Galilei, Galileo, The systems of the world, 1661

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1bed circle ſhall be in the line F G, which let be the point I; and
becauſe
that of ſuch lines as are drawn from the point G, which
is
not the centre, unto the circumference of the circumſcribed
circle
, the biggeſt is that which paſſeth by the centre, G F ſhall
be
bigger than any other that is drawn from the point G, to the
circumference
of the ſaid circle; and therefore that
rence
will cut the line G H (which is equal to the line G F) and
cutting
G H, it will alſo cut A H.
Let it cut it in L, and
joyn
the line L B.
Theſe two angles, therefore, A F B and A L B
ſhall
be equal, as being in the ſame portion of the circle
cumſcribed
.
But A L B external, is bigger than the internal H;
therefore
the angle F is bigger than the angle H.
And by the
ſame
method we might demonſtrate the angle H to be bigger
than
the angle E, becauſe that of the circle deſcribed about the
triangle
A H B, the centre is in the perpendicular G F, to which
the
line G H is nearer than the line G E, and therefore the
cumference
of it cutteth G E, and alſo A E, whereupon the
poſition
is manifeſt.
We will conclude from hence, that the
ference
of appearance, (which with the proper term of art, we
might
call the Parallax of the fixed ſtars) is greater, or leſſe,
cording
as the Stars obſerved are more or leſſe adjacent to the
Pole
of the Ecliptick, ſo that, in concluſion of thoſe Stars that
are
in the Ecliptick it ſelf, the ſaid diverſity is reduced to nothing.
In the next place, as to the Earths acceſſion by that motion to,

or
receſſion from the Stars, it appeareth to, and recedeth from
thoſe
that are in the Ecliptick, the quantity of the whole
ter
of the grand Orb, as we did ſee even now, but that acceſſion
or
receſſion to, or from the ſtars about the Pole of the Ecliptick,
is
almoſt nothing; and in going to and from others, this
rence
groweth greater, according as they are neerer to the
tick
.
We may, in the third place, know, that the ſaid difference

of
Aſpect groweth greater or leſſer, according as the Star
ved
ſhall be neerer to us, or farther from us.
For if we draw
nother
Meridian, leſſe diſtant from the Earth; as for example,
this
D F I [in Fig. 7.] a Star placed in F, and ſeen by the ſame
ray
A F E, the Earth being in A, would, in caſe it ſhould be
ſerved
from the Earth in B, appear according to the ray B F, and
would
make the angle of difference, namely, B F A, bigger
than
the former A E B, being the exteriour angle of the
gle
B F E.
* i. e. of the
cliptick
.
The Earth
proacheth
or
deth
from the
ed
ſtars of the
cliptick
, the
tity
of the
ter
of the Grand
Orb
.

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