Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/327

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G. Galilæus, his Systeme.

without encompassing the Earth; about the same Sun you make the three superiour Planets Mars, Jupiter, and Saturn, to move, comprehending the Earth within their circles. The Moon in the next place can move in no other manner than about the Earth, without taking in the Sun, and in all these motions you agree also with the same Copernicus. There remains now three things to be decided between the Sun, the Earth, and fixed stars, namely, Rest,Rest, the annual motion and the diurnal ought to be distributed betwixt the Sun, Earth, and Firmament. which seemeth to belong to the Earth; the annual motion under the Zodiack, which appeareth to pertain to the Sun; and the diurnal motion, which seems to belong to the Starry Sphere, and to be by that imparted to all the rest of the Universe, the Earth excepted, And it being true that all the Orbs of the Planets, I mean of Mercury,In a moveable sphere, it seemeth more reasonable that its centre be stable, than any other of its parts.Venus, Mars, Jupiter, and Saturn, do move about the Sun as their centre; rest seemeth with so much more reason to belong to the said Sun, than to the Earth, in as much as in a moveable Sphere, it is more reasonable that the centre stand still, than any other place remote from the said centre; to the Earth therefore, which is constituted in the midst of moveable parts of the Universe, I mean between Venus and Mars, one of which maketh its revolution in nine moneths, and the other in two years, may the motion of a year very commodiously be assigned, leaving rest to the Sun.Granting to the Earth the annual, it must of necessity also have the diurnal motion assigned to it. And if that be so, it followeth of necessary consequence, that likewise the diurnal motion belongeth to the Earth; for, if the Sun standing still, the Earth should not revolve about its self, but have onely the annual motion about the Sun, our year would be no other than one day and one night, that is six moneths of day, and six moneths of night, as hath already been said. You may consider withal how commodiously the precipitate motion of 24 hours is taken away from the Universe, and the fixed stars that are so many Suns, are made in conformity to our Sun to enjoy a perpetual rest. You see moreover what facility one meets with in this rough draught to render the reason of so great appearances in the Celestial bodies.

Sagr.I very well perceive that facility, but as you from this simplicity collect great probabilities for the truth of that System, others haply could make thence contrary deductions; doubting, not without reason, why that same being the ancient Systeme of Pythagoreans, and so well accommodated to the Phænomena, hath in the succession of so many thousand years had so few followers, and hath been even by Aristotle himself refuted, and since that Copernicus himself hath had no better fortune.

Salv.If you had at any time been assaulted, as I have been, many and many a time, with the relation of such kind of frivolous reasons, as serve to make the vulgar contumacious, and difficult to be perswaded to hearken, (I will not say to consent) to this novel-

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