Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/312

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Dialogue. III.
285

tical point in which the Star is, from the Meridian; Moreover, after a considerable interval of time, the operation must be repeated, and exact account kept of the time that passed, trusting either to Dials, or to other observations of the Stars. Such an Olio of Observations doth he set before you, comparing them with such another made by another observer in another place with another different instrument, and at another time; and from this the Authour seeks to collect what would have been, the Elevations of the Star, and Horizontal Latitudes happened in the time and hour of the other first observations, and upon such a coæquation he in the end grounds his account. Now I refer it to you, what credit is to be given to that which is deduced from such like workings. Moreover, I doubt not in the least, but that if any one would torture himself with such tedious computations, he would find, as in those aforegoing, that there were more that would favour the adverse party, than the Authour: But I think it not worth the while to take so much pains in a thing, which is not, amongst those primary ones, by us understood.

Sagr.I am of your Opinion in this particular: But this businesse being environed with so many intricacies, uncertainties, and errours, upon what confidence have so many Astronomers positively pronounced the new Star to have been so high?

Salv.Upon two sorts of observations most plain, most easie, and most certain; one only of which is more than sufficient to assure us, that it was scituate in the Firmament, or at least by a great distance superiour to the Moon. One of which is taken from the equality, or little differing inequality of its distances from the Pole, aswell whilst it was in the lowest part of the Meridian, as when it was in the uppermost: The other is its having perpetually kept the same distances from certain of the fixed Stars, adjacent to it, and particularly from the eleventh of Cassiopea, no more remote from it than one degree and an half; from which two particulars is undoubtedly inferred, either the absolute want of Parallax, or such a smalnesse thereof, that it doth assure us with very expeditious Calculations of its great distance from the Earth.

Sagr.But these things, were they not known to this Author? and if he saw them, what doth he say unto them?

Salv.We are wont to say, of one that having no reply that is able to cover his fault, produceth frivolous excuses, cerca di attaccarsi alle funi del cielo, [He strives to take hold of the Cords of Heaven;] but this Authour runs, not to the Cords, but to the Spiders Web of Heaven; as you shall plainly see in our examination of these two particulars even now hinted. And first, that which sheweth us the Polar distances of the Observators one by one, I have noted down in these brief Calculations; For a full under-stand-