others whose cohaerence is not so naturall Propositio 31. An other way to finde the length of the Artificiall day or night FInde the time of the Sunne rising for your day proposed by the 12. propositioÌ„ then dubble all those howers and partes of time which be from Sunne rise till noone for it giueth the Artificiall day Or if ye nuÌ„ber all the howers and parts from Sunne rise to his setting it giueth the same Propositio 32. To finde the hower of the day PLace the Globe in the Sunne shine and rectifie him to his vse by the 4. proposition then finde the place of the Sunne by the 5. proposition Againe rectifie his Index by the 14. proposition Lastly 〈◊〉 the needle or pinne directly vp in the place of the Sunne then turne the Globe vp till the pinne cast no shadowe for then the Index sheweth what is then of the clocke Propositio 33. To finde the eleuation of the Pole in any place DRawe in the open ayre vpon some table that is leuell a Meridian line by the 1. proposition and place the Globe so on it that his Meridian Circle hang directly â—uer it then hauing the place of the Sunne set a pinne right vp in it and put the said place and pinne close to the Meridian circle Lastly lift vp the Pole and Meridian Circle till the pinne cast no shadowe for then the degrees betwixt the Pole and the HorizoÌ„ be the true eleuatioÌ„ of that place But this practise is to bee performed at noone onely or height of the day Propositio 34. An other way to doe the same TAke the height of any fixed Starre whom ye know by the 2. proposition at such time as he pointeth with the Meridian line then take the same Starre on the Globe and by helpe of your Quadrant or Meridian Circle cause him to haue the same Altitude in the Globe and withall to be vnder the Meridian of the Globe for theÌ„ is the Pole at his true Eleuation So did I finde the Pole Starre making my obseruation at Oxford the 11. of December 1584. by the plaine Sphaere to haue 55. degrees 59. minuts in Altitude being theÌ„ in the Meridian of Heauen and when I set him at the same in my Globe I found the Pole eleuated there 51. degrees 50. minuts And here ye are to knowe that when soeuer ye haue by any way the eleuation of the Pole in any place if ye subduct the same eleuation from 90. degrees it shall leaue and sheâ—… the eleuation of the aequator in the sayd place So then the eleuation of the aequator at Oxford is 38. degrees 10. minuts Propositio 35. An other way of working the same with more praecisenes FIrst learne by some good Ephemeris the precise place of the Sunne at noone in the day of your obseruation then againe learne the exact declination of the said place Lastly with your 〈◊〉 take the Meridian height of the Sunne that day And if the declination bee Northerne then subduct it from the Meridian Altitude but if it be Southerne then ad it to the Meridian Altitude so shall wee bring forth the Altitude of the aequator and this Altitude being subducted from 90. degrees leaueth the Altitude of the Pole but if the Sunne in the time of obseruation be in the Aequinoctiall point then is the Meridian Altitude the Altitude also of the aequator and it subducted from 90. degrees leaueth the Altitude of the Pole Propositio 36. To make a Horizontall Diall by the Globe A Horizontall Diall is such a one as is made in a plaine Superficies and lyeth leuell with the Horizon For making whereof ye are to consider that from one Pole of the Globe to the other goe twelue great Circles called hower Circles and diuide the aequator into 24. aequall parts And two of these bee two Colures Put therefore the Solstitiall Colure precisely vnder the Meridian of your Globe the Globe being first perfectly rectified and fixe the Globe so that he cannot mooue Now marke how many degrees of the Horizon are inclosed betwixt the Meridian and the next hower Circle toward the East which for distinction sake I call the second hower Circle so likewise betwixt the first third the first fourth the first and fifth the first and sixt the first and seuenth which is he that cutteth in the true East point and set them all downe in tables then drawe on some plaine thing a Circle and diuide it into fower quarters by drawing two crosse lines Now take the one ende of any of the two lines and terme it the North point so shall his other end be the South point and the endes of the other line East and West Againe diuide that quarter of this Circle which is betwixt the North point and East into 90. aequall parts and let 90. stand at the East So doe by the quarter betwixt North and West Lastly recken from the North point toward East so many degrées as your tables shewe to haue 〈◊〉 betwixt the first and second hower line and from the point where they ende drawe a line by the Center of the saide Circle and so doe by all the numbers of your tables for so shall ye haue your hower lines drawne for a Horizontall Diall In whose Center must be a stile exected according to the eleuation of your Pole But this I leaue obscure as meaning to set out an ample treatise of Dialling by it selfe Propositio 37. How the Starres may be knowne by the Globe of Heauen REctifie your Globe in the open ayre by the 4. proposition theÌ„ take the height of any knowne Starre by your Instrument afterward looke the same Starre on the Globe and by helpe of your Quadrant of Altitude put the same Starre at his height taken before and in the same Coast then fixe the Globe Now if ye would knowe any other Starre of Heauen then take the same Starre his height with your Instrument lastly turne your Quadrant of Altitude toward the same Coast of the Globe in which the Starre was in looke what Starre ye finde in that Coast to haue that Altitude the same is he whom ye seeke The like is to be done by all others Propositio 38. To finde the Longitude of any fixed Starre THE Longitude of a Starre is the portion of the Ecliptick line taken from the head of Aries according to the order of the Signes to the point of the Ecliptick cut by a Circle which passeth froÌ„ the Pole of the Ecliptick by the Center of the sayd Starre and is thus found Take the Globe from his Horizon and take of his Meridian Circle and fixe the same Circle by some meanes on the Poles of the Zodiack then turne the Starre whose Longitude ye seeke vnder the Circle and recken all the Signes and parts from the head of Aries to that point of the Ecliptick which is vnder the Circle with the Starre for so much is his LoÌ„gitude And the same point of the
same time as the Sunne The last is the Moone making one perfect reuolution from West toward East in 27. daies 7. howers 43′ 7″ yet all these are caried by violence of the first moueable from East to West as is before saide OF THE CIRcles of the Sphaere of Heauen and of their names and how they be made AStronomers to the end they might shewe the motions of Heauen and the straūge and wonderful conclusions of the Coelestiall bodies haue imagined certaine Circles in the bodie of the first Sphaere or first mooueable and principally ten whereof some be greater Circles of the Sphaere so called because the Center of these Circles is also the Center of Heauen euery such Circle diuideth the whole Sphaere into two aequall parts Of this sort be sixe the Aequinoctiall Zodiack Horizon Meridian and two Colures Some bee lesser Circles of the Sphaere so called because they haue not the Center of the world for their Center neither diuide the whole Sphaere aequally Of this kinde be fower the Tropicke of Cancer the Tropicke of Capricorne the Articke and Antarticke The Aequinoctiall called the aequator or girdle of Heauen is a great Circle of the Sphaere diuiding the Sphaere into two aequal parts and is aequally distant from ech Pole of the worlde And tooke his name of the aequator either because it is aequally in the middle of Heauen as Euclide saith in his Opticks or for that the Sunne comming to this Circle maketh the day and night aequall it is diuided in 360. aequall parts which parts are called degrees His Axe is the Axe of the world and Poles the Poles of the world The Zodiack is a great Circle of the Sphaere which crosseth the Aequinoctiall in two points the one being the head of Aries the other of Libra and swarneth from him in all other points leaning toward ech Pole of the world in the point of his greatest swarning 23. degrees 30. minutes This Zodiack is of breadth 12. degrees and of length that is to say in compas 360. degrees and according to his length is diuided into 12. aequal parts which are called the 12. signes Aries Taurus Gemini Cancer Leo Virgo Libra Scorpio Sagittarius Capricornus Aquarius and Pisces And ech signe contayneth of length 30. degrees in the midle bredth of the Zodiack we imagine a Circle to passe which we call the Ecliptick Circle or line For that that when the Sunne and Moone bee both vnder this line in a Diameter then the Moone is Eclipsed Vnder this Circle the Sunne mooueth dayly without declining any waies the quantity of one degree very neere in ech day the rest of the Planets are found some times on one side the Ecliptick some time on the other This Zodiack taketh his name of a greeke word signifying a liuing creature or as the Latens will is called Signifer for that that it beareth the 12. Signes the Axe of the Zodiack and the Ecliptick is all one being a line diuers from the axe of the world and the Poles bee two points alwayes so much distant from the Poles of the world as the greatest declination of the Ecliptick commeth vnto A Colure doth generally signifie any Circle passing by the Poles of the worlde and hath his name of his vnperfect shewing himselfe in the motion of heauen But now by the name of Colures we vnderstād two great Circles the one going frō the Poles of the worlde by the points where the Aequinoctiall and Zodiack cut them selues which be called the Aequinoctiall points and is called the Aequinoctiall Colure The other passeth from the Poles of the worlde by those points of the Ecliptick which swarue most of all others from the Aequinoctiall line which points are called the Solsticiall points and this is called the Solsticial Colure And here be you to know that these foure greater Circles which we haue defined be still the same through the whole worlde and are sayd to be moueable Circles for so much as in the motion of heauen they be also mooued of which some are moueable perfectly as the Aequinoctiall and Zodiack for they in the going about of heauen doe ascend by little and little till the whole Circle haue gone oure the Horison some vnperfectly moueable as the two Colures which neuer shewe the whole Circle in any crooked Sphaere the other two greater Circles which followe be called fixed for that they neuer mooue by the motion of heauen But they be changeable in euery Region The Horizon is a greater Circle diuiding the halfe of the Heauen which we see from the halfe which we see not and is called in Latine Finitor because it endeth our sight The Horizon maketh fower principal points East West North and South His Axe is a line imagined to fall from the point of heauen which is directly ouer our head where we be downe to the groūd like a plumme line and his Poles be the endes of that line called the Verticall point and point opposite to the Verticall The Meridian is also a great Circle passing from the Poles of the world by our Verticall point cutting the Horizon in the North and South points his Axe is a line going from the East point of the Horizon to the West and his Poles be the same points and these two Circles doe alwayes chaunge are diuers in euery Region for so much as the Verticall point of euery Region is diuers by the which the Meridian of necessitie must passe and is the Pole also of the Horizon OF THE LESSER Circles of the Sphaere and their names and of their making THe lesse Circles of the Sphaere in number be fower The Tropicke of Cancer the Tropicke of Capricorne and the two Artickes The Tropicke of Cancer is a lesse Circle of the Sphaere which is aequally distant from the Aequinoctial lying betwixt the Aequinoctiall and the North Pole and touching the Ecliptick in the beginning of Cancer This Circle is described by the bodie of the Sunne in the longest day of Summer at which time the Sunne is entred the solstitiall point or beginning of Cācer is called the Tropick of a Greeke word which signifieth a returning because the Sunne being brought to this point falleth in his noone height and returneth againe The Tropicke of Capricorne is a like Circle betwixt the Aequator the South pole and is described by the Sunne in the shortest day of Winter at which time the Sunne is in the beginning of Capricorne whereof it is called the Tropick of Capricorne The Articke Circle is a lesse Circle of the Sphaere described by the Northerne Pole of the Ecliptick Proclus saith it is described by the formost foote of the great beare and thereof taketh his name The Antarticke is a like Circle described by the South Pole of the Ecliptick is called Antartick of the Greeke worde which signifieth Opposition because it is opposite to the other Of the vse of the Circles of the Sphaere or Globle THE most
principall cause why Artificers inuented the Aequinoctiall was first because it is the measure of the first Heauen by a conuenient perpetual and aequal swiftnesse Secondly it measureth and limitteth the time of rising of the Signes as also the length of the Artificial daies and times of the Aequinoctials with declinations and right ascentions of Starres together with Longitudes of Regions Lastly for the exection of the twelue howsen of Heauen In like maner the Zodiack serueth for Latitudes Longitudes of Starres for distinction of the times of the yeare for the motions of all the Planers and effects of the same Not vnlike be the vses of the Colures and Meridian ech shewing the greatest declination of the Ecliptick but especially the MeridiaÌ„ which giueth as well al declinations of Starres their noone height and distinguisheth the daies and nights into two aequal parts and serueth for the Horizon of the right Sphaere It beginneth likewise and endeth all Longitudes of Regions and sheweth Latitudes and Eleuations of the Pole It helpeth to diuide the 12. howsen In like maner sundrie and diuers be the vses of the Horizon As in seperating the hidden part of Heauen from that which is seene and sheweth the place of rising and setting of any Starre how farre from East or West with his height All which points are respected of Astronomers as the Sphaere is secondarily diuided that is to say as he is a right or a crooked Sphaere which bee his properties and affections ment in the diuision afore specified By a right Sphaere is ment such a kinde of position of Heauen as that neither Pole bee râ—ised aboue ground but that ech lye in the face of the earth And such a kinde of position haue they which dwell in Bersera and the Islands of Molucca or such like Contrariwise it is sayd to bee a crooked Sphaere when any one of the Poles is raised aboue ground Such a Sphaere haue we at Oxford and London and generally all which dwell not vnder the line All which thinges for our better conceate are shewed to the eye in the materiall Globe whose names and diuisions appeare at the first vewe two things only being waied First that the mechanicall or materiall Globe which representeth the first mooueable beareth in him the fixed Starres not because the Starres bee in the first mooueable but because their motion is so litle in their own Sphaeres in many yeares that they may seeme not to haue mooued at all in a man 's his age from their places vnder which they be of the first moueable therefore they may bee supposed to stand in it Secondly the Globe representeth the Starres to vs in his connexitie which appeare in Heauen in the concauitie For that our eye is not in the Globe but without Furthermore in the Globe besides the aforenamed Circles bee found three others of brasse the one being a perfect Circle of a litle quantitie placed about the Pole which is eleuated is called the hower Circle whose stile is called the Index An other is a thinne rule of brasse representing one quarter of a whole Circle called the quadrant of Altitude and is alwaie to be fixed when ye vse the Globe on the middle of the halfe of your Meridian which is aboue the Horizon that is to say 90. degrees aboue the Horizon The third and last is a great halfe Circle lying at the Horizon seruing aswell for the erection of the scheme of Heauen as any Circle of position All which things being aduisedly considered of ye may proceede in the vse of the Globe As followeth HOW THE Globe is to be placed readie for his vse and practise THe placing of the Globe ought to be such that the Horizon of the Globe may stand parallele or leuied to the true Horizon and the Meridian of the Globe stand in the Superficies of the true Meridian of Heauen and the Poles of the Globe and his Axe answere exactly to the Poles and Axe of Heauen Now to the leuying of the Horizon there ought to bee at your Globe a hanging plummet and for the Meridian a Needle touched of the lode stone and touching the rectifying of the Poles and Axe of the Globe the eleuation of the Pole of heauen is first to be knowen the meanes to performe and accomplish the same being such as followe Propositio 1. To finde a Meridian line in any place appoynted SEt vp on your Horizon or some plaine leuied boarde a Gnomon of any reasonable length then at such time as the same shineth describe from the top of your Gnomon a Circle by the tippe of his shadowe and make a marke in the Circle where the shadowe ended at your obseruation which must be before noone Then marke in the afternoone at what time the ende of the shadowe returneth into the same Circle againe and make a marke at his point of falling so shall ye haue a portion of the sayde Circle inclosed betwixt the two points If then ye diuide this portion into two aequal parts and drawe a line from this middle point by the point in which the Gnomon standeth it shal be a Meridian line Propositio 2. To take the height of any Starre FRrom the point of Heauen which is directly ouer our heads being called the Verticall point or Zenith are imagined diuers Circles to fall by euery degree and minute of the Horizon all which Circles are called Verticals serue for the height of Starres for so much as the altitude of Sunne or starre is the portion of the Vâ—…ticall Circle inclosed betwixt the Center of the Sunne or Starre in the time of his obseruation and the Horizon which height is thus found Take your Astrolabe and let him hang freely by his ring then turne vp his Dioptral so long that ye see the Starre whose height yee seeke thorowe his sights for then howe many degrees and minutes are inclosed betwixt the Dioptrall and the line of your Astrolabe which is parallele to the Horizon so many hath that Starrs of height as the seauenth day of Ianuarie Anno. 1585. vnder the Meridian of Oxford at 9. of the clocke I sought the height of the Sunne taking then my Astrolabe and hanging him towarde the Sunne and raising his Dioptrall till I espyed the Sunne I found betwixt the Dioptral and the line representing the Horizon seauen degrees and 16. minutes so much was the height of the Sunne at that time Propositio 3. To take the altitude of the Pole in in any place or countrey THe altitude of the pole is the portion of the MeridiaÌ„ Circle inclosed betwixt the Pole and the Horizon and is thus found Find a Meridian line and drawe him in the Horizon by the first proposition then take the height of any fixed Starre which setteth not and that at the fore part of the night at such time as he is pointed vppon your Meridian line by the second proposition Again the next morning or any other morning take the height of