Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/339

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G. Galilæus, his Systeme.

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

You see, Gentlemen, with what facility and simplicity the annual motion,The annual motion of the Earth most apt to render a reason of the exorbitances of the five Planets. 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, Venus and Mercury, taking them all away, and reducing them to equal and regular motions.The Sun it self testifieth the annual motion to belong to the Earth. And of this admirable effect, Nicholas 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 conjecture ariseth from the Sun it self, which sheweth that it is unwilling 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 wonder.

The first discoverer and observer of the Solar spots,The Lyncæan Academick the first discoverer of the Solar spots, and all the other celestial novelties. 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 Venice,The history of the proceedings of the Academian for a long time about the observation of the Solar spots. 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, ** Duumviro 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 revolved 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 about 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 figures, which, for the most part, are very unusual. And albeit those so inconstant mutations did somewhat alter the primary pe-

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