1equilibrated, and in their greateſt curvity, one while with
their convexity towards the upper part, and another while
towards the lower part of the Solar Diſcus. And becauſe
thoſe poſitions are in continuall alteration, making the
clinations and incurvations now greater, now leſſer, and
times reduce themſelves, the firſt ſort to perfect libration, and
the ſecond to perfect perpendicularity, it is neceſſary to aſſert that
the ſelf ſame Axis of the monethly revolution of the ſpots hath
a particular revolution of its own, whereby its Poles deſcribe
two circles about the Poles of another Axis, which for that
ſon ought (as I have ſaid) to be aſſigned to the Sun, the
ameter of which circles anſwereth to the quantity of the
nation of the ſaid Axis. And it is neceſſary, that the time of its
Period be a year; for that ſuch is the time in which all the
pearances and differences in the courſes of the ſpots do return.
And that the revolution of this Axis, is made about the Poles of
the other Axis parallel to that of the Ecliptick, & not about other
points, the greateſt inclinations and greateſt incurvations, which
are always of the ſame bigneſs, do clearly prove. So that finally, to
maintain the Earth fixed in the centre, it will be neceſſary to
ſign to the Sun, two motions about its own centre, upon two
ral Axes, one of which finiſheth its converſion in a year, and the
other in leſſe than a moneth; which aſſumption ſeemeth, to my
underſtanding, very hard, and almoſt impoſſible; and this
pendeth on the neceſſity of aſcribing to the ſaid Solar body two
other motions about the Earth upon different Axes, deſcribing
with one the Ecliptick in a year, and with the other forming
rals, or circles parallel to the Equinoctial one every day:
whereupon that third motion which ought to be aſſigned to the
Solar Clobe about its own centre (I mean not that almoſt
monethly, which carrieth the ſpots about, but I ſpeak of that
ther which ought to paſſe thorow the Axis and Poles of this
monethly one) ought not, for any reaſon that I ſee, to finiſh its
Period rather in a year, as depending on the annual motion by
the Ecliptick, than in twenty four hours, as depending on the
diurnal motion upon the Poles of the Equinoctial. I know, that
what I now ſpeak is very obſcure, but I ſhall make it plain unto
you, when we come to ſpeak of the third motion annual,
ed by Copernicus, to the Earth. Now if theſe four motions, ſo
incongruous with each other, (all which it would be neceſſary to
aſſign to the ſelf ſame body of the Sun) may be reduced to one
ſole and ſimple motion, aſſigned the Sun upon an Axis that never
changeth poſition, and that without innovating any thing in the
motions for ſo many other cauſes aſſigned to the Terreſtrial
Globe, may ſo eaſily ſalve ſo many extravagant appearances in
their convexity towards the upper part, and another while
towards the lower part of the Solar Diſcus. And becauſe
thoſe poſitions are in continuall alteration, making the
clinations and incurvations now greater, now leſſer, and
times reduce themſelves, the firſt ſort to perfect libration, and
the ſecond to perfect perpendicularity, it is neceſſary to aſſert that
the ſelf ſame Axis of the monethly revolution of the ſpots hath
a particular revolution of its own, whereby its Poles deſcribe
two circles about the Poles of another Axis, which for that
ſon ought (as I have ſaid) to be aſſigned to the Sun, the
ameter of which circles anſwereth to the quantity of the
nation of the ſaid Axis. And it is neceſſary, that the time of its
Period be a year; for that ſuch is the time in which all the
pearances and differences in the courſes of the ſpots do return.
And that the revolution of this Axis, is made about the Poles of
the other Axis parallel to that of the Ecliptick, & not about other
points, the greateſt inclinations and greateſt incurvations, which
are always of the ſame bigneſs, do clearly prove. So that finally, to
maintain the Earth fixed in the centre, it will be neceſſary to
ſign to the Sun, two motions about its own centre, upon two
ral Axes, one of which finiſheth its converſion in a year, and the
other in leſſe than a moneth; which aſſumption ſeemeth, to my
underſtanding, very hard, and almoſt impoſſible; and this
pendeth on the neceſſity of aſcribing to the ſaid Solar body two
other motions about the Earth upon different Axes, deſcribing
with one the Ecliptick in a year, and with the other forming
rals, or circles parallel to the Equinoctial one every day:
whereupon that third motion which ought to be aſſigned to the
Solar Clobe about its own centre (I mean not that almoſt
monethly, which carrieth the ſpots about, but I ſpeak of that
ther which ought to paſſe thorow the Axis and Poles of this
monethly one) ought not, for any reaſon that I ſee, to finiſh its
Period rather in a year, as depending on the annual motion by
the Ecliptick, than in twenty four hours, as depending on the
diurnal motion upon the Poles of the Equinoctial. I know, that
what I now ſpeak is very obſcure, but I ſhall make it plain unto
you, when we come to ſpeak of the third motion annual,
ed by Copernicus, to the Earth. Now if theſe four motions, ſo
incongruous with each other, (all which it would be neceſſary to
aſſign to the ſelf ſame body of the Sun) may be reduced to one
ſole and ſimple motion, aſſigned the Sun upon an Axis that never
changeth poſition, and that without innovating any thing in the
motions for ſo many other cauſes aſſigned to the Terreſtrial
Globe, may ſo eaſily ſalve ſo many extravagant appearances in