Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

Page concordance

< >
< >
page |< < of 701 > >|
1caſe, which Copernicus alledgeth, that by reaſon this motion is
natural to the Earth and not violent, it worketh contrary effects
to violent motions; and that thoſe things diſſolve and cannot
long ſubſiſt, to which impulſe is conferred, but thoſe ſo made
by nature do continue in their perfect diſpoſure; this anſwer
ficeth not, I ſay, for it is overthrown by that of ours.
For the
nimal is a natural body, and not made by art, and its motion is
natural, deriving it ſelf from the ſoul, that is, from an intrinſick
principle; and that motion is violent, whoſe beginning is
out, and on which the thing moved conferreth nothing;
ever, if the animal continueth its motion any long time, it grows
weary, and alſo dyeth, if it obſtinately ſtrive to perſiſt therein.
You ſee then that in nature we meet on all ſides with notions
trary to the Copernican Hypotheſis, and none in favour of it. And
for that I have nothing more wherein to take the part of this
ponent, hear what he produceth againſt Keplerus (with whom
he diſputeth) upon that argument, which the ſaid Kepler bringeth
againſt thoſe who think it an inconvenient, nay impoſſible thing,
to augment the Starry Sphere immenſely, as the Copernican
potheſis requireth. Kepler therefore inſtanceth, ſaying:
us ect, accidens præter modulum ſubjecti intendere, quàm ſub-

jectum ſine accidente augere. Copernicus ergo veriſimilius facit,
qui auget Orbem Stellarum fixarum abſque motu, quam Ptolomæus,
qui auget motum fixarum immenſà velocitate. [Which makes this
Engliſh.] Its harder to ſtretch the accident beyond the model of the
ſubject than to augment the ſubject without the accident. Coperni-
hath more probability on his ſide, who encreaſeth the Orb of the
fixed Stars without motion, than Ptolomy who augmenteth the
motion of the fixed Stars to an immenſe degree of velocity.

Which objection the Author anſwereth, wondering how much
Kepler deceived himſelf, in ſaying, that in the Ptolomaick
ſis the motion encreaſeth beyond the model of the ſubject, for in
his judgment it doth not encreaſe, ſave onely in conformity to the
model, and that according to its encreaſement, the velocity of

the motion is augmented.
Which he proveth by ſuppoſing a
chine to be framed, that maketh one revolution in twenty four
hours, which motion ſhall be called moſt ſlow; afterwards
poſing its ſemidiameter to be prolonged, as far as to the diſtance
of the Sun, its extreme will equal the velocity of the Sun; and
it being cantinued out unto the Starry Sphere, it will equal the
velocity of the fixed Stars, though in the circumferrnce of the
machine it be very ſlow.
Now applying this conſideration of the
machine to the Starry Sphere, let us imagine any point in its
midiameter, as neer to the centre as is the ſemidiameter of the
chine; the ſame motion that in the Starry Sphere is exceeding

Text layer

  • Dictionary
  • Places

Text normalization

  • Original
  • Regularized
  • Normalized

Search


  • Exact
  • All forms
  • Fulltext index
  • Morphological index