What
is the Sphere ?
- The Sphere is a solid body contained under
one surface, in the middle whereof there is a point or prick, which is the
center of the Sphere, from whence all right lines drawn to the circumference,
are equal the one to the other, whereby it is to be understood that the
center of the sphere is evenly placed in his midst, as that it hath like
distance from all parts of the circumference. And for as much as the Sphere
is an Instrument demonstrating unto us the universal Engine of the world,
we must therefore understand the Center to be this Terrestial Globe wherein
we have our being, which compared to the Celestial Globe or heavenly Circumference
doth here proportion, as the Center to his Circle: which earthly Globe by
the Divine mighty workmanship of God, doth admirably hang upon his center,
being of equal distance from all parts of the Circumference.
What are the distinctions
of the Sphere ?
- The Sphere is distinguished by the ten
Circles, whereof 6 are great Circles, and 4 are lesser circles: whereof
there are only 8 described upon the body of the Globe, limiting the Zones
and motion of the Planets, as the Equinoctial, the Ecliptick, the Equinoctial
Colure, the Solsticial Colure, the Tropick of Cancer, the Tropick of Capricorn,
the Artick Polar Circle, and the Antartick Polar circle. The Horizon and
Meridian are not described upon the body of the Globe, but artificially
annered therunto, for the better perfection of his use.
Which are the greater
Circles, and which the lesser ?
- The Equator, the Ecliptick, the 2 Colures,
the Meridian and the Horizon, are great Circles, because they divide the
Sphere into 2 equal parts. The 2 Tropicks, the Polar circles are lesser
circles, because they devide the Sphere into two unequal parts.
Which is the Equator,
or Equinoctial ?
- The Equinoctical is a great Circle dividing
the Sphere into two equal parts, leaving the one half towards the North,
and the other half towards the South, and equally distant from the Poles
of the world 90 degrees, placed evenly between them, and described upon
them, this lines crosseth the horizon in the true points of E. & W.
& hath always the one half above the Horizon, unless it be under either
of the poles, for there the equator is in the horizon: it crosseth the Meridian
at right sphere angles, & it also crosseth the ecliptick line in the
1 min. of Aries & Libra, dividing the ecliptick & horizon, &
is also by them divided into two equal parts: this line is also divided
into 360 equal parts or deg. which are the degrees of longitude beginning
the account in the point of Aries, reckoning towards the East, concluding
the number 360 in the place where the first account began, viz. where the
equator both intersect the ecliptick in the 1 minute of Aries, under which
meridian S.Mihels one of the Isles of the Assores to be placed in the Geographical
description of the terrestrial Globe.
What is the use of
the Equator ?
- The Use of the Equinoctical, is to know
the declination of the Sun, Moon, & Stars, whereby the latitude of place
is given for that portion of the Meridian which is contained between the
equator & the center of the Sun, Moon, or Stars, is their declination:
- Also by the Equinoctical is known the longitude
of places, for a quarter of a great circle being drawn from the pole, to
the place whose longitude is desired, & so continued to the Equinoctical,
that deg. and min.in which the quarter circle both touch the equator is
the longitude of the place, or if you bring any place (that is desided upon
the globe, whose longit. you would know under the meridian of the globe,
that deg. of the equinoctical that is then likewise directed under the meridian,
is the longitude desired:
- when the sun commeth upon the equator,
then the days & nights are of one length throughout the whole world,
& then the sun riseth upon the true point of E. & setteth upon the
true point of the W. & not else at any time:
- this circle being fixed in the firmament
is moved with the first mover in every hour 15 deg. by which account in
24 hours his motion is performed.
- And there note, that the deg. of the Equinoctical
have a double application, the one to time, & the other to measure:
in respect of time 15 deg. make an hour, so that every deg. containeth but
4 min. of time, but when his deg. have relation to measure, then every deg.
containeth 60 min. - being 20 leag. - of that every min. standeth for a
mile after our English account.
- But this allowance of 20 leag. to every
deg. of the equinoctical, in sayling or measuring of distances upon the
E. & W. corses is only when you are under the same, because the equinoctical
being a parallel, is likewise a great circle, & every deg. of a great
circle is truly accounted for 20 leag. or 60 miles.
- But in the rest of the parallels where
either of the poles are elevated above the horizon, if there you sayl or
measure upon the courses of E.or W. there are not 20 leag.to be allowed
to every deg. because such parallels are lesser circles, therefore they
have the fewer number of leag. to every deg. so that the farther you depart
from the equator, the lesser are the parallels, & the lesser any parallel
is, the lesser are his deg. because every circle containeth 360 deg. &
as the circles & deg. diminished by their quantity in like sort the
distance answerable to such degrees must abate, as their circles do decrease,
& further know, that the equator, is the beginning of all terrestrial
latitude, & destination of the celestial bodies.
What is the Ecliptick
?
- The Ecliptic line is a great circle, dividing
the sphere into 2 equal parts, by crossing the equator, in oblique sort
dividing him, & being divided by him into 2 equal parts, bending from
the equator towdards the N. & S. 23 deg. & 28 min. being in the
1st min. of Cancer & Capricorn, there determining the tropical limits,
this line likewise divideth the zodiack, by longit. into 12 equal parts,
& is divided together with the Zodiack into 12 equal portions, called
signs, & every of these signs is divided upon the ecliptick, into 30
equal parts or deg. so that this line is divided into 360 deg. upon which
line the center of the sun doth continually move:
- this circle is described upon his proper
poles, namely the pole of the zodiac, being in all his parts 90 deg. from
either of them:The zodiac is a circle contrary to all, for they are mathematical
lines, consisting only of length, without breadth or thickness: but the
zodiac hath latitude or breadth 12 deg. whose limits are 6 deg. or either
side of the ecliptick, wherein the sun, moon,& planets perform their
motions & revolutions,the center of the sun only keeping upon the ecliptick,
but the other planets have some time N.lat. & sometime S.lat.
- And here you must understand,that the lat.
of the planets or stars,is that portion of the eliptical meridian which
is contained between the center of the planet or star,& the ecliptick
line & their longit.is that portion of the line ecliptic, which is contained
between the said meridian & the ecliptical meridian that passeth by
the poles of the zodiac,& the first min. of Aries.
- The 12 divisions or signs of the zodiac
are these, Aries \/, Taurus Ta, Gemini ii, Cancer Cn, Leo Le, Virgo mx,
Libra Li, Scorpio Sc, Sagittari ^, Capricorn Cp, Aquarius Aq, Pisces )-(:
& these are their characters that stand by them.
- The 7 Planets that keep within the limit
of the Zodiac, are these, Saturn St, Jupiter Jp, Mars Mr, Sol Sn, Venus
Vn, Mercury Hg, Luna D. St performs his course through all the deg. of the
zodiac once in every 30 years: Jp in 12 years: Mr in 2 years: Sn in 365
days & 6 hours, being one year: Vn & Hg as Sn: & D performeth
her course in 29 days & 8 hours 44mins, through all the deg. of the
zodiac.
- And note that this natural motion of the
planets of the zodiac is from the W. toward the E. the diurnal motion is
violent, caused by the first mover, or primum mobile, who in every 24 h.
doth perform his circular motion from the E. to the W. carrying with him
all other inferior bodies whatsoever.
What is the use of
the Zodiac ?
- By the Zodiac & Ecliptic is known the
longit.& latit. of any celestial body, either planets or fixed stars,
for a quarter of a great circle drawn from the pole of the zodiac to the
center of any planet or star,& so continued until it touch he ecliptick,
that deg.& min. where the said quarter-circle toucheth the ecliptick,
is the longit.of the said body, which is to be accompted from the first
min.of \/,for the longit.of \/ is the portion of the Ecliptic line, which
is contained between the ecliptical meridian passing by the poles of the
zodiac, and the first min. of \/,& the ecliptical meridian which passeth
by the poles of the zodiac & the center of any planet or star. When
the Planets are upon the north side of the ecliptick, they have north latitude,&
being south from the ecliptick, they have south latitude.
- Also the motions of the Planets, the time
of any Eclipse & the Suns declination by his place in the ecliptick,
are known by this circle, whose use is very ample, & to great purpose
for all astromomical considerations.
What are the Colures
?
- The Solstical Colure is a great circle
passing by the Poles of the world, and the Poles of the Zodiack, and the
Solstical points or first min. of Capricorn and Cancer, cutting the Equinoctical
at right Spherick angles, in his 90 and his 270 degrees.
- The Equinoctial Colure is likewise a great
Circle passing by the Poles of the world, and the Equinoctial point of Aries
and Libra, and crosseth the Equator in his 360 and 180 degrees, and these
colures do intersect each other in the poles of the world to the right Spherick
angles.
What is the use of
these Colures ?
- Their use is to distinguish the four principal
seasons of the year, Spring, Summer, Autumme, and Winter, dividing the Equator
and Ecliptic into 4 equal parte: also that Arc of the Solstical Colure,
which is included between the first minute of cancer,& the Equinoctial,
is the Suns greatest declination toward the north, the like ark being between
the tropical point of Cp, & the equator, is the Suns greatest south
declination, being in these our dayes 23 deg. 28 min.
What is the Tropick
of Cancer ?
- The Tropick of Cancer, is one of the lesser
Circles dividing the Sphere into two unequal parts, and is described upon
the pole Artick, a parallel to the Equator 23 degrees, 28 minutes from him,
being the farthest limit of the Ecliptick bending towards the north, to
which when the Sun cometh, the days are then longest to all those that inhabit
the North parts of the world, & shortest to the Southern inhabitants:
- between this Circle and the Equator are
concluded the 6 septentrional signes, Aries, Tarus, Gemini, Cancer, Leo,
Virgo, in which signs during the time that the Sun abideth, being from the
11th of March to the 11th of September, he hath North declination, and then
is the Spring and Summer to all such as inhabit the north parts of the world:
and Autumne and Winter to the Inhabitants of the south parts of the world:
this circle doth touch the Ecliptick in the first minute of Cancer, where
the Sun beginneth his return toward the south, whereupon it took the name
Tropick, which signifieth conversion or return, by which point of the Ecliptick,
the diurnal motion describeth this circle.
(Readers after
1754 will add 11 days to these dates)
What is the Tropick
of Capricorne?
- The Tropick of Capricorn is one of the
lesser Circles dividing the Sphere into two unequal parts, and is described
upon the Pole Antartick a parrallel to the Equinoctial 23 degrees, 28 minutes
from him, being the farthest bending of the Ecliptick towards the south,
to which when the Sun cometh, the dayes are then longest to all those that
inhabit in the south parts of the world, and the shortest to the northern
Inhabitants: between this Circle and the Equator are included the 6 southern
signs, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces;
- in which signs, during the time that the
Sun abideth, being from the 11th of September to the 11th of March, he hath
south declination,& then is the Spring & the Summer to all such
as inhabit the south parts of the world; & Autumne & Winter to all
the Inhabitants in the north parts of the world; this circle toucheth the
ecliptick in the first minute of Capricorn, by which point the diurnal motion
describeth this parallel.
What is the use of
the Tropics?
- By the Tropicks the Suns declination is
known, as also the Tropicks by the suns farthest motion towards the north
and south, for so much as the Tropicks are distant from the Equator, so
much is the Suns greatest declination: and such as is the Suns greatest
declining, such is the distance between the Tropicks & the Equator:
they are also the limits of the durning Zone, separating the burning and
temperate Zones For between the two Tropicks, is contained the burning Zone.
What is the Artic
polar Circle?
- The Artic polar Circle is one of the lesser
Circles, dividing the Sphere into two unequal parts, and described upon
the pole Artick in parallel, to the Tropick of Cancer, having such distance
from the pole as the Tropick hath from the Equator, being 23 deg. 28 min.
upon which circle the Artick pole of the Zodiack is placed, which being
fixed in the firmament, by the virtue of the first mover is carried about
with the heavene, by which motion the Circle is described.
What is the Antartic
Polar Circle?
- The Antartick polar Circle is opposite
to the Artick, and parallel to the Tropick of Capricorn, being in all respect
of such distance and description, from and about the Pole Antartick, as
the Artick polar Circle is about the pole Artick.
What is the Use of
Artick and Antartick polar Circles?
- The Use of these two polar Circles, is
to shew the distance of the Poles of the Zodiack, from the Poles of the
World, for so much as the Solsticial points are distant from the Equator,
so much are the Poles of the Zodiack from the Poles of the World: the Circles
so also divide and limit the temperate & frozen Zones,
- for between the Tropick of Cancer &
the Artick polar Circle is contained the Northern temperate Zone, &
between the Artick polar Circle & the Pole Artick, that is within the
Artick polar circle is contained the Northern frozen zone.
- Also between the tropick of Capricorn &
the Antartick polar circle, is contained the Southern temperate Zone, and
within the said polar Circle, is included the Antarctick frozen Zone: And
these are all the Circles that are described upon the body of the Globe.
What is the Meridian
?
- The Meridian is a great Circle passing
by the Poles of the World, & by your Zenith, dividing the Horizon into
two equal parts, in the points North and South: it also divideth the Sphere
with all the parallel Circles therein contained, into two equal parts, crossing
them at right Spherick angles.
- And this Meridian is not fixed in the firmament
as the rest of the Circles are, for if it were, then so it be moved with
the first mover as the rest are, but it is not so: therefore the Meridian
is manifested upon the Globe by a Circle or ring of Copper fastened unto
the Globe upon the two Poles, so that the Globe moveth round upon the two
Poles within the Meridian: this Meridian is graduated in every of his quarters
into 90 degrees, by which his use is performed: and note, that one Meridian
may have many Horizons, but every Horizon hath but one Meridian; for if
you travel South or North, you keep still upon the same Meridian, yet in
every sensible difference of distance you shall enter into a change of Horizons,
for there be as many Horizons as there be sensible difference of distance;
so that the difference be not upon the points North & South: but this
Copper Meridian annexed to the Globe is to be applyed to all differences
& distances whatsoever, as amply as if the number were infinite.
What is the use of
the Meridian ?
- The Use of the Meridian is to know the
highest ascending of the Sun, Moon, or Stars from the Horizon, for when
they be upon the Meridian, then are they farthest from the Horizon, and
then is the most convenient time to take the Altitude of the Sun, or Stars,
whereby to find the Poles elevation.
- By the Meridian of your Globe is known
the latitude & longitude of any place upon the Globe containeth for
if you bring any place under the Meridian, the degrees of the Meridian do
shew the latitude of the same, and that degree of whe Equator, which the
Meridian doth cross is the
longitude.
What is the Horizon
?
- The Horizon is a great Circle dividing
the Heavens into two equal parts, the one half being above the Horizon is
always in sight, the other half is not seen being under the Horizon, and
therefore is called the finitor or limit of out sight, for where the heavens
and seas seem to joyn together, that is the horizon:
- the horizon is not sired in the firmament,
& yet is a fixed circle constant to his proper latitude, but because
in the Globe one and the same horizon may perform whatsoever is required
to all elevations, the horizon is so artificialy annexed to the Globe, that
by the motion of the Meridian, in the same there faulteth nothing in his
use: and the horizons in all respects distinguished as the Sea Compass.
- There are two kinds of horizons, a right
horizon and an oblique horizon: when the Poles are in the horizon, then
it is a right horizon, for then the Equator doth cut the horizon to right
angles, making a right sphere and a right horizon: an oblique horizon is
where either of the poles are elevated above the same, for then the equators
doth cut the horizon to unlike angles, making an oblique sphere and an oblique
horizon, and although the horizons be divers and many in number, for every
sensible difference of distance hath his proper horizon, yet is the horizon
of the Globe so conveniently annexed thereunto, as that by the moving of
the Meridian in the horizon,& by the Globes motion in the Meridian,
both the Horizon and the Meridian are to be applyed as proper to all places
whatsoever and note that the place where you are, is always the center of
the plain superficial horizon.
What is the use of
the Horizon ?
- The Horizon is the beginning of all altitude,
for whatsoever is above the horizon, is said to have altitude more or less,
and by the horizon such altitudes are given with help of the Cross Staffe,
for placing the Cross Staff at your eye, if by the one end of the transversary
you see the horizon, and up the other end (at the same instant) you see
the body observed, then doth the transversary shew upon the staffe the altitude
desired, by the horizon, the Navigable courses from place to place are likewise
known, as also the quantity of the rising and setting of the Sun, Moon,&
Stars:
- whereby is known the length of the dayes
& nights in all climates & all seasons: by the horizon is known
upon what degree of Azumuth the Sun, Moon, or Stars are, when they may be
seen in what part of the heaven soever, whereby the variation of the Compass
is found, and the Poles Altitude may at all seasons be given.
Are these all the
Circles appertaining to the Globe ?
There are other circles which are sired &
do properly appertain to every particular Horizon, as Azumuths, Almicanter,
the Artick, and Antarctick Circle.
What are Circles
of Azumuth ?
- Circles of Azumuth, or vertical circles,
are quarters of great circles, concurring together in the Zenith, as the
Meridians do in the pole, and are extended from the Zenith, to every degree
of the horizon.
- And because they cannot be conveniently
described upon the Globe to be applyed to all horizons, therefore upon the
meridian of the Globe there is a piece of coper artificially placed, to
be removed to any degree of the Meridian at pleasure, which piece of Copper
representeth the Zenith and must always be placed so many degrees from the
equator as the pole is elevated from the horizon, and unto this zenith there
is joyned a quarter of a great circle called a quarta altitudo, the end
whereof doth continually touch the horizon,& is so joyned to the zenith,
as that it may be moved round about the horizon, and to every part thereof
at your pleasure: this quarta altitudo is devided into 90 degrees, being
the distinction of all Altitude, and beginning the account from the horizon,
which is the beginning of Altitude, and concludeth 90 degrees in the Zenith,
being the end and extreme limit of all Altitude.
What are Almicanters
?
Almicanters or Circles of Altitude, or parallel
circles to the Horizon and are described upon the Zenith, as the parallels
to the equator, are described upon the poles, of which circles there are 90
answerable to the distinctions of the quarta altitudo, which are the degrees
contained between the horizon and zenith. These circles cannot be described
upon the Globe, to be applyed to every horizon, but they are distinguished
by the circular motion of the quarta altitudo, for if I desire to see the
Almicanter circle of 10 degrees, by moving the quarta altitudo round about
the horizon, the zenith degree of their quarter circle, doth shew the Almicanter
desired, in what elevation soever.
What is the use of
those two Circles ?
The Quarta altitudo performeth the use of
both, by the quarta altitudo and horizon, the courses from place to place
are known according to the true horizontal position, as hereafter shall plainly
appear: it also sheweth the degree of Azimuth, and observed altitude of any
celestial body, in what latitude soever: by the Quarta altitudo and Horizon,
you may describe a paraboral Compass upon the Globe, the poles height is at
all times thereby to be known, and the variation of the Compass is thereby
likewise given, as hreafter in the practice you shall be taught.
What are the Artick
and Antarctick Circles ?
Every horizon hath his proper artick or antarctick
Circle, those horizons that have the pole arctick elevated above them, have
their proper artick circle, and those that have the South pole elevated, have
their proper antarctick circle, the quantity of which circle is according
to the Poles elevation, for if the pole be much elevated, then is the artick
circle great, for the Poles altitude is the semidiameter of their circle,
if the Pole be in the Zenith, then half the heavens is the arctick Circle.
What is the use of
this Circle ?
If the Sun, Moon or any Stars be within this
Circle, they are never carried under the Horizon during the time of their
abode therein, whereupon it cometh to pass, that such as travel far towards
the north, have the Sun in continual view and those that inhabit under the
Pole (if any so do) the Sun is in continual sight for six months together,
because the six septentrional signs are within the Artick Circle, the Equator
being in the horizon.
There is another small Circle, which is called
Circulus Horarius, or the hour circle, to be annexed to the Meridian of the
Globe, for the perfection of his use, this circle must be divided into 24
equal parts, or hours, and those again into such parts as you please for the
better distinction of time: this circle must be fastened to the Meridian,
so that the hours 12 must stand directly upon the edge of the Meridian, &
the pole must be the center of this Circle, upon which pole there must be
fastened an Index to move portionably as the Sphere (upon any occasion) shall
be moved. There is also an half Circle, called the Circle of Position, which
uth it serveth to no great purpose for Navigation. I here omit, and thus is
the Globe fully finished for the perfection of this use.
What are the Poles
of the World ?
- There are two Poles, the North Artick pole,
and the South, or Antartick pole, which poles are two immoveable pricks
fixed in the firmament, whereupon the Sphere is moved by vertue of the first
mover, and are the limits of the Axis of the world, as also the extreme
term of band of all declination, being 90 deg. from all parts of the Equator.
- By the raising of the pole from the horizon,
is known the paralles of latitude of our being. it also giveth the quantity
of the Artick circle, and obliquity of the Sphere.
What is the Axis
of the World ?
The Axis of the World is a right line passing
by the Center of the Sphere, & limited in the Circumference, about the
which the Sphere moveth, and is therefore called the Axis of the Sphere;&
as all lines commensurable are limited between 2 points or pricks, so is the
Axis of the world, & those 2 limiting pricks are called the Poles of the
World.
What are the Poles
of the Zodiack ?
- The Zodiack hath likewise two Poles, Artick
& Antartick, being 2 pricks fixed in the firmament, uniting the Axis
or the Zodiack, & are distant from the poles of the world 23 deg. 28
min. which poles by the motion of the sphere do describe the poles circles,
performing their motion about the poles of the world in every 24 hours,
by vertue of the first mover, upon these poles the ecliptick, & zodiack
is described: also a quarter of a great circle graduated into 90 deg. being
fastened to either of these poles & brought to the center of the Star,
sheweth by that graduation the latitudes of the same star, & where the
quarter circle toucheth the Ecliptick, that is likewise his longitude: also
the 7 Planets do perform their natural revolutions upon the poles, where
motion is from the West towards the East, contrary to the motion of the
first mover.
What is the Axis
of the Zodiack ?
The Axis of the Zodiack, is a right line passing
by the center of the Sphere, & limited in the circumference, whose limiting
points are the poles of the zodiack, and his Axis is moved by the Sphere as
are his Poles,
What are the Poles
of the Horizon ?
There are two Poles of the Horizon, which
are the limits of his perpendicular diameter being equidistant 90 degrees
from all parts of the horizon, & are the extreme limits of all altitude,
that Pole which is in the upper hemisphere is called the Zenith, and his opposite
Pole is called Nadir, they are extended in the firmament, but not fixed in
it, for they move never, but remain always stable in their proper horizon,
which could not be if it were fixed in the firmament, for then should they
be moved with the firmament as the rest are, by the help of these poles is
found the Azumuth and Almicanter of any celestial body, for a quarter circle
devided into 90 degrees, and fixed to the Zenith as is the quarta altitudo,
being moved to any celestial body, doth by those deg. shew the almicanter
or altitude of the same body from the horizon,& that part of the horizon
which the quarter circle traces, is the Azumuth of the same body, always provided
that the Zenith stand answerable to the poles elevation, that is, so many
degrees from the equator, as the Pole is from the Horizon.