Archimedes Texts

309
ties of the Planets motions, with these two new suppositions, all
which things jumpt exactly with his purpose; and seeing the whole
correspond, with admirable facility to its parts, he imbraced this
new Systeme, and it took up his rest.

SIMP. But what great exorbitancies are there in the Ptolo
maick Systeme, for which there are not greater to be found in this
of Copernicus?

SALV. In the Ptolomaick Hypothesis there are diseases, and in

the Copernican their cures. And first will not all the Sects of
Phylosophers, account it a great inconvenience, that a body na
turally moveable in circumgyration, should move irregularly upon
its own Centre, and regularly upon another point? And yet
there are such deformed motions as these in the Ptolomæan Hypo
thesis, but in the Copernican all move evenly about their own
Centres. In the Ptolomaick, it is necessary to assign to the Cæ
lestial bodies, contrary motions, and to make them all to move,
from East to West, and at the same time, from West to East;
But in the Copernican, all the Cælestial revolutions are towards
one onely way, from West to East. But what shall we say of
the apparent motion of the Planets, so irregular, that they not on
ly go one while swift, and another while slow, but sometimes
wholly seace to move; and then after a long time return back a
gain? To salve which appearances Ptolomie introduceth very great
Epicicles, accommodating them one by one to each Planet, with
some rules of incongruous motions, which are all with one sin
gle motion of the Earth taken away. And would not you, Sim
plicius, call it a great absurditie, if in the Ptolomaick Hypothe
sis, in which the particular Planets, have their peculiar Orbs as
signed them one above another, one must be frequently forced
to say, that Mars, constituted above the Sphære of the Sun, doth
so descend, that breaking the Solar Orb, it goeth under it, and
approacheth neaer to the Earth, than to the Body of the Sun,
and by and by immeasurably ascendeth above the same? And
yet this, and other exorbitancies are remedied by the Soul and
fingle annual motion of the Earth.

SAGR. I would gladly be bettter informed how these stations,
and retrograde and direct motions, which did ever seem to me
great improbalities, do accord in this Copernican Systeme.

Its a great Ar
gument in favour
of Copernicus, that
he obviates the sta
tions & retrograda
tions of the motions
of the Planets.

SALV. You shall see them so to accord, Sagredus, that
this onely conjecture ought to be sufficient to make one that
is not more than pertinacious or stupid, yield, assent to all the
rest of this Doctrine. I tell you therefore, that nothing being
altered in the motion of Saturn, which is 30 years, in that
of Jupiter, which is 12, in that of Mars, which is 2, in that of
Venus, which is 9. moneths, in that of Mercury, which is 80.