middle line of the diametrall Stay representing East and West and the Base of the Quadrant produced seruing for North and South c. But when it is eleuated according to the height of the Equator whose angle by the fiduciall line of the Inlet the Quadrant sheweth in one number and the height of the Pole in the other it performeth the vse of an Equinoctiall Dyall generally throughout the whole world For supposing the Circle raysed as apperteyneth let the Needle and a Crosse-needle seemeth the best keepe his due place agreeable to the Variation Then turne the Ruler with his Sights about till the shadowe of the Lute string being toward the Sunne doe fall vpon the middle line or slit of the opposite Sight being perpendicularly erected on the Ruler like vnto the other So shall the vppermost end of the Ruler directed toward the Sunne declare the true houre either in the vpper superficies of the Circle to be reckoned by 15. degrees continually from East to South in the Forenoone and from thence to West in the Afternoone or else for more expedition in a peculiar Border of houres drawen according to euery of those 15. degrees in the voide superficies vnderneath I had once purposed to haue written somewhat of an Instrument deuised by Robert Norman who although he was not learned yet was hee a very expert Mechanician of an honest and good mind and found that by his owne industrious practise concerning a strange propertie of the Magneticall Needle which no man I thinke before him did euer finde and which the more is the shamefull slouth of men very fewe Nauigators haue practised euer sithence Although the Instrument be very easie to be made and the propertie no doubt in Nauigation of great consequence But vnderstanding by conference with a man of rare learning both in Phisicke his owne profession and in diuers other laudable knowledges besides that he many yeeres hath laboured in the consideration of the properties of that Stone and mindeth nowe out of hand for the common benefite to publish those his labours I surceassed altogether from that purpose of mine assuring me that hee if any other will be able most exactly to handle that Argument For I found him excellently skilled farre beyond any thing that I either knewe or imagined in that matter Albeit I had read all that I could heare to haue written thereof and had practised as many of their Conclusions as I made any reckoning of But I found mine Authours euen of the best accompt in many things very friuolous and vaine and ignorant of the chiefest properties of importance He that seemeth to haue written most learnedly is a Neapolitane whose footesteps I followed and found his Assertions erroneous in sixe seuerall Conclusions The Pantometer The Authors purpose in this Treatise THis Instrument that in respect of the manifold and generall vses thereof I call the Pantometer I haue framed chiefly for the Variation And that principally to serue at land yet some partes of it shalbe employed on practise of good importance at Sea both by helping the Hemisphere wherewith hereafter you shall be further acquainted in some things by performing other some for it self And although the vniuersalitie of the Pantometer would haue ministred matter of very large discourse yet for as much as my maine purpose is as in the rest so in this Treatise likewise to be ayding and assisting the Nauigator by al good meanes possible To his principal and most necessarie vses I haue therefore directed and as it were contracted the diffused nature of this Instrument Notwithstanding whatsoeuer Master Thomas Digges hath written of Measurings with his Topographicall Instrument may bee done aswell and better with this Howe conuenient it is for obseruations Astronomical the expert wil soone perceaue Al which and many other Mathematicall Conclusions easie by this Instrument to be performed I must leaue to the diligent tryall of the studious delighted with those noble Sciences The Declaration of the partes of the Pantometer THe chiefe partes of this Instrument are two The Horizontall to be placed alwayes equidistant to the plaine of the Horizon which it representeth And the Verticall perpendicularly erected vpon the former and therefore in power any Azimuth or Verticall whereof also it is named In the Horizontall there are two Semicircles The one hath the ordinarie Points of the Compasse the other the common degrees of a Circle both of them meeting in one Diameter The round voide space in the middle
c. till you haue obteyned a most sufficient precisenesse The Obseruing of the Variation at Land by the Sunne SEt the Instrument vpon a Staffe prepared for this purpose his Horizontall being parallele to the Horizon of the World And placing the Verticall vpon the line of North and South in the Horizontall turne the Horizontall about till the Needle stand equidistant to the Verticall Then fasten the Horizontall to the staffe with the skrewe pinne of his Socket which in that sort remaining steaddy and immoueable turne the Verticall in the Forenoone towards the East mouing the Sight Ruler vp and downe till the Sunne beame doth pearce both Sights and immediatly note what partes the edge of the Verticall doth cut in the Horizontall Also what part the Sight-Ruler falleth on in the Verticall where if it light not on a iust part in the vtter Quadrant marke where it doth vpon one in any of the inner Quadrants Againe in the Afternoone the Horizontall continuing still in his former place and the Ruler likewise abiding vpon the foresaid part vnchangeable turne the Verticall towards the West till the Sunne entreth in at both the sights And note therewithall what part the edge of the Verticall cutteth in the Horizontall If then the partes cut by the edge of the Verticall in the Forenoone and those other in the Afternoone bee equally distant from the South point of the Horizontall then is there no Variation at all For the line of North and South in the Horizontall is one and the selfe same with the true Meridian But if the partes of the Forenoones obseruation be fewer then those of the Afternoone subtrahe the smaller number from the greater and halfe the remainder discouereth the Variation from the South Westwards to bee so many degrees and the Northerly end of the Needle to decline so many parts from the true North towards the East Wherefore the line of North and South in the Horizontall doeth not possesse the true Meridian but swarueth therefrom as the partes obserued doe shewe Lastly if the partes of the Forenoones obseruation be moe then those of the Afternoone subtrahe as before the smaller number from the greater and halfe the remainder sheweth the Variation of the South end of the Needle to be so many degrees Eastward and the Northerly end thereof to vary so many partes Westward Nowe for the more certeinetie in your working you must euer be mindfull to make 3. or 4. seuerall obseruations in the Forenoone that although a Cloude should hinder you of your first in the Afternoone yet some one at the least of the other may be clearely obserued where otherwise if you misse of one all your labour for that whole day is lost The obseruing of the Variation at Land by the Starres THe Variation of the Compasse and so likewise the Latitude may bee taken as well by the Starres in the night as by the Sunne in the day And sithe the Almightie hath ordeyned but one Sunne and a great multitude of Starres Nauigators should offer themselues much wrong if they would not make their benefite of these as they do of that And so much the rather because the Sunne is South but once in foure and twentie houres The Starres come to the Meridian continually one after another all the night long The ordinarie instrument for the Variation is not of any vse at all in respect of the Starres no not though he haue his Astrolabe to helpe him whereas this instrument by it selfe without the ayde of any other performeth all things exquisitely by the Starres And by the Sunne so exactly with all aduantage that when many Instruments can doe nothing without a cleare Sunneshine this in a mystie or foggie weather through a Cloude if that you may but onely discerne the body of the Sunne craueth no more to accomplish your desire The maner of obseruing a Starre is this First prepare a little Notche or slit of equall deapth in the two sights of the sight-Ruler parallele to the leauell line thereof And the Instrument being placed as before is specified turne the Verticall towards the Starre being on the Eastside of the Meridian mouing the sight-Ruler vp or downe till you may perceaue the Starre euen with those two Notches Then note the partes that the sight Ruler doth cut in the Quadrant And those also that the edge of the Quadrant or Verticall cutteth in the Horizontall Afterward doe the like againe when the same starre is on the West side of the Meridian And for the rest following the same maner of Operation that aboue I deliuered you shall here obteine the selfe same trueth of Variation by any starre that there you found onely by the Sunne Touching the Latitude the like kinde of working is to be vsed for the taking thereof by a starre as is by the sunne I meane the obseruing of his Meridian height and subtrahing or adding as the nature thereof requireth And for this cause is the Verticall so placed that about an ynch of it more or lesse according to the proportion of the Instrument at that corner where the Ruler is fastened to the Center may alwayes in the turning about reache ouer the Horizontall that you may conueniently apply your eye by the sights to discerne any starre or espie the top of any body erected whose height you would measure which otherwise you could not doe if the Verticall were but euen with the Horizontall As for the other end of the Base of the Verticall it is no matter howe farre it be extended but onely according as the quantitie and comelines of the Instrument shall require so that the Border wherewith the Base of the Verticall is lengthened doe reache precisely streight and euen vnto the edge of the Horizontall for the cutting of the partes therof Moreouer if the halfe Circle of the Horizontall which is parted into degrees were diuided also into a payre of Proportionall Quadrants then both for the former vses and infinite others woulde this Instrument prooue most exact and persite But those that are willing to bestowe so much cost I wish they should doe it in mettall and not in wood If in wood then let the same especially be chosen whereof Cypers chests are made For that I take to be best as being most free from warping and receauing any worke very easily and fairely The imperfection of bricklenesse a little the more care must amend and strengthen And thus much for the vse of the Pantometer complete The maner of obseruing the Variation at Sea WHen the Verticall of the Pantometer together with his Compasse is fitted to the handle holde it directly toward the Sunne in the Forenoone in such sort that the Perpendicle keeping his due place the Sunne may pearce both the sights And noting the height of the sunne marke also at that instant what Point or Degree the Needle doth shew Againe when the Sunne commeth to the same height in the Afternoone obserue likewise what Point
the Equator and Axis of the World with the two extreame points thereof being the Poles The halfe Circles being foure in number are all belonging to the former two entire Circles For either are they placed vpon the great Meridian aforesaid and then if fixed or moueable thereupon it is the halfe Horison if moueable it is the Semicircle of Altitudes to be turned to and fro vpon his owne Poles equidistant on all sides from the Horizon or else they are situated vpon the Deferent and those two likewise in number hauing the selfe same differences betweene them that the former had For one of them is fixed or fastened vpon the Deferent and that is the Semi-equator the other is voluble which I call the Moueable Meridian The Backe of this Instrument needeth not any thing but the vsuall Mariners Compasse to be artificially annexed thereunto with the line of North and South parallele to the Backe The Mechanicall Description of all those seuerall Partes 1 The fixed Meridian 2 The Deferent with the Axis and Poles 3 The halfe Horizon 4 The Semi-circle of Altitudes 5 The Semi-equator 6 The moueable Meridian with the two Sight-Rulers 7 The Backe with the Mariners Compasse The agreeing of the Hemisphere with the Globe BY that which hath hitherto beene spoken touching the Structure of this Instrumēt may soone be discerned the originall descent thereof to be from the Globe For the better conceauing whereof vouchsafe I pray you a litle to remēber with me the chiefe Circles belonging to the Globe as the Horizon cutting it in two Hemispheres the Meridian wherein it is hanged the Quart of Altitudes whereby it is measured And then those other two not adioyned only as the former but continual therwith being described in the superficies or outface of the Globe it selfe the Equator I meane and the Zodiake with their appendāts the two Colures one Equinoctiall the other Solstitiall All these to make and vse together in this sort with the Globe when experience had taught to be a matter of great difficultie the learned of former times of these our dayes haue laboured how without the Globe by sundry rare inuentions to represēt the Globe in seperating those necessarie Circles frō the massines of the Instrument wherein the Astronomers Ring commonly so called doth iustly deserue right worthy cōmendation And I now the rather make mention of it for that it first gaue occasion of deuising and ministred good helpe toward the framing and perfecting of this Instrument Both of them are as it were Anatomeis of the Globe But whether in all respects the more absolute let eyther speake for itselfe and let the skilfull Reader iudge Touching the Hemisphere if you imagine the Meridian of the Globe to be a Plaine it shall passe through the Center thereof and cut it together with all the great Circles thereunto belonging in two equall partes The selfe same doth the Meridian likewise in the Hemisphere And therefore haue you here the Equator Horizon Moueable Meridian and that of Altitudes all these halfe in steade of whole Circles As for the Zodiake it is not heere wanting for sith all great Circles and so their medieties are equall the one vnto the other the halfe Horizon here may well be vsed for the halfe Zodiake when the Equator is placed according to the greatest declination or contrariwise the Horizon to be the Equinoctiall the Semiequator shall be the halfe Zodiake Thus haue you the Zodiake both wayes that I say nothing of the little one in the limbe of the Moueable Meridian For the two Colures there serues the two Meridians here the fixed for the Sostitiall the Moueable for the Equinoctiall The little Circle for the houres there is here the Equator it selfe and so it is also in effect in the Globe The Index there is the Moueable Meridian here and so must you likewise vnderstand it in the Globe Of the Axis and Poles you haue heard ynough before To conclude here is presented to your viewe a Halfe-sphere in name and shewe but a whole or entire Sphere in deede practise For proofe whereof omitting many other I referre you to these fewe Propositions ensuing Onely by the way in the behalfe of the Instrument I am to request the Reader that he be circumspect to foresee that the Circles and Semicircles be perfect in any case and truely diuided that they be exactly placed vpon their right Centre that the hanging of the instrument be exquisite hauing the Horizon thereof parallele to the great Horizon of the world Finally that all things be accomplished accordingly as aboue by the Patterne is signified before hee proceede to any experimentall handling of it least otherwise the worke be vniustly blamed for the errors and imperfections of the workeman let as reason would the fault there lie where the fault is To finde the place of the Sunne THe day being giuen the Place that is the signe and degree of the Zodiake wherein the Sunne is may thus bee found Seeke in the vttermost Circle described vpon the Deferent the Moneth and day giuen whereupon if you place the linea fiduciae or leuell line of the Ruler the same shall in the lower or inner Circle thereof being the Zodiake shew you the thing sought for And the opposite point thereof shalbe the Sunnes Nadyr for that day But if the yeere be leape wherein the place of the Sunne is demaunded then must you from the 24. of Februarie till the ende of that yeere adde alwayes one moe to the number of that day which you seeke for as if the day required be the 2. of March set the Ruler at the 3. if the 3. then at the 4. and so foorth The place of the Sunne being giuen to finde his Declination FOr as much as all the Declinations of the whole Zodiak may exactly be considered in one onely Quadrant thereof thus briefly shall you worke by the Hemisphere Let the Horizon be in steade of the Zodiake Then number in the fixed Meridian which now must be taken for the Solstitiall Colure the Sunnes greatest Declination thereat fasten the Equinoctial So shal the pinne whereupō the two Semicircles cut one an other be the beginnings of Aries and Libra and the point of the Horizons meeting with the fixed Meridian the beginnings of Cancer and Capricorne Betweene which two extreames the space of euery 30. degrees in the Horizon of the Instrument shall be as a whole signe in the Zodiake to bee reckoned in order thus From the pinne to 60. is Aries from thence to 30. Taurus from thence to the fixed Meridian Gemini Then backe againe from the Meridian to 30. Cancer from thence to 60. Leo from thence to 90. being in the Intersection Virgo The selfe same order must be vsed in the other halfe of the Zodiake For the reason is like in both Hauing therefore found the true place of the Sunne in the Horizon of the Instrument nowe the Zodiake turne
The fixed Meridian shall be one Circle of Longitudes and the Moueable Meridian any other of the same sort And euery degree of the Moueable Meridian shalbe the Intersection of any Parallele defining the Latitude either Septentrionall or Austrine and therefore the place of one of the Starres proposed The other starre shall be in the zenith of the Instrument And finally as before the Semicircle of Altitudes shall serue for Mensurations Nowe then according to the Latitude of one of the starres which for distinctions sake I call the first remoue the Equator now the zodiake from the zenith of the Instrument now that first starre And the zodiake thus standing immoueable number therein from the fixed Meridian the degrees of the differēce of Lōgitude and at the end thereof fasten the Moueable Meridian In which Semicircle beginning frō the Zodiak reckon the Latitude of the second starre either vpward or downeward as it is either Septentrionall or Austrine And vnto the ende thereof being the true place of that second starre fitte the Semicircle of Mensurations aforesaid So shall that portion of it which is intercepted betweene both points be the precise distance in the heauens betweene the two starres demaunded And of the Hemisphere thus much Hereunto might I haue added the doctrine of right and oblique Ascensions together with Dialling and other matters Gnomonicall But because the fruite and vse of the doctrine of Ascensions cōsisteth in the measuring of the true quantitie of time whereof you haue before sufficiently heard I thought it not expedient any further to enlarge this Treatise therewith The rather considering my principal purpose namely the Seamans Commoditie who little needeth that doctrine and Dialling lesse then that Yet whoso desireth to be doing in both of them shall by that which hitherto hath beene deliuered diligent practise withall finde the Hemisphere very able to satisfie his desire And not onely so but to minister vnto him many rare and goodly conclusions of further inuention Among which I earnestly wish that chiefe secret of Nauigation the sayling I meane by a great Circle to be alwayes principally remembred Not doubting but this Instrument if any other will proue a most apt and seruiceable one for that purpose which knowledge because it requireth long learned and very painefull experience ioyned with singular dexteritie I willingly leaue vnto those that make speciall profession of that Art The description and vse of a Trauerse Boord seruing readily to set downe the Shippes way according to the vsuall accompt and at all times to pricke in the Card accordingly the true place that she commeth vnto LEt there be a Table prepared after the forme of a long square of 16. inches in length and 12. in breadth or else 20. long and 16. broade as you thinke good more or lesse plaine and smooth with Angles precisely right and hauing a square border inclosing it to keepe downe a sheete of Paper like as Surueying tables haue Diuide the foure sides of the border into equall diuisions of 8. vnto an ynche or any other as may be most conuenient reaching all a long the inner side of the square and number them by fiues the figures of euery side being twise set downe to be reckoned both wayes as occasion shall serue Againe subdiuide euery of those diuisions by two prickes into 3. partes not adding any numbers If these diuisions be wrought vpon Latten plates being laide on riuetted to the Border it wilbe a great deale the fairer Your Table thus finished you must prouide a Ruler and a Quadrant as necessarie furniture belonging thereunto Let the Ruler be as long as the Diagoniall line of your square that is reaching athwart frō corner to corner hauing the oneside handsomely abated and both sides perfectly diuided from within halfe an ynch of one ende throughout into the very same diuisiōs wherewith the Border was parted with his numbers also redoubled and as that both wayes to bee accompted in such sort that the diuisions bee drawen downe to the lowermost edge of the sides of the Ruler that lieth close on the Table The Quadrant is best of Latten with his semidiameter of 3. or 4. ynches more or lesse somewhat thinne hauing al the middle of his substance cut away saue about a quarter of an ynch breadth reserued for his Circular limbe there about also for the breadth of his two right sides Diuide the limbe into ordinarie points of the Compasse expressing them in siphers 1. 2. 3. c. Let those numbers be twise set downe to be reckoned forward backward and betweene euery Point let there be halfes and quarters All which parts as before in the Ruler must be produced to the neathermost edge of the limbe Diuide also the two outsides of the Quadrant into such diuisions as the Ruler hath so farre as they will reach placing the numbers along from the Center-corner to the meeting of the sides with the limbe and drawing those diuisions likewise to the lowermost edge of the sides Nowe must you consider that the Nauigator hath three helpes to finde out the place of his Ship that he may set downe the pricke thereof vpon his Carde viz. 1. The Angle on which the Ship maketh her way which is giuen by the Compasse 2. The quantitie of the Ships way to wit howe many leagues she sayleth in an houre or a watche which they terme the dead reckoning and is learned by often experience 3. The Latitude taken by obseruation with Mathematicall Instruments Any two of these being giuen this Instrument maketh the third manifest and giueth the pricke in the Carde very readily Except it so be that the Ship doth runne vpon the Points of East or West for then all three are necessarily required You are further here to note that the place from whence any course is begun is called a Radicall place And so is euery place in the proceeding of the voyage named whereof the Nauigator either by his owne or by other mens practise hath learned the true situation And nowe to approch vnto the vse spread a sheete of large papervpō the Table fastening it with the Border placed thereon to keepe it euen and smoothe And set a Flower de luce or any other note for the North hard by the edge of any one of the sides which your course shall shewe to be most conuenient about the middle thereof That one marke is sufficient to determine all the other sides towards which of the 4. principall windes they doe beare for his opposite must needes be South and the other two East and West So that the diuisions in the sides of East and West doe al of them in power represent so many Paralleles and those of North and South in like maner so many Meridians The vse of the Trauerse Boorde FIrst of all marke by the viewe of your Notes of the Ships way course whether it be Northerly or Southerly from the Radicall place and likewise whether
marine trades should be ayding vnto those Faculties whereby the greatest part of their well gotten goodes doeth accrewe vnto them And especially that honorable Citie which is not onely made riche but by the meanes of Nauigation is growē famous also throughout the whole World As therefore I vnfainedly acknowledge that in diuers good respectes no one Citie of the whole Earth is comparable vnto it so doe I heartely wish an increase in all commendable actions among which this was none of the least and not a decrease The rather sith the augmentour of the publique benefite in that behalfe shall thereby highly commend his owne true loue towards his Citie and Countrey vnto all Posteritie and become more renowmed by such actions then by any painted glorious Tombe or the like kinde of monuments The onely good methode of teaching and learning Cosmography after a fewe principles of Geometry and Arithmetike first knowen is to beginne with the Celestiall Globe and to be perfect therein before you deale with the Terrestriall for this dependeth on that and the former being once reasonably vnderstoode the other is not two dayes worke After you haue thus receaued a sufficient impression of the Globe wherevnto all true Mappes and Cardes haue a necessarie reference then will the consideration of them become exceeding pleasant and easie vnto you but neuer before This I mention because I haue heard ere nowe of certaine Teachers that vndertaking men of good habilitie to be instructed by them haue beene a great while about a little spending the time about diuerse pretie particular toyes which full easely would haue beene knowen of themselues without any teaching if they had taken the course that I speake off But such imitate ill disposed Surgeons which loue to protract a cure of purpose to sucke the more gaine therefrom Mappes and Cardes of the Globe of the Earth are of three sortes most vsuall distinguished by their seuerall kindes of Meridians and Paralleles The first hath his Meridians and Paralleles described by Circular lines And among those I take that manner of Proiection which Rumoldus Mercator hath vsed proposed long before by Orontius in his Frenche Cosmography as I haue heard to be of all other the very best hauing the Meridians and Paralleles drawen according to the Mater of Gemma Frisius generall Astrolabe The reason that I so greatly like of this is for that the proiection is very Regular and therein the natiue Geographicall description may neerest of all others obteyne their due situation An other sort there is wherein the Globe of the Earth is diuided in two Hemispheres the Center in both of them being one of the Poles and the Circumference the Equator In this the Meridians are streight lines drawen from the Poles vnto the Equator and the Paralleles are Circles These Paralleles may be described after two wayes The one enlarging the landes described towardes the Equator the other towardes the Poles The former is thus delineated Set the one end of a Ruler vpon the ende of one of the Diameters or Meridians aforesaide and the other part of the Ruler 90. degrees from that And keeping the former ende fixed vpon his place remooue the other to euery one or fifth or tenth degree of the next Quadrant till your Ruler passing through the Pole becommeth all one with the same Diameter noting continually in the Semidiameter of 90. degrees distance whence you first beganne to moue your Ruler where it cutteth the saide Semidiameter Then placing one foote of the Compasse vpon the Center or Pole the other vpon any of those diuisions of the Semidiameter describe a Circle which shall be a Parallele answerable to that diuision And so may you drawe as many or fewe as you thinke conuenient The other is thus described Beginne at the ende of any Semidiameter where it toucheth the Equator and numbring still equall degrees on eache side thereof marke what intersections your Ruler applyed vnto them maketh in that Semidiameter Then may you drawe the Paralleles here also euen as before The former of these two is represented vnto you by the figure A. the later by the figure B. This kinde of Proiection serueth most aptly to expresse in a Carde the Spirall course of a Ship which some terme Paradoxall But whether of these names being both as yet strangers shall best deserue to bee freedenized I leaue to other mens iudgements Onely I say Paradoxall is beside the purpose and astonisheth with an emptie sound but Spirall apperteineth directly to the matter and declareth the true essence of the thing signified The third sort of Cardes haue both their Meridians and Paralleles of streight lines equidistant and these onely are in ordinarie vse with Saylers Of these I neede not write any thing they are so commonly knowen and their imperfections in long voyages so manifest though in short they may well serue the turnes And yet I cannot here conceale one great secrete concerning these Cardes namely that there is a certaine draught of them very Artificiall and regular which being well vnderstoode redresseth the errours of the other and as farre as I canne discerne will so satisfie the Nauigators expectation as no Carde hitherto inuented was euer comparable vnto it neither as I thinke any that shalbe hereafter wil in al respects surpasse it Although for the Geographicall descriptions they may and must alter from time to time as newer discoueries by light of trueth shall make them better knowen vnto vs. This manner of Carde hath beene publiquely extant in print these thirtie yeeres at least but a cloude as it were and thicke myste of ignorance doth keepe it hitherto concealed And so much the more because some who were reckoned for men of good knowledge haue by glauncing speaches but neuer by any one reason of moment gone about what they coulde to disgrace it The Carde which I meane is the same that was set foorth by the excellent Cosmograpber Gerardus Mercator in shewe resembling ordinarie Sea Cardes saue that the degrees of the Meridians in it doe proportionally encrease from the Equator toward eache Pole vpon good reason and firme Demonstration thereby shewing the true Position of any one place in respect of an other which the vsuall Cardes in a farre distance cannot doe being yet the very principall point that the Nauigator desireth For the better vnderstanding and making of Sea Cardes of that sort I haue here immediatly ensewing set downe a Demonstration which I obteined of a friende of mine of like profession vnto my selfe euidently shewing the proportionall encreasing of those degrees wherein consisteth the excellencie of that Carde First determine the degree of the Equator in respect whereof you woulde frame the Meridian of your Carde for example the little line a. Next describe the Quadrant of a Circle so large that it may perfectly and distinctly receaue euery of the vsuall 90. degrees into which it must be diuided Then from the Centre A. towarde B. take in the Semidiameter
are commonly so vnhandsomely made and ill fauouredly hanged vpon their pinnes that you should offer a Tincker discredit to compare his worke with this Adde hereunto the riuetting of the Circles with yron and hanging the bigger of them vpon yron nayles which although they be but little yet you must esteeme a litle in this case to bee a great deale too much And if they had any care of that they haue in hand they would not commit such a needelesse grosse absurditie onely as it were in despite of Arte to make expense of wit without gaine or profite The piece of Lead that is fastened to the bottome ought to be round and of equall thicknesse the pinne passing through the Center thereof If you haue it otherwise then marke the Boxe and the bottome when it hangeth aright and whensoeuer hauing taken off the bottome you will set it on againe see that you make your markes in the Boxe and bottome agree or else it can neuer with any certeintie hang as it should Although it be exceeding lothsome vnto me to deale in these mechanicall base practises yet the necessitie is such that one must needes deale therein For of all the Instruments that the Nauigator vseth this is farre the most excellent and yet of all others this is most negligently and vnartificially made Their Staues and Sea Cardes made in England are neate and fine Their Astrolabes are tolerable but these are euen such as I haue shewed vnto you which I could not so well haue shewed but by this anatomizing of them that the blame may bee apparant either in those that make them or in such as buy them that will not goe to the price of better wherein folly would shewe it selfe very eminent if when a shippe with her lading may bee woorth many thousands of poundes besides the inestimable value of the mens liues that are in her halfe a pound should be thought much to be bestowed on a perfect Compasse vpon the goodnesse whereof many times both shippe and goods and liues of men doe take their triall yea all these doe they ieopard as it were vpon a wager that their Compasse is true and perfect To conclude I would wish in any wise that Artificers of these Instruments shoulde make euen great conscience of that they haue in hand and not sleightly to passe them ouer after the order of dozen ware Also that such as exactly make them should be rewarded and esteemed accordingly And finally that they which are to vse them doe well examine their goodnesse before they buy them Moreouer it many times falleth out that the hollowe side of the Capitall is made too narrowe in the bottome and then will the Flie neuer play well except the pinne be exceeding small sharpe which assoone as by vse it is a little dulled the Flie will neuer shewe his pointes truely though hee were touched with the best stone in the world And very oftentimes the ouersight herein is imputed wrongfully to the weaknesse of the Touch. And therefore take care that the greater Boxe being square be not set together with yron nayles But if it be round then see that it be handsomely turned And in any wise that the lesser Boxe wherein the Flie standeth be well exactly turned of seasoned wood and hauing the inside coloured with some white glistering colour and not according to the common custome rubbed about with a piece of Chalke or a little white lime Furthermore because it is very necessarie that whosoeuer sayleth by any Carde ought diligently to foresee that the Set of his Compasse be answerable to his Card of the like Set I meane vnto that his Card was made by And for that the wyers being once glewed on may not well be altered or remoued And the double Flie by reasō of his vnwildie corpulēcie is nothing nimble I haue framed one after this sort a briefe description whereof I thought not impertinent here to insert The endes of the wyers must bee welded together The wyers themselues are halfe round with the otherside flatte to be placed vpon the bottome of the Flie. The Capitell hath two thinne narrowe Stayes of Latten reaching to the wyers on each side and fast soldered vnto them The toppe of the Capitell must bee skrewed on the outside and a little square piece of Latten with a small hollowe bent fitted for to skrewe vpon him vnto this ende that the Capitell being put through the bottome of the Flie in the Centre and the skrewe on the vpper side being turned on the top of the Capitell the Flie and wyers both may by this meanes bee closely combined together without any paste or glewe and bee left bare throughout to the most aduantage at any time for receauing the touche of the Stone and more easily be kept from rust being the greatest enemie that the touche of the Stone can haue vnto which all your pasted or glewed wyers are necessarily subiect insomuch as you shall very seldome and as I thinke neuer in the whole many of your vsuall Flies see any one that is not infected herewith being farre more noisome then Garlike or Oile and all the rest of those fondly surmised conceites If the skrewe come not close ynough vpon the Flie a little piece of pastboorde put on before the skrew will be a remedie sufficient therein When the wyers are thus fastened vnto the Flie you may at al times remoue them to any point or part of a point at your pleasure without anoyance vnto any thing In such as I haue caused to be made for this purpose I haue vsed a narrowe forme of a loope the distance betweene the wyers in the middle being little more then the fifth part of their length and haue abated also the mettall of the wyars about the middle of them and allowed somewhat the more towards their ends The Compasse of Variation THe Compasse of Variation is made in all respects like vnto the ordinary sayling Compasse is the very same in deede excepting these two Additions The one is that on the inside of the lesser Boxe round about iust with the height of the Flie either vpon the Boxe it selfe or else vpon Paper or Pastboorde fastened to the side thereof there be a Circle diuided into 360. partes And at euery 90. let a line be produced both vpward to the top and by the space of halfe an ynche downeward At any one of which lines make a Flower de luce representing the North and there begin your numbers on both sides thereof from 1 vnto 90. doe the like also from the opposite part betokening the South The other is that a thwart the vpper face of the Glasse there be placed a Ruler of Latten in length answerable to the Diameter of the Boxe bearing in breadth the third part of an ynche or halfe an ynche if you thinke good for a very great Compasse In the middle of which Ruler there must a line bee drawen according to the length