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G. Galilæus, his Systeme.
tick, A concipt that came suddenly into the minde of the Academian Lyncæus concerning the great consequence that followed upon the motion of the Solar spots. but is inclined upon the same, as its crooked course, but even now observed, makes me believe, we shall be able to make such conjectures of the states of the Sun and Earth, as neither so solid or so rational have been hitherto deduced from any other accident whatsoever. I being awakened at so great a promise, importun'd him to make a free discovery of his conceit unto me. And he continued his discourse to this purpose.Extravagant mutations to be observed in the motions of the spots, foreseen by the Academick, in case the Earth had the annual motion. If the Earths motion were along the Ecliptique about the Sun; and the Sun were constituted in the centre of the said Ecliptick, and therein revolved in its self, not about the Axis of the said Ecliptique (which would be the Axis of the Earths annual motion) but upon one inclined, it must needs follow, that strange changes will represent themselves to us in the apparent motions of the Solar spots, although the said Axis of the Sun should be supposed to persist perpetually and immutably in the same inclination, and in one and the same direction towards the self-same point of the Universe. Therefore the Terrestrial Globe in the annual motion moving round it, it will first follow, that to us, carried about by the same, the courses of the spots shall sometimes seem to be made in right lines, but this only twice a year, and at all other times shall appear to be made by arches insensibly incurvated. Secondly, the curvity of those arches for one half of the year, will shew inclined the contrary way to what they will appear in the other half; that is, for six moneths the convexity of the arches shall be towards the upper part of the Solar Discus, and for the other six moneths towards the inferiour. Thirdly, the spots beginning to appear, and (if I may so speak) to rise to our eye from the left side of the Solar Discus, and going to hide themselves and to set in the right side, the Oriental termes, that is, of their first appearings for six moneths, shall be lower than the opposite termes of their occultations; and for other six moneths it shall happen contrarily, to wit, that the said spots rising from more elevated points, and from them descending, they shall, in their courses, go and hide themselves in lower points; and onely for two dayes in all the year shall those termes of risings and settings be equilibrated: after which freely beginning by small degrees the inclination of the courses of the spots, and day by day growing bigger, in three moneths, it shall arrive at its greatest obliquity, and from thence beginning to diminish, in such another time it shall reduce it self to the other Æquilibrium. It shall happen, for a fourth wonder, that the course of the greatest obliquity shall be the same with the course made by the right line, and in the day of the Libration the arch of the course shall seem more than ever incurvated. Again, in the other times, according as the pendency shall successively diminish, and make it ap-
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