1ficies of an oblique Cylinder, which hath for one of its baſes
the ſaid annual circle, and for the other a like circle
rily deſcribed by its extremity, or, (if you will) Pole, amongſt
the fixed ſtars. And this ſame cylinder is oblique to the Plane of
the Ecliptick, according to the inclination of the Axis that
ſcribeth it, which we have ſaid to be 23 degrees and an half,
the which continuing perpetually the ſame (ſave onely, that in
many thouſands of years it maketh ſome very ſmall mutation,
which nothing importeth in our preſent buſineſſe) cauſeth that
the Terreſtrial Globe doth never more incline or elevate, but
ſtill conſerveth the ſame ſtate without mutation. From whence
enſueth, that as to what pertaineth to the mutations to be
ſerved in the fixed ſtars dependant on the ſole annual motion,
the ſame ſhall happen to any point whatſoever of the Earths
ſurface, as befalleth unto the centre of the Earth it ſelf; and
therefore in the preſent explanations we will make uſe of the
centre, as if it were any whatſoever point of the ſuperficies.
And for a more facile underſtanding of the whole, let us deſign
the ſame in lineal figures: And firſt of all let us deſcribe in the
Plane of the Ecliptick the circle A N B O [in Fig. 7.] and let
us underſtand the points A and B, to be the extreams towards
the North and South; that is, the beginning of [or entrance into]
Cancer or Capricorn, and let us prolong the Diameter A B,
determinately by D and C towards the Starry Sphere. I ſay
now in the firſt place, that none of the fixed ſtars placed in the
Ecliptick, ſhall ever vary elevation, by reaſon of any
ever mutation made by the Earth along the ſaid Plane of the
Ecliptick, but ſhall alwayes appear in the ſame ſuperficies,
though the Earth ſhall approach and recede as great a ſpace as is
that of the diameter of the Grand Orb, as may plainly be
ſeen in the ſaid figure. For whether the Earth be in the point
A or in B, the ſtar C alwayes appeareth in the ſame line A B C;
although the diſtance B C, be leſſe than A C, by the whole
diameter A B. The moſt therefore that can be diſcovered in the
ſtar C, and in any other placed in the Ecliptick, is the
mented or diminiſhed apparent magnitude, by reaſon of the
proximation or receſſion of the Earth.
the ſaid annual circle, and for the other a like circle
rily deſcribed by its extremity, or, (if you will) Pole, amongſt
the fixed ſtars. And this ſame cylinder is oblique to the Plane of
the Ecliptick, according to the inclination of the Axis that
ſcribeth it, which we have ſaid to be 23 degrees and an half,
the which continuing perpetually the ſame (ſave onely, that in
many thouſands of years it maketh ſome very ſmall mutation,
which nothing importeth in our preſent buſineſſe) cauſeth that
the Terreſtrial Globe doth never more incline or elevate, but
ſtill conſerveth the ſame ſtate without mutation. From whence
enſueth, that as to what pertaineth to the mutations to be
ſerved in the fixed ſtars dependant on the ſole annual motion,
the ſame ſhall happen to any point whatſoever of the Earths
ſurface, as befalleth unto the centre of the Earth it ſelf; and
therefore in the preſent explanations we will make uſe of the
centre, as if it were any whatſoever point of the ſuperficies.
And for a more facile underſtanding of the whole, let us deſign
the ſame in lineal figures: And firſt of all let us deſcribe in the
Plane of the Ecliptick the circle A N B O [in Fig. 7.] and let
us underſtand the points A and B, to be the extreams towards
the North and South; that is, the beginning of [or entrance into]
Cancer or Capricorn, and let us prolong the Diameter A B,
determinately by D and C towards the Starry Sphere. I ſay
now in the firſt place, that none of the fixed ſtars placed in the
Ecliptick, ſhall ever vary elevation, by reaſon of any
ever mutation made by the Earth along the ſaid Plane of the
Ecliptick, but ſhall alwayes appear in the ſame ſuperficies,
though the Earth ſhall approach and recede as great a ſpace as is
that of the diameter of the Grand Orb, as may plainly be
ſeen in the ſaid figure. For whether the Earth be in the point
A or in B, the ſtar C alwayes appeareth in the ſame line A B C;
although the diſtance B C, be leſſe than A C, by the whole
diameter A B. The moſt therefore that can be diſcovered in the
ſtar C, and in any other placed in the Ecliptick, is the
mented or diminiſhed apparent magnitude, by reaſon of the
proximation or receſſion of the Earth.
The annual
tion made by the
centre of the Earth
under the
tick and the
nal motion made
by the Earth about
its own centre.
tion made by the
centre of the Earth
under the
tick and the
nal motion made
by the Earth about
its own centre.
The axis of the
Earth continueth
alwayes parallel to
it ſelf, and
beth a
cal ſuperficies,
clining to the
grand Orb.
Earth continueth
alwayes parallel to
it ſelf, and
beth a
cal ſuperficies,
clining to the
grand Orb.
The Orb of the
Earth never
neth, but is
mutably the ſame.
Earth never
neth, but is
mutably the ſame.
The fixed ſtars
placed in the
cliptick never
vate nor deſcend,
on account of the
annual motion, but
yet approach and
recede.
placed in the
cliptick never
vate nor deſcend,
on account of the
annual motion, but
yet approach and
recede.
SAGR. Stay a while I pray you, for I meet with a certain
ſcruple, which much troubleth me, and it is this: That the ſtar
C may be ſeen by the ſame line A B C, as wel when the Earth
is in A, as when it is in B, I underſtand very well, as alſo
thermore I apprehend that the ſame would happen in all the
points of the line A B, ſo long as the Earth ſhould paſſe from A
to B by the ſaid line; but it paſſing thither, as is to be ſuppoſed,
by the arch A N B, it is manifeſt that when it ſhall be in the
ſcruple, which much troubleth me, and it is this: That the ſtar
C may be ſeen by the ſame line A B C, as wel when the Earth
is in A, as when it is in B, I underſtand very well, as alſo
thermore I apprehend that the ſame would happen in all the
points of the line A B, ſo long as the Earth ſhould paſſe from A
to B by the ſaid line; but it paſſing thither, as is to be ſuppoſed,
by the arch A N B, it is manifeſt that when it ſhall be in the