Galilei, Galileo Dialogues on two world systems 1661, tr. Salusbury, Thomas

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318
scending towards the right, in the point F. What I have hi­
therto said, being understood, I believe that there remains no
difficulty in conceiving how srom the passing of the terminator of
the Solar Hemispheres by the Poles of the Suns conversion, or
neer or far from the same, do arise all the differences in the appa­
rent courses of the spots; so that by how much the more those Poles
shall be remote from the said terminator, by so much the more shall
those courses be incurvated, and lesse oblique; whereupon at
the same distance, that is, when those Poles are in the section of
the Meridian, the incurvation is reduced to the greatest, but the
obliquity to the least, that is to Æquilibrium, as the second of
these three last figures [viz. Fig. 5.] demonstrateth. On the
contrary, when the Poles are in the terminator, as the first of
these three figures [viz. Fig. 4.] sheweth the inclination is at
the greatest, but the incurvation at the least, and reduced to
rectitude. The terminator departing from the Poles, the curvity
begins to grow sensible, the obliquity all the way encreasing,
and the inclination growing lesser.

The first Ac­
cident to be obser­
ved in the motion
of the Solar spots;
and consequently
all the rest explai­
ned.

These are those admirable and extravagant mutations, that my
Guest told me would from time to time appear in the progresses
of the Solar spots, if so be it should be true that the annual mo­
tion belonged to the Earth, and that the Sun being constituted
in the centre of the Ecliptick, were revolved in it self upon an
Axis, not erect, but inclined to the Plane of the said Eclip­
tick.

SAGR. I do now very well apprehend these consequences,
and believe that they will be better imprinted in my fancy, when
I shall come to reflect upon them, accommodating a Globe to
those inclinations, and then beholding them from several pla­
ces. It now remains that you tell us what followed afterwards
touching the event of these imaginary consequences.

The events be­
ing observed, were
answerable to the
predictions.

SALV. It came to passe thereupon, that continuing many se­
veral moneths to make most accurate observations, noting down
with great exactnesse the courses or transitions of sundry spots at
divers times of the year, we found the events punctually to cor­
respond to the predictions.

SAGR. Simplicius, if this which Salviatus saith be true; (nor
can we distrust him upon his word) the Ptolomeans and Aristo­
teleans hadneed of solid arguments, strong conjectures, and
well grounded experiments to counterpoise an objection of so
much weight, and to support their opinion from its final over­
throw.

SIMP. Fair and softly good Sir, for haply you may not yet
be got so far as you perswade your self you are gone. And
though I am not an absolute master of the subject of that narra­