The Path-way to perfect SAYLING. Shewing briefly the six principall Points or Grounds of NAVIGATION.
Written by Mr. RICHARD POLTER, one of the late principall Masters of the Navie Royall. And now published for the Common good of all Masters, Pilots, and other Sea-men whatsoever.
Whereunto is added, A NAVTICALL DISCOVRSE necessary to be knowne of all SEA-MEN to prove the way of a Ship (upon the Superficies of the Sea) outward and homeward to be both one, returning by the opposite Point of the Meridian Compasse: And also to prove the East and West directed by the Meridian Compasse to lead in a Magneticall paralell. First penned by JOHN BASSET deceased, a Teacher of Navigation at Chattam in Kent. And now put forth to publike view with some Addition, By HENRY BOND.
LONDON, Printed by T. FORCET for GEORGE HURLOCK, and are to be sold at his shop neere St. Magnus corner. 1644.
THE PATH-WAY to perfect SAYLING.
Shewing the sixe principall Points or Grounds, concerning Navigation.
- 1 The Card,
- 2 Compasse,
- 3 Tide,
- 4 Time,
- 5 Wind,
- 6 Way.
TO deliver the opinions (concerning the Card and Compasse) of a great sort of Sea-Matters and others, even in these times such is their knowledge, being altogether ignorant even vaine and frivolous, that I will not spend the time once in nominating any such their knowledge, but will procéed to the matter.
The Compasse to be rectified two wayes.
FIrst, there is to be delivered two wayes for a mans farther knowledge, that the Compasse is to be rectified, as felloweth.
The Compasse is said to be rectified when the wyer is set right vnder the Flower-deluce, for the Flower-deluce and his opposite point delivereth the true Meridian.
Also, the Compasse is said to be rectified, when the Wyer is [Page 2]set right vnder the Flower-deluce, the Flower-deluce and his opposite point, delivereth the true Mutation or Variation of the Compasse.
Further, there are foure opinions concerning the Compasse: which foure opinions and wayes conceived of the Compasse, being rectified from the true Meridian that it is presupposed to lead in, which I will give a tast of for this present, and so leave them to more convenient places.
The first Opinion of the Compasse.
THe most Absurdest way of the Compasse, is according to flat Cards-used in Navigation: which some sort of men (and the greatest number hold opinion, that the Compasse leadeth no otherwise then according to these usuall Plats or Cards right lyned, whose lynes generally are paralell each to other, and that the East and West of the Compasse leadeth in a paralell, which opinion is absurd: for how can the thing that is false deliver the way of truth, as hereafter followeth.
The 2 Opinion of the Compasse.
This way of the Compasse (in déed) which is more perfect then the former (according to the judgement of Astronomers) is called the Astronomicall deducture of the Compasse and by other sort of men called the paradoxall Compasse, because the lineaments are spirall: which spirall lines by some are called Helicall lines. This Astronomicall deducture (as above said) some sort of men hold to be principallest. In this judgement the Meridians have their coartation, but the Compasse (the East and West thereof) is said to lead in a paralell, therefore though néerer the truth then the former, yet absurd.
The 3 Opinion of the Compasse.
Is the demonstrature of the Compasse, which is more excellent then the two former, being knowns aright: which demonstrature of the Compasse, some sort of men séeth (but with heads filled with infirmities, &c.) and wanting knowledge, knoweth not the meaning thereof, and but very few vnderstand the goodnesse that is to be delivered thereby, yet the way of a Ship is not according to the present view thereof.
The 4 Opinion of the Compass.
Last of all (which fewest or none know) is the onely true and excellent way, the way of the Compasse according to the difference never yet delivered by any, nor knowne vnto those that make themselves most artificiallest.
I am now to deliver my reasons or examples concerning these foure opinions (above said) which are to condemne the small knowledge, opinion or judgement of men, concerning them: and to justifie and mainetaine the good knowledge that hereafter shall be delivered.
The Card and Compasse handled together.
WHereas, before I have delivered a tast of the foure opinions concerning the Compasse, the first opinion relying onely vpon the truth of the Card, Therefore it is most necessary for me, next of all to deliver the absurdities of the Card, or to lay the Card open in his colours, that when the truth thereof is séene and knowne, then that the way of the Compasse (according to the Card used in navigation) may be left, and a more true way taken how of &c. Now to procéed as followeth.
The 1 Absurdity.
A generall Card straight or right lyned, as it is, representeth, yea delivereth the whole vniversall world at the view thereof, as a plaine flat or levell and not otherwise, and maintaineth a scale correspondent thereunto, and how absurd this delivery is, hereafter is proved.
The 2 Absurdity.
This generall Card maintaineth a Compasse in the midst that shall extend it selfe, and the points thereof to the extreames of the Card, and so delivereth courses by one Compasse to sayle to the extreames of the world, deliuered thereby if it were navigable, even to any part thereof, and to returne the same way againe: which is absurd, as by the demonstrature and way of the difference following is proved.
The 3 Absurdity.
This Card will direct by halfe a Compasse made on the side of the Card, over the whole world, and the returne to be the same way, which is more absurd.
The 4 Absurdity.
Yet this Card will direct farther, that is by a quarter of the Compasse made in one of the corners of the Card over the whole world, which will be made most absurd and monstrous by the grounds before spoken of.
The 5 Absurdity.
This Card also maintaineth from the Poles themselves an East and West line, a Meridian and seaven points of eyther side, whereby the North Pole delivereth from it a Southeast quarter and a Southwest quarter, and the South Pole the like, which is absurd: my reason to proove it to be so, is this, because there passeth no lynes imaginary from the Poles, but onely Meridians according to the spheare.
The 6 Absurdity.
This Card also maintaineth all the paralells of the East and West therein, to be of one length, which is absurd: for paralells are lesse towards the Poles: likewise y Card justifieth she paralells to make right angles with the Meridians even to the Poles, which is absurd, for paralells are inferior Circles vnto the Meridians, which are great Circles, therefore cannot make right Angles with them.
The 7 Absurdity.
This Card also maintaineth all Meridians to be paralells each to other, and thereby maketh a polar line of East and West in the Pole it selfe as long as the Equinoctiall, which is an error of 360 degrees, or 21600 miles, which is most absurd: my reason is this, because the Pole it selfe is but an imaginary point.
The 8 Absurdity.
Again, there cannot be a right signe (for the way of a Ship) delivered from the plaine of a Meridian in the Card, for the delivery of the longitude the Meridians being paralells each to other (and wrested from their nature) as they be, neither can there be a second right [...] (for the way of a Ship delivered from the East and West of a Card) for the delivery of the Latitude: because the paralells therein cannot deliver neither the plaine of a great Circle nor small: therefore the Card absurd.
The 9 Absurdity.
Likewise this presupposed way of the Compasse, according to the Card delivereth vpon any point of the Compasse, for any Segment in Navigation a lesse way in Longitude and Latitude then the Astronomicall deducture of the Compasse, or way vpon the difference doth but if the Longitude of this first way be compared and reckoned after the coarting of the Meridians for any segment in Latitude and Longitude: then it is more swifter in Longitude then any opinions else delivered of the Compasse: therefore absurd.
The 10 Absurdity.
All the lynes in a Card are supposed to be Segments or pieces of great Circles, which is absurd and false: for example, great Circles must crosse themselves at opposite points of necessity, and therefore cannot be paralells each to other: likewise I am sure they count them not spirall lines, for spirall lines are not paralell either to other.
The 11 Absurdity.
The Equinoctiall and Meridian, in a Card graduated as they be by even degrees, both in Longitude and Latitude, being in plano not lawfully projected, is absurd.
The 12 Absurdity.
Likewise, the Card delivereth this rule for his truth, vpon what point of the Compasse soever, the points being of one quality, in what Latitude or Longitude soever you are in like distantes for the differences of degrees in Longitude: which is absurd, and confuted by the Astronomicall deducture, and by the way vpon the difference.
The 13 Absurdity.
Also the Card delivereth this for his truth, vpon what point of the Compasse soever, the point being of one kinde, in what Latitude or Longitude soever: like distances for the raising or laying of a degree in Latitude, which is absurd and false, as shall be delivered by examples vpon the difference.
The 14 Absurdity.
This Card delivereth no truth in Longitude: nor so neere the truth as is to be delivered, therefore in places that [Page 6]are distant from other, the difference of time in no sort is to be delivered thereby, therefore more absurd, then that which will deliver the time more certaine.
The 15 Absurdity.
Whereas one Compasse (as before) in the midst of the Card, the point thereof being extended to the extreames thereof, and widest there, it is as contrary to the truth as falshood is; for the points of the Compasse being extended in delatation but to the Quadrant, which is 90 deg. according to the demonstrature in plano, not lawfully projected, is absurd.
But some of the points to be extended (without) or beyond the Quadrant 105 deg. too much, and continued in delatation, is absurd, but a halfe Compasse in the East or West part of the Card, as the Card delivereth, some of which points, from his halfe Compasse being extended from the Quadrant in delatation 276 deg. 45 min. too much, is more absurd. Nay a quarter of the Compasse delivered from one corner of the Card, as the Card delivereth, some points thereof are extended in delatation beyond the Quadrant 300 deg. (of a great Circle) too much, which is most absurd, as the 15 part in the Astronomicall deducture, and first part of the demonstrature justifieth.
The 16 Absurdity.
Whereas in this Card, the Compasses in the midst, sides or corners thereof, extending their delatation and coartation accordingly beyond the quadrant, as aforesaid, which is absurd: yet the delatation and coartatiō within the quadrant, is also absurd: as for example; Prove from the center of any of the Compasses in the Card, at 30 deg, delatation, and see whether the degrees there, be halfe so big as they are in the quadrant (as they should be) or no, and you shall find 3 of the deg. there, at 30 deg. delatation, to make but a degree in the quadrant, which is ⅓ part false: but it delivereth at 45 deg. delatation 2 deg. there, to be 1 deg. on the quadrant, which delatation is 15 deg. false, or out of his due place.
The 17 Absurdity.
It is a great matter, how absurd the Card is: for let a Ship in her navigation in any Longitude or latitude whatsoever, sayle in the lyne of North-east or the like points, as North-west and South-West, before she can accomplish one Quadrant, she must [Page 7]vse so much way in her navigation, as cōmeth to 127 deg. 15 min. of a [...] Circle, which is 37 deg. 15 min. too much onely in that distance: but a quadrant according to the Sphere is about 90 deg. of a great Circle, which is the truth: therefore the Card absurd.
The 18 Absurdity.
A Ship in her navigation differing in longitude according to the Card altereth the pole from the first place on the polar line to the mer [...]d [...]an on the Card which the Ship is said to be in, which is absurd, as by the 18. part in the Sphere is justified.
The 19. Absurdity.
It is a [...]erva [...]le that the Card (being so monstrous) flowing with nothing but absurd ties that one [...]rror thereof being [...] myle [...] (as aforesa [...]d) should be so greatly [...]n request as it is being no life or helpe in the world [...]n it to that which is [...] in navigation: how it is pos [...]ble for the [...]smography, Geography o [...] [...] thereof to be true: surely in this Card the one is as true as the [...]ther and no tr [...]er therefore all false and [...]bsurd.
So that the Compasse is [...] from the good nature it hath [...] t [...]sel [...]e or the delivery of a [...]hips way, by the absurd opinion delivered to be or received from the Card.
If I could alleadye more condemnations for the Card and the opinions of the compasse (being accordingly) [...]et enough suf [...]ceth. [...]lesse the matter in the Card and knowledge thereby received) were better: And thus I lea [...] the Card and the judgement by it at the Compasse.
The Sphericall Description of the Globe, with the Astronomicall deducture of the Compasse accordingly which by some sort of men, is called the paradoxall Compasse.
NO is will I procéed with the Astronomicall deducture of the Compasse: and because it dependeth upon the lineaments of the Sphere which is the ground thereof, as the Card is of the Compasse used thereby in navigation therfore I will entreat somwhat concerning both the Sphere and deducture of [...] compasse upon it: and as there are 19 absurdities [Page 8]before delivered, for the confuting or delivering the Card in his colours: so many parts I will touch in this Astronomicall deducture, that the difference (between them) may be seene. But this in briefe by the way: The Astronomicall deducture cleareth a way from it many absurdities, by cearting of the Meridians (onely) it maintaineth absurdly the East and West of the Compasse, to lead in a paralell as herafter shall appeare.
The 1. part.
THis whole description of the world, in Globe or round forme spherically lyned with meridians (one being graduated) likewise with paralels and spirall lines, which by some men are called Rhombes, by others called Helicall lynes, and by some called Parado [...]all lines, [...] downe with the Geographie, the scale thereof being the graduated meridian, which is correspondent thereunto, is very profitable to the knowledge thereof, and confuteth the flat Card.
The 2. 3. and 4. part.
This Globe maintaineth a Compasse, being in the Zenith of the earth and water, to ertend it selfe according to the domon [...]rature in delatation to the Horizon and no farther: deviding it into 32 parts or points correspondent thereunto, but maketh the way of a Ship out and home to be all one, and spirally according to this Astronomicall opinion, that the East and West of the Compasse leadeth in a paralell is absurd, and causeth great difference, which in this place and time cannot be delivered.
The 5. part.
This Globe maintaineth the Poles of the world, to be but imaginary pricks or points, delivering or from which points pro [...]eedeth onely meridians, which is true.
The 6. part.
This Globe maintaineth all the paralels of Latitude therein, to be in their d [...]e forme, proportion, or Magnitude biggest neerest the equator, and smallest neerest the Poles dis-allowing paralels, to make right angles with meridians, which is true.
The 7, part.
In which Globe, likewise the meridians hath their delatation and Coartation, admitting no polar line, which is true.
The 8. part.
This Globe, according to the East and west, leading in a Paralell, [Page 9]delivereth one right signe (for the way of a Ship) from the plaine of the meridian (as it should) for the delivery of the longitude the difference respected, and the other right signe, from the plaine of the paralell for the delivery of the latitude, which is absurd: for if the plaines of a great Circle and a small to deliver the place of a Ships being, agreeth not, neither is true, as the difference justifieth.
The 9. part.
The way of the compasse, according to this astronomicall delivery, for any sagments in navigation vpon what Point soever, is more swifter in latitude, and more flower in longitude, then the delivery vsed in navigation by the Card, delivering the point of a Ships being, by the signes as aforesaid, which is absurd.
The 10. part.
This opinion of East and West, leading in a paralell, delivereth no sagments of any spirall lines, to be sagments of great circles, which is absurd.
The 11. part.
The Equinoctial and meridian, in the Globe graduated as they be, by even degrees both in longituds and Latituds, being in round Globe forme, is very true.
The 12. part.
This opinion delivereth vpon any Spirall line (of one quality) which are the points of the Compasse, according to this judgement, not like distances for the difference of degrées in longitude, but is different in every place betweene the equator and the poles yet not the truth, as the difference justifieth.
The 13. part.
And for this Astronomicall delivery by any the spirall points thereof, to raise or lay degrees in latituds: it difforsth little from thecard, which is absurd.
The 14. part.
This Globe, the meridians thereof deli [...]ereth or distinguisheth it selfe into degres of longitude, by which degrees is delivered the difference of time betweene any two places or distances, yet not very true, as in the delivery of the time shall appeare.
The 15. part.
As by this Globe (before) the compasse according to the demonstrature [Page 10]from any one place, delivereth delatation to the Horizon where it is greatest, so from the Fonitor or horizon to the Nadir, all the Arches of depression suffer coartation so that the intersections or crossings of those points of demonstrature, are in the Zenith and his Nadir, which is true: therefore the 15 absurditie in the Card proved by this to be most absurd.
The 16. part.
By this Globe a compasse in the Zenith thereof delivering the Azimuthes to the horizon which is at 90 degrées from the zenith you shall find these Azimuths at 30 degrées delatation, There a degrées maketh 1 degree in the horizon, and all the rest of the Azimuthes or degrees of them, is delivered with truth, either in delatation or coartation, therefore the 15 absurdity in the Card is acknowledged.
The 17. part.
This Globe delivereth by any point of demonstrature, 90 degrees and no more to the quadrant, therefore confuteth the Card according to the 17 absurdity.
The 18. part.
This Globe maintaineth the poles of the world to continue in their places which is true.
The 19. part.
The Cosmography, Geography and Geometry, of the Globe, is farre more perfect then that in the card, yet if the Cosmography and Geography were set downe according to the difference, it would be more perfect: but then there must be more descriptions then one: and thus I leave the Astronomicall deducture of the Compasse. This alwayes to be noted, looke what Lineaments is said to be in the Sphere of the Heavens, as meridians for the delivery of the time, and a helpe for the delivery of the Longitude the equinoctiall and all the paralels, for the delivery of the latituds, the horizon, and all the Almicanters of Altitude, for the delivery of heights, the verticall circles or Azimuthes, for horizontall distances, spirall lines according to the difference for the delivery of a Ships way and such like: is imagined to be in the earth and waters correspondent to these in the Heavens, for the travailers help and comfort: the conceit of which aright, is mo [...] excellent.
Heere followeth the demonstrature of the Compasse, which is a notable knowledge and light in Navigation, being rightly conceived and used as it ought.
The 1. part.
IN any latitude and longitude whatsoever, the demonstrature of the Compasse representing as it doth, the Zenith of the earth and water, and divideth the horizon, not onely into 32 parts, as in the 2. 3. and 4. absurdities of the Card is set downe, but also into 360. parts, nay rather into infinit parts called verticall Circles or Azimuths going with delatation from the Zenith or Verticall point to the horizon where the delatation is greatest, and from this horizon or Fenitor to the Nadir (as is said in the 15 part of the Astronomicall deducture) these Azimuthes or Verticall circles (in the Hemisphere, not seene, being arches of depression) suffer coartation, so that the intersections or crossings of these Azimuthes one another, is onely in the Zenith and his Nadir.
The 2. part.
This demonstrature is moneable or alterable, according to a Ships differing in longitude and latitude, because a Ship caristh her Zenith with her, so that the devision of the horizon according to this demonstrature is variable, according to the distance (from any one place) that the Ship is remeved: &c. A [...]confuting of the 2. absurdity of the Card.
The 3. part.
The devisson that the Zenith, horizon and Nadir hath, or is diuided withall, is onely by almicanter circles, which otherwise are called circles of Altitude or height (being above the horizon) all which are paralels to the horizon, but those from the Horizon to the Nadir, notwithstanding paralell to the Horizon are circles of depression, any one of which Almicanters, may be delivered upon any degree or minute of the height above the Horizon, likewise taken (in some working spherically) in profundity and depth under the Horizon.
The 4. part.
This demonstrature delivereth upon any Azimuth whatsoever, the distance from the Zenith to the Horizon to be but 90 degrées.
The 5. part.
The East and west of this demonstrature (from the zenith) 90 degrees in longitude, toucheth the Equinoctiall, in the horizon at opposite points.
The 6. part.
Now the quality of the Globe is this, the pole thereof being elevated or set to his purposed latitude in his horizon, according to this demonstrature, delivereth the obliquitie of the Sphere, which in truth is a confuting of the East and west to lead in a paralell: as for example.
The 1 Example.
The Globe set to the paralell of 50 degrees north latitude, then a perpendienler lyne imagined to descend, from this Zenith of 50 degrees North latitude, delivereth his Nadir to be in 50 degr. south latitude, so that it delivereth the opposite part of the paralel to be from the Nadir or the arch of the meridian, contayned betweene the opposite part of the paralell and the nadir, to be a 100 degrees oblique or different, and from the place of being in the zenith upon the meridian, to the oposite part of the paralell directly, is but 80 deg. of a great circle, so that this opposite part of the paralells is 10 deg. aboue the Horizon, which is oblique to the zenith and Nadir, also 90 degr. North from the east and west of the demonstrature, in the equinoctial. So that a Ship being in (or having) this zenith before spoken of, the perpendicularity of the ship, being in this Zenith and Nadir line, and the opposite part of this Paralell so oblique unto her, as before how is it possible, for the East and west of the compasse to lead in a paralell.
The 2. Example.
Likewise when the ship, the right line of her caping in the verticall circle of east and west extended both the wayes, crosseth the equator at opposite points, 90 degr. different in longitude, and the Ship being a segment of that great circle, and no sagment of a smal circle as paralels are how is it possible, then for the east and west to lead in a paralell; it is not possible as the way of the difference justifieth. &c.
The third Example.
Being in the paralell of 80 degrees North latitude,If the [...] sayle upo [...] verticall [...] of East o [...] that the [...] passe doth [...] whé ye sh [...] gins its co [...] but as the [...] is guided b [...] magnetica [...] Wiers or [...] dle, so tha [...] Line or its [...] makes eq [...] Angles wi [...] very mag [...] call Merid [...] The way [...] ship leadin [...] the East o [...] doth descri [...] magnetica [...] ralell. a perpendiculer line delivereth the Nadir to be in 80 deg. S. latitude, so that the arch of the meridian contayned betweene the nadir and the opposite part of the paralell is 160 degrees.
But the arch of the meridian, contained betweene the point of being, and the opposite part of the paralell is but 20 degrees.
So that the opposite part of the paralell is 70 degrees above the horizon: and likewise 90 deg. North from the east and west, according to the demonstrature in the equinoctiall: ☞ Here you see the obliquity of the opposite part of the paralell to the zenith, and his nadir; shewing how unnaturall it is to deliver the way of a Ship, leading in the east and west to describe a paralell.
And whereas before I have delivered the East and west of the demonstrature of the Compasse in the horizon, and that the north and south is likewise very plain to be delivered; therefore I will omit them: and will give examples of the demonstrature in the latitude 51 degrées 30 min. and 80 degrées North latitude, only of the north-east, south-east, south-west, and north-west to the Horizon, as bereafter followeth.
North-east in the Latitude 51 Degrees 30 Minutes.
FRom our point of being in our Meridian, which is the beginning of our longtitude, our Zenith being in the paralell of 51 degrees 30 min. north latitude: I am to demonstrate 3 sagments of a great circle contayning 30 degrees a peece by the demonstrature north-east: the end of which first sagment of 30 degrees, shall touch the Meridian in longitude East-ward, 54 degrees from the first, and there likewise shall touch the paralell of north latitude 64. degrees.
And the end of the second sagment of 60 degrees in longitude shall touch the 105 degrees 30 min. or Meridian in longitude east-ward from the first, and there likewise toucheth the 50. deg. 30. min. paralell north.
Likewise the end of the third sagment, at 90 degrees in longitude, shall touch the 128 degree or Meridian in longitude East-ward from the first, and there likewise toucheth the 26 degrée [Page 14]ward 13 min. paralell North: also it there toucheth the horizon 45 deg. either from the cardines East or North.
North-west.
Likewise the demonstrature of the North-west cutteth the Meridians and paralels in longitude West-wards as the demonstrature of North-east cutteth them East-wards, onely that it cutteth the Horizon 45 deg. either from the cardines West or North.
South-east in the same Latitude 51 deg. 30 min.
IN our place of being (as aforesaid) I am to demonstrate thrée sagments of a great Circle containing 20 deg. a péece by the demonstrature South-east, the end of which first sagment of 30 deg. shall touch the 23 deg. 30 min. or Meridian in longitude East-ward from the first and there likewise toucheth the 27 degrees 20 min. paralell North.
And the end of the second sagment of 60 deg. in Longitude. wall touch the 3 deg. 40 min. or meridian in longitude East-ward frō the first and there likewise toucheth in [...] deg. 25 min. N. latitude.
Likewise the end of the third sagment at 90 deg in Longitude, shall touch the 51 degrée 40 min. or meridian, in Longitude east-ward from the first and there likewise toucheth the 26 deg. 15 m. paralell south: Also there toucheth the Horizon 45 degrees either from the cardines East or south.
South-west.
Likewise the demonstrature of the South-west toucheth the meridians and paralell in longitude west-ward as the demonstrature of south-east toucheth them east-ward, onely that it cutteth the horizon 45 deg. either from the cardines south or west.
Examples in the Paralell of 80 deg. North latitude beginning with the first example of North-east in the north latitude 8 deg.
FRom our point of being in our meridian which is the beginning of our longitude our zen [...]th being in the paralel of 80. deg. north latitude I am to demonstrate; sagments of a great circle, containing [...]0 deg. apéece by the demonstrature north-east the end of which first sagment of 30 degrées, shall touch the meridian in longitude east-ward 119 degrees 30 minutes from the first and there likewise shall [...] the paralell of North latitude 60 de [...]r.
[Page 15]And the end of the second sagment. 160. deg. in longitude, wall touch the 130. deg. [...]. min. or meridian in longitude east-ward frō the first, & there likewise toucheth the 36. deg. 45. mi. paralel north.
Likewise t [...]t end of the 3. sagment at 90. deg. in Longitude shall touch the 134 deg. 30 min. or meridian in longitude east-ward from the first & there likewise toucheth the 7 paralell north Also there toucheth the horizen 45 deg. either from the cardines east or north.
North-west.
Likewise, the demonstrature of north-west cutteth the meridians and paraellls in longitude west-ward, as the demon [...]rature of north east, cutteth them east-ward onely, that it cutteth the horizon 45 deg. either from the cardines west or north.
Example of the South-east in the same Latitude 8. deg.
IN our place of of being, (as aforesaid) I am to demonstrate thrée sagments of a great circle, containing 30 deg. apéece, by the demonstrature south-east, the end of which first sagment of 30 deg. shall touch the 35 deg. 40 mi. or meridian in longitude east-ward from the first and there likewise toucheth the 52 degrée 10 min. paralell north.
And the end of the second sagment of 60 deg. in longitude wall touch the 41 degrees 40 min. or meridian in longitude Eastward from the first, and there likewise toucheth the 22 degrees [...] min. paralell north.
Likewise, the end of the third sagment at 90 deg. in longitude wall touch the 45 deg. 30 min. or meridian in longitude eastward from the first, and there likewise toucheth the 7 paralell South. Also there tuecheth the horizon 45 deg. either from the cardines East or south.
South-west.
Likewise the demonstrature of south-west, cutteth the meridians and paralells in longitude westward, as the demonstrature of the south-east cutteth them eastward, onely that it cutteth the horizon 45 deg. either from the cardines south or west.
And as for the arches of depression, from the horizon or senitor to the nadir of these points before spoken of, the delivery of them is even as easie as the former, and so is the arch of altitude, or arch of depression upon any Azimuth whatsoever. Onely this [Page 16]following to be respected as a preparative: before I deliver any nice examples according to the difference, it is necessary for me to explain in a more familiar sort (at large) some part of the difference onely according to the demonstrature, for the more confuting of the Card, and the opinion holden thereof for the way out and home to be all one. It is delivered in the 15 absurdity of the Card, that upon some points of the Compasse, the Card delivereth a way outward, to be 390 degrées of a great circle, and to returne homeward (to the first place) againe, the like distance upon the same line, which shall be proved most false by the examples following: which examples shall be from the latitude of 50 degr. and from the first example, as before in the latitude 51 degrées 30 min. yet these deliver not the truth neither, as by examples upon the difference, hereafter follow.
The 1 Example in North Latitude 50 deg.
IN which latitude, our zenith or place of being in one meridian, where we make our beginning of longitude and place of departure; I am now to deliver from this our zenith or place of being, the demonstrature of north-west for one sagment of 30 degrées in longitude: which sagment end of 30 degr. North-west, there cutteth the 11 degr. 30 minutes or meridian westward in longitude, and the 63 degree paralell north.
Our Zenith now being altered and the latitude 63 degrées as aforesaid, we will make proofe to returne back againe to our first place by the line south-east the like sagment of 30 degrées in longitude, where this sagment end cutteth the 26 degree 20 minutes or meridian in longitude eastward, and there likewise cutteth the 37 degree 40 minutes paralell north.
So that this line of north-west extended to 30 degrees as aforesaid, and from thence returning south-east to 30 degrees likewise there is difference in longitude westward, from the first meridian or place of departure 25 degrées 10 minutes or meridians, and in latitude southward from the first 12 deg. 20 minutes.
Here you sée the difference of the way out and home, onely for 30 degrees according to the demonstrature, and only for the lines of northwest and southeast, the rest of the points, hath their like difference in their kind.
The 2. example in north Latitude 51 deg. 30 min.
I Am now to deliver from this our zenith or place of being, the demonstrature of the northeast to 90 degr. which line of north-east there cutteth the 128 degree or meridian in longitude east-ward from the first, and there likewise cutteth the 26 deg. 15 minutes paralell north, as in the demonstrature is delivered.
Our Zenith now being altered, and in the latitude 26 degr. 15 minutes as before said, we will make a proofe to return back again to the first place, by the demonstrature south-west to 90 degr. where this line of south-west cutteth but the 65 degr. 30 minutes meridian in longitude westward and there likewise cutteth the 39 degree 30 minutes paralell south. So that this line of north-east extended to 90 degrees as aforesaid, and from thence returning southwest to 90 degr. likewise, there is difference in longitude east-ward from the first, 62 degrees 30 minutes, and in latitude southward from the first 91 deg.
Here you see also the difference of the way out and home, only for 90 degr. according to the demonstrature, and only for the lines of North-east and south-west, and all the rest of the points is the like in their kind. And so I leave the demonstrature.
Now will J deliver Example worthy the noting, of the way of the Compasse according to the difference.
THe East or west of that Compasse, rectified to the true meridian upon the difference, maketh a spirall line in delatation to the equinoctiall frō what paralell soever, by sagments (of great circles) correspondent for this purpose: which sagments maketh right angles with the meridians, and which sagments delivereth a right signe from the plaine of the verticall circle of east & west for the way of a Ship in her navigation, and the meridian according to this difference delivereth the other. This part of the difference only confuteth the generall Card and the lines of inclination, with the Geography of the Globe.
This difference, the east and west thereof delating as aforesaid, ruleth notwithstanding the variation of the Compasse, generally spoken of, as for example: the Compasse here with us at London, is set at halfe a point variation Eastward, where it should be 10 degrees 38 minutes 45 seconds by my owne observations, [Page 18](which was made in the yeere 1586.) which maketh the west to be halfe a point to the north-ward of the west: therefore in go [...]ng from Silly (which is in latitude 50 degrées 15 minutes or there abouts) west by the Compasse (which is in truth west half north) with Cape Race, in New-found-land the places distant some 600 leagues from other causeth a falling more southerly into the latitude 46 degr. 30 minutes or thereabouts, which sheweth the way of the difference to rule in this distance.
And by a Compasse rectified to the truemeridian that is a Compasse that the north and south thereof, delivereth or pointeth according to that true meridian of Silly on which meridian is delivered the arch of altitude or almicanter of the Sunnes height at n [...]ne, by which or such Compasse, Cape Race heareth from Silly due west and by north and there toucheth the paralell of north latitude 46 degrées 30 minutes, likewise toucheth the meridian in longitude westward from Silly the 45 degrées 40 minutes according to the coarting of the meridians in this distance.
And to speake the truth, in this distance there is but litle or novariation of the Compasse to be respected for the compasse at Silly set at the whole variation as it ought to be, yet in sayling by that compasse, you runne some 400 leagues before the north and south points thereof, delivereth the true meridian: and in sayling the other 200 leagues, the compasse is varied westward a point and a halfe or there abouts, which is no more then will answer the variation eastward, as before, so that in this distance, the nutation of the Compasse, eastward, & westward, considered aright, is as nothing to be respected, (but the one set against the other,) as by the examples following is proved.
The first Example.
Let a compasse be rectified to the nutation and sayle from Silly therewithall to Cape Race, west: & when you come on the coast of Newfoundland you shall be delated from the paralell of Silly, onely according to the difference, and not otherwise.
The second Example.
Let the compasse be set at halfe a point nutation, as most commonly it is and sayle by the Compasse from Silly west with Cape Race, and you wall perforce (keeping that course directly) fall into more southerly latitude, which is into 46 degrées 30 min. [Page 19]or thereabouts, according to the difference, and not otherwise.
The third Example.
Let the Compasse be rectified to the true meridian, and sayle by that Compasse from Silly west with; Cape Race and you shall likewise fall into the latitude 44 degr. or thereabouts, according to the difference.
And as for this way (aboue said) is delivered a delating from the paralell in going west: so likewise in returning east frō thene againe, you shall likewise delate from that paralell againe, according to the difference: which delivery overthroweth the whole Card.
Againe, looke how the difference of the east and west ruleth in the distance and differedce in longitude (as aforesaid) so in any other distance and difference in longitude, it is likewise to be respected. Also this difference of the east and west, is the ground frō whence the difference is delivered, for all the rest of the points of the Compasse.
So that you see, this way upon the difference, delivereth way outward to any place, different unto the way homeward, being not both alike, as by the examples of the north-east, and returning south-west: likewise of the north-west, and returning south-east, as heereafter appeareth.
The 1 part of the 1 example from the Equator.
Being in the Equinoctiall in any one meridian, I will there make my beginning of longitude: from which equator and meridian of longitude, I will deliver the line of inclination, northeast continuing it to the latitude 75 degr. 6 minutes 14 seconds according to the difference.
The 2 part of the 1 Example.
The line of the north-east continued to the latitude 75 degrees 6 minutes 14 seconds, according to the difference, endeth in the longitude 131 degrees from the first, reckoned according to the meridians in this distance coarted.
The 3 part of the 1. Example.
Being in the latitude 75 degrees 6 minutes 14 seconds, and in the longitude 131 degrees as aforesaid, I am now to returne back againe by the line of inclination, south west to the Equinoctiall.
Conclusion of the 1 Example.
Being returned to the Equinoctiall as aforesaid, I doe [...]nd the length of the line of inclination south-west homeward, to be shorter then the line of north-east outward, by 130 leagues, and I am in longitude eastwerd from the first place on the Equinoctiall 70 leagues, therefore the way out and home not all one.
Another Example North latitude 50 degrees.
I sayle north-west 50 leagues, at the 50 leagues end I have altered my longitude from the first, 2 degrées 38 minutes, and my latitude 1 degrée 40 minutes.
I returne back againe south-east 50 leagues, and being returned, I find my selfe in lesse longitude or westward from the first, 3 minutes, and in latitude more then the first 6 minutes.
Another Example in the North latitude 60 degrees.
I sayle north-west 50 leagues, at this sagment end, my longitude from the first is 3 degrées 30 minutes, and latitude from the first 1 degree 50 minutes, I returne back againe south-east 50 leagues, and being return'd, I find my selfe in lesse longitude or westward from the first, 5 minutes, and in latitude more then the first 10 minutes.
And for the more confuting of the way out and home to be all one, and the more justifying the delating from the paralell to be true, I will deliver some more examples upon the east, for a sagment of 20 leagues, in the latitude 51 degrees 30 minutes, and 75 degrees, delivering the horizontall distance betweene the east (according as is said) to lead in a paralell, and the way of the east according to the difference, as followeth.
In Latitude 51 deg. 30 minutes, my first place.
From any one meridian of longitude, I take a sagment of the paralell in this latitude of 20 leagues, presupposed by some to be East from the first place: and againe, I doe depart from my first place of being 20 leagues eastward according to the difference: now at this 20 leagues end, I am delated from the paralell according to the way upon the difference, which maketh my place (now of being) to heare from the first place, two Azimuthes, and [...] more southerly.
As for Example.
To explaine it more briefly, I imagine one lyne from the first [Page 21]place east, according to the paralell 20 leagues: imagine another line from the first place East by the Compasse, according to the way upon the difference: now the horizontall distance betweene these two lines at 20 leagues end, from the first place, shalbe (as before) two Azimuths [...].
In the latitude 75 my first place and meridian of longitude, I take a sagment of the paralell in this latitude, of 20 leagues, presupposed likewise by many to be East from the first place: and againe, I doe depart from my first place of being [...] leagues east, according to the way upon the difference: now at this twenty leagues end, my horizontall distance betweene my place of being, and place (as aforesaid) on the paralell, from the first place, in 3 azimuths [...].
Likewise this way of the difference delivereth upon any Aziemuth, or point of Compasse, sagments of great Circles, different from other, correspondent as they ought to bee for the difference in longitude as hereafter by thrée examples of the North north-west following appeareth, which confuteth the 12 absurdity of the Card.
Three Example of the North North west, for the difference of the length of the Sagments in longitude from the Equinoctiall, to 80 degrees in latitude, as followeth.
The first Example from the Equator.
BEing in the Equinoctiall in one meridian, the sagment of N. north-west to reach to the next Meridian which is one degree in longitude, is in length 52 leagues ⅓.
The 2 Example from 40 deg. of latitude.
Being in 40 degr. of latitude, and in one Meridian, the sagment of north north-west, to touch the next meridian, is in length 17 leagues ⅓.
The 3 Example from 80 degrees of Latitude.
Being in 80 degrees of Latitude, and in one meridian, the sagment of north north-west, to touch the next meridian, is in length [...] leagues ⅔.
Also, this way of the difference delivereth upon any Azimuth or point of the compasse, sagments of great circles, different from [Page 22]other, for the laying or raising of a degree in latitude whatsoever, as by 3 examples of the west, north west following appeareth, which confuteth the 13 absurdity of the card.
The 1 example from the Equator.
I Being in the equinoctiall, am required to deliver a sagment of the west north west, onely to raise a degree in latitude, which according to the difference is 52 leagues and ⅔.
The 2 example from 40 deg. of Latitude.
I being in 40 degrees of latitude the sagment of west northwest to raise a deg. in latitude upon the difference is 56 leagues.
The 3 example from 80 deg. of Latitude.
I being in 80 degrees of latitude the Segment of a west north-west, to raise a deg. in latitude upon the differ once is 60 leagues.
And thas will I leave the way of the Compasse upon the difference for this time.
And because the variation, or nutation concerneth the compasse and is a thing delivered in print, meant belike to some purpose: therefore I will touch this variation, or nutation, in some few words as hereafter followeth.
If a man for his delivery of the variation in print, would observe by a needle touched by some, who maketh the common or ordinary Compasses, I take it, precise fellowes, would soone be delivering forth, that the variation so set in print, were wide from the truth.
Because with some men in the touching of a Needle, or Compasse, though the stone they touch withall, be not, the best, neither shall an inch in bredth of the north part of that stone, breake any square with them, by whose compasses many time shipping at the Seas be indangered.
It were better for a man for the security of his charge, or that purposed to set downe the variation in print, to take a needle touched by a better stone and a more perfect man to handle the touching thereof: truely when Robert Norman dyed (who had a good stone) Sea man had a great losse, yet Maister Mullinux of Lambeth, who having a better stone was as carefull & as precise in hi [...] [...] concerning the touching of Needles, & Compasses, as over Maister Norman was.
[Page 23]Notwithstanding the variation (by such a good Néedle) set down in print and delivered as a generall thing,This [...] to passe [...] mistakin g [...] true place [...] the Poles c [...] Stone, f [...] Master G [...] brand, an [...] thers with [...] observing [...] variation [...] two severa [...] Needles to [...] ed with tw [...] verall Sto [...] found the [...] riation to [...] the same, [...] the like I [...] seene befor [...] since. H.B [...] would bée but [...]ested at: and made a thing indéed that a man might spend much time to no purpose and lesse edifying to the Seamen as some have done: my reason is this, because this Stone (though a notable one) and I have not séene a better, and good to make abservations withall to be kept to a mans selfe, or out of print or for the amplyfying of some note in writing: ☞ It cannot deliver the variation of another Stone; for in truth the Variations delivered by many stoues are different: you shall not have two Stones alike qualited, or that will deliver one or a like Variation, but the variation of every stone differeth from other: there cannot generally be set downe a certaine variation for any one place, which let suffice for this time.
Therefore, that man that was conceited to set the Variation in print, as a generall thing: though it were my selfe, all things to nothing, I would there in my deliverie, likewise hee condentning all mens knowledge saving my owne, to justifie my doings.
But to the matter, the variation or nutation of the compasse as it shall at any time or place be found, is a thing to be noted, yet my delivery is of it, that it is not surpassing all other knowledge, neither the overthrow of good knewledge, neither will I accept of it as a thing notable above all the rest, my reason is this, because the way upon the difference, being more excellent, over ruleth it, which indeed they impute to variation, which is untrue: and thus will I leave the nutation of the Compasse.
And whereas before in my delivery of the nutation, I had forgotten to give a tast of the error, which is likewise set in print, and conceiveth the nice delivery of the said nutation: I thought it now therefore good (though late) not to overpasse it but to give knowledge thereof: it is said that the middle point betwéene any two Azimuthes observed upon equall elevations in forenoone and afternoone, is the true Meridian.
For the confuting hereof I will deliver you an example in the north Latitude 51 degrées 32 minutes as followeth.
The Sun being in her swift declination, in or néere the Equanor, I purpose to make two observations: the former observation to be 2 min, before 8 of the clock in the forenoone, the Almicanter [Page 24]delivered then by the center of the Sun, being 18 deg. in elevation, & the horizontall distance eastward from the true meridian delivered by the Azimuth of the Sunne to be 66 degr. 38 min.
The second observation in the afternoone, the Sunne having the same Almicanter 18 degrées: the declination increasting respected, for 8 houres, which is 8 min. North declination, maketh the time to be 3 min. after 42 clock in the afternoone, wherein there is a min. of time different from the South and the horizontall distance westward from the south, to be 66 deg. 53 min. So that I find this last observation to be farther from the true Meridian, then the former by 15 min. but if the declination were decreasing, then the last observation will be nearer the true meridian then the former by 15 minutes, which maketh a difference of variation, sometime too much, or sometime too little, by 15 minut. good, which is an error and therefore not the truth.
Concerning the Tides.
EVen as mens minds for the most part are setled in the absurdities of the Card and compasse accordingly, so are they setled likewise in an absurd reckoning of their Tides, as hereafter by the grace of God shall appeare, divided into two parts, first by the delivery of the Cpact, next according to the time observed, by the point of the Compasse, as follweth.
The first part.
These men doth not only know the prime by ye date of our Lord, and the Epact by the prime, and the day of conjunction by the epact which is tollerable, according to the order of the Epact, allowing 30 dayes to every Moone: or on the 30 day end, to be Conjunction, which is notwithstanding partly at randome, being without respect of the precise time of the conjunction.
But they justifie also the departure of Sunne and Moone in 24 houres to be continually 48 min. as though the motions of the Sunne and Moone continued all one, or that 48 minut. were their meane departure.
For they bring the 32 Points, every poynt being a 11 degr. and [...] a sunder, the whole being 260 degr. to 30 whole dayes, allowing to every 24 houres the departure to be (as aforesaid) 48 min. for 30 times 48 minutes is 24 houres: and 4 minutes of time is [...]nswerable to one degrée of the equator: therefore the departure [Page 25]is 12 degrées in 24 houres, allowing the just revolution of the Equator to be in 24 houres, neither more nor lesse, for 30 times 12 degrées is 360 degrées, in which their reckoning in my conceit, the course of the Sunne in those 30 daies, which is about 29 degrées 30 min. is forgotten or not respected, but either they must of necessity, grant that the revolution of the Equator, and the departure of the Sunne and Moone, to be as hereafter shall be delivered: or else they must allow the Moones error in her yéerely course, to be 5 dayes 15 houres 2 minut. too much, which is an absurdity, and maketh the sinodicall error more then it should be by 11 houres, 15 minut. 56 sec. 49 thirds, but if they doe acknowledge, (which I take it, is in few or none of their heads) that the whole revolution of the Equator is turned about in 24 houres, (as hereafter wall be delivered) and so doe reckon the odde time, to be for the meane course of the Sunne in the 30 daies, yet they must acknowledge by that reckoning, that the conjunction of the Sunne and Moone, must happen almost at like times of every yéere, or at least-wise, make the difference sooner of the yeerely period of the conjunction, to be but 5 dayes 6 houres 9 minutes, which indeed should be 10 dayes, 21 houres, 11 minutes, as hereafter shall be delivered.
The 2 part.
1 Also these men I justify in reckoning their Tides, in what place and time soever: that where it floweth a southeast moone in conjunction or opposition (and possible by a false Compasse) then it floweth till 9 a clock: or where it floweth an East Moone in conjunction or opposition then it floweth 6 a clock, & so its their judgments generally of all the rest of the points of the Compasse.
2. And to justifie my sayings to be true, they have set forth, printed tide tables thereof, and in those tables also, have set their judgements, that in conjunction or opposition it floweth 48 min. after the time upon any point as aforesaid, which is absurd.
Therefore these their judgements, for the security of their charge, had as much néed of refining as the East and west of the Compasse, as is said before, to lead in paralell.
Now to the matter, for the refining of the first part as aforesaid, let this first part following suffice.
To know the times of the Conjunction otherwise then by the [Page 26]Epact, is delivered by Ephemerides, or Alminacks, but rather knowne by that man that hath the knowledge himselfe in the Theorickes of the Sunne and Moone: which knowledge ought to be in a man that would be artificall to refine these absurdities.
In Mesl [...]nes Astronomie the metions of the Sunne and Moone are distinguished into three parts; Slow, swift, and meane: that is to say; in Apogaeum slow, when they are farthest from the earth: in Perigeun, swift, when they are néerest the earth: and in their meane betwéene the Apogaeum and Perigenm, notwithstanding by these thrée motions there is knowledge understood, that the motions of the Sunne and Moone are alwayes different, that is to say, the Sunne from this place in Apogeum, to his Perigeum: likewise the Moone from her Apogeum and Perigeum of her epicicle, & from her Apogeum in her almost an oval forme of the center of her Epicicle, to her Perigeum thereof being the like qualited.
To justifie the Motions to be the truer: it is also delivered in this Astrouomy, that the Sunne hath thrée Orbes or particular Spheres, as followeth.
First an Excentricke which is called the difference of the body of the Sun. second is called the difference of ye Apogeum of the excentrick the which 2 doth containe the excentrick betwéen them: and 3. maketh the whole sphéere of the Sun to be concentrick. I could delate more of this theorick then I purpose, but it would be to small effect concerning the tides, only respect this that follows.
Three reasons to be delivered for this Hypothesis as aforesaid to be true.
1 First reason which causeth the Sunne to be in an excentricke, is the difference of the Sunnes motion: which is prooved sometimes swift, sometimes slow, as aforesaid.
2 Second reason is, because the Diamiter of the Sunne, is prooved sometime bigger (as in Perigeum 33 min. 44 sec.) then at some other time by 2 minutes 6 seconds, therefore néerer at sometimes then at other times.
3 The third reason is the inequality of the Epicicles because it is proved that the Sun farthest from the earth causeth the Eclipses to be longer and neerer the earth to be sooner.
Mesline delivereth also in his Astronomy, that the greatest excentricity of the Sunne is 48 semidiamiters of the earth.
[Page 27]And the least excentricity which is néere in this our age about the 9 degrée of Cancer, is 37 semidiamiters of the earth.
So the difference is a 11 semidiamiters of the earth, and the semediamiter of the earth is 3436 miles and [...].
So that the sunne is néerer unto us at some time, then at some other times by 74 semediamiters of the earth.
Mesline delivereth likewise, one yearely Period of the sunne to have 365 dayes 6 hour. 9 min. 39 sec. and this yéere he calleth Sideriall or starry, the diurnall mean motion of the Sunne accordingly to be 59 min. 8 sec. 11 thirds 22 fourths 16 fifths.
- Her swift motion in 24 houres, is — 1 deg. 1 min. 16 second.
- Her meane motion in 24 houres, is — 0 — 59 — 8
- Her slow motion in 24 houres, is — 0 — 57 — 0
Mesline delivereth likewise in his Astronomy, that the Moone hath five Orbs or particular Spheres as followeth:
- 1 First, an Excentricity.
- 2 Second, the difference of the Epicicles center.
- 3 Third, the difference of the excentricity in Apogeum and Perigeum.
- 4 Fourth is the Epicicle which carieth the body of Luna.
- 5 Fifth, which is Concentrick called aequans Luna.
Foure reasons following to prove this Hypothesis to be true.
1 First reason which causeth the Moone to be in an excentrick, is the difference of the Moones motion, which is proved sometime swift, sometime slow.
2 Second reason, is because the Diameter of the Moone is prooved sometime bigger as in Perigeum 35 miu. 38 seconds then at some other time by 5 min. 38 sec. therefore néerer at some times then at other times.
3 Thirdly, the inequality of the Eclipses, because the moone farthest from the earth, causeth the Eclipses to be longer, and néerer the earth to be sooner.
4 Fourthly, the inequality of the Paralax, because the Moone sarthest from the earth, causeth the Horizontali paralax, to be the lesse, and néerer to be more.
[Page 28]And the greatest excentricity of the Moone is 10 semidiamiters of the earth, and [...] a little lesse.
And the semidiamiter of the Epicicle is 5 semidiamiters of the earth and [...]. So that the Moone is neerer unto us at sometime, then at some other times by 30 semidiamiters of the earth, and [...], and likewise by the whole diamiter of the Circulus parvus: which is 20 semidiamiters and [...].
For the Moone maketh a Circulus parvus, (contrary to her owne motion) about the center of the world, according to the semidiamiter of the excentrick, which is 10 semidiamiters, and 8 min. 30 seconds.
Likewise the Moone hath latitude of the Ecliptick on either side 5 degrées, which for the tides is greatly to be respected.
Mesline delivereth one meane periodicall period of the Moone to have 27 dayes, 7 houres 24 minutes.
Also delivereth the meane time to make vp the periodicall period to a meane sinodicall period to have dayes, 2 dayes, 5 houres 20 minutes.
So that the meane sinodicall month of the Moone to be in conjunction againe with the Sunne hath dayes, 29 dayes 12 houres, 44 minutes 3 sec. 11 thirds.
The motions of the Moone as followeth.
The swift motion of the Moone, sometimes in 24 houres is 15 degrées 0 min.
The meane motion in 24 houres, is 13 degrées 30 minutes.
And her slow motion in 24 houres, is 12 degrées 0 minutes.
Now having delivered so much as needeth of the Theoricks of the Sunne and Moone concerning the Tides, we are come to the point to know their departure, which is as followeth.
The departure of the Sunne and Moone.
The Moone presently after the conjunction departeth Eastward from the Sunne in Apogeum in 24 houres 11 deg. 3, min. which is answerable in min. to 44 min. 12 seconds.
The Moone presently after the conjunction, departeth from the Sunne in Perigeum in 24 houres 13, degrees 58 minutes 44 seconds answerable in minutes, to 55 min. 55 seconds.
The Moone presently after the conjunction departeth from the Sunne in meane motion, in 24 houres 12 degrees, 30 min. 52 [Page 29]seconds, answerable in min. to 50 min. 3, seconds [...].
Sometimes the departure of the Sunne and Moone, when the Sunne is in her slow motion, and the Moone in her swift motion, in 24 houres, is 14 degrees, 3 minut. which maketh the departure in minutes answerable to be 56 min. 12 seconds.
And sometime the departure of the Sunne and Moone, when the Sunne is in his swift motion, and the Moone in her slow motion, in 24 houres, is but 10 degrees, 58 min. 44 seconds, which maketh the departure in min. answerable to be 43 min. 55 sec.
And the meane motion, between both these motions, next above in 24 houres, is 50 min, 2 seconds, 30 thirds.
Which motion is justified twise, as above: therefore I conclude the meane departure of the Sunne and moone in 24 houres to be 50, min, 3, seconds 30 thirds.
And the hourely departure accordingly to be 2 min. 5 secon. 8 thirds, 45 fourths.
Stadius affirmeth in his Ephemerides, that in 24 houres the whole equator and 50 minutes 8 seconds is turned about, which is most certaine.
Likewise in a meane be affirmeth that the conjunction of the Sunne and Moone in one period, at any one time in the yeere, shall differ from the same time the next yeere, and be sooner 10 dayes, 21 houres 11 min. as for example:
In the 12 meane sinodicall moneths, the time that wanteth of 12 times, 30 dayes, is 5 dayes 15 houres 2 minutes, which maketh 360 dayes, the remainer of the dayes of the whole yeere, is 5 dayes, 6 houres, 9 minutes, which both together is 10 dayes 21 houres 11 min.
Now for the refining of the first 2 parts, let these last 2 parts following suffice, concerning their error in reckoning their tides delivering the time by the points of the Compasse: for the confuting hereof. I will deliver six examples, three examples in the north latitude 30 degr. and the other 3 examples in the north latitude 51 degrees 32 minutes.
North latitude 30 degrees, the Sunne in Capricorne.
1 The Sunne at southeast, it is then ¼. before 9 a clock in the morning, but if the Moone hath 5 degrees South latitude, then it is 24 minutes before 9 a clock: if the Moone have 5 deg. North [Page 30]latitude, then it is 16 min. past 9 a clocke.
Sunne in the Equator.
The Sunne at Southeast, it is then 14 min. past 10 aclock in the morning: but if the Moone have 5 degrées south latitude, then it is 7 min. before 10: if the Moone have 4 degrées north latitude, then it is 30 minutes past 10 a clok
Sunne in Cancer.
The Sunne at southeast, it is then 32 min. past a 11 a clock in the morning, but if the Moone have 5 degr. south latitude, then it is 15 minut. past a 11: if the Moone hath 5 degr. north latitude, then it is 54 minutes past a 11 of the clock.
And at an east Sunne, it is then 18 min. past 9 a clock in the morning, but if the Moone have 5 degrées South latitude then it is 24 min. past 8 a clock: if the Moone have 5 degr. north latitide, then it is 40 min past 10 a clock. So that in this north latitude of 30 degrées, there is difference of time in the Moones being sentheast &, 3 houres. 18 min. and in the same latitude, difference from 6 a clock in the east 4 houres 40 min.
The other 3 Examples in the North Latitude 51 deg. 32 min. the Sunne in Capricornus.
1 The Sunne at the Southeast &, it is then 20 minut. before 9 a clock in the morning: but if the Moone hath 5 degrees south latitude, then it is 18 minutes past 8: if the Moone have 5 deg. north latitude, then it is 51 min. past 8 a clock.
Sunne in the Equator.
The Sunne at the southeast, it is then 28 min. past 9 a clock in the morning: but if the Moone have 5 degrées south latitude, then it is 18 min. past 9: if the moone have 5, degr. north latitude then it is 38 min. past 9 a clock.
Sunne in Cancer.
The Sunne at the southeast, it is then 18 min past 10 a clock in the morning: but if the Moone hath 5 degrées south latitude, then it is 6 minut. past 10. If the Moone have 5 degrées north latitude, then it is 30 min. past 10 a clocke.
But at an East sunne it is then 22 min. past 7 a clocke in the morning, but if the Moone have 5 degrees South latitude, then it [Page 31]is 2 minutes past 7. If the moone have 5 degrées north latitude: then it is 42 minutes past seven a clock: likewise in this north latitude 51 degrées 32 minutes, there is difference of time in the Moone being southeast 2 houres, 2 minutes.
And in this same Latitude, difference in the east from 6 a clock 1 houre 42 minutes: the mistaking of so much time, from the high water, may overthrow their charge in going into a harbor, where it is to be respected.
2 And whereas they deliver in their Tide Tables, a hoying of the tide in conjunction, aspect or opposition, to 48 m. after the order in that Tide Table, it is not so, but in a river or in-draft, where the Tides in their prime runneth quick, there Tides of flouds will runne 48 minutes after high water; and thus I will leave the delating of the Tides.
Concerning the Time.
SUch is the conceit or knowledge of the Sea-men in these times, they take a common Compasse, little respecting the error thereof, being touched with a Stone of no strength, and made wise by a man of no knowledge: which Compasse they devide into 24 houres, to deliver unto them, (they observing the Sunne therewith) the time they looke for, which is as lame a delivery of the times as may be, and is somewhat touched before in the delivery of the Tides, and likewise as hereafter followeth.
Also, they observe the time by an houre, or halfe houre glasse, made by as carefull a man, as the Compasse before spoken off, who indéed careth but little what error more or lesse, is delivered in those glasses in 24 houres, nay in halfe an houre, with whom (as the proverb is) an inch breaketh no square.
Which Compasses and glasses had néede to be carefully respected, nay rather to be reformed, for the security (as aforesaid) of the Navy of England, which is greatly indangered by them: and although these appendances for Nauigation be méere false, yet the Market-folkes being not experienced by them, in consideration of the cheapenesse of them, holding themselves thereby, profitable servants to the owner.
And although the time generally from one Moone to the other, cannot be perfectly delivered by any man, as hereafter [Page 32]shall be shewed: yet by precise Instruments carefully made the time may be delivered more truely which is the greatest helpe we have in Longitude, and for a man most carefull in making of his Compases, and running glasses, I commend Maister Emerie Mollineux of Lambeth (while he lived) as for my conceit, which I have learned concerning the time, it is as hereafter followeth.
First, for the confuting of the time delivered by the compasse, as aforesaid, which Compasse is delivered by 360 degrees, which indeed are Azimuths, and they justify as many Azimuths, which is 15 for one houre, as for another which is contrary, therefore I will deliver three examples to that effect in the Latitude 51 degrees 32 minutes as followeth.
Sunne in Capricornus.
From the Sunne rising to one houre of time, there is 12 Azimuths and a ¼, and from a 11 a clock to 12 at Noone, there is 14 Azimuths.
Sunne in the Equator.
From the Sunne rise to one houre of time, there is 12 Azimuthes, and from a 11 a clock, to 12 at noone, there is 18 Azimuths and ¾.
Sunne in Cancer.
From the Sunne rise to one houre of time, there is a 11 Azimuths and ⅓. and from a 11 a clock to 12 at noone, there is 28 Azimuths.
Also followeth two examples, the one in the north latitude 51 degrees 32 minutes: the other in the north latitude, 66 degrees, concerning the difference of time, as followeth.
The 1 Example in Latitude 51 degr. 32 min.
Aries whole signe, hath declination a 11 degrees 20 min. which reacheth in longitude Eastward, according to the degrees on the Equator to the 28 meridian likewise this whole signe of Aries doth lengthen the dayes 1 houre and 58 min.
Taurus, his whole signe, hath declination 8 degrees 50 min. which reacheth in longitude Eastward according to the degrees on the Equator, to the 29 and a halfe Meridian: also this whole signe of Taurus doth length the dayes one houre and 44 minutes.
Gemini, his whole signe hath declination 3 degr. 18 min. [Page 33]which reacheth in Longitude eastward, according to the degrees on the equator to the 32 and a halfe Meridian, also this whole signe of Gemini doth length the dayes 1 houre 40 minutes.
The 2 Example in North Latitude 66 degr.
- Aries whole signe, lengthen the dayes, — 3 hour. and 46 min.
- Taurus whole signe, lengthen the dayes, — 3 hour. and 38 min.
- Gemini his whole signe lengthen the dayes, — 3 hour. and 0 min.
But seeing that generall time from one Noone to an other, cannot be delivered certaine, but there shall be error, so that one 24 houres shall be longer, or shorter then an other by 1 houre and 28 min. as hereafter shall be delivered: what certaine time then can be delivered by any Instruments for that purpose, which delivereth but a second error.
Now will I deliver some causes, why the time from one noone to another cannot be of like time.
Mesline in his Astronomy, delivereth that there is three Ecliptickes as followeth.
First the ecliptick of the 10 Spheare which is fixed.
Second, the ecliptick of the 9 Spheare which is mooveable.
Thirdly the ecliptick of the 8 Spheare which is the true ecliptick of the starry firmament.
Likewise he delivereth that the Sunne in Aries of the 9 Sphere, is gone to the Eastward of the Sunne in Aries of the 10 spheare, 27 degrees and better, but directly vnder it, in the same plaine.
Also that the Sunne in Aries of the 8 sphears never is neerer to the Sunne in Aries of the 9 Spheare, then by the semidiamiter of the small circle, which is 9 degrees.
Now Mesline delivereth the difference of the judgements of the Astronomers, and that Ptolomy maketh the 8 and 9 Sphears all one, delivering the opinion of Prolomy and others, as followeth.
The opinion of Prolomie concerning the motions of the fixestarres, comparing the observations made 400 yeeres before him, with his owne: he finding therby that the fixed Starres had mooved in consequence 4 deg. therefore Prolomie all owed to the whole revolution of the fixed starres, to accomplish one period, according to the rate of 36000 yeeres, that was for every 100 yeeres, one deg.
Mesline delivereth also that the opinion of the Alfonfines, concerning our revolution, or accomplishing of one period of the 9 [Page 34]Spheere is in 49000 yéeres, but according to Copernicus his observations, one periodicall revolution is in 25816 yeeres, delivering that an houre of the longest day is 63 minut. 40 seconds, such as an houre of the shortest day is onely 60 min.
Copernicus maketh (likewise) the yeere 365 dayes, 5 houres, 49 min. 15 seconds, 46 thirds, which he calleth the yeere Tropicall, equally supputated, or counted to the middle Equinoctiall.
The Aifonsines in their account, wanteth in their yeerely period 13 thirds.
Mesline maketh the yeere 365 dayes, 6 houres, 9 minutes, 39 seconds, and this yeere he calleth syderiall or starry, numbred under the Spheere of the fixed Starres, which is more then the yeere delivered by Copernicus by 20 min. 23 seconds 14 thirds.
Delivering the causes of this difference to be this, making these beginning of the yéeres to be in one point of the 10 and 9 sphéeres and the 9 Sphéere (before the yeere end) being remooved Easterly from the 10 spheere, the yeere end comming to that point of the 12 Spheare againe, is to proceed from it to that point of the 9 sphere also before the yeere endeth.
Mesline delivereth (the Sunne being in the Apogeum part) that from middle motion to middle motion, the sun passeth 176 deg. 20 min. of the ecliptick: And the sun being in the Perigeum part from middle motion to middle motion, passeth 183 degr. 40 minutes of the ecliptick, which maketh a difference of 7 degr. 20 minutes.
But from the points of true motions, the halfes are equall, each 180 deg. of the Ecliptick: and the arch of time betweene the middle and middle motion of the Sunne in Apogeum part, is 182 dayes and 6 houres.
Also the Arch of time betweene the true motion and true motion of the Sun in the Perigeum part, is 179 dayes, which maketh the arch of time betweene the middle & the midle motion of the sunne in Apogeum; more then in Perigeum by three dayes and 6 houres.
Also maketh the arch of time, betweene the midle and true motion of the sunne in both the meane motions, to be 4 dayes, and the arch of time different from the true motion, to the true motion of the sunne in Apogeum, from the same points in his Perigeum to be 7 dayes and 6 houres.
And as for the rest of the Theoricks of the Sunne and Moone [Page 35]I have delivered sufficient in my delivery before, concerning the tides.
But to conclude, Stadius in his Ephemerides, folio 57, of the Equation of the naturall dayes, delivereth as followeth, concerning the time.
We have computed all the places of all the Planets, and also of the Sunne and Poone in this our Ephemerides, for the naturall dayes (to wit,) for the space, in the which the whole equator is turned about, and moreover 59 minutes and 8 seconds: but because the apparent, and true day now and then doth exceed this time, and now and then is lesse: to wit,
Partly when the Sunne goeth swifter, or flower, by reason of his Prosthopherisis.
Partly for that equall times of the Equator, in the diurnall coartation, or revolution, doe not answer to equall sagments, or parts of the Zodiack, it commeth to passe, that this inequality of time also needeth a prosthopherists, the which notwithstanding cannot be alwayes equall nor certaine.
For the conversion of the Circle of the Equator, though vnto the middle and equall Equinoctium, which is the yéere divided into foure equall parts, is evermore equally constant, yet neverthelesse, unto the apparant Equinoctium which are the true equinoctiis which the excentrick yeelds, is found not equall.
Neither doth the Sunnes Apogeum occupy a stable seat, because the Apogeum flecteth in the ecliptick every 13 yeeres 1 degree 27 minutes: moreover the Sunne in his excentricity doth some hurt by his shifting for the excentricity is more and lesse by a eleven semidiamiters of the Earth, as aforesaid, and goeth about with the ecliptick.
Wherefore also no limit can be appointed perpetually to this insquallity, but in this our Age all these causes conferred one with another, and added together, doe show that the greatest day and lesse day doe differ one from an other, one houre and 28 minutes, that is to say, 22 times (or Meridians) and 20 minutes of the Equator.
But seeing that this inequality of dayes cannot missever the rest of the motions, therefore it is necessary that we should admit them to be equall, vnto the which equall dayes, the Tables [Page 36]of the motions s [...]ould be both made and set together, the which course we have taken in this our Ephemerides, and for that cause we have borrowed the Canon of equation of dayes out of Erasmus Rheinholdus which agréeth neerest with our age, vntill the yéere 1600.
Therefore according as you find the number in that cannon to adde or substract: that is the time that the day is eyther longer or shorter, then the equall day, or the day of the Ephemerides, that is the first equated day, or day equated vpon the difference of 88 minutes, whereas the second equation is of dayes once equated, and now doth equate them vpon the difference of 44 minutes, whose halfe is 22 minutes, the greatest number within the cannon.
Séeing there is a first error concerning the time delvered, even in the motions of the Heavens, as aforesaid, therefore these running Glasses delivering but a second error: the reason is this: because they cannot be made without their imperfections, had need to be most carefully made, and by the precisest workman: that the time delivered by them, may be but according to the second error, for the delivery of the Longitude, by which running glasses, next hereafter nominated, the longitude is better delivered then by any other Instruments.
A glasse whose sand is mettall and the mettal said by some will not rust, notwithstanding in my opinion, it will rust somewhat, and be sometimes moyster, then at other times, likewise the hole that the sand runneth thorough, will grow wider with the force of the sand, the rather being violated by the surges of the sea: which impersections considered, the glasse must needs deliver the time, sometime shorter, and sometime longer, according to the weather, therefore a second error: yet this glasse is more tollerable then the rest for this delivery, and is to be vsed before all other, of which glasses there may be divers sorts, for the delivery of more and lesse at pleasure.
And because the running glasses with sand is more grosser, and that clockes and watches hath their more imperfections, then the former glasse, I will omit them, and leave the delivery of the time for this present.
Concerning the Windes according to Experience.
DIfferences or diversities of windes, I have séene at sea, in some calme day (in Summer time) among divers shipping, being of one fléete, so that some sixe of them or more, have all had contrary windes till the wind was setled.
Likewise in Summer time I have knowne in places of small distance, as at Hambrough, the winde at west south west, so much winds, that we have rid with our top-mast downe, and at Lee the very same time, the Ships then bound for Hambrough, had asmuch wind (by report) at east north east, but both those winds continued not long, and betwéene which windes no doubt it was calme for the time.
Also in Winter time, I have séene it often in being at sea, the wind being at South southeast, much wind and vpon a sudden the wind hath altered to the northwest, or north northwest, very much wind, and so alterations of winds I have likewise séene vpon other points of the Compasse.
And in sayling toward Head-lands, or in sayling about Headlands I have found the wind sometime too large vnto vs, and other times againe too scant vnto vs: Therefore the wind very difficult to delate vpon, my farther reason is this, because it is delivered in the Scriptures that the wind bloweth, but from whence it commeth or whether it goeth no man knoweth.
Yet notwithstanding, many times in Summer time, but especially in winter time, when growen stormie windes are setled, we may conjecture that they extend farre, and in my opinion (which opinion I hold for a truth) ye wind then bloweth in a great circle, therefore cannot be paralell to any great circle of that nature, my reason is this, because great Circles doth crosse themselves at opposite points, as in the demonstrature of the compasse is delivered.
Therefore this delivery confuteth the flat Cards, my reason is this, because the flat cardes delivereth the windes to blow in paralells, according to the lineament thereof.
Likewise by the Card the wind at East, and a Ship going west, eyther in the latitude 33 degrées, 35 minutes, and latitude 60 degrées, or in the north latitude 40 degr. 15 minut, or in what latitude else soever, it is said to lead in paralell, notwithstanding, [Page 38]the Card delivereth the going West to make right angles with the Meridians which is very absurd, and that the wind continuing, they shall goe west still asore the wind.
Concerning the Wind by Sphericail working. The 1 Example.
PResuppose a first place (which I will call our place of departure) in any one degrée of Longitude whatsoever, and in the North latitude of 33 degrées, 35 minutes, in which place the east and west of the Compasse, according to the demonstrature, is a Tangent vnto this paralell, and crosseth the equator at opposite points 90 degrées in longitude Eastward and westward, which east and west points in the Equinoctiall kéepe in mind.
I purpose from this first place (as aforesaid) to sayle to a second place according to the way of the west vpon the difference, which shall be in Longitude from the first place 90 degrées, which 90 degrées, in these paralells is 75 degrées of a great circle or little more: now in this second place which is at this present my place of being, I find my selfe delated from the paralell according to the difference, where I purpose to deliver the East and west (likewise) according to the demonstrature, being also a Tangent unto this paralell, and crosseth the Equator at opposite points according to the former, but 90 degrées different in longitude, which two demonstrated semicircles doe crosse each other in 24 degrées 15 minutes of Latitude, 46 degrées in longitude from the first place, and 44 degrees in longitude from the second place.
Now from my first place of departure, the second place doth beare according to the demonstrature of the Compasse, west northwest, and 5 degrees Northerly, vpon which point the two places are distant 73 degrees 15 minutes of a great circle, which is a neerer way then the way vpon the West according to the difference as aforesaid, by 1 degree 45 minutes.
And from my second place of being, the first place of departure doth beare according to the demonstrature of the Compasse East northeast, and 7 degrees northerly, vpon which point likewise the two places are distant 73 degrees 15 minutes.
So by this delivery having continued the Ships caping or course west from the first place of departure to the second place, [Page 39]I doe conclude that the wind being constant and stable in blowing from the first place to the second place, that at the second place the wind is altered of you two points and 7 degrées to the Northward, as aforesaid, though it were at East in the first place, which delivery in my judgement is the truth.
But if the wind being at the first place, be at East, and in sayling to the second place, be variable and alterable, as the East and west by the demonstrature is variable by crossing the equator according to the difference in Longitude, then you shall goe from the first place to the second place west as aforesaid (the wind being at east) right afore the wind, but this way in my judgement is impossible and not the truth.
A second Example.
Being in 60 degrées North latitude and in one Meridian of longitude, which is my first place, which hath his demonstrature of East and west accordingly, being a tangent vnto this paralell, and in crossing the equator at opposite points, after the manner in the first Example, from whence I sayle West accordingly to the difference to 90 degrées in longitude, which 90 degrées in longitude in these paralells is 45 degrées of a great circle, little more, which is my second place: in which second place I finde my selfe there to be delated from the paralell according to the difference, and in which second place likewise I purpose to deliver the east and west according to the former, but 90 degrées different in longitude; and these two demonstrated semicircles, doe crosse each other in 50 degrées of latitude 46 degrées 20 minutes in longitude from the first place, and 43 degrées, 40 minutes in longitude from the second place.
So that from my first place of departure, the second place doth beare (according to the demonstrature of the Compasse) Northwest and by west 5 degrées 20 minutes northerly, vpon which point the two places are distant 42 degrées 35 minutes of a great Circle, which is likewise a néerer way then the way of the west according to the difference, as aforesaid, 2 degr. 25 minutes.
And from the second place of being, the first place of departure, doth beare according to the demonstrature of the Compasse, northeast and by east and 8 deg. 20 minut. northerly, vpon which point the two places are also distant 42 deg, 35 minut. of a great circle.
[Page 40]So that by this delivery being at this second place, the wind is altered of me thrée points, and 8 degrées 20 minutes Northward, though it were at the East in the first place.
The 3 Example.
Being in 80 degrées 15 minutes North latitude and in one meridian of longitude, which is my first place, which hath his demonstrature of East and west accordingly, being a tangent vnto this paralell, and in crossing the equator at opposite points, after the manner in the first example, from whence I sayle west according to the difference to 90 degr. in longitude, which 90 degrées in longitude in these paralells, is 15 degrées of a great circle, little more which is my second place: in which second place I find my selfe there to be delated from the paralell, according to the difference.
And in which second place, I purpose to deliver also the East and west, according to the demonstrature, which likewise crosseth the equator at opposite points according to the former, but 90 degrées difference in longitude, and these two demonstrated semicircles doe crosse each other in 75 degrées, 45 minu. in latitude, 48 degrées in longitude from the first place, and 42 degrées in longitude from the second place.
So that from my first place of departure, the second place doth beare according to the demonstrature of the Compasse northwest and by west, and 8 degrees northerly: vpon which point the two places are distant 14 degrees of a great circle, which also is an neerer way then by the west as aforesaid by one degree.
And from my second place of being, the first place of departure doth beare according to the demonstrature of the Compasse north-East, one degree 20 minutes northerly, vpon which point the two places are distant 14 degrees of a great circle.
So that by this delivery being at the second place, the wind is altered of me 4 points and one degree 20 minutes to the northward, though it were at the East in the first place.
A thing worth the Noting.
In all the three examples, as aforesaid this thing worthy the noting might be delivered, yet I will deliver but one of them according to the second example in latitude 60 deg. in which second example or delivery, the intersection or crossing of these two semicircles of east & west according to the demonstrature from the first [Page 41]place of departure and second place, is in latitude 50 deg, which intersection is from the first place west, & from the second place east.
Yet being in this intersection, the first place beareth from it northeast by east, and 5 degrees, 38 minutes northerly, and distant 27 degrées 32 minutes of this great circle.
And the second place beareth from it northwest & by west, 1 degrée 40 minutes northerly, and distant 26 degrées, 20 min. of this great circle according to the demonstrature of the compasse: and thus much concerning the wind.
Concerning the way of a Ship or Shipping at Sea.
FIrst, there is to be vnderstood and likewise to be respected by him that hath the charge (whatsoever in navigation) that there is two lawfull and good navigable courses to be vsed at the Seas, and no more, eyther of which courses is very artificiall (the kéeping of them aright) & resteth in the good descretion of the said Master. being likewise artificiall, which of them he will use.
But if the said Master be not artificiall, but a man of great conceit, the manner or way of these courses be too deepe for his vnderstanding, and therefore he not worthy to take charge at all.
My reason is this, because all other courses whatsoever more then these two, are absurd, frivolous and false: the names of which two courses followeth.
First the course vpon the great Circle being the neerest way from place to place.
The first course is to sayle vpon a great Circle which is after this manner: being in any one latitude and longitude whatsoever, which is your first place, and doe purpose to sayle from thence vpon any Azimuths of demonstrature whatsoever, which are great circles, vntill you come to 90 degrees in longitude, which is vnto the Horizon of your first place, in which way you are to respect every day at noone your Latitude (if you may) and likewise your time as before, or hereafter shall be delivered. For the delivery of your longitude, you are likewise to respect your Sagments, being of what length soever vpon the Azimuths you sayle, how you are, (vpon any distance) to crosse the meridians and paralells: for if you finde your selfe in such a latitude, as you should be in, and not in the right longitude, which the Azimuths you should sayle vpon giveth, then are you also wide and to seeke [Page 42]reformation: also if you finde your selfe in such a longitude and not in the right latitude which your Azimuthes giveth, then are you also wide & to séeke reformation, therefore being a harder way or course to sayle vpon the great circle (notwithstanding this way the néerest way, or course from place to place of all other wayes) requiring alwayes reformation with great Judgement, I will onely deliver 6 examples from one meridian of longitude and latitude 51 deg. 32 min. vpon the demonstrature, northwest and by north, continuing it from the first place to the Horizon by Sagments of 15 deg. of a great Circle a péece, onely for a tast and your farther knowledge of this way and so will leave it, and hereafter will deliver the remainer of the second course or way, which is more easie, according to the difference, being the onely and naturall way indéed that the Compasse leadeth in.
The 1 Example.
Being in the Latitude and longitude, as aforesaid, 15 degrées of a great Circle from thence, according to the demonstrature of N. west and by north, crosseth the 18 deg. 30 minutes, or meridian in longitude westward from the first, and the paralell of north latitude 62 degrées 50 minutes.
The 2 Example.
Other 15 degrées which maketh 30 deg. from the first according to the demonstrature of northwest and by north, toucheth the meridian of 50 degr. in longitude westward from the first, and the paralell of north latitude 69 deg 28 min.
The 3 Example.
Other 15 degrées which maketh 45 degr. from the first according to the demonstrature, of Northwest and by north, toucheth the Meridian of 92 deg. 50 minutes in longitude westward from the first, and the paralell of North latitude 66 degrées, 45 minutes.
The 4 Example.
Other 15 degrees which maketh 60 degrees from the first, according to the demonstrature of Northwest and by north, toucheth the Meridian of 118 degrees in Longitude westward from the first, and the paralell of north latitude 57 degrees,
The 5 Example.
Other 15 degrees which maketh 75 degrees from the first, [Page 43]according to the demonstrature of N. west and by north, toucheth the Meridian of 130 deg. 32 min. in longitude westward from the first, and the paralell of north latitude 44 degrees 35 minutes.
The 6 Example.
The other or last 15 degrees, which maketh 90 degrees from the first, and is the Horizon thereof according to the demonstrature of the northwest and by north, toucheth the Meridian of 139 degrees, 15 minutes in longitude westward from the first, and the paralell of north latitude 31 degrees 10 minutes.
And as for the second course or way of the Compasse vpon the difference which we will rely vpon, I have delivered sufficiently thereof, as a foresaid, and for that which is also needfull besides concerning this way vpon the difference to be delivered, hereafter in good sort and order followeth
There is to be respected by a Master of a Ship, or the man that taketh charge in navigation, the goodnesse of the Compasse which he sayleth by, with the nutation thereof in any place if it be needfull, otherwise it will cause the way of a Ship to be in an Azimuth contrary to his expectation, which will cause an error.
And for the vnderstanding of this nutation what it is, in any place may be delivered by a man of good conceit, as followeth, having a Topographicall instrument or otherwise called a Theodolite of brasse, perfectly made, and the Needle good, being well touched with an excellent Stone, and handled for the purpose, delivereth the nutation very well: but if the sea-gate be so great that this Instrument cannot deliver it certain, then will no Instrument (set forth for this purpose) deliver it neither, then must you worke thus, the height of the Sunne in the Meridian at Noone observed by the Compasse, the Compasse it selfe, then delivereth the nutation from Noone, but rather thus: the latitude at Noone knowne, then vpon any observation of the Sunne by the Compasse on any elevation about 3. a clock in the afternoone, the declination respected, the Compasse delivereth the nutation more truer, my reason is this: because the descention of the Sunne in his diurnall Arch at this time in the afternoone is more swifter towards the Horizon, then it is, the Sunne being néere the Meridian.
Also that the said Master have with him of the best running Glasses that can be made, as aforesaid, to deliver the time vnto him, [Page 44]as certaine as may be, which must be regarded as a principall thing, the coarting of the Meridians respected, for the delivery of the Longitude in any place, by which way the longitude is delivered after the best manner, the latitude being knowne, otherwise, the time not respected or regarded, the longitude will be delivered with the more error.
Likewise the Azimuth of the way must be delivered or set downe according to the difference, and not otherwise, and not above 20 leagues the Sagment: for the snorter the Segments be the truer the reckoning, which Azimuths of way vpon the differance, delivereth the longitude also in reasonable sort the latitude being knowne, yet in this way is more absurditie, then in the former way for the delivery of the longitude.
Moreover there is to be respected by him that hath the charge in navigation, the violence of winds, Sea-gates, Tide-gates, surrents, Edies or whatsoever else, that may eyther be helping of the ship in her way, or a hinderance of her way, which causeth an Azimuth of way, contrary to expectation, which not regarded, bringeth also an error.
And for the observing of Latitudes at the Seas, it had néed to be very precisely done, having a large Quadrant of brasse with a mooveable perpendiculer accordingly, delivereth it in the best sort: for in observing with Crosse, staves there is error, my reason is this, the staffe not lawfully projected to the great circle, delivereth error: my further reason also is this in observing with the staffe, the eye is faine to behold and note two things at once, which is the center of the Sunne, and the Horizon, which is not possible to be done truely.
And in a Sea-gate it can neither be precisely delivered by an Astrolabe, therefore the Quadrant best for this purpose: for in observing therewith, there is but onely the center of the Sun, to be respected. Also there must be great care had by him that hath the charge in navigation, vnto the Steeridge of the ship that it be greatly respected of him, and of these principall men which goeth in the ship with him. which he doth appoint for this purpose, because the man at the Steridge may be negligent, and by some men that may be at the Steridge, as I have séene my selfe er [...] now, a 3 or 4 points of eyther side of the course, commanded to be kept, [Page 45]breaketh no square with him, which had or contrary Steridge to expectation, not counted of or noted, causeth a foule error.
And whereas there are infinite sorts of shipping, for bignesse, length, and draft, so they are as different in qualities, wherefore I will deliver as many qualities concerning all sorts of Shipping, as at this present I can remember, leaving the consideration of the rest, (not now remembred of mée, vnto him that hath the charge for the present) with those nominated according as he shall finde the Ships quality to be which he goeth in, the qualities as followeth.
Of Shipping there are divers sorts which have divers qualities the reason is this, because they are different in bignesse and mould, and may be mistrived. To procéed, some of them are long, and some short, some of them flottie, and other some of great charge, or draft, some have a desire or cast to Portward, and some other to starbord, some of them good to sayle (try) weather about without sayles or hull, & other some qualited to the contrary, some are desirous to have there stayes and shrowds slacked, and some to have them set tought, some Ships desire to be trimmed a head, some a sterne, and some others of an even kéele, some stéereth hard every way, and other some easie of stéeridge any way: some Ships being in a sea-gate will stay, or wend to windward, and other some cannot, but must wend afore the wind, which is a great losse of way, long and short shipping being flotty, are laborsome in a seagate, but long or short being déepe Shipping, is easie at Sea, some are fast Ships vpon a wind, and some others are léeward, some are good Ships of asayle quarter winds, and some not so good: some are good a fore the wind, and some others to the contrary, some Ships are stiffe sided which is a principall quality, and some other are tender sided, which is a bad quality, some Ships are of advantage most wayes, and other some are to the contrary.
Therefore the quality of a Ship is greatly to be regarded of him that hath the charge, for a Ship of advantage or disadvantage, causeth an Azimuth of way contrary to expectation, which not being respected causeth an error.
Now for your diurnall by some called a Travers booke, or booke wherein you kéepe reckoning of the Ships way at the Seas, in [Page 46]my conceit and as I doe use, is in manner as followeth.
In the head or beginning of which Booke, set downe the Title thereof, with the Moneth, day, and date of our Lord, at the time of your beginning to enter into your navigation: after which being set downe, devide the leafe and so the rest of the leaves vp & down into 10 spaces or columes, and set downe in every colume as followeth.
IN the first colume of which Booke, set downe the Months and Dayes, according to the sequell of them as the time spendeth.
In the second colume, set downe the Houres of time spent in sayling upon the Azimuths used.
In the third colume, set downe the Azimuth of the wind, or that wind for the time it was in.
In the 4 colume, set downe the Course which you have kept, that is the course on the true Azimuth, according to the difference.
In the 5 colume, set downe the quantity of Leagues runne vpon the Azimuth as aforesaid.
In the 6 colume, set downe the degrées of the Pole elevated.
In the 7 col. also the min. if there be any, of the Pole elevated.
In the 8 colume, set downe the degrées of Longitude delivered by the time and Latitude as aforesaid.
In the 9 colume, also the minutes (if there be any) of the Longitude so delivered.
In the 10 colume, set downe your Discourse of things, according as you find occasion.
And to Conclude.
Every of which inconveniences, or rather good knowledge and vnderstanding as aforesaid, being thus noted, knowne and regarded by him that hath the charge, he shall deliver in his Navigations the Ships way he goeth in with all advantages, who is worthy to be trusted with any charge, and to receive great commendations.
But to the contrary, he that hath the charge, not respecting these things, as aforesaid, he delivereth the Ships way with all nvsurdities and error, and to speake the truth, he is not worthy to take charge at all, but to have an inferiour place, which he is more fitter for: and thus will I leave delating of the way of Shipping at Sea.
AN APPENDIX, OR A necessary Discourse (concerning the Helisphericall lyne that a Ship describeth upon the Superficies of the Sea, being directed by the Magneticall Needle or Compasse.) Betweene Mr. Geograph, and Mr. Nautae Enterloquitors.
WEll met, Mr. Geograph?
Mr. Nautae and so are you also well met, I have much desired a long while to have some discourse with you.
With me Sir, about what I pray you?
About that which I suppose you are well séene in, I meane the way of a Ship upon the Superficies of the Sea, being guided by the Magneticall Needle or Compasse?
Sir, I am very willing to entertaine your motion, and at this present to discourse with you, there are diversities of opinions, concerning the way, motion or mooving of a Ship vpon the Superficies of the Sea, which way, motion, or mooving of a Ship is two-fold, principally in Sayling. That is first spirall, alias Helisphericall, or else secondly if is vnder a great Circle, the spirall or Helisphericall way is produced by the Ships continuall kéeping of one course, the foure Cardinall points excepted.
But in the way of sayling vnder a great Circle, the course is alwayes alterable.
[Page 48]And whereas the most part of Sea-men will thinks that the demonstration which is delivered by the common plaine Sea-chart (because it is eastest done) is of all other the most exquisite for the truth thereof; Yet is the same indéed, [...]ld with many grosse errours, so that such men must and are often times of necessity greatly deceived of their expectation.
Therefore for the better vnderstanding of those that are Practitioners in the Art of Navigation, we will in this discourse make relation both of the spirall way of a Ship, in kéeping alwayes one course, with the Solution of such doubts, and answering such allegations and objections as may arise thorough want of judgement therein; as also of sayling vnder a great Circle with the various and changeable position thereof; let me therefore heare your opinion concerning the Rudiments and grounds thereof.
First, it is necessary for all Practitioners of Navigation to know, that the Earth and Water together doe make a round or Sphericall body being enclosed with one converity or superficies, and that the earth and the waters are not plaine or flat formed, but like vnto a round Spheare or Globe, it may thereby easily be vnderstood, that the courses extended from place to place, cannot be truely described with right lynes, especially in a sarre distance, because they are Segments of great Circles and are circularly extended, from one place to another.
Hence it followes, that the superficies of the Sea being Sphericall not plaine or flat formed, that a Ship departing from any assigned place betwéene the Equator and either of the Poles, by any one Rhombe or point of the Marriner & Compasse, the Meridian onely excepted, I say that in kéeping one and the same course she maketh her way neither in streight lyns, great Circle or lesser Circle, but in a spirall lyne composed of Segments of great Circles, and returning by the opposite of that Rhombe or point towards the place of her departure, she shall make her way in another spirall lyne, by reason whereof she cannot according to that course fall with the place of her departure.
That the course or way of a Ship is Spirall yet concentrick to the center of the Earth, and therefore in Segments of [Page 49]great Circles, when it is continued by any one Rhombe or point of the Compasse (the East and West, North and South, onely excepted, and that when the Compasse hath no variation) is vndoubtedly true.
But whereas you say, that in returning to the place of her departure by the opposite point or Rhombe she sayled out, she shall not fall with the place of her departure, (no current nor any such thing to hinder her) you erre very much, yet I would willingly heare by what reason you can proove your opinion.
If you will grant that a Ship maketh her way in Segments of great Circles, then know héereby that all great circles doe in every severall Latitude make severall Angles with the Meridian, also those circles that doe in severall Latitudes make like Angles with the Meridian, have their severall declinations or greatest distance from the Equator.
And by reason of these varieties both in Angles and declinations, or greatest distances from the Equinoctiall, there must also be a variety in the courses made by opposite Angles, and yet both spirall.
For being vnder the Equinoctiall, an Azimuth of Northeast toucheth the Hortzon in Latitude 45 deg. 0 min. North Latitude, 90 deg. distant from the place of being under the Eqinoctiall; Then comming to the second place in Latitude 45 deg. 0 min. North Latitude, and intending to returne to the first place vnder the Equinoctiall by the opposite point of Northeast, which is Southwest 45 deg. 0 min. from the Meridian, that great circle or Azimuth intersecteth or cutteth the Equator at néere 54 deg. 45 min, which distance is lesse (to returne to the Equator by the opposite point) by 35 deg. 15 min. and is short of the place of departure; also being vnder the Equinoctiall the Northeast, Southeast, and Southwest Azimuths doe require 1 deg. 24 min. 51 seconds 24 thirds to raise one degrée of Latitude.
But being in a paralell 60 deg. 0 min. North, the Northeast and Northwest require 1 deg. 26 min. 13 seconds 3 thirds of distance to raise one degrée of Latitude.
And in the same paralell of 60 deg. 0 min. the Southeast and Southwest, require no more but 1 deg. 23 min. 32 seconds 53 [Page 50]thirds, for one degrée of the Poles depression. Hereby it appeareth that the Segments of Northeast and Northwest, are greater to raise one degrée, then the Segments of Southeast and Southwest to depresse one degrée, by 0 deg. 2 min. 35 second 10 thirds.
Moreover the greater Segments which doe raise the Pole one degrée in that Latitude, excéed these vnder the Equinoctiall by 0 deg. 1 min. 21 seconds 39 thirds, and the lesser Segments which depresse the Pole, are lesse then those of the Equinoctiall by 0 deg. 1 min, 13 seconds 3 thirds, which might serve for sufficient satisfaction that the way outward and homeward are not alike, againe for your better vnderstanding, you may note, that being at the Equinoctiall, a Segment of a great circle of 20 leagues, which maketh with the Meridian an Angle of 45 deg. 0 min. doth raise the Pole and differ the Longitude néere 0 deg. 42 min. 25 seconds 3 thirds.
And in paralell 60 deg. 0 min. North Latitude, a Segment of 20 leagues Southeast or Southwest depresseth the Pole 0 deg. 42 min. 58 seconds 8 thirds, and differs the Longitude néere 1 deg. 23 min. 4 seconds 6 thirds, and in the same paralell of 60 deg. 0 min. the like segment of 20 leagues distance Northeast or Northwest elevateth the Pole 0 deg. 41 min. 57 seconds 40 thirds, whereby it plainly appeare [...], that if the way of a Ship be composed of Segments of great Circles, the way outward and homeward being made by opposite Angles are not alike, yet both Spirall.
Therefore a Ship making her way by any one Rhombe or point the Meridian onely excepted, and returning by the opposite point thereof, cannot by course fall with the place of her departure.
And further it must be considered that the greater Latitude is, and the greater the Angle of the course is in respect of the Meridian, the greater is the variety, and the East and West are most variable, moreover in North Latitude, if the course be betwéene the South and the East or West, then the way homeward returning by the opposite to the Meridian of the place of departure shall be shorter then the way outwards, and falleth into a lesser Latitude according to the course, distance, and declination from the Equinoctiall, but if the course be betweene the North and the East, and the North and the West, then in returning by the opposite, to the Meridian of the place departure, the way homewards [Page 51]shall be longer then the way outwards, falling likewise into a lesser Latitude, according to the course, distance, and the declination from the Equinoctiall.
If the Spirall or Helisphericall way of a Ship vpon the Superficies of the Sea, being composed of Segments of great Circles, had also those Segments limited or honded to containe 20 or 30 leagues a péece, then should all your former allegations be true, but those Segments in regard of their smalnesse cannot be sensibly distinguished, neither can it be certainly said, that a Ship in kéeping alwayes one course, continueth vnder one great circle 1 league or 1 mile; for when the course is alwaies continued according to any one point of the Compasse, it maketh an oblique Angle with the Meridian, and then so often as the Ship changeth her Zenith, so often shée changeth likewise the great Circle shée maketh her way in, that is to say, so many Zeniths as shée passeth vnder, so many great Circles shée maketh her way in, and each of those Circles make severall Angles with the Equinoctiall, and the greater the Latitudes are the greater are the Angles, for in the Latitude of 59 deg. 30 min. the verticall circle of Southwest and Northeast maketh an Angle of 68 deg. 58 min. with the Equator, and in Latitude 60 deg 0 min. the Azimuth of Southwest and Northeast maketh an Angle of 69 deg. 18 min. with the Equinoctiall. Also in paralell 60 deg. 30 min. the Southwest and Northeast Azimuthes make an Angle of 69 deg. 37 min. with the Equator, and in the Latitude of 68 deg. 58 min. it makes an Angle of 69 deg. 18 min. and in the Latitude of 69 deg 37 min. the foresaid great circles make right Angles with the Meridian, and are circles of West and East, yet notwithstanding the variable Angles that these great circles make with the Equinoctiall, and the contrary Angles, that every great circle maketh with every new Meridian. I say that in regard those Segments that a Ship maketh her way in are so small and insensible, shée shall in kéeping one course outwards, produce a spirall or Helisphericall line, and returning by the opposite point thereof thée shall againe passe vnder all those Zenithes, that shee did in her may outward and in like Segments, and shall by the same lyne of inclination, fall again with the place of her departure.
[Page 52]But when a Ship maketh an East or West way the lyne of her Caping maketh alwayes right Angles with the Meridian, then shall those great Circles of whose Segments the Ships way is composed make like Angles with the Equator, that is to say equall to the Latitude, and the Ship shall according to that course runne a paralell to the Equinoctiall.
Mée thinkes that is strange that you will allow the East and West way of a Ship being made in Segments of great Circles to entersect the Equator at East and West, by reason whereof they are Touch-lines to the paralell of Latitude, and yet you will not allow or grant the East and West to make a spirall way as well as the rest.
For how is it possible that the lyne of Inclination or way of a Ship being composed of Segments of great Circles, and those Touch-lines to the paralell of Latitude, so that the Ships Caping is quite contrary to the paralell, and maketh oblique Angles therewith, and that especially in great Latitudes, how then is it possible that the East and West should lead in a paralell or produce a lesser Circle or any part thereof.
Take a small Compasse slye, and fasten it to a threed that may passe thorow the North and South points thereof, and make a noose in the end of the threed and put it vpon the Axis of the Globe at the Pole, then carrying the fly with the thréed about the body of the Globe, and you shall sée the center of the fly describeth a paralell to the Equinoctiall, and yet the East and West of the fly alwayes respecteth the Equinoctiall at 90 degrées 0 minut. of distance.
And so would a Ship if shée had a haser or some thing else fast about the Pole to attract her thereunto.
But by the Globe thus doe fasten the quadrant of Altitude to the Equinoctiall in the brasse Meridian, and bring the beginning of the degrées of the quadrant to paralell 60 deg. 0 min. and then from that point where the beginning of the degrées of the quadrant do touch in paralell 60 deg. 0 min. along by the edge of the quadrant to the Equinoctiall is the lyne of East and West, [Page 53]now with the point of an néedle or some such thing prick of by the edge of the quadrant 1 deg 0 min. and make a marke there, then moove [...]lobe vntill the beginning of the degrees of the quadrant doe fit with that marke, and then as before prick of againe 1 deg. 0 min, by the edge of the quadrant, and so proceed by 1 deg. 0 min. vntill you have gone round about the Globe, and that the point of the Néedle fall in the first Meridian where you began, and you shall find the lyne of the Inclination to be dilated from Latitude 60 deg. 0 min. about 2 deg. 20 min. and for further proofe hereof suppose your selfe to be vnder the Equinoctiall, and the Compasse to have no variation, and the Ship to cape East or West, also the Maine-mast to stand vpright in the steppe, the head thereof pointing to the Zenith, and the heele to the Nadir or rather to the center of the earth, and the mid-ship beame making right Angles with the mast to be paralell to the Axis of the world, I say, that this Ship proceeding East or West in this manner maketh her way in a great Circle to wit in the Equinoctiall, and returning by the opposite point thereof shall againe fall with the place of her departure.
Now I say by the same reason, that if the said Ship being in any Latitude between the Equator and either of the Poles, in Caping East or West, her mid-ship beame shall then be a paralell to the plane of the Horizon, and also to the Axis of that great Circle or Circles which in her proceeding lyne of Inclination she maketh her way in; the head of the maine-Mast pointing to the Zenith, and the heele to the Nadir, and the lyne of her Caping maketh contrary Angles with every new paralell. Now if a Ship in sayling vnder one Circle must have her mid-ship beame alwayes paralell to the Axis of that great Circle shee maketh her way in, then in keeping directly vnder one paralell, her mid-ship beame must be alwayes paralell to the Axis of the world, for that is the Axis of every paralell, and so likewise the maine-must being rectified perpendicularly in manner as aforesaid, must be also a paralell to the Equinoctials diameter, and make an Angle with the Horizon equall to the Latitude, the head thereof not respecting the Zenith, nor the heele the Nadir nor the Center of the earth, but the Center of the paralell of her Latitude, and in this manner a Ship may runne in a paralell to the Equinoctiall.
[Page 54]But now this may stand with humane reason, I leave to your further construction.
Here in you are notably deceived as it shall presently at large be made plaine and evident, for whereas you say that the way of a Ship, cannot describe a paralell to the Equinoctiall except her mid-ship beame be paralell to the Axis of the world, I say that so long as the mid-ship-beame remaineth due North and South, that is to say paralell to the Meridians Diameter in the plane of the Horizon, although the head of the maine-Mast (it being perpendicularly erected) point to the Zenith, and the héele to the Nadir, so long I say, her way shall describe a paralell to the Equinoctiall, but as I said before you séeme by all your former allegations to proove, that the way of a Ship; being composed of Segments of great Circles should have those Segments limited or terminated to containe 15, 20, or 30 leagues a péece, which if it were so, then should it be altogether according to your saying.
But now far as much as there is some difficulty in the premises and few Mariners know how to censure thereof, I will therefore briefly proove by Arithmeticall calculation, the East and West in any Latitude to lead in a paralell as well as the Equinoctiall.
Example.
The paralell of 60 deg. 0 min. is equall to the length of halfe the Equinoctiall or 180 deg. 0 min. of a great Circle; we will therefore in the same make our beginning, and from the first place being scituate therein, produce 18 Segments which containe 10 deg. 0 min. a péece, which by Arithemeticall calculation may be thus found out.
The Theorem. viz.
AS the Radius is to the sine of the Latitude 60 deg 0 min. so is the sine of the Complement of the distance the sine of 80 deg. 0 min. to the sine of the Latitude of that place where the first Segment of 10 deg. 0 min. endeth, and so againe in like manner for the second Segment.
viz. As the Radius is to the sine of the Latitude where the first Segment endeth, so is the sine of the Complement of 10 deg. 0 min. to the sine of the Latitude where the second Segment endeth, [Page 55]and this is to be continued 18 times, so shall you find the last worke to bring forth the sine of 41 deg. 06 min. but if you worke by Logarithme sines, multiply the Legarithme sine of 80 deg. 0 min. (the Complement of 10 deg. 0 min.) by 18, because there are 18 Segments, and the product adde to the Logarithme sine of 60 deg. 0 min. the Latitude given, the summe will be the Logarithme sine of 41 deg. 06 min. the Latitude of the 18 Segment, which dilateth from Latitude 60 deg. 0 min. the sum of 19 deg. 0 min. wanting but 0 deg. 06 min.
From whence we may sée, that if great Segments haue such great alterations, then lesser Segments must have their correspondent varieties proportionall vnto them, but marke what followes, and I make no doubt but that anon you will be of another opinion then formerly you have bin concerning this matter, as from the aforesaid paralel 60 deg. 0 min. let there be produced 36 Segments according as was afore shewed, each Segment containing 5 deg. 0 min. or 100 leagues a peece, and you shall find the end of the last Segment to fall in Latitude 49 deg. 41 min. which is dilated from paralell 60 deg. 0 min. but 10 deg. 59 min. where note that this dilatation is lesse then the former by 7 deg. 55 min.
In like manner, in the same paralell 60 deg. 0 min. let there be produced 180 Segments of 1 deg. 0 min. or 20 leagues apèece, and you shall find the end of the last Segment to fall in Latitude 57 deg. 25 min. which is dilated but 2 deg 35 min. from paralell 60 deg. 0 min.
Againe, let 10800 Segments be produced in the same paralell of 60 deg 0 min. of 0 deg. 1 min. one minute apeece due East or West and working according to the former manner, the last Segment will end in 59 deg. 57 min. ½. which dilateth from paralell 60 deg. 0 min. but 2½. minutes, wherefore the consideration hereof may serve for a sufficient satisfaction plainely to proove that the East and West directed by the magneticall Needle or Compasse doth lead in a Magneticall paralell, for as great Segments have their great varieties. and lesser Segments have their lesser alterations correspondent vnto them so by the same reason insensible Segments must have insensible differences and the like reason holdeth for any other point of the Compasse as well as for the East or West as I have formerly shewed you, and at our next [Page 56]meeting I will set you downe or shew you the Theorems for operating of it.
But you will say, here is in 10800 minutes a difference of 2½. minutes, and Segments of minutes in a mans judgement are so small that a Ship cannot make her way in lesser Segments and yet these Segments are not voyd of a sensible difference, I answer as before, that neither in sayling East or West, nor in the spirall or Melisphericall way by any other course or point of the Compasse, a Ships continuance vnder a great Circle or Circles cannot be terminated, and whereas 10800 minutes doe in the East or West from Latitude 60 deg. 0 min. produce a difference of 2½ minutes, I say inrespect of [...]0 great a distance, the difference is insousible.
But if you please to take so much paines for the former paralell of 60 deg. 0 min. to make a tryall from second to second, that is [...] 648000 Segments be produced East or West each Segment to containe one second and the end of the last Segment shall not be from the first place, so much as one second, and thus having prooved sufficiently that the East and West being directed by the magneticall Needle or Compasse, doth lead in a magneticall paralell, and also that in keeping one course the Ships way is spirall or Helisphericall, and returning by the opposite point thereof, the Ship shall againe fall with the place of her departure, we will finish this discourse, and speake of some principall rules which of all sea-men and Marriners ought to be knowne.
What is the first and most usefull Proposition in the Pariners practise to be taken notice of.
By the course and both Latitudes to find the difference of Longitude and the distance.
For what reason is that proposition is sayling the primary and most usefull.
Because the course is commonly given, and the Latitudes may be knowne by observation, but the distance and the difference of Longitude by sayling may be supposed but not certainly knowne without the helpe of the former, and so likewise the distance in sayling East or West may be supposed, but not certainly knowne.
I pray you Sir, let vs then procéed, [...] the practise without any further circumstance, that having both Latitudes and the course we may [...]nde the difference of Longitude and the distance
We will Sir.
Suppose a ship to be in Latitude 50 deg. 0 min. North Latitude sayles South South-west ½ point West, vntill she be in the Latitude of 47 deg. 0 min. I demand the difference of Longitude and the distance the Ship hath runne.
The Theorem.
AS a meane proportionall betwéene the fines of the Complements of both Latitudes is to the Tangent of the course, so is the difference of Latitude to the difference of Longitude, which by the Logarithmes is thus.
Adde the Logarithme tangent of the course 28 deg. 7 min. to [...] Logarithme of the difference of Latitude 60 leagues, and from that summe subtract halfe the sine Complement of 50 deg. 0 min. which is halfe the sine of 40 deg. 0 min. and halfe the sine Complement of 47 deg. 0 min. which is halfe the sine of 43 deg. 0 min. added together, (I meane Logarithme sines) and the remainer shall be the Logarithme of the difference of Longitude.
What is the second most usefull proposition that a Marriner in his practice is to take notice of.
By both Latitudes and the departure from the Meridian to find the difference of Longitude the course and the distance.
Wherefore doe you account this to be the second most usefull proposition in the Marriners practice.
Because all Marriners that kéepe their account by difference of Latitude and difference of Longitude (which onely is the true way) after that they have ca [...] vp their Traverse by difference of Latitude and departure from the Meridian, doe find their difference of Longitude as well as their course and their distance from their first place, where they began their Traverse this way.
I pray you Sir, set me downe the Theorems for the operating of this.
I will Sir, which are these following.
1 As the summe of halfe the Logarithme sines of the Complements of both Latitudes is to the departure from the Meridian, so is the Radius to the difference of Longitude.
[Page 58] 2 As the difference of Latitude is to the departure from the Meridian, so is the Radius to the Tangent of the course.
3 As the sine of the Complement of the course is to the Radius, so is the difference of Latitude to the distance that the ship hath runne from the first place where she began her Traverse.
What is the third, and as I remember you said the last usefull peoposition to be taken notice of in the Mariners practice.
By having given the Latitudes of two places and their difference of Longitude to find the magneticall course or Rhomb, and the distance.
How can this be usefull for a Mariner in his practise.
Because many times it chanceth that a Marriner is to sayle from one port whose Latitude and Longitude he hath in Geographicall tables (as in Mr. Hughes his use of the Globes or in the Tables of the Sea-mans Kalender) and is to sayle so another port, whose Latitude and Longitude he hath also in the said Tables, and by this proposition be may examine the truth of his Sea-chart he sayles by.
Set me downe the Theorems for this proposition, and I will trouble you no further at this time.
Sir, I am in some hast because the time is farther spent then I supposed since we met, but I will performe your request, and then I will take my leave of you for this time.
First, as the difference of Latitude is to the difference of Longitude, so is halfe the sines Complements of both Latitudes (I meane of the Logarithme sines) to the Tangent of the course.
Secondly as before, as the sine Complement of the course is to Radius, so is the difference of Latitude to the distance runne.
Master Nautae, I thanke you very kindly for your company, and your conference, you have informed my judgment very much in the matter of Navigation,
Sir, I am very joyfull of it, fare you well.