Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/365

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G. Galilæus, his Systeme.
Salv.I am of the same judgment, and verily believe that they argue contra hominem, studying more to defend another man, than desiring to come to the knowledge of the truth. And I do not only believe,Astronomers, perhaps, have not known what appearances ought to follow upon the annual motion of the Earth. that none of them ever applied themselves to make any such observation, but I am also uncertain, whether any of them do know what alteration the Earths annual motion ought to produce in the fixed stars, in case the starry Sphere were not so far distant, as that in them the said diversity, by reason of its minuity dis-appeareth; for their surceasing that inquisition, and referring themselves to the meer assertion of Copernicus, may very well serve to convict a man, but not to acquit him of the fact:Copernicus understood not some things for want of Instruments. For its possible that such a diversity may be, and yet not have been sought for; or that either by reason of its minuity, or for want of exact Instruments it was not discovered by Copernicus; for though it were so, this would not be the first thing, that he either for want of Instruments, or for some other defect hath not known; and yet he proceeding upon other solid and rational conjectures, affirmeth that, which the things by him not discovered do seem to contradict: for, as hath been said already, without the Telescope, neither could Mars be discerned to increase 60. times; nor Venus 40. more in that than in this position; yea, their differences appear much lesse than really they are and yet neverthelesse it is certainly discovered at length, that those mutations are the same, to an hair that the Copernican Systeme required.Tycho and others argue against the annual motion, from the invariable elevation of the Pole. Now it would be very well, if with the greatest accuratenesse possible one should enquire whether such a mutation as ought to be discoverable in the fixed stars, supposing the annual motion of the Earth, would be observed really and in effect, a thing which I verily believe hath never as yet been done by any; done, said I? no, nor haply (as I said before) by many well understood how it ought to be done. Nor speak I this at randome, for I have heretofore seen a certain Manuscript of one of these Anti-Copernicans, which said, that there would necessarily follow, in case that opinion were true, a continual rising and falling of the Pole from six moneths to six moneths, according as the Earth in such a time, by such a space as is the diameter of the grand Orb, retireth one while towards the North, and another while towards the South; and yet it seemed to him reasonable, yea necessary, that we, following the Earth, when we were towards the North should have the Pole more elevated than when we are towards the South. In this very error did one fall that was otherwise a very skilful Mathematician, & a follower of Copernic. as Tycho relateth in his * * Christophorus Rothmannus.Progymnasma. pag. 684. which said, that he had observed the Polar altitude to vary, and to differ in Summer from what it is in Winter: and because Tycho denieth the merit

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