_Of the circles of the earth._
In a round body as the earth is, there can be no distinction of
parts, & places, without the helpe of some lines drawen or
imagined to be drawen vpon it. Now though there are not, nor can
be any circles truly drawen vpon the earth, yet because there is
a good ground in nature and reason of things for them, we must
imagine them to be drawen vpon the earth, as truly as we see them
described vpon a Globe or in a plaine paper. Further this must be
noted, that all circles on the earth haue the like opposite vnto
them conceaved to be the Heavenes, vnder which they are directly
scituated. Thus knowen, the circles that wee are to take the
speciall notice of are of two sorts, Greater and Lesser.
_The greater circles are those which devide this earthly globe
into equall halfes or Hæmispheres._
_The lesser are those which devide it into two vnequall parts,
one bigger, another lesse._
{ 1 Æquator.
Of the former sort there { 2 Meridian.
are foure, the { 3 Horizon.
{ 4 Zodiack, or Eclipticke.
1 _The Æquitor or Æquonoctiall line, is a line drawen iust in the
midst of the earth, from East to West, which compasseth it as a
girdle doth a mans body, and devidith it into two equall parts,
one on the North side, the other on the South_ The two points in
the earth that are every way farthest distant from it North, &
South are called the Poles of the earth which doe directly stand
vnder the two like points in the Heaven, so called because the
Heaven turnes about vpon them, as the Earth doth in a Globe
that's set in a frame. This circle is of the first & principall
note and vse in Geography, because all measurings for distances
of places and quarters of the Earth are reckoned in it, or from
it. It is called the Æquinoctiall, because when the Sunne in the
Heavens comes to be directly over that circle in the earth, the
daies & nights are of equall length in all parts of the world.
Marriners call it by a kind of excellency, _The line_. Vpon the
Globe it is easily discerned being drawen bigger then any other
circles from East to West, and with small divisions.
2 _The Meridian, if a line that is drawen quite crosse the
Æquinoctiall, and passeth through the Poles of the Earth, going
directly North and South._ It is called the Meridian, because
when the Sunne stands just over that circle it is _Meridies i.d._
noone day. It may be conceaued thus, at noone day, when it is
just twelue a clocke, turne your face towards the South, and then
imagine with your selfe two circles drawen, one in the Heavens,
passing from the North iust over your head through the body of
the Sunne downe to the South, and so round vnder the earth vp
againe to the North Pole. Another vpon the surface of the earth
passing through your feete just vnder the Sunne, and so
compassing the earth round till it meete at your feete againe,
and these are Meridians answering one to another. Now the
Meridian is not one only, as was the Æquinoctiall, but many still
varying according to the place wherein you are, as for example.
At _London_ there is one Meridian, at _Oxford_ another, at
_Bristow_ another, & so along Eastward or Westward. For it is
noone at _London_ sooner then at _Oxford_, and at _Oxford_ sooner
then at _Bristow_. Vpon the globe there are many drawen, all
which passe through the poles, and goe North and South, but there
is one more remarkeable then the rest, drawen broad with small
divisions, which runneth through the Canary Ilands, or through
the Ilands of _Azores_ Westward of _Spaine_, which is counted the
first Meridian in regard of reckoning and measuring of distances
of places one from another; for otherwise there is neither first
nor last in the round earth. But some place must bee appointed
where to beginne the account and those Ilands haue beene thought
fittest, because no part of the World that lay westward was
knowne to the Ancients further then that: and as they began to
reckon there, we follow them. This circle is called in greeke
[Greek: Mesêmbrinos].
3. The Horizon is two fold: { Sensible or appearing.
{ Intelligible or true.
_The Sensible or appearing Horizon is the space of the earth so
farre as in an open plaine, or vpon some Hill a man may see round
about him._ The brim or edge of the earth further then which you
cannot see, that is the Horizon, or as some call it the
_Finitor_. Because _finet_ or terminat _visum_ it setts the
limits or bounds to your sight, beyond which nothing can bee
seene vpon the earth. This is greater or lesser, according as the
height of the eye aboue the plaine superficies of the earth, is
more or lesse. The most exact triall hereof is at Sea, where
there are no mountaines nor any vnequall risings of the water to
hinder the sight, as there are at land. For example let (_CBAF_)
be the superficies of the Sea and let a mans eye bee placed in
(_X_) aboue the Sea; as the eye stands higher or lower so will
the distance seene be more or lesse, as if the hight of (_XA_) be
6 foot which is ordinary the height of a man, the eye looking
from (_X_) to (_B_) shall see 2 miles and 3 quarters, if (_X_) be
20 foote high (_BA_) will bee fiue miles, if 40 foote 7 miles, if
50 foote 8 miles.[1] So that from the mast of a ship 50 foote
high, a man may see round about at sea 8 miles every way, toward
(_BG_) and (_F_). So farre may the water it selfe be seene, but
any high thing on the Water may be seene farther, 16, or 20 miles
according as the height is, as the ship at (_C_) may be seene
from (_X_) as far more as it is from (_A_) to (_B_). There can be
therefore no certaine quantity and space set downe for this
sensible Horizon, which continually varies according to the
height of the eye aboue the plaine ground or sea. This Horrizon
is not at all painted on the globe nor can be.
[Footnote 1: See _Wright_ of Navigation p. 229.]
[Illustration]
_The intelligible or true Horizon is a line which girts the earth
round in the midst, and divides it into two equall parts or
Hæmispheares the vppermost vpon the top & middle point
whereof wee dwell, and that which is vnder vs._ Opposite to this
in the Heavens is another Horizon, which likewise cuts the Heaven
into two Hemispheres, the vpper and the lower. Aboue which circle
when any starre or the Sunne is moued, it then riseth vnto vs,
and setteth vnto those that dwell opposite vnto vs, and so on the
contrary, you may conceiue it best thus, if standing vpon a hill,
or some open place, where you may perfectly see the setting of
the Sunne, you marke when the Sun is halfe gone out of your
sight, you may perceiue the body of the Sunne cut in two, as it
were by a line, going along through it, the halfe aboue is yet
seene, that vnderneath is gone out of your sight. This line is
but a peece of the Horrizon, which if you conceiue to be drawen
vpward about the World from the West to the North, and so by East
and South, to West againe you haue the whole Horrizon described.
This circle is not drawen vpon the body of the globe, because it
is variable; but stands one the outside of it, beeing a broad
circle of wood couered with paper on which are sett the moneths
and days of the yeare, both in the old and new Calender, and also
the 12 signes, and the points of the compasse. All which are
easily discerned by the beholdinge. The vse of this Horizon is
not so much in Geographie as in Astronomie.
_The Zodiake is a circle which compasseth the earth like a belt,
crossing the æquator slopewise, not streight as the Meridians
doe._ Opposite to it in the Heauens is another circle of the same
name, wherein are the 12. signes, and in which the Sunne keepes
his owne proper course all the yeare long, neuer declining from
it on the one side or other. The vse hereof in Geography is but
litle only to shew what people they are ouer whose heads the
Sunne comes to bee once or twice a yeare; who are all those that
dwell with in 23. degrees of the Aequator; for so much is the
declination, or sloping of the _Zodiacke_. This circle is also
called the Eclipticke line, because when the Sunne and Moone
stand both in this circle opposite each to other, then there
happens an Eclipse of the Sunne or Mone, vpon a globe it is
easily discerned, by the sloping of it from the Aequator, and the
diuisions of it into 12. parts, and euery of those 12. into 30.
degrees.
_These are the greater circles: the lesser follow; which are all
of one nature, and are called by one generall name: sc.
Parallels, because they are so drawen on each side of the
Aequator, as they are equidistant vnto it euery way._ Many of
this kinde are drawne vpon the globe (as is easie to bee seene)
and may bee conceaued to bee drawne vpon the earth: but there are
only two sorts cheifely to bee marked: namely the
{ Tropickes and the }
{ Polar circles. }
_The tropickes are two, parallel circles distant on each side of
the Aequator 23. degrees shewing the farthest bounds of the Sunns
declination North or South from the Aequator, or the midest of
heauen._ And therefore they are called tropickes a [Greek:
trepôthai] _vertendo_, because when the Sunne comes ouer these
lines, hee either turnes away from vs, as in the Summer, or
turnes toward vs againe as in the winter: There are then two of
them _vid._
{ 1 The Tropicke of Cancer which lies on the North side
{ of the Aequator, to which when the Sunne comes, it
{ makes the longest day in Summer.
{
{ 2 The Tropicke of Capricorne, lying Southward of the
{ Aequator, to which when the Sunne comes, it makes the
{ shortest day in winter.
_The Polar circles are two parallels drawne by the poles of the
Zodiacke compassinge about the poles of the world, being distant
from them euery way 23 degrees. These are two._
1 _The Articke Circle that compasseth about the North Pole: it is
so called because that in the Heavens (where vnto this in the
earth lies opposite) runs through the constellation of the great
Beare, which in greeke is called [Greek: arktos]_
2 _The Antarticke circle that compasseth about the South Pole, &
is placed opposite vnto the former._ All these with the former
are easily known vp[~o] the Globe by these descripti[~o]s, &
names vsually added vnto th[~e]. But because maps are of an esier
price, & more c[~o]mon vse then Globes, it will be needfull to
shew how all these circles, which are drawne most naturally vpon
a round Globe, may also as truly, and profitably for knowledge
and vse be described vpon a plaine paper. Whereby we shall
vnderstand the reason of those lines which We see in the vsuall
Mapps of the world, both how they are drawne, and wherefore they
serue. Vnderstand therefore, that in laying downe the globe vpon
a plaine paper, you must imagine the globe to be cut in two
halfes through the midst, and so to be pressed downe flat to the
paper; as if you should take a hollow dish, and with your hand
squieze the bottom down, till it lie flat vpon a bord, or any
other plaine thing for then will those circles that before were
of equall distance, runne closer together towards the midst.
After this conceit, vniversall Maps are made of two fashions,
according as the globe may be devided two waies, either cutting
quite through by the meridian from North to South, as if you
should cut an apple by the eye and the stalke, or cutting it
through the Æquinoctiall, East and West, as one would divide an
apple through the midst, betweene the eye & the stalke. The
former makes two faces, or hemispheares, the East and the West
hemispheare. The latter makes likewise two Hemispheares, the
North and the South. Both suppositions are good, and befitting
the nature of the globe: for as touching such vniversall maps,
wherein the world is represented not in two round faces, but all
in one square plot, the ground wherevpon such descriptions are
founded, is lesse naturall and agreeable to the globe, for it
supposeth the earth to be like a Cylinder (or role of bowling
allies) which imagination, vnlesse it be well qualified, is
vtterly false,[2] and makes all such mappes faulty in the
scituation of places. Wherefore omitting this, we will shew the
description of the two former only, both which are easie to be
done.
[Footnote 2: Of this Hypothesis see _Wrights_ errors of
navigation.]
1 To describe an Æquinoctiall planispheare, draw a circle
(_ACBD_) and inscribe in it two diameters (_AB_) & (_CD_) cutting
each other at right angles, and the whole circle into foure
quadrants: each whereof devide into 90. parts, or degrees. The
line (_AB_) doth fitly represent halfe of the Æquator, as the
line (_CD_) in which the points (_C_) & (_D_) are the two poles,
halfe of the Meridian: for these circles the eye being in a
perpendicular line from the point of concurrence (as in this
projection it is supposed) must needs appeare streight. To draw
the other, which will appeare crooked, doe thus. Lie a rule from
the Pole (_C_) to every tenth or fift degree of the halfe circle
(_ADB_) noting in the Æquator (_AB_) every intersection of it and
the rule. The like doe from the point (_B_) to the semicircle
(_CAD_) noting also the intersections in the Meridian (_CD_) Then
the diameters (_CB_) and (_AB_) being drawne out at both ends, as
farre as may suffice, finding in the line (_DC_) the center of
the tenth division from (_A_) to (_C_) and from (_B_) to (_C_), &
of the first point of intersection noted in the meridian fr[~o]
the Æquator towards (_C_) by a way familiar to Geometricians
connect the three points, and you haue the paralell of 10.
degrees from the Æquator: the like must bee done in drawing the
other paralells on either side, the Æquator; as also in drawing
the Meridians from centers found in the line (_AB_) in like maner
continued. All which is illustrated by the following diagram.
[Illustration]
2 To describe a Polar Planisphære, draw a circle (_ACBD_) on the
center (_E_) & as before, inscribe in it two diameters (_AB_) and
(_BC_) cutting each other at right angles, and the circle into
foure quadrants. Each quadrant being deuided into 90. parts, draw
from euery 5^{th} or 10^{th} of those parts a diameter to the
opposite point: these lines all concurring in the center (_E_)
being the pole, are as so many Meridians. Next, hauing cutt the
halfe of any one of the former diameters into 9 parts, as (_ED_)
in the points (_FGHIKLMN_) draw on the center (_E_) so many
circles and these represent the paralells of the Globe, being
also here true paralells.
[Illustration]