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

1together with Appollonius Pergæus in lib. 5. of his Revolutions,
Chap. 35.

The ſole annual
motion of the
Earth cauſeth
great inequality of
motions in the five
Planets.

A demonſtration of
the inequalities of
the three ſuperiour
Planets dependent
on the annual
tion of the Earth.

Retrogradations
more frequent in
Saturn, leſſe in
piter, and yet leſſe
in Mars, and why.

The
tion of Venus and
Mercury
ſtrated by
nius and
cus.

You ſee, Gentlemen, with what facility and ſimplicity the

al motion, were it appertaining to the Earth, is accommodated
to render a reaſon of the apparent exorbitances, that are obſerved
in the motions of the five Planets, Saturn, Jupiter, Mars,
nus and Mercury, taking them all away, and reducing them to

equal and regular motions. And of this admirable effect,
cholas Copernicus, hath been the firſt that hath made the reaſon
plain unto us. But of another effect, no leſſe admirable than
this, and that with a knot, perhaps more difficult to unknit,
bindeth the wit of man, to admit this annual converſion, and to
leave it to our Terreſtrial Globe; a new and unthought of
jecture ariſeth from the Sun it ſelf, which ſheweth that it is
ling to be ſingular in ſhifting, of this atteſtation of ſo eminent a
concluſion, rather as a teſtimony beyond all exception, it hath
deſired to be heard apart. Hearken then to this great and new

The annual
tion of the Earth
moſt apt to render
a reaſon of the
orbttances of the
five Planets.

The Sun it ſelf
teſtifieth the
al motion to belong
to the Earth.

The Lyncæan
Academick the
firſt diſcoverer of
the Solar ſpots, and
all the other
ſtial novelties.

The firſt diſcoverer and obſerver of the Solar ſpots, as alſo of
all the other Cœleſtial novelties, was our Academick Lincæus; and
he diſcovered them anno 1610. being at that time Reader of the
Mathematicks, in the Colledge of Padua, and there, and in
nice, he diſcourſed thereof with ſeveral perſons, of which ſome

are yet living: And the year following, he ſhewed them in Rome
to many great perſonages, as he relates in the firſt of his Letters
to Marcus Velſerus, ^{*} Sheriffe of Auguſta. He was the
firſt that againſt the opinions of the too timorous and too jealous

aſſertors of the Heavens inalterability, affirmed thoſe ſpots to be
matters, that in ſhort times were produced and diſſolved: for as
to place, they were contiguous to the body of the Sun, and
volved about the ſame; or elſe being carried about by the ſaid
Solar body, which revolveth in it ſelfe about its own Centre, in
the ſpace almoſt of a moneth, do finiſh their courſe in that time;
which motion he judged at firſt to have been made by the Sun
bout an Axis erected upon the plane of the Ecliptick; in regard
that the arches deſcribed by the ſaid ſpots upon the Diſcus of the
Sun appear unto our eye right lines, and parallels to the plane of
the Ecliptick: which therefore come to be altered, in part, with
ſome accidental, wandring, and irregular motions, to which they
are ſubject, and whereby tumultuarily, and without any order
they ſucceſſively change ſituations amongſt themſelves, one
while crouding cloſe together, another while diſſevering, and
ſome dividing themſelves into many and very much changing
gures, which, for the moſt part, are very unuſual. And albeit
thoſe ſo inconſtant mutations did ſomewhat alter the primary

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