Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/139

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G. Galilæus, his Systeme.
from the Earth, continue a good space of time in the Air, such as are the Clouds, Birds of flight; and as of them it cannot be said that they are rapt or transparted by the Earth, having no adhesion thereto, it seems not possible, that they should be able to keep pace with the velocity thereof; nay it should rather seem to us, that they all swiftly move towards the West: And if being carried about by the Earth, passe our parallel in twenty four hours, which yet is at least sixteen thousand miles, how can Birds follow such a course or revolution? Whereas on the contrary, we see them fly as well towards the East, as towards the West,An argument taken from the air which we feel to beat upon us when we run a Horse at full speed. or any other part, without any sensible difference. Moreover, if when we run a Horse at his speed, we feel the air beat vehemently against our face, what an impetuous blast ought we perpetually to feel from the East, being carried with so rapid a course against the wind? and yet no such effect is perceived. Take another very ingenious argument inferred from the following experiment. An argument taken from the whirling of circular motion, which hath a faculty to extrude and dissipate. The circular motion hath a faculty to extrude and dissipate from its Centre the parts of the moving body, whensoever either the motion is not very slow, or those parts are not very well fastened together; and therefore, if v. g. we should turn one of those great wheels very fast about, wherein one or more men walking, crane up very great weights, as the huge massie stone, used by the Callander for pressing of Cloaths; or the fraighted Barks which being haled on shore, are hoisted out of one river into another; in case the parts of that same Wheel so swiftly turn'd round, be not very well joyn'd and pin'd together, they would all be shattered to pieces; and though many stones or other ponderous substances, should be very fast bound to its outward Rimme, yet could they not resist the impetuosity, which with great violence would hurl them every way far from the Wheel, and consequently from its Centre. So that if the Earth did move with such and so much greater velocity, what gravity, what tenacity of lime or plaister would keep together Stones, Buildings, and whole Cities, that they should not be tost into the Air by so precipitous a motion? And both men and beasts, which are not fastened to the Earth, how could they resist so great an impetus? Whereas, on the other side, we see both these, and far lesse resistances of pebles, sands, leaves rest quietly on the Earth, and to return to it in falling, though with a very slow motion. See here, Simplicius, the most potent arguments, taken, to so speak, from things Terrestrial; there remain those of the other kind, namely, such as have relation to the appearances of Heaven, which reasons, to confesse the truth, tend more to prove the Earth to be in the centre of the Universe, and consequently, to deprive it of the annual motion about the same, ascribed unto it

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