1things; and that motion where it is common, is as if it never
were; and as you change not habitude to the Terreſtrial Poles
(habitude I ſay, whether that they riſe, or deſcend) ſo neither
ſhall you change poſition to the Poles imagined in Heaven;
wayes provided that by Celeſtial Poles we underſtand (as hath
been already defined) thoſe two points that come to be marked
out by the prolongation of the Terreſtrial Axis unto that length.
Tis true thoſe points in Heaven do change, when the Earths
ſportment is made after ſuch a manner, that its Axis cometh to
paſſe by other and other points of the immoveable Celeſtial
Sphere, but our habitude thereunto changeth not, ſo as that the
ſecond ſhould be more elevated to us than the firſt. If any one
will have one of the points of the Firmament, which do anſwer
to the Poles of the Earth to aſcend, and the other to deſcend,
he muſt walk along the Earth towards the one, receding from the
other, for the tranſportment of the Earth, and with it us our
ſelves, (as I told you before) operates nothing at all.
were; and as you change not habitude to the Terreſtrial Poles
(habitude I ſay, whether that they riſe, or deſcend) ſo neither
ſhall you change poſition to the Poles imagined in Heaven;
wayes provided that by Celeſtial Poles we underſtand (as hath
been already defined) thoſe two points that come to be marked
out by the prolongation of the Terreſtrial Axis unto that length.
Tis true thoſe points in Heaven do change, when the Earths
ſportment is made after ſuch a manner, that its Axis cometh to
paſſe by other and other points of the immoveable Celeſtial
Sphere, but our habitude thereunto changeth not, ſo as that the
ſecond ſhould be more elevated to us than the firſt. If any one
will have one of the points of the Firmament, which do anſwer
to the Poles of the Earth to aſcend, and the other to deſcend,
he muſt walk along the Earth towards the one, receding from the
other, for the tranſportment of the Earth, and with it us our
ſelves, (as I told you before) operates nothing at all.
Motion where
it is common, is as
if it never were.
it is common, is as
if it never were.
SAGR. Permit me, I beſeech you Salviatus, to make this a
little more clear by an example, which although groſſe, is
commodated to this purpoſe. Suppoſe your ſelf, Simplicius, to
be aboard a Ship, and that ſtanding in the Poope, or Hin-deck;
you have directed a Quadrant, or ſome other Aſtronomical
ſtrument, towards the top of the Top-gallant-Maſt, as if you
would take its height, which ſuppoſe it were v. gr. 40. degrees,
there is no doubt, but that if you walk along the ^{*} Hatches
wards the Maſt 25. or 30. paces; and then again direct the ſaid
Inſtrument to the ſame Top-Gallant-Top. You ſhall find its
vation to be greater, and to be encreaſed v. gr. 10. degrees; but
if inſtead of walking thoſe 25. or 30. paces towards the Maſt,
you ſtand ſtill at the Sterne, and make the whole Ship to move
thitherwards, do you believe that by reaſon of the 25. or 30.
paces that it had paſt, the elevation of the Top-Gallant-Top
would ſhew 10. degrees encreaſed?
little more clear by an example, which although groſſe, is
commodated to this purpoſe. Suppoſe your ſelf, Simplicius, to
be aboard a Ship, and that ſtanding in the Poope, or Hin-deck;
you have directed a Quadrant, or ſome other Aſtronomical
ſtrument, towards the top of the Top-gallant-Maſt, as if you
would take its height, which ſuppoſe it were v. gr. 40. degrees,
there is no doubt, but that if you walk along the ^{*} Hatches
wards the Maſt 25. or 30. paces; and then again direct the ſaid
Inſtrument to the ſame Top-Gallant-Top. You ſhall find its
vation to be greater, and to be encreaſed v. gr. 10. degrees; but
if inſtead of walking thoſe 25. or 30. paces towards the Maſt,
you ſtand ſtill at the Sterne, and make the whole Ship to move
thitherwards, do you believe that by reaſon of the 25. or 30.
paces that it had paſt, the elevation of the Top-Gallant-Top
would ſhew 10. degrees encreaſed?
An example
ted to prove that
the altitude of the
Pole ought not to
vary by means of
the Earths annual
motion.
ted to prove that
the altitude of the
Pole ought not to
vary by means of
the Earths annual
motion.
* Corſia, the bank
or bench on which
ſlaves ſit in a
ly.
or bench on which
ſlaves ſit in a
ly.
SIMP. I believe and know that it would not gain an hairs
breadth in the paſſing of 30. paces, nor of a thouſand, no nor of
an hundred thouſand miles; but yet I believe withal that
ing through the ſights at the Top and Top-Gallant, if I ſhould
find a fixed Star that was in the ſame elevation, I believe I ſay,
that, holding ſtill the Quadrant, after I had ſailed towards the
ſtar 60. miles, the eye would meet with the top of the ſaid
Maſt, as before, but not with the ſtar, which would be
ted to me one degree.
breadth in the paſſing of 30. paces, nor of a thouſand, no nor of
an hundred thouſand miles; but yet I believe withal that
ing through the ſights at the Top and Top-Gallant, if I ſhould
find a fixed Star that was in the ſame elevation, I believe I ſay,
that, holding ſtill the Quadrant, after I had ſailed towards the
ſtar 60. miles, the eye would meet with the top of the ſaid
Maſt, as before, but not with the ſtar, which would be
ted to me one degree.
SAGR. Then you do not think that the ſight would fall upon
that point of the Starry Sphere, that anſwereth to the direction
of the Top-Gallant Top?
that point of the Starry Sphere, that anſwereth to the direction
of the Top-Gallant Top?